JP2000052552A - Liquid drop jet apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a piezoelectric element in a minute structure by forming a bottom electrode to a bottom face of a recessed part, forming a back electrode to a rear face of a piezoelectric block to be opposite to the bottom electrode and inserting a piezoelectric part between the electrodes. SOLUTION: A lid part 2 for covering a recessed part 3 in which a liquid is to be stored and a liquid channel groove 4 is fitted to a front face of a piezoelectric block material 1. The recessed part 3 covered with the lid part 2 forms a liquid storage chamber for storing the liquid, and the liquid channel groove 4 covered with the lid part 2 forms a liquid channel for guiding the liquid outside. A bottom electrode 5 is formed to totally cover a bottom face of the recessed part 3. A back electrode 6 opposite to the bottom electrode 5 is formed to a rear face of the piezoelectric block material 1. A piezoelectric element is formed of a piezoelectric part 7 at a bottom part of the liquid storage chamber inserted between the bottom electrode 5 and back electrode 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid droplet ejecting apparatus used for an ink jet printer head or the like.

[0002]

2. Description of the Related Art In recent years, an ink jet printer has attracted attention as an output terminal of a personal computer. The driving method of the ink jet printer head, which can be said to be the heart, is roughly classified into a piezoelectric driving method and a heat driving method. The piezoelectric driving method is superior to the thermal driving method in terms of responsiveness and durability.

[0003] As a conventional piezoelectric drive type ink jet printer head, there is a nozzle head using a liquid droplet ejecting apparatus for ejecting a liquid such as ink into particles by utilizing deformation of a piezoelectric element. The configuration of a nozzle head using such a droplet ejecting apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 55-94660.
No. 6,086,045.

The nozzle head disclosed in this document has a pressure chamber for containing ink, a nozzle hole for ejecting ink as droplets, that is, ink particles, and a conduit for guiding ink from the pressure chamber to the nozzle hole. And an ink reservoir in communication with the pressure chamber via another conduit section.

[0005] Each element of the above-described nozzle head includes a groove formed by chemical etching on the surface of a body made of silicon or the like, and a plate-like base arranged by electrostatic bonding on the surface of the body so as to cover the groove. Is formed by The base is made of, for example, Pyrex glass.

Further, silicon dioxide (Si) is provided on the surface where the nozzle hole is opened so that the interface characteristics with the ink become uniform.
A thin film of O ₂ ) is formed by vapor deposition or sputtering.

A piezoelectric element is externally mounted at a position corresponding to the pressure chamber on the back surface of the main body made of silicon or the like. The piezoelectric element is made of a piezoelectric body having electrodes formed on both surfaces. By contracting the pressure chamber by deformation based on the piezoelectric effect (bimetal effect) of the piezoelectric element, ink in the pressure chamber is ejected from a nozzle hole as ink particles through a conduit portion.

However, in the liquid droplet ejecting apparatus used in the conventional nozzle head, if each element including the pressure chamber and the piezoelectric element have minute shapes, the piezoelectric element is externally mounted at a position corresponding to the pressure chamber. It was not easy to accurately arrange the elements. Therefore, there is a problem that it is difficult to manufacture a droplet ejecting device having a fine structure.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid droplet ejecting apparatus capable of having a fine structure.

[0010]

In order to solve the above problems, in the present invention, a concave material and a groove are formed on a surface by etching a block material made of a piezoelectric material, and a cover is formed so as to cover the concave material and the groove. The liquid storage chamber and the liquid flow path are provided by mounting the unit. Then, electrodes are formed on the bottom surface of the concave portion and on the back surface of the block material corresponding to the bottom surface of the concave portion, and the piezoelectric portion sandwiched between these electrodes is driven as a piezoelectric element. Since the position of the piezoelectric element is defined by the concave portion in this manner, it is easy to accurately arrange the piezoelectric element at a position corresponding to the liquid storage chamber, and to realize a droplet ejecting apparatus capable of having a fine structure. Can be.

That is, according to the present invention, a recess for accommodating a liquid and a groove for a liquid flow passage having one end connected to the recess and the other end opened on the side surface are formed in the surface. A block material, a lid mounted on the surface of the block material so as to cover the concave portion and the groove, and a liquid stored in a liquid storage chamber formed by the concave portion and the lid. A piezoelectric element that deforms so as to shrink the liquid storage chamber in order to extrude the liquid as liquid droplets through a liquid flow path formed by the lid, wherein the block material is formed of a piezoelectric material, and the piezoelectric element is A bottom electrode formed on the bottom surface of the concave portion, a back electrode formed on the back surface of the piezoelectric block facing the bottom electrode, and a piezoelectric portion sandwiched between both electrodes. Is provided.

In the present invention, a wiring groove is formed on the surface of the piezoelectric block, one end of which is connected to the recess and the other end of which is open on the side surface. A wiring electrode connected to the bottom electrode of the concave portion is formed, and an opening of the wiring groove is filled with a liquid outflow preventing material for preventing the liquid from flowing out from the opening. In the opening of the groove for the liquid flow path, a droplet form adjusting means for adjusting the form of the droplet extruded from the opening to the outside is disposed, and the liquid form adjusting means is provided on the lid. It is preferable that a liquid supply source for supplying the liquid to the concave portion is disposed, and the lid portion be provided with a liquid supply hole for passing the liquid from the liquid supply source to the concave portion.

Further, in the present invention, it is preferable that the bottom electrode and the back electrode of the piezoelectric element have different thicknesses and / or are formed of a conductive material having different Young's modulus.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings.
This will be described in detail. FIG. 1 shows a droplet ejecting apparatus according to the present invention. FIG. 1A is a schematic perspective view thereof, and FIG.
FIG. 2 is a sectional view taken along line BB ′ of FIG.

The droplet ejecting apparatus according to the present invention includes one piezoelectric block 1 and a lid 2 attached to the surface of the block. The piezoelectric block material 1 usually has a shape such as a rectangular parallelepiped.

The dimensions of the piezoelectric block 1 include, for example, a width of about 10 mm, a length of about 10 mm, and a thickness (or height) of about 0.5 mm. The piezoelectric block 1 is formed of, for example, ceramics. The ceramic is not particularly limited as long as it can obtain piezoelectricity. Examples of ceramics that can obtain piezoelectricity include lead zirconate titanate (PZT) -based ceramics, lead zinc niobate and lead titanate (PZN-
PT) -based ceramics, lead magnesium niobate and lead titanate (PMN-PT) -based ceramics, and the like.

The piezoelectric block material 1 is made of, for example, a material obtained by firing the above-mentioned ceramic material powder or a material obtained by grinding or cutting a single crystal such as a solid solution single crystal of the ceramic material.

The piezoelectric block material 1 is more preferably ground or cut out of a single crystal than fired material powder. This is because a single crystal has a higher orientation and a higher density than a sintered one and has excellent piezoelectric characteristics.

On the surface of the piezoelectric block 1, a recess 3 for containing a liquid, and a groove 4 for a liquid flow path for guiding the liquid contained in the recess 3 to the side surface of the piezoelectric block 1. Are formed. One end of the groove 4 for the liquid flow path is connected to the concave portion 3, and the other end is opened on the side surface of the piezoelectric block material 1.

Examples of the liquid include inks and chemicals used in ink jet printers and the like. Recess 3
The groove 4 for the liquid flow path can be formed on the surface of the piezoelectric block material by selective etching using plasma of a reactive gas, as described later.

The shape of the concave portion 3 is circular or square, and is not particularly limited. FIG. 1 shows a circular recess 3 as an example. The dimensions of the recess 3 and the fluid flow channel 4 are as follows:
The use of the droplet ejecting apparatus according to the present invention is determined by the specifications of an ink jet printer head, for example, and is not particularly limited. As an example, when the concave portion 3 is circular, the diameter of the circular shape is about 5 mm and the depth is about 0.4 m.
m, and the width of the liquid channel groove 4 is about 10 μm.
m, depth is about 0.4 mm.

The cover 2 for covering the recess 3 and the liquid flow channel 4 is mounted on the surface of the piezoelectric block 1 in a liquid-tight manner. The lid 2 has, for example, a sheet-like shape. When the lid 2 is a sheet member, the thickness is, for example, about 0.2 mm. The material forming the lid 2 is, for example, the same kind of piezoelectric material as the piezoelectric block material 1.

The recess 3 covered by the lid 2 forms a liquid storage chamber for storing a liquid, and the groove 4 for the liquid flow path covered by the lid 2 is used to guide the liquid to the outside. Form a flow path.

The bottom electrode 5 is entirely covered with the bottom surface of the recess 3.
Are formed on the back surface of the piezoelectric block material 1, and a back electrode 6 facing the bottom electrode 5 is formed. The back electrode 6 may be formed on at least a portion of the liquid storage chamber facing the bottom electrode 5, and may be formed on the entire back surface of the piezoelectric block material 1, for example.

The material of the bottom and back electrodes 5, 6 and the method of formation are not particularly limited. As the material of the electrode,
For example, a conductive material such as a metal material can be used. Examples of the metal material include a single metal such as gold, silver, copper, platinum, titanium, nickel, and chromium, and a laminate of a metal such as chromium / gold that combines these single metals. Examples of the method of forming the electrode include CVD (chemical vapor deposition), electroplating, sputtering, vapor deposition, and ion plating.
Alternatively, a plate-shaped electrode made of the above-described metal material may be prepared in advance, and the plate-shaped electrode may be attached to the piezoelectric block 1 by bonding.

It is preferable that the bottom and back electrodes 5 and 6 have different thicknesses and / or are made of a conductive material having a different elastic modulus such as Young's modulus. By forming the bottom and back electrodes 5 and 6 in this manner,
The amount of elasticity in the in-plane direction of each electrode can be different. That is, the amount of elongation and the amount of contraction of each electrode with respect to a constant stress in the in-plane direction can be made different. The larger the thickness and / or the Young's modulus, the smaller the elongation for a constant in-plane tensile stress and the smaller the shrinkage for a constant in-plane compressive stress. Conversely, the smaller the thickness and / or Young's modulus, the greater the elongation for a constant in-plane tensile stress and the greater the amount of shrinkage for a constant in-plane compressive stress.

The thickness of the bottom electrode 5 and the back electrode 6 is preferably, for example, about 1 to 50 μm on one side and about 0.01 mm to 0.1 mm on the other side.
The Young's modulus of the bottom electrode 5 and the back electrode 6 is, for example, 1E10Pa (Pascal) to 10E
About 10 Pa, and the other is 5E10 Pa to 50E10
It is preferably about Pa.

A piezoelectric element is formed by the bottom and back electrodes 5, 6 and the piezoelectric portion 7 at the bottom of the liquid storage chamber sandwiched between the electrodes. The piezoelectric member 7 sandwiched between the two electrodes is hereinafter referred to as a driving piezoelectric member. The driving piezoelectric body 7 is polarized in the thickness direction, that is, polarized in the direction from the bottom electrode 5 to the back electrode 6 or in the opposite direction. The driving piezoelectric element 7 may be polarized, for example, by applying a voltage between the bottom electrode 5 and the back electrode 6 while the sample is placed in the air or oil, and Polarization.

By applying a voltage to the bottom and back electrodes 5, 6, this piezoelectric element can be deformed so as to shrink the liquid storage chamber, as described later. As a result of the contraction of the liquid storage chamber, the liquid stored in the liquid storage chamber is extruded and ejected to the outside as droplets through the liquid flow path.

The thickness of the driving piezoelectric body 7 is, for example,
50 to 200 μm is preferred. When the thickness exceeds 200 μm, the deformation of the piezoelectric element when a voltage is applied to the electrode is too small to be sufficient for ejecting a droplet. On the other hand, when the thickness is less than 50 μm, the driving piezoelectric element 7 is too thin and is likely to be broken during manufacturing and use, resulting in low reliability.

In the liquid droplet ejecting apparatus according to the present invention, the piezoelectric element is formed by using the piezoelectric body at the bottom of the liquid storage chamber. That is, since the bottom surface of the liquid storage chamber becomes the piezoelectric element as it is, the position of the piezoelectric element is automatically defined by the liquid storage chamber, that is, the concave portion. Therefore, if an electrode is formed on the bottom surface of the concave portion, the positioning of the piezoelectric element with respect to the liquid storage chamber is accurately performed even if the back electrode is roughly formed at a position corresponding to the concave portion. Therefore, even if each of the liquid storage chamber and the piezoelectric element has a fine shape, it is easy to accurately dispose the piezoelectric element at a position corresponding to the liquid storage chamber. A droplet ejection device can be realized.

Next, the operation of the droplet ejecting apparatus shown in FIG. 1 will be described. As described above, the liquid droplet ejecting apparatus shown in FIG. 1 deforms the piezoelectric element including the bottom electrode 5, the back electrode 6, and the driving piezoelectric body 7 sandwiched between these electrodes, thereby forming the liquid storage chamber. Liquid can be ejected as droplets.

Therefore, the deformation of the piezoelectric element will be described first. <Description of Deformation of Piezoelectric Element> The piezoelectric element performs (1) deformation to contract the liquid storage chamber or (2) deformation to expand the liquid storage chamber by applying a voltage to the bottom and back electrodes 5 and 6. I do.

The respective modifications will be described below with reference to FIG. FIG. 2 is a schematic sectional view mainly showing a liquid storage chamber and a piezoelectric element of the droplet ejecting apparatus of FIG.

(1) Deformation for Shrinking the Liquid Storage Chamber (a) First, the bottom electrode 5 is designed to have a larger amount of elongation and contraction for a given stress in the in-plane direction of the electrode than the back electrode 6. The case in which it is formed will be described.

This corresponds to the case where the bottom electrode 5 has a smaller thickness and / or Young's modulus than the back electrode 6. As an example, this corresponds to a case where the thickness of the bottom electrode 5 is about 10 μm and the thickness of the back electrode 6 is about 0.1 mm.

The thickness and Young's modulus of the bottom and back electrodes 5 and 6 are made substantially the same, and a member such as a glass plate having a small in-plane elongation and shrinkage is attached to the back electrode 6 with an adhesive or the like. May be joined. Since the elongation and shrinkage of the back electrode 6 are suppressed by a member such as a glass plate, the bottom electrode 5 should have a larger amount of elongation and shrinkage in the in-plane direction than the back electrode 6. it can.

A voltage is applied to the bottom and back electrodes 5 and 6 so that an electric field is applied to the driving piezoelectric body 7 in a direction opposite to the polarization direction of the piezoelectric body. That is, when the driving piezoelectric body 7 is polarized in a direction from the bottom electrode 5 to the back electrode 6, for example, a negative voltage is applied to the bottom electrode 5 and a positive voltage is applied to the back electrode 6. Conversely, when the driving piezoelectric element 7 is polarized in the direction from the back electrode 6 to the bottom electrode 5, for example, a positive voltage is applied to the bottom electrode 5 and a negative voltage is applied to the back electrode 6.

In general, when an electric field is applied to a piezoelectric body in a direction opposite to the direction of polarization of the piezoelectric body, the piezoelectric body deforms so as to contract in the polarization direction and expand in the direction perpendicular to the polarization direction. In the droplet ejection device shown in FIG.
The driving piezoelectric body 7 contracts in the thickness direction, which is the polarization direction, and extends in an in-plane direction perpendicular to the thickness direction. Along with the driving piezoelectric body 7, the bottom and back electrodes 5, 6 also extend in the in-plane direction.

Now, both electrodes are formed so that the bottom electrode 5 extends more in the in-plane direction than the back electrode 6. As a result of the bottom electrode 5 extending more in the in-plane direction than the back electrode 6, the piezoelectric element having both electrodes on both sides deforms so as to bend toward the bottom electrode 5. In this case, the deflection of the piezoelectric element toward the bottom electrode 5 is caused by a unimorph operation composed of the back electrode 6 and the driving piezoelectric element 7.

FIG. 2A shows bottom and back electrodes 5 and 6.
1 is a schematic sectional view showing a piezoelectric element when no voltage is applied to the piezoelectric element. FIG. 2B is a schematic cross-sectional view showing a piezoelectric element that is bent toward the bottom electrode 5 (in the direction of arrow A in the figure) as described above when a voltage is applied to the bottom and back electrodes 5 and 6. Show.

As a result of the deflection of the piezoelectric element toward the bottom electrode 5, the volume of the liquid storage chamber is reduced, and the liquid storage chamber contracts. (B) Next, a case will be described in which the back electrode 6 is formed to have a larger amount of elongation and contraction for a given stress in the in-plane direction of the electrode than the bottom electrode 5.

This corresponds to the case where the thickness and / or the Young's modulus of the back electrode 6 are smaller than those of the bottom electrode 5. As an example, this corresponds to the case where the thickness of the back electrode 6 is about 10 μm and the thickness of the bottom electrode 5 is about 0.1 mm.

A voltage is applied to the bottom and back electrodes 5 and 6 so that an electric field in the same direction as the polarization direction of the piezoelectric body is applied to the driving piezoelectric body 7. That is, the driving piezoelectric body 7
Is polarized in the direction from the bottom electrode 5 to the back electrode 6, for example, a positive voltage is applied to the bottom electrode 5 and a negative voltage is applied to the back electrode 6. Conversely, when the driving piezoelectric body 7 is polarized in the direction from the back electrode 6 to the bottom electrode 5, for example, a negative voltage is applied to the bottom electrode 5 and a positive voltage is applied to the back electrode 6.

In general, when an electric field having the same direction as the direction of polarization of the piezoelectric body is applied to the piezoelectric body, the piezoelectric body deforms so as to expand in the polarization direction and contract in the direction perpendicular to the polarization direction. In the droplet ejecting apparatus shown in FIG. 1, the driving piezoelectric element 7 extends in the thickness direction, which is the polarization direction, and contracts in an in-plane direction perpendicular to the thickness direction. Along with the driving piezoelectric body 7, the bottom surface and the back electrodes 5, 6 also shrink in the in-plane direction.

Now, both electrodes are formed so that the back electrode 6 shrinks more in the in-plane direction than the bottom electrode 5. As a result of the back electrode 6 shrinking more in the in-plane direction than the bottom electrode 5, the piezoelectric element having both electrodes on both surfaces also bends toward the bottom electrode 5, as shown in FIG. Make a great deformation. In this case, the bending of the piezoelectric element toward the bottom electrode 5 is caused by a unimorph operation composed of the bottom electrode 5 and the driving piezoelectric element 7.

As a result of the piezoelectric element bending toward the bottom electrode 5, the liquid storage chamber also contracts. (2) Deformation for expanding the liquid storage chamber (a) First, the bottom electrode 5 is formed to have a larger amount of expansion and contraction with respect to a constant stress in the in-plane direction of the electrode than the back electrode 6. Will be described.

A voltage is applied to the bottom and back electrodes 5 and 6 so that an electric field is applied to the driving piezoelectric element 7 in the same direction as the polarization direction of the piezoelectric element. As described above, when an electric field in the same direction as the polarization direction of the piezoelectric body is applied to the driving piezoelectric body 7, the driving piezoelectric body 7 sandwiched between the bottom surface and the back electrodes 5, 6 extends in the thickness direction and , Shrinks in an in-plane direction perpendicular to the thickness direction.

Now, both electrodes are formed so that the bottom electrode 5 shrinks more in the in-plane direction than the back electrode 6. As a result of the bottom electrode 5 shrinking more in the in-plane direction than the back electrode 6, the piezoelectric element having both electrodes on both surfaces deforms to bend toward the back electrode 6. In this case, the deflection of the piezoelectric element toward the back electrode 6 is caused by a unimorph operation composed of the back electrode 6 and the driving piezoelectric element 7.

FIG. 2C shows bottom and back electrodes 5 and 6.
FIG. 2 is a schematic cross-sectional view showing a piezoelectric element that is bent toward the back electrode 6 (in the direction of arrow B in the drawing) as described above when a voltage is applied to the piezoelectric element.

As a result of the piezoelectric element bending toward the back electrode 6, the volume of the liquid storage chamber increases, and the liquid storage chamber expands. (B) Next, a case will be described in which the back electrode 6 is formed to have a larger amount of elongation and contraction for a given stress in the in-plane direction of the electrode than the bottom electrode 5.

A voltage is applied to the bottom and back electrodes 5 and 6 so that an electric field is applied to the driving piezoelectric element 7 in a direction opposite to the polarization direction of the piezoelectric element. As described above, when an electric field is applied to the driving piezoelectric body 7 in a direction opposite to the polarization direction of the piezoelectric body, the driving piezoelectric body 7 sandwiched between the bottom surface and the back electrodes 5 and 6 contracts in the thickness direction. At the same time, it extends in an in-plane direction perpendicular to the thickness direction.

Now, both electrodes are formed so that the back electrode 6 extends more in the in-plane direction than the bottom electrode 5. As a result of the back electrode 6 extending in the in-plane direction more greatly than the bottom electrode 5, the piezoelectric element having both electrodes on both surfaces also bends toward the back electrode 6 as shown in FIG. Make a great deformation. In this case, the deflection of the piezoelectric element toward the back electrode 6 is caused by a unimorph operation composed of the bottom electrode 5 and the driving piezoelectric element 7.

As a result of the piezoelectric element bending toward the back electrode 6, the liquid storage chamber also expands. As described above, the piezoelectric element deforms to contract the liquid storage chamber or expands the liquid storage chamber.

In the liquid droplet ejecting apparatus shown in FIG. 1, the piezoelectric element is deformed so as to contract the liquid chamber as described in the above (1). By contracting the liquid storage chamber, the liquid stored in the liquid storage chamber can be extruded and ejected to the outside as droplets through the liquid flow path.

In addition to the above-described elements, the liquid droplet ejecting apparatus according to the present invention includes a wiring groove 8 formed on the surface of the piezoelectric block 1, and a liquid filled in the opening of the wiring groove 8. An outflow preventing member, a droplet form adjusting means 9 disposed at the opening of the liquid flow channel groove 4, a liquid supply source disposed on the lid 2, and a liquid provided on the lid 2. It is preferable that a supply hole 11 is further provided.

FIG. 3 is a schematic perspective view showing a droplet ejecting apparatus provided with these elements. FIG. 4 is a sectional view taken along line X-
It is a schematic sectional drawing which followed X '. One of the wiring grooves 8 is connected to the concave portion 3 and the other end is opened on the side surface of the piezoelectric block material 1, similarly to the liquid channel groove 4. The side surface of the piezoelectric block material 1 in which the wiring groove 8 is open may be the same as or different from the side surface in which the liquid channel groove 4 is open. In FIG. 3, these two
Figure 2 shows a droplet ejector with two different sides.

As shown in FIG. 4, a wiring electrode 12 connected to the bottom electrode 5 of the recess 3 is formed on the bottom of the wiring groove 8. The wiring electrode 12 is connected to an external lead wire (not shown) by soldering (not shown) or the like at the opening of the wiring groove 8. Wiring electrode 12
The material and the method of formation are the same as those of the bottom and back electrodes 5 and 6 described above.

Note that, instead of the tip of the wiring groove 8 opening on the side surface of the piezoelectric block material 1, the tip of the wiring groove 8 is connected to a lead wire connecting groove, and the lead wire connecting groove is connected to the lead wire connecting groove. An opening may be provided on the side surface of the piezoelectric block 1.

In the case where a lead wire connecting groove is provided, the above-mentioned wiring electrode 12 is formed on the bottom surface of the lead wire connecting groove together with the bottom surface of the wiring groove 8. The groove for connecting the lead wire is for facilitating the connection between the external lead wire and the wiring electrode 12 and has, for example, a width wider than the width of the wiring groove 8.

FIG. 3 shows a liquid droplet ejecting apparatus provided with a lead wire connecting groove 13 which is wider than the wiring groove 8.
The liquid outflow prevention material is filled in the opening 3 in order to prevent the liquid contained in the concave portion 3 from flowing out of the opening of the wiring groove 8 to the outside. In FIG. 3, a liquid outflow prevention member is omitted to make the structure of the droplet ejecting device easy to see. Examples of the liquid outflow prevention material include a resin such as an epoxy resin. When the above-described lead wire connection groove 13 is provided, the liquid outflow preventing material is filled in the opening of the lead wire connection groove 13.

The droplet form adjusting means 9 is provided with a groove 4 for a liquid flow path.
Size of the final droplet ejected from the opening of the outside,
This is for adjusting the form such as the shape. As the droplet form adjusting means 9, for example, a sheet member or the like in which the droplet ejection holes 14 having a form such as a predetermined size and shape are formed is cited. The shape of the droplet ejection hole 14 is adjusted to a predetermined shape necessary to obtain a desired shape of the droplet. As a form of the droplet ejection hole 14, for example, about 10
It is a circle with a diameter of μm. Examples of the sheet member include a polyimide tape whose surface is treated with Teflon. The sheet member is bonded to the side surface of the piezoelectric block material 1 with an adhesive or the like such that the droplet ejection holes 14 are positioned at the openings of the liquid flow channel grooves 4.

The liquid supply source disposed on the lid 2 is for supplying liquid ejected to the outside as liquid droplets to the liquid storage chamber. The liquid supply source is produced, for example, by bonding a rectangular parallelepiped box 10 having an open surface to the lid 2 with this opening downward using an adhesive or the like.
By storing the liquid in the space formed by the lid 2 and the box 10, it becomes a liquid supply source to the liquid storage chamber.

Incidentally, a liquid tank for replenishing the liquid supply source with liquid may be connected to the liquid supply source. When the liquid in the liquid supply falls below a certain amount,
Liquid is supplied to the liquid supply from the liquid tank.

The liquid supply hole 11 provided in the lid portion 2 is for allowing the liquid to pass from the liquid supply source to the liquid storage chamber, and is located between the liquid supply source and the liquid storage chamber. The cover 2 is provided. The shape of the liquid supply hole 11 is, for example, circular.

Next, the operation of the droplet ejecting apparatus shown in FIG. 3 will be described. The liquid droplet ejecting apparatus shown in FIG. 3 deforms the piezoelectric element so as to shrink the liquid accommodating chamber, and extrudes and ejects the liquid contained in the liquid accommodating chamber to the outside as liquid droplets through the liquid flow path. The piezoelectric element is deformed so as to expand the liquid storage chamber, and the liquid from the liquid supply source is supplied to the liquid storage chamber through the liquid supply hole 11.

The method of deforming the piezoelectric element so that the liquid storage chamber is contracted is based on the description of “(1) Deformation of contracting the liquid storage chamber” in the above “description of deformation of piezoelectric element”. The method of deforming the piezoelectric element so as to expand the liquid storage chamber is based on the description in “(2) Deformation for expanding the liquid storage chamber” in the above “Description of Operation of Piezoelectric Element”.

As described above, by alternately contracting and expanding the liquid storage chamber, the liquid in the liquid storage chamber is ejected to the outside and the liquid from the liquid supply source is supplied to the liquid storage chamber alternately. As a result, continuous operation as a droplet ejecting apparatus is realized.

An example of a specific method for alternately contracting and expanding the liquid storage chamber in the apparatus shown in FIG. 3 will be described below. Adjustment of the contraction and expansion operations of the liquid storage chamber is performed by adjusting the manner in which a voltage is applied to the piezoelectric element.

FIG. 5 shows, as an example, a method in which the back electrode 6 is fixed to the ground potential and a voltage is applied only to the bottom electrode 5. The horizontal axis indicates time, and the vertical axis indicates the voltage applied to the bottom electrode 5.

In FIG. 5, the liquid storage chamber expands when a positive voltage is applied to the bottom electrode 5, and contracts when a negative voltage is applied to the bottom electrode 5. The electrodes 5 and 6 are formed, and the driving piezoelectric body 7 is polarized. The specific formation of both electrodes and the manner of polarization of the driving piezoelectric element 7 are based on the description in the above-mentioned “deformation of piezoelectric element”.

In order to fix the back electrode 6 to the ground potential, for example, a GND line is directly connected to the back electrode 6. The application of the voltage to the bottom electrode 5 is performed by the wiring electrode 1.
2 is performed by applying a voltage to the lead wire connected thereto.

(1) Application of Voltage for Preliminary Operation First, a positive voltage is applied to bottom electrode 5 (that is, from time “0”). As a result of the positive voltage being applied to the bottom electrode 5, the liquid storage chamber expands and the liquid from the liquid supply source is supplied to the liquid storage chamber. The applied positive voltage is gradually increased with time, and the liquid from the liquid supply source is excessively supplied into the liquid storage chamber.

(2) Application of Voltage for Injecting Droplet Next, a voltage that continuously changes from positive to negative is applied to the bottom electrode 5. As a result of such a voltage being applied to the bottom electrode 5, the volume of the liquid storage chamber continuously decreases, and the liquid storage chamber changes from expansion to contraction. As a result of the contraction of the liquid storage chamber, the liquid stored in the liquid storage chamber is ejected to the outside as droplets.

As described above, the time during which a voltage that continuously changes to eject a droplet is applied to the piezoelectric element is defined as the droplet ejection time. (3) Application of Voltage for Supplying Liquid to Liquid Storage Chamber Next, a voltage that continuously changes from negative to positive is applied to the bottom electrode 5. As a result of applying such a voltage to the bottom electrode 5, the volume of the liquid storage chamber continuously increases, and the liquid storage chamber changes from contraction to expansion. As a result of the expansion of the liquid storage chamber, the liquid from the liquid supply source is excessively supplied to the liquid storage chamber.

The time during which a voltage that changes continuously to supply the liquid to the liquid storage chamber is applied to the piezoelectric element is defined as the liquid supply time. By alternately repeating the voltage application for ejecting the droplets and the voltage application for supplying the liquid to the liquid storage chamber, the liquid storage chamber contracts and expands alternately to continuously operate the droplet ejection apparatus. Can be operated. Then, the sum of the liquid supply time and the droplet ejection time is one cycle time of the operation of the droplet ejection device in FIG.

In order to efficiently perform continuous operation of the liquid droplet ejecting apparatus, the size, shape, length, and the like of the liquid supply hole 11 and the form, for example, the size and shape of the liquid And the operation of contraction and expansion of the liquid storage chamber,
Each is adjusted appropriately.

That is, when the liquid storage chamber contracts,
The amount of liquid ejected from the liquid storage chamber to the outside through the liquid flow path is larger than the amount of liquid flowing backward from the liquid storage chamber through the liquid supply hole 11 to the liquid supply source. Is expanded from the liquid supply source to the liquid supply hole 1.
1 so that the amount of liquid supplied to the liquid storage chamber through the liquid flow path 1 is larger than the amount of liquid remaining in the liquid flow path back to the liquid storage chamber. , And the contraction and expansion movements of the liquid storage chamber are each appropriately adjusted.

As a form of the liquid supply hole 11 and the droplet ejection hole 14, for example, the size of the liquid supply hole 11 is made larger than the size of the liquid ejection hole. As an example, the liquid supply hole 11 may be a circular hole having a diameter of about 50 μm, and the droplet ejecting hole 14 may be a circular hole having a diameter of about 10 μm.

As the operation of contracting and expanding the liquid storage chamber, for example, the contraction of the liquid storage chamber is performed in a short time,
The expansion of the liquid storage chamber is performed relatively slowly over a longer period of time than the contraction. That is, the above-described droplet ejection time is shortened, and the liquid supply time is longer than the droplet ejection time. Such a droplet ejection time is, for example, 10 μs to 1 ms,
The liquid supply time is, for example, 100 μs to 10 ms.

In order to stop the operation of the liquid droplet ejecting apparatus if necessary and restart it after stopping for a predetermined time, it is necessary to stop the change in the voltage applied to the bottom electrode 5 and stop the operation. Is applied to the bottom electrode 5 for a predetermined stop time, and then the applied voltage may be changed again.

The droplet ejecting apparatus according to the present invention may be composed of a plurality of droplet ejecting mechanisms manufactured on one piezoelectric block. Providing a plurality of droplet ejecting mechanisms makes it easy to apply the droplet ejecting apparatus according to the present invention to an ink jet printer head or the like.

FIG. 6 is a schematic plan view showing an example of a droplet ejecting apparatus having a plurality of droplet ejecting mechanisms. Each droplet ejection mechanism has the same structure as the droplet ejection device shown in FIG. In FIG. 6, the lid 2 and the box 10 shown in FIG. 3 are omitted.

Each of the grooves 4 for the liquid flow path of each droplet ejecting mechanism is open on one side surface of the piezoelectric block material 1. The opening of the liquid channel groove 4 is 1
A part of the liquid flow channel groove 4 that has come out of the recess 3 in parallel with each other so as to gather at the location is bent on the way to the one side surface. In addition, each of the grooves 13 for connecting lead wires of each droplet ejecting mechanism is open on a side surface opposite to the one side surface.

Next, a method of manufacturing the liquid droplet ejecting apparatus according to the present invention will be described. First, an example of a method for manufacturing the droplet ejecting apparatus shown in FIG. 1 will be described. The method for producing the droplet ejecting apparatus shown in FIG. 1 includes (A) a step of manufacturing a piezoelectric block material, (B) a mask and a back surface. Each step includes an electrode formation step, (C) an etching step, (D) a bottom electrode formation and polarization step, and (E) a lid attaching step.

Hereinafter, each step will be described. (A) Manufacturing Step of Piezoelectric Block Material First, the piezoelectric block material 1 is manufactured and prepared.

As a material for forming the piezoelectric block material 1, for example, ceramics having piezoelectricity can be mentioned as described above. The production of the piezoelectric block material 1 is performed, for example, by baking the above-mentioned ceramic material powder or grinding or cutting a single crystal such as a solid solution single crystal of the ceramic material. As described above, those that are ground or cut out of a single crystal are more preferable than those that are fired.

For the production of the piezoelectric block material 1 by firing, a method well known in the art can be used. For example, the powder of the ceramic material described above is mixed with a desired composition, the mixed powder is calcined and then pulverized, and the pulverized mixture is mixed with a binder for improving formability, and then sized, The pellets are pressed to produce ceramic pellets. 600 pellets
After heating at about 100 ° C. to remove contained organic matter, hot pressing at about 1200 ° C. and sintering are performed to obtain a fired body. The fired body is formed using a slicer, a surface grinder, and, if necessary, a double-sided lapping machine, etc., to produce the piezoelectric block material 1.

When a single crystal is used as the piezoelectric block material 1, the piezoelectric block material 1 is manufactured in consideration of the crystal orientation of the single crystal. For example, the single crystal is ground or cut out to obtain the piezoelectric block material 1 such that the crystal orientation of the single crystal having the best piezoelectric characteristics such as <111> is in the thickness direction of the driving piezoelectric element 7.

(B) Step of Forming Mask and Back Electrode A mask for etching and the back electrode 6 are formed on the piezoelectric block material 1 produced in the step (A).

The material for the mask is not particularly limited as long as it has a lower etching selectivity (etching rate) than the material forming the piezoelectric block material 1. Further, the method for forming the mask is not particularly limited.

Examples of such a mask material include a metal material and a compound material. Examples of the metal material include copper and nickel (Ni). Examples of the compound material include an organic material and an inorganic material. Examples of the organic material include a resin such as a photoresist resin, and examples of the inorganic material include silicon oxide (Si).
O ₂ ) and silicon nitride (Si ₃ N ₄ ).

The mask is formed by forming a patterned film made of the above-mentioned material on the surface of the piezoelectric block 1. Examples of the method for forming the film include a coating method, a CVD method, an electrolytic plating method, and a sputtering method. For example, a film made of a resin such as a photoresist resin can be formed by a coating method. For example, a film of silicon oxide or silicon nitride is formed by CVD.
It can be formed by a method. Further, a film made of a metal material such as nickel and copper can be formed by an electrolytic plating method or a sputtering method.

The thickness of the mask may be such that the mask remains after etching in the etching step described below, may be such a thickness that the mask is just removed by etching, or may be a thickness during etching. The thickness may be such that all of them are removed. When the mask is completely removed during the etching, the etching may be stopped after the mask is completely removed, the mask may be re-formed, and then the etching may be performed again. Also,
Such mask formation and etching may be repeated.

The mask pattern is, for example, a pattern in which windows corresponding to the shapes and positions of the concave portions 3 and the liquid flow grooves 4 formed on the surface of the piezoelectric block material 1 are opened.

Hereinafter, an example of a method of performing this step will be described. (I) First, the back electrode 6 made of the above-described conductive material for the back electrode 6 is formed on the back surface of the piezoelectric block material 1.
The back electrode 6 may be formed at least in a portion facing the bottom electrode 5 of the liquid storage chamber, and may be formed on the entire back surface of the piezoelectric block material 1.

(Ii) Next, chromium (Cr) and gold (Au) are formed on the front surface of the piezoelectric block material 1 on which the back electrode 6 is formed as described above, by sputtering or the like. A front electrode made of Au is formed.

(Iii) A resin photoresist is applied on the front electrode. (Iv) The resist pattern is exposed to the mask pattern described above. The exposed resist layer is developed to leave a resist layer patterned such that a portion corresponding to the window remains. That is, the resist layer is left so as to correspond to the concave portions 3 and the liquid flow grooves 4 provided in the piezoelectric block material 1.

(V) The piezoelectric block material 1 on which the front electrode and the patterned resist layer are formed is immersed in a nickel ion solution. Apply a negative voltage to the front electrode in the nickel ion solution to perform electrolytic nickel plating,
A nickel film is formed on the front electrode exposed at the opening of the resist layer. By using electrolytic nickel plating, a nickel film having a large thickness can be formed in a relatively short time. The nickel film is formed corresponding to the surface of the piezoelectric block material 1 other than the region where the concave portion 3 and the liquid flow channel 4 are formed.

(Vi) By removing the resist layer with a solvent, a patterned nickel film is formed on the front electrode. The nickel film has a pattern in which windows are opened corresponding to the concave portions 3 and the liquid flow grooves 4 provided on the surface of the piezoelectric block 1, and serves as a mask for etching the piezoelectric block 1.

(C) Etching Step The surface of the piezoelectric block material 1 is etched according to the pattern of the mask formed in the step (B).

The etching is performed by dry etching using reactive gas plasma. Dry etching using reactive gas plasma generates reactive gas radicals and performs etching with these radicals. The etching technique using radicals is a technique well known in the field of silicon processes.

Reactive gases for generating radicals include sulfur hexafluoride (SF ₆ ) and carbon tetrafluoride (CF
_Use fluoride such as ₄ ). SF ₆ is more preferable than CF ₄ . This is because SF ₆ has a higher etching rate.

As the dry etching method using the above reactive gas, for example, reactive ion etching (RI
E) method, ICP (inductively coupled plasma) etching method, deep RIE method and the like.

The RIE method is a method using both reactive gas radicals and neutral active species. The ICP method is an etching method in which electrons are accelerated by an induction electric field generated by a high-frequency induction magnetic field, and plasma of a reactive gas generated by the accelerated electrons is used. Deep R
The IE method repeats reactive ion etching and masking on the piezoelectric block material 1.

The etching step may be performed not only once but also repeatedly. (D) Step of Forming Bottom Electrode and Polarizing Treatment A bottom electrode 5 is formed on the bottom surface of the concave portion 3 on the surface of the piezoelectric block material 1 formed by etching in the step (C).

The bottom electrode 5 can be provided by forming a conductive layer made of a conductive material such as copper on the bottom surface of the concave portion 3 by sputtering or the like.

When the conductive layer is formed, a mask member or the like may be arranged on the surface of the piezoelectric block 1 to form the conductive layer only on the bottom surface of the concave portion 3.
Instead, a conductive layer was formed on the entire surface of the piezoelectric block material 1 without disposing a mask member or the like, and then formed on a surface other than the formation region of the recess 3 and the liquid flow channel 4. The conductive layer may be removed by polishing or the like. That is, a conductive layer may be formed on the side surface of the concave portion 3 and the bottom surface and the side surface of the liquid channel groove 4. These regions are regions where it is not necessary to form a conductive layer, but this is because a conductive layer is formed and does not hinder the operation as a droplet ejecting apparatus.

After the bottom electrode 5 has been formed, a voltage is applied between the bottom electrode 5 and the back electrode 6 in the air or oil to polarize the driving piezoelectric body 7 sandwiched between both electrodes. I do.

(E) Attachment Step of Lid Part The lid part 2 is bonded to the surface of the piezoelectric block material 1 using an adhesive or the like. The concave portion 3 on the surface of the piezoelectric block material 1 covered by the lid 2 forms a liquid storage chamber. The liquid flow channel 4 covered by the lid 2 forms a liquid flow channel.

By the steps (A) to (E) described above, the droplet ejecting apparatus shown in FIG. 1 is manufactured. Next, an example of a method for manufacturing the droplet ejecting apparatus shown in FIG. 3 will be described.

The method of manufacturing the droplet ejecting apparatus shown in FIG.
The method is basically the same as the method of manufacturing the droplet ejecting apparatus of FIG.
That is, first, the piezoelectric block 1 is formed, and the mask and the back electrode 6 are formed on the piezoelectric block 1. The pattern of the mask is such that windows corresponding to the wiring groove 8 and, if necessary, the lead wire connecting groove 13 are opened in addition to the concave portion 3 and the liquid flow channel groove 4. After the piezoelectric block material 1 is etched according to the pattern of the mask, the bottom electrode 5 and the wiring electrode 12 are formed. Next, after performing the polarization treatment of the driving piezoelectric body 7, the lid 2 is attached and the liquid outflow preventing material is filled. Finally, a liquid supply source is provided, and the droplet form adjusting means 9 is joined.

As described above, the droplet ejecting apparatus shown in FIG. 3 is manufactured. Next, a method for manufacturing the droplet ejecting apparatus shown in FIG. 6 will be described. For ease of explanation,
The following description is directed to a method of manufacturing each droplet ejecting mechanism of the droplet ejecting apparatus shown in FIG. In the case of manufacturing the droplet ejecting apparatus shown in FIG. 6, the method for producing individual droplet ejecting mechanisms described below may be performed simultaneously for the number of droplet ejecting mechanisms to be produced.

The method of manufacturing each droplet ejecting mechanism is the same as the method of manufacturing the droplet ejecting apparatus shown in FIG. 3 described above, and includes the following steps. That is, (A) a step of manufacturing a piezoelectric block material, (B) a step of forming a mask and a back electrode,
(C) an etching step, (D) a step of forming a bottom electrode and an electrode for wiring and a polarization treatment, (E) a step of attaching a lid portion and filling a liquid outflow prevention material, (F) disposing a liquid supply source and This is the step of joining the liquid shape adjusting means.

The manufacturing method will be described below with reference to FIGS. (A) Step of Manufacturing Piezoelectric Block Material The step is performed in the same manner as the step (A) in the method of manufacturing the droplet ejecting apparatus of FIG. 1 described above.

(B) Step of Forming Back Electrode and Mask In order for the pattern of the mask to correspond to the droplet ejecting apparatus shown in FIG. Then, except that the pattern is such that a window is opened corresponding to the position and the shape of the lead wire connection groove 13, the same as the step (B) in the method of manufacturing the droplet ejecting apparatus of FIG. 1 described above. Do.

(C) Etching Step The etching step is performed in the same manner as the step (C) in the method of manufacturing the droplet ejecting apparatus shown in FIG. FIG. 7A is a plan view showing the piezoelectric block material 1 in which the concave portion 3 and each groove are formed by the main etching process.

FIG. 8A is a schematic sectional view taken along the line AA ′ in FIG. 7A. 8A to 8E show, as an example, the piezoelectric block material 1 in which the back electrode 6 is formed on the entire back surface.

(D) Step of Forming Bottom Electrode and Wiring Electrode and Polarizing Process The bottom electrode 5 is formed on the bottom surface of the concave portion 3 on the surface of the piezoelectric block material 1 formed in the step (C), and the wiring groove 8 is formed. And, if necessary, a wiring electrode 12 connected to the bottom electrode 5 of the concave portion 3 is formed on each bottom surface of the lead wire connection groove 13.

The bottom electrode 5 can be provided by forming a conductive layer made of a conductive material for the bottom electrode 5 on the bottom surface of the recess 3. The wiring electrode 12 can be provided by forming a conductive layer made of a conductive material for the wiring electrode 12 on the bottom surface of the wiring groove 8 and, if necessary, the lead wire connecting groove 13.

FIG. 7B is a plan view showing the piezoelectric block 1 on which the bottom electrode 5 and the wiring electrode 12 are formed. FIG. 8B is a schematic cross-sectional view along the line BB ′ in FIG. 7B.

When the conductive layer is formed, a mask member or the like may be disposed on the surface of the piezoelectric block material 1 to form the conductive layer only on the bottom surface of the above-described region.
Instead, a conductive layer is formed on the entire surface of the piezoelectric block material 1 without disposing a mask member or the like, and then the concave portion 3, the wiring groove 8, the lead wire connecting groove 13, and the liquid flow path are formed. The conductive layer formed on the surface other than the region where the groove 4 is formed may be removed by polishing or the like. That is, the recess 3,
Conductive layers may be formed on the side surfaces of the wiring groove 8 and the lead wire connecting groove 13 and on the bottom and side surfaces of the liquid flow channel 4. These regions are regions where it is not necessary to form a conductive layer. However, even if a conductive layer is formed, it does not hinder the operation as a droplet ejecting apparatus.

After the bottom electrode 5 and the wiring electrode 12 are formed, the wiring electrode 1 is
The lead wire 16 is joined to 2 using a solder 15 or the like. FIG. 7C is a plan view showing the piezoelectric block material 1 in which the lead wire 16 is joined to the wiring electrode 12. FIG.
In (c), the solder 15 is omitted for easy viewing.

FIG. 8C is a schematic sectional view taken along the line CC ′ in FIG. 7C. After connecting the lead wire, the lead wire 16 and the back electrode 6 are placed in the air or oil.
Is applied to perform polarization processing of the driving piezoelectric body 7.

(E) Attaching the Lid and Filling the Liquid Outflow Prevention Material On the surface of the piezoelectric block material 1, for example, a sheet-like lid 2 provided with the liquid storage chamber 11 is attached using an adhesive or the like. Join.

FIG. 7D is a plan view showing the piezoelectric block 1 to which the lid 2 is joined. FIG. 8D shows FIG.
FIG. 3D is a schematic cross-sectional view along the line DD ′. Lid 2
The concave portion 3 on the surface of the piezoelectric block material 1 covered by
A liquid storage chamber is formed. The liquid flow channel groove 4 covered by the lid 2 forms a liquid flow channel. Further, the wiring groove 8 and the lead wire connecting groove 13 covered by the lid 2 are provided.
Has a function of protecting the wiring electrode 12.

After the lid 2 is joined, the opening of the wiring groove 8 or the lead wire connecting groove 13 is filled with a liquid outflow preventing material. (F) Step of Arranging Liquid Supply Source and Joining Liquid Shape Adjusting Means As described above, on the lid 2 joined in step (E),
For example, a liquid supply source is provided by bonding a rectangular box 10 having an opening on one side with an adhesive or the like with this opening facing down.

FIG. 7E is a plan view showing the piezoelectric block 1 to which the box 10 is joined. FIG. 8E shows FIG.
(E) is a schematic sectional view along a line EE '. Lid 2
The liquid to be supplied to the liquid storage chamber is stored in a space defined by the rectangular box 10.

A liquid supply pipe 17 is joined to the upper part of the rectangular box 10 by a connector 18. The liquid supply pipe 17 is connected to a liquid tank (not shown) for supplying liquid to a liquid supply source.

As shown in FIG. 7 (e), on the side of the rectangular box 10, a droplet ejecting device is mounted on a base (not shown).
May be provided.
The mounting portion 19 has a screw fixing hole 2 for mounting the droplet ejecting device to a base (not shown) using a screw or the like.
0 and the like are provided.

Finally, the liquid droplet form adjusting means 9 is disposed at the opening of the liquid channel groove 4. The arrangement of the droplet form adjusting means 9 may be, for example, such that a sheet member or the like having the droplet ejection holes 14 formed thereon is placed on the piezoelectric member so that the droplet ejection holes 14 are positioned at the openings of the liquid flow channel 4. This is performed by bonding to the side surface of the block material 1 with an adhesive or the like.

FIG. 9 (a) is a schematic perspective view showing an example of the opening of the liquid flow channel groove 4 before the droplet form adjusting means 9 is arranged. In FIG. 9A, the lid 2 and the liquid supply source are omitted.

FIG. 9B is a schematic plan view showing an example of the opening of the liquid channel groove 4 after the droplet form adjusting means 9 has been arranged. In FIG. 9B, the lid 2 and the liquid supply source are omitted. As described above, (A) to
By the step (F), the droplet ejecting apparatus shown in FIG. 3 is manufactured.

[0134]

As described in detail above, according to the present invention, it is possible to provide a droplet ejecting apparatus capable of having a fine structure. By using the droplet ejecting apparatus according to the present invention for an ink jet printer head, effects such as high-definition printing can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view and a cross-sectional view illustrating an example of a droplet ejecting apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view showing deformation of a piezoelectric element according to the present invention.

FIG. 3 is a schematic perspective view showing another example of the droplet ejecting apparatus according to the present invention.

FIG. 4 is a schematic cross-sectional view showing another example of the droplet ejecting apparatus according to the present invention.

FIG. 5 is a diagram showing an example of a method of applying a voltage to a piezoelectric element according to the present invention.

FIG. 6 is a schematic plan view showing another example of the droplet ejecting apparatus according to the present invention.

FIG. 7 is a process chart showing an example of a method for manufacturing a droplet ejecting apparatus according to the present invention.

FIG. 8 is a process chart showing an example of a method for manufacturing a droplet ejecting apparatus according to the present invention.

FIG. 9 is a schematic perspective view and a plan view showing an example of a droplet form adjusting means according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piezoelectric block material 2 ... Lid 3 ... Recess 4 ... Liquid channel 5 ... Bottom electrode 6 ... Back electrode 7 ... Driving piezoelectric 8 ... Wiring groove 9 ... Droplet shape adjusting means 10 ... Box 11 ... Liquid supply hole 12 ... Wiring electrode 13 ... Lead wire connection groove 14 ... Droplet ejection hole 15 ... Solder 16 ... Lead wire 17 ... Liquid supply pipe 18 ... Connector 19 ... Mounting part 20 ... Screw fixing hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiya Takahashi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Industrial Co., Ltd. (72) Katsuhiro Wakabayashi 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Inventor Yukihiko Sawada 2-43-2 Hatagaya, Shibuya-ku, Tokyo Within Olympus Optical Co., Ltd. (72) Inventor Shio Wang 3-chome Yawata, Aoba-ku, Sendai, Miyagi 12-8 (72) Inventor Masaki Esashi 1-11-9, Yagiyama-Minami, Taihaku-ku, Sendai City, Miyagi Prefecture F-term (reference) 2C057 AF33 AF38 AF93 AG12 AG38 AG40 AG42 AG44 AP11 AP16 AP32 AP52 AQ08 4D074 AA01 BB05 CC02 CC32 CC60 FF09 4F033 BA03 RA07

Claims (3)

[Claims] A block member having a recess for accommodating a liquid, a groove for a liquid flow passage having one end connected to the recess and the other end opened on a side surface, formed in a surface thereof; A lid mounted on the surface of the block material so as to cover the concave portion and the groove, and a liquid contained in a liquid storage chamber formed by the concave portion and the lid is formed by the groove and the lid. A piezoelectric element that deforms so as to shrink the liquid storage chamber in order to extrude the liquid as liquid droplets through the liquid flow path, wherein the block material is formed of a piezoelectric material, and the piezoelectric element is provided on the bottom surface of the concave portion. A bottom electrode formed,
A droplet ejecting device comprising: a back electrode formed on the back surface of the piezoelectric block facing the bottom electrode; and a piezoelectric portion sandwiched between both electrodes. 2. A wiring groove having one end connected to the concave portion and the other end opened on the side surface is formed on the surface of the piezoelectric block, and the bottom surface of the wiring groove is formed on the bottom surface of the wiring groove. A wiring electrode connected to the bottom electrode of the recess is formed, and an opening of the wiring groove is filled with a liquid outflow preventing material for preventing the liquid from flowing out from the opening. At the opening of the groove for the liquid flow path, a droplet form adjusting means for adjusting the form of the droplet extruded from the opening to the outside is arranged. 2. A liquid supply source for supplying a liquid is provided, and the lid is provided with a liquid supply hole for passing the liquid from the liquid supply source to the recess.
The described device. 3. The piezoelectric element according to claim 1, wherein the bottom electrode and the back electrode of the piezoelectric element have different thicknesses and / or are formed of conductive materials having different Young's moduli. Equipment.