JP3149902B2 - Piezoelectric driver for inkjet recording head and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric driver used for an ink jet recording head and a method of manufacturing the same.

[0002]

2. Description of the Related Art In general, an ink jet recording head utilizing a longitudinal vibration mode has a diaphragm provided with a narrow gap behind a nozzle plate having a plurality of nozzles, as shown in Japanese Patent Laid-Open No. 4-1052. It is arranged so that the piezoelectric vibrator of the vertical vibration mode divided to correspond to each nozzle is brought into contact with the back surface of the vibration plate, and the pressure formed by the ink from the ink flow path by the nozzle plate and the vibration plate After the ink is guided to a chamber, the ink is pressurized by a piezoelectric vibrator driven according to a recording signal, and is ejected from a nozzle as an ink droplet.

[0003] This type of ink jet recording head has the advantage that the finer the piezoelectric vibrator is divided, the smaller the nozzle pitch can be. As you can see,
While each pressure chamber is lengthened in the ink discharge direction to ensure sufficient internal volume for ink droplets to be discharged,
It is necessary to form an annular groove in a portion of the diaphragm corresponding to the peripheral portion of each pressure chamber so that the thinned portion efficiently receives a small displacement of the piezoelectric vibrator.

[0004] However, even with such a configuration, there is a limit to this, and if the island-shaped portion formed by the annular groove becomes longer than a certain length, it comes into contact with the piezoelectric vibrator. As a result, only the portion is deformed like a bow, which causes a problem that it becomes impossible to apply a certain pressure or more to the ink in the pressure chamber.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide a new piezoelectric driver that can efficiently pressurize ink in a pressure chamber with limited displacement, and a new manufacturing method that can easily and accurately form the piezoelectric driver.

[0006]

That is, according to the present invention, a piezoelectric driver for achieving the above object comprises a piezoelectric plate having at least a leading end portion left as an inactive region and a conductive layer laminated on other portions. By dividing it into many piezoelectric elements,
Wherein the surface of at least a hand of the inactive region of the piezoelectric element, the tip is the tip plate for pressurized auxiliary to match the tip of the piezoelectric element is stacked.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 shows a piezoelectric driver according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a piezoelectric vibrator assembly as a piezoelectric driving body. The assembly 1 includes a comb-shaped piezoelectric plate 2 and a tip plate 6 for increasing a contact pressure area, In order to attach the plate 2 to the ink jet recording head, the plate 2 is constituted by a metal plate 10 fixed to the rear end of the piezoelectric plate 2 via a rear end plate 7 for coupling piezoelectric elements.

More specifically, the central piezoelectric plate 2 is composed of a paste-like piezoelectric material layer 2a.
The conductive layer 2b is laminated on the middle part in the longitudinal direction, the middle part is the active part 5, the tip part and the rear end are the tip inactive part 4f, respectively.
A rear end inactive portion 4r, and a front end plate 6 and a rear end plate formed of a pasty free-cutting ceramic material made of, for example, the same material as the piezoelectric material on the front end inactive portion 4f and the rear end inactive portion 4r. 7 are laminated, and these are integrally formed by sintering.

As shown in FIG. 3 (e), the piezoelectric plate 2 in this embodiment is defined by a line L connecting the top rear edge 6a of the front plate 6 and the front edge 4ra of the rear inactive portion 4r. As a plurality of piezoelectric driving elements 3 っ て, the tip side of which is cut into a comb shape by a wire saw or a dicing saw, and pressurizes the ink in the corresponding pressure chambers by displacement in a direction orthogonal to the electric field when a voltage is applied. Be composed.

On the piezoelectric plate 2 thus formed, the lower surface of the active part 5 is passed through the tip plate 6 to the active part 5.
The external electrodes 8 and the external common electrodes 9 are formed by vapor deposition or the like on the portion up to the upper surface of the substrate and on the portion from the rear end inactive portion 4r to the rear end surface of the rear end plate 7 (FIG. 3).
(C)) Finally, a metal plate 10 made of stainless steel or the like is fixed on the rear end plate 7 to constitute the piezoelectric vibrator assembly 1.

[0011] The piezoelectric vibrator assembly 1 configured as described above.
Can not only increase the rigidity of the piezoelectric plate 2 by the rear end plate 7, but also
This facilitates the assembly to the holding block 51 attached to the back surface of the vibration plate 47, and furthermore, the front end plate 6 and the piezoelectric vibrator 3 uniformly contact substantially the entire surface of the island portion 49 of the vibration plate 47 to be described later. The nozzle plate 4
The ink in the pressure chamber 45 is efficiently pressurized by being flatly displaced toward the first surface.

FIG. 2 shows an ink jet recording head provided with the piezoelectric vibrator assembly 1 described above. In the drawing, reference numeral 41 denotes a nozzle plate in which a number of nozzles 43 # are arranged on both sides of a flow path forming spacer 42 in a direction orthogonal to the paper surface. A vibration plate 47 is provided in parallel via a common ink chamber 44 and a pressure chamber 45 to constitute a flow path forming member 40.

On the back surface of the vibration plate 47, an annular concave groove 48 is formed along the periphery of each pressure chamber 45, and the island-like portion 49 formed by the annular concave groove 48 forms a piezoelectric vibration. It is configured to bend inward while being parallel to the nozzle plate 41 over substantially the entire surface due to the displacement of the child 3.

On the other hand, reference numeral 51 in the figure denotes a plastics positioning and holding block fixed to the back surface of the flow path forming member 40 and positioning and holding the piezoelectric vibrator assembly 1. Two piezoelectric vibrator unit mounting holes 52, 52 having a width corresponding to the length of the pressure chamber 45 in the longitudinal direction, and provided along the row of nozzles, are provided in the flow path forming member 40. It is integrally attached to the back surface of the diaphragm 47 with an adhesive with reference to a reference hole (not shown).

A pair of piezoelectric vibrator assemblies 1 and 1 are inserted into these mounting holes 52 and 52 so that they protrude from the upper and lower ends of the rear end plate 7 and also protrude to both sides. The metal plate 10 having an appropriate size is integrally adhered to the inner surface of each mounting hole 52 with an adhesive 54, and the metal plate 10 is attached to the mounting holes 52, 5 and 5.
(2) By positioning and sandwiching by the guide grooves (not shown) on both sides, the inclination in the thickness direction of the piezoelectric vibrator 3 is suppressed, and the accurate surface contact between the tip and the island-like portion 49 is ensured.
The piezoelectric vibrator 3 is configured such that it is bonded to the back surface of each island-shaped portion 49 of the vibration plate 47 by an adhesive 59 previously applied to each end of the piezoelectric vibrator 3 by a transfer method. Note that reference numeral 5 in FIG.
Reference numeral 5 denotes a circuit board mounted on the top surface of the positioning holding block 51, and reference numeral 56 denotes a flexible cable.

Next, a manufacturing process of the above-described piezoelectric vibrator assembly 1 will be described with reference to FIG. First, a piezoelectric material layer 2a having substantially the same shape and thickness as the piezoelectric plate 2 is formed using a paste-like piezoelectric material such as lead zirconate titanate or barium titanate. 1.0 mm, silver palladium as the conductive layer 2b is coated or vapor-deposited on the upper and lower surfaces of the intermediate portion to a thickness of approximately 3 μm on the upper and lower surfaces of the intermediate portion, leaving a margin of approximately 3.0 mm at the rear end portion. Is formed into a single sheet type piezoelectric plate 2 having inactive portions 4f and 4r (a-1).

On the other hand, for the laminated piezoelectric plate, a
As shown in -2, the paste-like piezoelectric material layer 2a is
The conductive layer 2b is applied alternately to a thickness of about 3 μm so that the internal electrodes from both sides are overlapped on the middle part while leaving a margin at the leading end or the trailing end, and this is applied. By repeating the laminating process several times, green sheets of the multiple piezoelectric plates 2 having the front and rear end portions as the inactive portions 4f and 4r are formed.

The subsequent steps will be described with reference to the laminated piezoelectric plate 1. The green sheet of the piezoelectric plate 2 thus formed will be described next with reference to FIG. As shown, the plates 6, 7 are stacked on one surface of the front and rear inactive portions 4f, 4r.

That is, the tip inactive portion 4f provided at the tip portion of the piezoelectric plate 2 is provided with a slight gap δ, preferably 0.0 to 0.5 mm, from the boundary of the active portion 5 to cover one surface thereof. A tip plate 6 made of a free-cutting ceramic material having substantially the same thickness as that of the piezoelectric plate 2 is laminated. Similarly, a rear end plate 7 wider than the front end plate 6 is provided on one surface of the rear end inactive portion 4r. Finally, the two are trimmed so that the tip of the piezoelectric plate 2 and the tip of the tip plate 6 coincide with each other, and the piezoelectric plate 2 and the front and rear plates 6, 7 are integrated by sintering. Alternatively, after being formed by sintering and integrated, the tip of the piezoelectric plate 2 and the tip of the tip plate 6 are trimmed with a dicing saw or the like so as to match. Note that the front end plate 6 and the rear end plate 7 can overlap with the active portion 5 within a range that does not hinder the displacement.

Next, as shown in FIG. 3 (c), the piezoelectric plate 2 formed in this manner has arrows D and D on the upper and lower surfaces of the active portion 5 including the tip plate 6, respectively.
While the external segment electrode 8 is deposited from the direction E, the external common electrode 9 is deposited from the direction of arrow F on the lower surface of the rear end inactive portion 4r and the rear end surface 7a of the rear end plate 7.

By the way, the external segment electrodes 8 are formed on the rear surface of the front end plate 6 and the upper surface of the piezoelectric plate 6 by the vapor deposition process in the direction of arrow D, but in order to prevent disconnection at the corner 6a. As shown in FIG. 9, the rear surface 6b of the end plate 6 may be inclined.
For this purpose, the contraction rate of the piezoelectric material may be made slightly larger than that of the front plate 6 by the sintering step, or the rear end 6b of the front plate 6 may be processed so as to be inclined.

Next, as shown in FIG. 3D, a metal plate 10 such as stainless steel, which is larger than the width and the length of the rear end plate 7, is placed on the upper surface of the rear end plate 7 and integrated with an adhesive. Fixed to.

Finally, the piezoelectric vibrator assembly 1 constructed as described above is fixed by a jig, and FIG.
As shown in (e), the top rear edge 6 of the tip plate 6
a and the front end side 4ra of the rear end inactive portion 4r is divided into a comb-teeth shape with a gap corresponding to the arrangement pitch of the nozzles 53 as a boundary of a straight line L.
To form

FIG. 4 shows an example of an apparatus used in this gear cutting process. The inclination angle of the straight line L is placed on a jig body 32 that moves up and down in parallel with the wire saw 31. An inclined mounting member 34 having a work mounting surface 33 corresponding to θ is fixed so that the mounting surface 33 is oblique to the wire saw 31, and the tip of the piezoelectric plate 2 faces the mounting surface 33 upward. The metal plate 10 is fixed so that it protrudes from
The gear cutting is performed while raising the jig body 32 toward the wire saw 31.

FIG. 5 shows a molding method according to another embodiment of the present invention in which a large number of the piezoelectric plates 2 are taken in the form of chocolate flakes. FIG. 3 is a diagram showing a piezoelectric plate forming layer, and FIG.

First, a piezoelectric plate forming layer 12a having a size capable of arranging a large number of piezoelectric plates 12 # in the vertical and horizontal directions is formed using a paste-like piezoelectric material. As shown in (b), by alternately printing two types of patterns of the internal electrodes 12b of the upper right diagonal line and the left diagonal diagonal line, an interval corresponding to the longitudinal dimension of the piezoelectric plate 12 or slightly more than this. Active portions 15 are formed at large intervals.

At this time, both internal electrodes 12b are formed by applying a print mask to the scales + provided on the piezoelectric plate forming layer 12a.
2b is formed so as not to be exposed from the periphery of the piezoelectric plate forming layer 12a. A reference hole 12c is formed in the piezoelectric plate forming layer 12a with the scale + as a reference position.

On the other hand, the front and rear end plate forming layers 14 forming the front end plate 14f and the rear end plate 14r are formed in the same size as the piezoelectric plate forming layer 12a, and as shown in FIG. A reference hole 14 formed in accordance with the reference hole 12c of the piezoelectric plate forming layer 12a.
With reference to c, a window hole 14d # corresponding to the area of the active portion 15 is punched in this surface.
The piezoelectric plate forming layer 12a and the front and rear end plate forming layers 14 are laminated by inserting pins through the pins c and 14c, and both are sintered under pressure.

Next, the laminate is cut along one or two cutting lines B such that the laminate is divided into a front plate 14f and a rear plate 14r, and external electrodes are attached to the surface.

The external electrodes can be attached without masking since the internal electrodes 12b are formed so as not to be exposed from both sides of the piezoelectric plate forming layer 12a in the previous step. After the electrodes are attached, finally, a voltage of 75 V is applied to these electrodes for 1 minute to perform a polarization treatment, and the laminate is cut along the cutting line A to be cut into individual piezoelectric plates 2.

In the piezoelectric vibrator assembly 1 formed in this manner, the respective piezoelectric vibrators 3 # are integrally connected with the rear plate 7 as a common base, and the tip plate 6 is
Along with each piezoelectric vibrator 3 #, it is cut off from the piezoelectric plate 2, and each island portion 49 # on the vibration plate 47 is pressed uniformly over a wide area.

FIGS. 6 and 7 show still another piezoelectric vibrator assembly of the present invention and a method of manufacturing the same. In this embodiment, the dummy vibrator 2 is provided on both sides of the piezoelectric plate 22.
3 ', that is, a piezoelectric vibrator assembly which has a positioning function at the time of assembly and forms a piezoelectric vibrator which does not participate in image formation. The front end plate 26 and the rear end plate 27 are integrated via side plates 28, 28 stacked on top of the piezoelectric plate 22 'to reinforce the piezoelectric plate 22 during molding and assembly.

As shown in FIG. 7, this forming method is first performed on one surface of a wide green sheet 60 for forming a piezoelectric plate, which is made of a laminate of a piezoelectric material layer 21a and a conductive layer 21b provided on an active portion 25 thereof. In the longitudinal direction, a plurality of plates 24 having a width a that is equal to the width of the front end plate 26 and the rear end plate 27 or slightly larger than the width.
Are stacked on each inactive portion 24 at a pitch corresponding to or longer than the length of the piezoelectric plate 22, while having a width b that is twice or slightly larger than the side plate 28 in the width direction. The plate 29 is stacked on the active portion 25 at a pitch corresponding to the width of the piezoelectric plate 22 or a pitch larger than that.

Then, in the longitudinal direction,
While each plate 24 # is cut along a cutting line B # dividing the front plate 26 and the rear end plate 27 or two cutting lines B'B ', each plate 29 # is cut in the width direction. After cutting along the cutting line A ‥‥ which divides into two or two cutting lines A'A 'to form individual piezoelectric plates 22 ‥‥, firing, or firing, then cut in the same manner as described above. After that, a large number of piezoelectric vibrators 23 # are formed on these through the above-described tooth splitting process.

Incidentally, the above-described method for forming a laminate firstly includes the tip plates 6, 2 on the piezoelectric plates 2, 22.
6 and the rear end plates 7, 27 are laminated, and then the whole is sintered to be integrated, but the piezoelectric plates 2, 22, the front end plates 6, 26, and the rear end plates 7, 27 May be individually formed and sintered, and then joined by an appropriate adhesive to be integrated.

Also, as shown in FIG.
It is also possible to fix a pair of tip plates 6 and 6 to the upper surface and the lower surface of the tip inactive portion 4f. In such a configuration, the island-like portion 49 of the diaphragm 47 is Pressure can be applied over a wide area and in a more stable state.

FIG. 10 shows another embodiment of the present invention. FIGS. 10 (a) and 10 (b) show the structure on both the front and back sides, and FIG. 10 (c) shows the structure from the front end side. In the figure, reference numerals 23, 23, and 23 'denote the above-described piezoelectric vibrators, and reference numerals 23' and 23 'denote the above-described dummy vibrators, which are the piezoelectric vibrators 23 and 23'. , 23 are provided on both sides of the piezoelectric vibrator and have only a positioning function at the time of assembling and are not involved in image formation. On the rear end side of the piezoelectric vibrator 23 and the dummy vibrator 23 ′,
The above-mentioned rear end plates 27, 27 ', 2
7, 27 ′}, and front end plates 26, 26 ′ are provided on the front and back sides of the piezoelectric vibrator 23,
Further, on the front and back surfaces of the dummy electrodes 23 ', 23', there are provided side plates 28, 28 'extending to the front end so as to be continuous with the rear end plates 27, 27'.

As shown in FIG. 11, this forming method is first performed on one side of a wide green sheet 60 for forming a piezoelectric plate formed of a laminate of a piezoelectric material layer 21a and a conductive layer 21b provided on an active portion 25 thereof. In the longitudinal direction, a plurality of plates 2 having a width a that is equal to the width of the front end plate 26 and the rear end plate 27 or slightly larger than this width
4 ‥‥ are stacked on each inactive portion 24 at a pitch corresponding to the length of the piezoelectric plate 22 or at a pitch greater than that, while the width of the side plate 28 is
Plate 29 with a width b that is twice or slightly greater than this
A layer 61 made of the same material as the ceramic, for example, the green sheet 60 for shaping the piezoelectric plate, is laminated on the active portion 25 at a pitch corresponding to the width of the piezoelectric plate 22 or more. Then, a ceramic layer 61 'having the same structure is laminated on the other surface.

In the longitudinal direction, each plate 2
4 ‥‥ is cut along the cutting line B ‥‥ dividing the front end plate 26 and the rear end plate 27 or two cutting lines B′B ′.
Cut along the cutting line A # or two cutting lines A'A 'to form individual piezoelectric plates 22 #,
After sintering, or after sintering, cutting is performed in the same manner as described above to form individual piezoelectric plates, and thereafter, a large number of piezoelectric vibrators 23
Then, dummy vibrators 23 'and 23' are formed on both sides thereof.

The thus constructed piezoelectric vibrator assembly is inserted into the mounting holes 52, 52 as shown in FIG. 12, and protrudes from the upper and lower ends of the rear end plates 27, 27 '. A metal plate 10 having a size protruding from both sides is integrally adhered to the inner surface of each mounting hole 52 with an adhesive 54, and the metal plate 10 is attached to guide holes (not shown) on both sides of the mounting holes 52, 52. The piezoelectric vibrator 2 is positioned and clamped by the groove.
The adhesive 59 previously applied to each tip of the piezoelectric vibrator 3 by a transfer method while suppressing the inclination of the tip of the piezoelectric vibrator 3 in the thickness direction and ensuring accurate surface contact between the tip and the island-shaped portion 49 is removed. The diaphragm 47 is adhered to the back surface of each island portion 49.

According to this embodiment, the dummy vibrator 23 '
Since both sides are reinforced by the side plates 28 and 28 ', the deflection in the recording head is reliably prevented.

FIG. 13 shows another embodiment of the present invention. In this embodiment, a piezoelectric vibrating plate 64 formed by alternately stacking piezoelectric materials 60 and conductive layers 61 and 62 is shown.
On the front and back surfaces, the other electrode, an external conductive layer 67 serving as a common electrode in this embodiment, is formed from the front end to the boundary of the rear end plates 65 and 66.
9 and 70, and rear end plates 65 and 66 are fixed to the rear end side. The front end plates 65 and 66 and the rear end plates 69 and 70 are made of a ceramic material, preferably the same material as the piezoelectric vibration material.

A conductive layer 67 formed on the surface of the piezoelectric vibrating plate 64 and a conductive layer 73 are formed on the front end so as to be electrically connected to the conductive layer 62 exposed from the front end. In the rear end plates 65 and 66, conductive layers 74 and 75 are formed on the side surfaces and a part of the upper surface thereof so as to conduct with the conductive layer 67 on the surface of the diaphragm 64. The other pole exposed from the other end of the piezoelectric vibrating plate 64 with an interval 76 formed therein is formed with conductive layers 77 and 78 connected to the conductive layer 61 serving as a drive electrode in this embodiment.

The piezoelectric vibrating plate constructed as described above is shown in FIG.
As shown in FIG. 4, the pattern 80 connected to the conductive layer 75 serving as a common electrode at the leading end side is used as a drive electrode at a predetermined interval, as in the case described above. Patterns 81, 81 connected to the conductive layer 61,
The cable 82 formed with 81 ° is fixed by soldering or the like.

According to this embodiment, the tip of the piezoelectric vibrator,
And a front end plate 6 having the same structure on the front and back sides at the rear end
Since the rear plates 9 and 70 and the rear end plates 65 and 66 are fixed, not only the warpage can be prevented but also the external conductive layers 67 and 67 function as a reinforcing material to some extent to prevent deflection. Since the cable 82 for external connection can be attached to the rear end plate 65 having a greater strength than the piezoelectric vibrator, the connection strength between the piezoelectric vibrator and the cable 82 can be increased, and if necessary, Further, a conductive layer can be formed to reduce the electric resistance and reduce the connection resistance. In particular, in a recording head used for high-density printing, the width of the piezoelectric vibrator is small and the connection area is extremely small, so the connection resistance is large, and this portion tends to generate heat intensively. This connection resistance can be reliably reduced to prevent thermal damage and minimize loss of driving energy.

FIG. 15 shows a method of manufacturing the above-mentioned piezoelectric vibrating plate. In the drawing, reference numeral 64 denotes a piezoelectric vibrating plate in which a piezoelectric material 60 and conductive layers 61 and 62 are alternately laminated, and the piezoelectric vibrating plate is viewed from the tip side. External conductive layers 67, 67 having the same polarity as one conductive layer 61 up to the boundary line with the rear end plates 65, 66 are formed by vapor deposition, application of a conductive paint, or the like (FIG. 15).
(I)).

The front plates 69 and 70 are fixed to the front end and the rear plates 65 and 66 are fixed to the front end and the rear end of the diaphragm 64, respectively.
Trim to C'-C '. Each of the front plates 69 and 70 and the rear plates 65 and 66 has one or more layers of green sheets having the same composition as the piezoelectric vibrating plate or green sheets of free-cutting ceramic as described above. The layers are stacked until they become as much as possible, and can be integrally formed by firing (FIG. 15 (ii)).

Next, the piezoelectric vibrating plate 64 and the tip plate 6
A conductive layer 73 is formed at the front end of each of the electrodes 9 and 70, and a conductive layer 78 serving as a connection terminal with an external device is formed on the rear end surfaces of the piezoelectric vibrating plate 64 and the rear end plates 65 and 66, and a part of the surface. FIG. 15 (iii)). The diaphragm having such a configuration may be fixed to the substrate 10 with an adhesive or the like as described above, and may be divided at a constant pitch.

FIG. 16 shows another embodiment of the piezoelectric vibrating plate in the manufacturing process. In the same manner as described above, the tip side of the piezoelectric vibrating plate 64 in which the piezoelectric material 60 and the conductive layers 61 and 62 are alternately laminated. The outer electrodes 67, 67 having the same polarity as the one conductive layer 61 are formed from to the boundary line with the rear end plates 65, 66 (FIG. 16 (i)).

The front end plates 85 and 86 are fixed to the front end and the rear end plates 87 and 88 are fixed to the front end and the rear end of the diaphragm 64, respectively. And in this example,
Each of these plates 85, 86, 87, 88 is formed by alternately forming green sheets 91, 93, 95, 97 of a piezoelectric material and conductive layers 90, 92, 94, 96 similarly to the piezoelectric vibrating plate. , And fired.

The conductive layers 94 and 96 embedded in the rear end plates 87 and 88 are formed inwardly by a predetermined distance g from the end in order to prevent a short circuit between the external conductive layers 75 and 77. Also, a break is provided on the way.

By embedding not only the ceramic green sheet but also the conductive layer as described above, the degree of shrinkage during firing can be made approximately the same as that of the piezoelectric vibrating plate 64, so that distortion and warpage are extremely reduced. . Then, the end faces are trimmed as needed (FIG. 16 (ii)).

Next, the piezoelectric vibrating plate 64 and the tip plate 8
A conductive layer 73 is formed on the front end of each of the piezoelectric plates 5 and 86, and a conductive layer 78 serving as a connection terminal for an external device is formed on the rear end surfaces of the piezoelectric vibrating plate 64 and the rear end plates 87 and 88 and on a part of the surface. FIG. 16 (iii)).

The vibrating plate having such a structure may be fixed to the substrate 10 with an adhesive or the like and divided at a constant pitch in the same manner as described above.

FIG. 17 shows a cross-sectional structure of an ink jet recording head using the piezoelectric vibrating plate constructed by the above-described steps. The sectional structure is formed at the front ends of the end plates 85 and 86 and the piezoelectric vibrating plate 64. A cable 82 which abuts on the island upper portion 49 via the conductive layer 73 and which is externally connected to the conductive layers 75 and 78 formed on the rear end plate 87.
Has been fixed. As described above, since the conductive layers are embedded in the front end plates 85 and 86 and the rear end plates 87 and 88, the piezoelectric vibrating plate 64 is free from warping or distortion. As a result, sufficient accuracy can be obtained even if the thickness of the piezoelectric vibrating plate, or substantially the layer thickness of the piezoelectric material 60, is reduced, and downsizing of the recording head and low-voltage driving become possible.

In the above-described embodiment, the case where the conductive layers are embedded in the front plate and the rear plate fixed to both surfaces of the piezoelectric plate has been described. However, only the one surface of the piezoelectric plate as shown in FIG. It is clear that even when the front plate and the rear plate are formed by firing ceramic, distortion and warpage can be prevented by embedding the conductive layer.

[0057]

According to the present invention as described above, according to the present invention, the surface of the at least hand forms an inactive portion having no conductive layers the leading end of the piezoelectric vibrator, pressurized so as to match the tip than attaching the tip plate for pressure support, the pressure chamber to eject ink droplets even when elongated in the ink droplet discharge direction, parallel widely uniformly pressed the diaphragm overlying over its longitudinal direction Can be displaced to
Ink displacement even pressure chamber of the displacement amount is small piezoelectric vibrator can be pressed efficiently pressurizing a.

In addition, when molding, a small number of piezoelectric plates are required.
Without even after having laminated the above tamp rate on one surface, the tip
Since the plate and the piezoelectric plate are divided by a predetermined width, not only can a tip plate for assisting pressing be easily provided at the tip of each piezoelectric vibrator, but also the piezoelectric plate before firing can be provided by this plate. By reinforcing the plate, the piezoelectric vibrator can be more accurately formed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a piezoelectric vibrator assembly showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of an ink jet recording head to which the above assembly is assembled.

FIGS. 3 (a) to 3 (e) are views showing a manufacturing process of the above assembly.

FIG. 4 is a perspective view showing a tooth splitting device for a piezoelectric vibrator.

FIG. 5 shows a second embodiment of the present invention;
(A) is a diagram showing the front and rear end plate forming layers, (b) is a diagram showing a piezoelectric plate forming layer, and (c) is a diagram in which these are laminated.

FIG. 6 is a perspective view of a piezoelectric plate showing another embodiment of the present invention.

FIG. 7 is a perspective view showing a molding method of the plate.

FIG. 8 is a perspective view showing still another embodiment of the present invention.

FIG. 9 is a perspective view of a piezoelectric vibrator assembly showing still another embodiment of the present invention.

FIGS. 10A and 10B are perspective views of a piezoelectric vibrator assembly showing another embodiment of the present invention, wherein FIGS. 10A and 10B show the structure as viewed from the front and back, respectively, and FIG. The figure seen from the side is shown.

FIG. 11 is a perspective view showing a method of shaping the piezoelectric vibrator assembly according to the third embodiment.

FIG. 12 is a cross-sectional view showing an embodiment of the ink jet recording head in which the piezoelectric vibrator assembly is incorporated, at a position where the dummy vibrator of the piezoelectric vibrator assembly and the piezoelectric vibrator can be seen.

FIG. 13 is a perspective view showing another embodiment of the piezoelectric vibrator assembly of the present invention.

FIG. 14 is a perspective view showing a state where the piezoelectric vibrator assembly is divided into teeth.

FIGS. 15 (i) to (iii) are views showing steps of manufacturing the piezoelectric vibrator assembly, respectively.

FIGS. 16 (i) to (iii) are views showing another embodiment of the piezoelectric vibrator assembly in the manufacturing process.

FIG. 17 is a cross-sectional view showing a structure of an ink jet recording head using the piezoelectric vibrator assembly.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric vibrator assembly 2, 22 Piezoelectric plate 3, 23 Piezoelectric vibrator 4, 24 Inactive part 5, 25 Active part 6, 26 Front plate 7, 27 Rear end plate 10 Metal plate 28 Side plate 40 Flow path formation Member 41 Nozzle plate 47 Diaphragm 51 Positioning and holding block

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-366643 (JP, A) JP-A-4-1052 (JP, A) JP-A-4-347644 (JP, A) JP-A-5-Japanese 220956 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/045 B41J 2/055 B41J 2/16

Claims (25)

(57) [Claims] 1. A leaving at least the tip portion as an inert region, to the tooth breaking the piezoelectric plate formed by laminating a conductive layer on the other part to a large number of piezoelectric elements, at least hand before Symbol inactive region of said piezoelectric element the surface, the tip is the tip plate for pressurized auxiliary to match the tip of the piezoelectric element is laminated
Piezoelectric driving body for the ink jet recording head is. On both sides of the front Symbol inactive region of 2. A front Symbol piezoelectric element, an ink jet according to claim 1 whose tip is the tip plate for pressurized auxiliary to match the tip of the piezoelectric element are laminated Piezoelectric driver for recording head. 3. A slope in the rear surface of the front Symbol pressure auxiliary plate
Piezoelectric driving body for the ink jet recording head according formed to claim 1 or 2. Wherein to form the inactive region having no conductive layer at the tip portion and the rear end portion of the front Symbol piezoelectric plate, the tip of the prior SL on the surface of at least a hand of two inactive regions, pressurized auxiliary plate and the rear plate piezoelectric elements bonded are stacked
Piezoelectric driving body for the ink jet recording head according to claim 1 in which. On both sides of 5. Before SL piezoelectric plate, before Symbol tip plate before Symbol rear plate and piezoelectric for ink jet recording head according to claim 4 which is laminated side plates formed integrally Driving body. 6. The surface of the pre-Symbol inactive region of said piezoelectric element,
And the rear surface, the tip is the tip plate for to pressure assist to match the tip of the piezoelectric element is laminated, also before
Surface of the piezoelectric element positioned on both sides of the column arrangement direction of the serial piezoelectric elements, and the molded on the rear end plate integrally on the rear surface
Piezoelectric driving body for the ink jet recording head according to claim 4 or 5 side plates is fixed. Wherein said tip plate, and the piezoelectric driving body for the ink jet recording head according to any one of claims 1 to 6 at least one of the rear plate is constituted by the firing of the ceramic. Wherein said tip plate, and the piezoelectric driving body for the ink jet recording head according to any one of claims 1 to 6 conductive layer is embedded in at least one of the rear end plate. 9. Before SL piezoelectric drive for an ink jet recording head according to any previous SL plate of machinable ceramics <br/> is constituted by a material according to claim 1 to 8 that is laminated on the piezoelectric plate body. 10. On the top surface of the front Symbol rear plate, before Symbol for tilting without retained in the mounting hole of the piezoelectric element holding block, 請 Motomeko 4 fixed a large plate area than the rear end plate 10. The piezoelectric driver for an ink jet recording head according to any one of claims 9 to 9. 11. An external conductive layer is formed on the surface from the tip of the piezoelectric element, and a tip plate for assisting pressurization is provided on at least one surface of the piezoelectric element so as to coincide with the tip. It was laminated on the outer conductive layer and the piezoelectric one conductive layer using the piezoelectric element which connects the conductive layer to be the polar elements, and 請 Motomeko 1 formed at the tip of the tip plate, 7. The piezoelectric driver for an ink jet recording head according to any one of 4 to 6. 12. A conductive layer connected to an external conductive layer formed on a surface of the piezoelectric element and a conductive layer connected to a rear end of the piezoelectric element are formed on a surface of the rear end plate. 5. The connection to the cable via a layer.
7. The piezoelectric driving body for an ink jet recording head according to any one of claims 1 to 6. A step 13. At least the distal end portion to form a piezoelectric plate by laminating a conductive material on the piezoelectric material such that the inactive region, on at least one hand of the plane of the front Symbol inactive region, the tip is pre-Symbol laminating a tip plate for to pressure assist to align the tip of the piezoelectric plate, before SL and tooth breaking the previous SL piezoelectric plate with a predetermined width including the tip plate forming a plurality of piezoelectric elements A method for manufacturing a piezoelectric driver for an ink jet recording head, comprising: 14. A piezoelectric plate is formed by laminating a conductive material on a piezoelectric material so that a leading end and a trailing end are inactive regions. Then, at least one surface of both inactive regions is provided with a pressure assisting member. 14. The method according to claim 13 , wherein the front end plate and the rear end plate for coupling the piezoelectric element are laminated. The inactive region of at least the tip portion of 15. Before SL piezoelectric material and before Kishirubeden material and a laminated molded before Symbol piezoelectric plates, stacking the plates made of a machinable ceramic material, then sintering them The method for manufacturing a piezoelectric driving body for an ink jet recording head according to claim 13 or 14 , wherein the piezoelectric driving body is integrated by: 16. By the previous SL piezoelectric material and before Kishirubeden material
And firing the laminate molding pre Symbol piezoelectric plate, then over the piezoelectric plate, the plate is molded and fired by pasty machinable ceramic material are laminated to claim 13 or 14 as an integral The manufacturing method of the piezoelectric driving body for an inkjet recording head according to the above. At least one surface of the front Symbol inactive region of 17. Before SL piezoelectric material and before Kishirubeden material and piezoelectric plate forming laminated sheet was laminated by, To integrally a front Symbol tip plate before Symbol rear plate laminated with a pitch, then before the line that divides the front Symbol tip plate before Symbol rear plate before Symbol molded plate member as a boundary SL corresponding to the length of the substantially pre-Symbol piezoelectric plate molded plate layer without The method for manufacturing a piezoelectric driving body for an ink jet recording head according to claim 14 , wherein the laminate is divided. A reference portion provided in a part of the 18. Before SL piezoelectric material as a reference, to form a pre-Symbol piezoelectric plate forming laminated sheet as superimposed with each other two of the internal electrode pattern on the piezoelectric material The method for manufacturing a piezoelectric driving body for an ink jet recording head according to claim 13 or 17 , wherein: 19. The method for manufacturing an ink jet recording head piezoelectric driving body according to claim 13 or 17 before SL internal electrodes so as to mold the pre-Symbol piezoelectric plate forming laminated sheet so as not to be exposed from at least two sides. To 20. One side of the inactive region of the piezoelectric plate forming laminated body formed of a piezoelectric material and a conductive material, the longitudinal in the direction, before Symbol tip plate before Symbol rear plate molded plate material was integrated with substantially before Symbol laminated with a pitch interval corresponding to the length of the piezoelectric plate, the width direction, laminated with a pitch interval corresponding to the width of the front Symbol piezoelectric plate molded plate material having approximately twice the width of the side plates and, then, with dividing the pre Symbol laminate longitudinally lines defining the pre-Symbol tip plate before Symbol rear plate before Symbol molded plate material as a boundary, before SL side plates before Symbol molded plate member The method for manufacturing a piezoelectric driving body for an ink jet recording head according to claim 14, wherein the laminate is divided in the width direction at a line that substantially divides the piezoelectric element into two, and a plurality of piezoelectric plates are formed. To 21. The surface and two sides of the back surface of the inactive region of the piezoelectric plate forming laminated body formed of a piezoelectric material and a conductive material, in the longitudinal direction, To integrally pre SL tip plate before Symbol rear plate plates profiled laminated with a substantially pitch interval corresponding to the length of the previous SL piezoelectric plate, the width direction, corresponds to the plate shaped member having a substantially double the width of the side plates in the width of the front Symbol piezoelectric plate to stacked with pitch, then with dividing the pre Symbol laminate longitudinally lines defining the pre-Symbol tip plate before Symbol rear plate before Symbol molded plate material as a boundary, before Symbol molded plate member manufacturing method of the preceding SL side plates by dividing the pre-Symbol laminate in the width direction as a boundary line for 2 minutes approximately plurality of piezoelectric plates molded claim 14 inkjet recording head piezoelectric driving body according to. And the rear end edge of the front Stories tip plate 22. The piezoelectric plate, the line connecting the substantially front edge of the rear inactive region as a boundary, the teeth split the distal end side of the front Symbol piezoelectric plate with a predetermined width The method according to claim 13 or 14 , wherein a plurality of piezoelectric elements are formed. 23. A step of forming a piezoelectric plate by laminating a conductive material on a piezoelectric material; a step of forming an external conductive layer extending to a tip on a surface of the piezoelectric plate; with aligning the tip of the plate tip plate for the auxiliary pressure laminated at least one surface, before the tip of Kishirubeden material and a conductive layer using the piezoelectric plate to connect the outer conductive layer, and forming the tip of the tip plate 15. The method of manufacturing a piezoelectric driving body for an ink jet recording head according to claim 13, further comprising a step of forming a plurality of piezoelectric vibrators by dividing the tip plate and the piezoelectric plate by a predetermined width. 24. according to any one of claims 13, 14, 23 of the tip plate and a step of laminating a ceramic green sheet to a plurality of layers a predetermined thickness, and a step of firing the laminated green sheets Of manufacturing a piezoelectric driving body for inkjet. 25. The tip plate, and a rear end plate, a manufacturing method of the piezoelectric driving body for the ink jet recording head according to claim 24 where the conductive layer is formed.