JP3166537B2 - Ink jet device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plurality of ink chambers to which ink is supplied from an ink supply source, an actuator section for changing the volume of the ink chamber to eject ink, and an actuator section formed in the actuator section. those related to the ink jet equipment with a power source circuit and an electrode to which a voltage is applied.

[0002]

2. Description of the Related Art Conventionally, a so-called thermal jet type print head using a heating element which is an electro-thermal conversion element as an on-demand type print head used in an ink jet printer or the like, and a piezoelectric element which is an electro-mechanical conversion element. Piezo print heads utilizing elements have been put to practical use. Compared to print heads that use heating elements, print heads that use piezoelectric elements do not generate heat, so there are fewer restrictions on the liquid that can be ejected, and the print head is more durable. have.

There are various types of piezoelectric elements. For example, as disclosed in Japanese Patent Application Laid-Open No. 55-71572, there has been proposed an ink jet head in which an ink chamber is formed in a circular tube type. The configuration will be described.

As shown in FIGS. 21 and 22, a multi-nozzle type ink jet head comprises a housing 301, a large number of cylindrical electrostrictive vibrators 302, and a nozzle plate 30.
3 and a printed electrode plate 304.

[0005] The housing 301 is formed by joining a case plate 301b to a housing substrate 301a provided with a plurality of through holes 307, and a space formed by these is a manifold 313. The manifold 313 is supplied with ink from a not-shown ink supply source via a pipe 305. The printed circuit board 30 is mounted on the housing substrate 301a.
4 are joined, and a plurality of positioning holes 312 are formed in the printed electrode plate 304 at positions corresponding to the through holes 307.

One end of each of the electrostrictive vibrators 302 is fitted into each of the positioning holes 312 and the housing substrate 301
The space in the electrostrictive vibrator 302 is connected to the manifold 313 through the through hole 307.
The other end of the electrostrictive vibrator 302 is joined to a nozzle plate 303 on which a nozzle 326 is formed.

Electrodes 308 are formed from the inner surface of the electrostrictive vibrator 302 to both ends and the outer surface thereof, and the electrode 309 is formed on the outer surface of the electrostrictive vibrator 302. A water-repellent Teflon coating 310 is formed over the entire surface of the electrode 308. Each electrostrictive oscillator 302
Electrode 308 is connected to the common ground line 311 and the electrode 3
09 denotes the divided electrodes 306 of the printed circuit board 304, respectively.
Connected to each other.

[0008] Usually, mold sintering is used for manufacturing the cylindrical electrostrictive vibrator 302.

Then, by applying a drive voltage to the electrode 309 of the electrostrictive vibrator 302 corresponding to the nozzle 326 to be jetted, the electrostrictive vibrator 302 is deformed and the nozzle 326 jets ink.

[0010]

However, in the conventional single-layered electrostrictive vibrator 302, the thickness of the electrostrictive vibrator 302 had to be increased in order to obtain rigidity. Here, the driving voltage required for injection is the electrostrictive oscillator 3
02 increases in proportion to the thickness of No. 02. Therefore, in the electrostrictive vibrator 302, the driving voltage for injection was large. When the driving voltage is large as described above, it is necessary to increase the distance between each electrical connection point connecting the divided electrode 306 of the printed circuit board 304 and the electrostrictive vibrator 302. For this reason,
There is a problem that it is difficult to reduce the size of the inkjet head. Further, when the driving voltage is large, there is a problem that the circuit becomes expensive.

[0011] The present invention has been made to solve the problems described above, the driving voltage is reduced, and an object thereof is to provide an ink jet equipment can be downsized.

[0012]

In order to achieve this object, according to the first aspect of the present invention, ink is supplied from an ink supply source and ink is ejected by changing the volume of the ink chamber. In an ink ejecting apparatus having an actuator portion and an electrode formed on the actuator portion and to which a voltage is applied from a power supply circuit, the actuator portion includes a plurality of the electrodes and a plurality of piezoelectric ceramics stacked alternately in a cylindrical shape. It has a hollow part in the center of the lamination,
A hollow portion forms the ink chamber, and a plurality of the ink chambers are formed.
A tutor is provided to cover the plurality of actuators.
The plurality of electrodes are integrated by a
Every other first electrode in the stacking direction is
Exposed at one end face of each of the multiple actuators
Connected to a common electrode formed over one end of each
And every other second electrode is the integrated plurality.
Exposed on the other end face different from the one end face of the actuator section
And connected to each drive electrode formed on the other end face
Outer surfaces of the integrated plurality of actuator portions
The common electrode and the printed circuit board provided along
And a contact electrode connected to each drive electrode
And a pattern to connect the contact electrode to the power supply circuit
Is provided .

According to a second aspect of the present invention, a plurality of ink chambers to which ink is supplied from an ink supply source and a plurality of actuator sections for ejecting ink by changing a volume in each of the ink chambers by applying a voltage to an electrode. And a manifold for supplying ink supplied from an ink supply source to each of the ink chambers , wherein each of the actuator units has the electrode and the piezoelectric ceramic laminated in a tubular shape. A hollow portion is formed at the center of the stack, the hollow portion forms the ink chamber, and one end of the plurality of actuator portions communicates with each ink chamber by a layer continuous with the piezoelectric ceramic of each actuator portion. The manifold is formed, and the plurality of electrodes are stacked in the stacking direction.
Every other first electrode is located outside the manifold.
Exposed on one end of the manifold along the circumference
Every second electrode reaches the outer periphery of the manifold.
And the plurality of actuator sections
The first electrode and the second electrode are exposed at the other end surface different from the one end surface.
Print base with contact electrodes connected to two electrodes respectively
The board is provided with a pattern to connect the contact electrode to the power supply circuit.
And wherein the digit.

[0014]

In the ink jetting apparatus according to the present invention having the above-described structure, when a voltage is applied to the electrodes of the actuator section, the multilayer piezoelectric ceramics can change the volume of the cylindrical hollow section. Deforms and ejects ink. Here, multiple electrodes and multiple piezoelectric ceramics
And alternately stacked to form a cylinder with a hollow portion
, Which increases the rigidity of the actuator and lowers the drive
Injection can be performed with a voltage.

Further, the plurality of actuator sections are integrated by a holding section provided so as to cover the plurality of actuator sections, so that an ink ejecting apparatus integrally having a plurality of ink chambers can be provided. Further , every other first electrode in the stacking direction among the plurality of electrodes of each actuator section is one end face of the integrated actuator section.
Are connected to a common electrode formed over each end face of the actuator section, and every other second electrode is connected to the other end face different from the one end of the integrated actuator section.
As it is connected to the drive electrodes formed on each end face, said common electrode and the drive electrode flop while exposed to
It is easily connected to each contact electrode of the lint board, and is also easily connected to the power supply circuit.

[0016] In the ink jet apparatus of claim 2, the one end of the plurality of actuators, a layer continuous with the piezoelectric ceramics of each of the actuator elements, the manifold communicating with the respective ink chambers are formed, cylindrical A plurality of actuator parts are integrated in the manifold part. Also, when the second electrode reaches the outer periphery of the manifold,
Does not deform any cylindrical actuator
Then, ink is ejected .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a structural perspective view of the inkjet head. Inkjet head 40
Is composed of an actuator member 30, a manifold member 17, and a flexible printed circuit board 41.
The actuator member 30 includes a plurality of hollow cylindrical actuator portions 4 and a resin holding portion 5 that holds the plurality of actuator portions 4. For example, the holding unit 5
An epoxy resin having a Rockwell hardness of M-85 is used. If the resin used for the holding section 5 has a Rockwell hardness of M-60 to M-130, the ejection from each actuator section 4 can be performed well.

As shown in FIG. 2, the actuator section 4 is formed by alternately laminating a plurality of conductive layers 3 and piezoelectric ceramic layers 2. In the first embodiment, four conductive layers 3 are stacked, and three piezoelectric ceramic layers 2 are stacked. A conductive layer 3 is formed on the inner surface of the hollow cylindrical piezoelectric ceramic layer 2a.
a, a conductive layer 3b is formed on the outer surface, a piezoelectric ceramic layer 2b is formed outside the conductive layer 3b, and a conductive layer 3c is formed on the outer surface of the piezoelectric ceramic layer 2b.
A piezoelectric ceramic layer 2c is formed outside the conductive layer 3c, and a conductive layer 3d is formed on the outer surface of the piezoelectric ceramic layer 2c. The conductive layers 3a and 3c are exposed on the end face 30a side and are not exposed on the end face 30b side. Further, the conductive layers 3b and 3d are exposed on the end face 30b side and are not exposed on the end face 30a side.

For this reason, the conductive layers 3a and 3c are connected to the metal electrode 61 formed on the end face 30a of the actuator member 30, and the conductive layers 3b and 3d are connected to the metal electrode 62 formed on the end face 30b. The metal electrode 61 connects the conductive layers 3a and 3c of all the actuator units 4 in common,
Since each metal electrode 62 is separated by the groove 9, each metal electrode 62 is formed corresponding to each actuator section 4 and connected to the conductive layers 3b and 3d of each actuator section 4.

As shown in FIG. 4, the piezoelectric ceramic layer 2
a is an arrow A indicating a direction from the conductive layer 3b to the conductive layer 3a.
The piezoelectric ceramic layer 2b is polarized in the direction of arrow B, which is the direction from the conductive layer 3b to the conductive layer 3c, and the piezoelectric ceramic layer 2c is polarized in the direction of the direction from the conductive layer 3d to the conductive layer 3c. Polarized in the C direction.

As shown in FIG. 2, the hollow portion of the cylindrical actuator portion 4 has an ink chamber 1 filled with ink.
And the opposite end face 30 of the actuator member 30
a, 30b. The opening on the end face 30a side is
The nozzle 6 from which ink is ejected.

As shown in FIG. 1, the manifold member 17
A manifold 22 communicating with all the ink chambers 1 and an ink supply port 23 communicating with an ink tank (not shown).
Are formed, and the opening side of the manifold 22 is bonded to the end face 30 b of the actuator member 30. The manifold 22 has a size that covers the openings of all the actuator units 4.

The flexible printed board 41 is bonded to the surface 30c (the upper surface in FIG. 1) of the actuator member 30. Note that the surface may be opposite to the surface 30c. The flexible printed circuit board 41 has contact electrodes 43, 4
4 are formed, the contact electrode 44 is arranged corresponding to the metal electrode 61, and the contact electrode 43 is arranged corresponding to each metal electrode 62. Each contact electrode 43 has a pattern 42
, And the contact electrode 44 is connected to each pattern 45.

Each of the patterns 42 and 45 is connected to an LSI chip 51 as shown in FIG. 3, and a clock line 52, a data line 53, a voltage line 54 and a ground line 55 are also connected to the LSI chip 51. I have. The LSI chip 51 determines from the data appearing on the data line 53 which nozzle 6 should eject an ink droplet based on the continuous clock pulse supplied from the clock line 52, and drives the ink chamber 1 to be driven. Is applied to the pattern 42 conducting to the metal electrode 62 corresponding to. Further, the pattern 42 conducting to the metal electrode 62 other than the ink chamber 1 to be driven and the pattern 45 conducting to the metal electrode 61 are connected to the ground line 55.

Next, driving of the ink jet head 40 will be described. When the LSI chip 51 determines that the ink is to be ejected from the ink chamber 1a shown in FIG. 5, the LSI chip 51 connects the voltage line 54 to the pattern 42 electrically connected to the metal electrode 62 of the ink chamber 1a. Pattern 4 electrically connected to metal electrode 62 of ink chamber 1
2 and the pattern 45 electrically connected to the metal electrodes 61 of all the ink chambers 1 are connected to the ground line 55. Then, an electric field in the direction from the conductive layer 3b to the conductive layer 3a is generated in the piezoelectric ceramic layer 2a of the actuator section 4 of the ink chamber 1a, and the conductive layer 3b is generated in the piezoelectric ceramic layer 2b.
An electric field is generated in the direction from the conductive layer 3c to the conductive layer 3c, and an electric field in the direction from the conductive layer 3d to the conductive layer 3c is generated in the piezoelectric ceramic layer 2c. That is, the piezoelectric ceramic layers 2a, 2b, 2c of the ink chamber 1a have the respective polarization directions A, B,
An electric field is generated in the same direction as C.

Then, the piezoelectric ceramic layers 2a, 2b, and 2c of the actuator section 4 of the ink chamber 1a have the same polarization directions A, B, and C as the direction of the electric field. 2a, 2b, and 2c expand in the ink chamber 1a, and reduce the volume of the ink chamber 1a. As a result, pressure is applied to the ink in the ink chamber 1a, and the ink is ejected from the nozzle 6. Thereafter, the metal electrode 62 of the ink chamber 1a is connected to the earth line 55, and the volume of the ink chamber 1a is increased from the reduced state to the natural state (the state shown in FIG. 4). Supply ink.

The piezoelectric ceramic layers 2a, 2b, 2c
The ink is supplied by increasing the volume of the ink chamber 1a, and then applying the drive voltage, and then reducing the volume of the ink chamber 1a to a natural state by setting the polarization direction of the ink and the direction of the generated electric field in opposite directions. Ink droplets may be ejected from the chamber 1a.

As described above, in the ink-jet head 40 of the present embodiment, the rigidity of the actuator section 4 is high because the plurality of piezoelectric ceramic layers 2 are stacked. For this reason, the drive voltage value for ejecting ink from the ink chamber 1a can be reduced. Therefore, the distance between the metal electrodes 62 connected to the contact electrodes 43 and 45 of the flexible printed board 42 can be made shorter than before. Therefore, the size of the inkjet head 40 can be reduced, and the degree of nozzle integration can be improved. Further, the cost of the driving circuit is reduced.

Further, since all the actuator parts 4 are integrated by the resin holding part 5, there is no need to position each actuator part 4.

Further, since the connection between the flexible printed circuit board 41 connected to the LSI chip 51 and the metal electrodes 61 and 62 is made on the upper surface 30c of the actuator member 30, the connection is easy.

Further, since the opening on the end face 30a side of the actuator section 4 is the nozzle 6, there is no need for a conventional nozzle plate in which a nozzle is formed. Can be reduced.

Since the conductive layer 3a exposed on the inner surface of the ink chamber 1 is always grounded, the ink and the conductive layer 3a are exposed.
There is no need to provide an insulating layer to insulate the semiconductor device from the semiconductor device, and a device and a process therefor are not required, so that the manufacturing cost can be reduced.

It should be noted that the power supply circuit of the present invention
1, a clock line 52, a data line 53, a voltage line 54, an earth line 55, and the like. The first electrode of the present invention comprises the conductive layers 3a and 3c, and the second electrode comprises the conductive layers 3b and 3d. The common electrode in the claims is a metal electrode 61, and the drive electrode is a metal electrode 62.

Next, a method of manufacturing the ink jet head 40 will be described. First, as shown in FIG. 6, a master 10 in which a plurality of cylinders 21 having a predetermined size are arranged at predetermined intervals on a nickel conductive substrate 11 is manufactured. The cylinder 2
1 corresponds to the ink chamber 1. For example, the number of the cylinders 21 is 62, the cylinder diameter is 40 μm, the height is 1 mm, and the pitch is 300 μm. Incidentally, in FIG.
Only 1 is shown.

The master 10 is manufactured by using a rigging process often used in a micromachine. In particular,
As shown in FIG. 7, first, an X-ray resist 12 of 1 mm or more is formed on a conductive substrate 11 made of nickel. The X-ray resist 12 is formed by applying a positive resist having good sensitivity and resolution a plurality of times to a predetermined thickness, or by thermocompression bonding a film-shaped resist having slightly reduced resolution.

Subsequently, a mask 13 is formed on the positive resist 1
2 is brought into contact with the conductive substrate 11 formed thereon. In FIG. 7, the mask 13 and the conductive substrate 11 are shown for easy understanding.
And are shown apart. However, in X-ray exposure, resist 1
The adhesion between the mask 2 and the mask 13 is not so required. The mask 13 has a non-transmissive portion 13a that does not transmit X-rays.
And a predetermined pattern 13b that transmits X-rays. The pattern 13b has a circular shape with a diameter of 40 μm and is arranged 62 in a line (only three patterns are shown in the figure). Then, synchrotron radiation (X-ray) from the top in FIG.
14 is irradiated on the mask 13. Only the portion corresponding to the pattern 13b of the resist 12 (the portion shown by oblique lines in the figure) is irradiated with the synchrotron radiation 14.

Next, when development is performed with an alkali-based developer, the portion of the resist 12 irradiated with the X-ray 14 is dissolved in the developer and removed. That is, a cylindrical hole having a diameter of 40 μm, in which the thickness of the resist 12 is high, is formed. As described above, cylindrical holes can be formed in the resist 12 having a high aspect ratio having a height of 1 mm or more because synchrotron X-ray exposure is used. Using the resist 12 having the cylindrical hole as a mold, the resist 12 on the conductive substrate 11 is formed.
In a portion corresponding to the cylindrical hole of, for example, nickel is deposited by about 1 mm by electrolytic plating. Then, when the resist 12 is removed with an organic solvent or the like, a master 10 in which a plurality of cylinders 21 formed of nickel are arranged on the conductive substrate 11 as shown in FIG.

Next, the production of the actuator member 30 will be described. First, a titanium conductive layer 3a of 1 μm is formed on the cylinder 21 of the master 10. This is formed as follows. As shown in FIG. 8A, a shielding plate 32 is set on the base end portion of the cylinder 21 and a portion corresponding to the conductive substrate 11, and vapor deposition is performed in two directions (arrows 15 and 16).
The conductive layer 3a is formed on the cylinder 21 as shown in FIG. Since vapor deposition is a well-known method, detailed description is omitted, but it is a method of depositing flying atoms and molecules from a vapor deposition source,
Because of the straightness, the film formation area can be relatively easily limited by shielding in that direction.

Next, a piezoelectric ceramic layer 2a is formed on the cylinder 21 from above the conductive layer 3a. Specifically, first, the conductive layer 3
The master 10 with a is made of 4% lead zirconate titanate (PZ).
T) Immerse in a bath of sol-gel liquid (manufactured by Kojundo Chemical Co., Ltd.) (this step is called a dip step). Note that at least the entire cylinder 21 is immersed in the sol-gel liquid. Next, it is pulled up at a speed of 2 mm per minute. Then, it is calcined at 150 ° C. for 10 minutes in a clean atmosphere. Through such a process, a film thickness of 0.3 μm
Because only about a piezoelectric ceramic layer can be formed,
The dipping step, the pulling step, and the calcining step are repeated until the thickness becomes 5 μm. Then, the piezoelectric ceramic layer 2a is formed on the master 10 as shown in FIG. Further, since the sol-gel liquid reacts with moisture in the air and the like, it is necessary to close the entire bath.

Next, as shown in FIG. 9C, a 1 μm conductive layer 3b made of titanium is formed on the piezoelectric ceramic layer 2a. This is formed as follows. As shown in FIG. 8B, the shielding plates 31 and 32 are set on the tip of the cylinder 21 and the portion corresponding to the conductive substrate 11, and are set in two directions (arrow 1).
5, 16), the conductive layer 3b is formed.

Next, as shown in FIG. 9D, a piezoelectric ceramic layer 2b is formed in the same manner as the piezoelectric ceramic layer 2a. Subsequently, a titanium conductive layer 3c of 1 μm was formed on the piezoelectric ceramic layer 2b in the same manner as the conductive layer 3a.
Further, the piezoelectric ceramic layer 2c is
a, and then the piezoelectric ceramic layer 2c
A 1 μm conductive layer 3d made of titanium is formed thereon in the same manner as the conductive layer 3b.

As described above, the conductive layers 3a, 3b, 3c, 3d
The master 10 on which the piezoelectric ceramic layers 2a, 2b, and 2c have been manufactured is subjected to main firing at about 600 ° C. for about 30 minutes to obtain a piezoelectric ceramic layer 2 having excellent piezoelectric characteristics.

Thus, the PZT structure 33 having a laminated cylinder (FIG. 10) is manufactured. The PZT structure 33 is made into a block shape by covering a plurality of laminated cylinders with an epoxy resin or the like (FIG. 11). The resin serves as the holding unit 5. And it cut | disconnects by the XX line | wire of the front-end | tip part side of the cylinder 21,
1 is cut along the line YY on the base end side. The conductive layers 3a and 3c are exposed at the XX line cut surface, and the conductive layers 3b and 3d are exposed at the YY line cut surface.

Next, the master disk 10 made of nickel is eluted by wet etching with a ferric chloride solution. Then, a portion corresponding to the cylinder 21 becomes hollow. Then, as shown in FIG. 12, first, a two-layered film of chromium and nickel is formed on the entire end face where the conductive layers 3a and 3c are exposed by vapor deposition in the direction of arrow 18. Subsequently, a two-layered film of chromium and nickel is formed by an arrow 19 on the entire end face where the conductive layers 3b and 3d are exposed.
Formed by vapor deposition from the direction of. At this time, the two-layer film of chromium and nickel formed on the exposed side of the conductive layers 3a and 3a in the ink chamber 1 and the two-layered film of chromium and nickel formed on the exposed side of 3b are not short-circuited. The shielding plate 135 slightly larger than the ink chamber 1 and slightly smaller than the distance between the conductive layers 3b (in FIG. 12, the distance between the upper conductive layer 3b and the lower conductive layer 3b) is positioned as shown in FIG. And vapor deposition is performed in the direction of arrow 19 to prevent the two-layer film formed on the exposed side of the conductive layer 3b from entering the ink chamber 1. Thereafter, the two-layer film on the end face side where the conductive layers 3b and 3d are exposed is mechanically divided using a diamond blade to form the groove 9 shown in FIG. The divided two-layer film is the metal electrode 62, and the two-layer film on the end face side where the conductive layers 3 a and 3 c are exposed is the metal electrode 61.

Then, the metal electrode 61 is grounded, and a high voltage is applied to all the metal electrodes 62. That is, all the conductive layers 3a, 3c are grounded, and a high voltage is applied to all the conductive layers 3b, 3d, so that the piezoelectric ceramic layers 2a, 2b, 2
Polarize c in the directions of arrows A, B and C.

As described above, the manifold member 17 is joined to the end face 30b and the flexible printed circuit board 41 is joined to the upper surface 30c of the actuator section 30 thus produced, whereby the ink jet head 40 is produced.

In the manufacturing method of the ink jet head 40 described above, the piezoelectric ceramic layer 2 on which the actuator section 4 is laminated is formed of a sol-gel liquid, so that the thickness of the piezoelectric ceramic layer 2 can be reduced. it can. For this reason, the drive voltage value for ejecting ink from the ink chamber 1a can be made extremely low. In the case of three 15 μm piezoelectric ceramic layers 2, only a few volts are required. Therefore, the distance between the metal electrodes 62 connected to the contact electrodes 43 of the flexible printed circuit board 41 can be made shorter than before. Therefore, the size of the inkjet head 40 can be reduced, and the degree of nozzle integration can be improved. Further, the cost of the driving circuit is reduced.

Since the inner surface of the ink chamber 1 is the conductive layer 3a formed on the very smooth master 10, the inner surface of the ink chamber 1 is very smooth, has no air accumulation portion, and provides stable ejection. It becomes possible.

Further, since the nozzle 6 and the ink chamber 1 can be formed at the same time, there is no need for a conventional nozzle plate in which nozzles are formed. can do.

Further, since all the actuator parts 4 are manufactured integrally by the holding part 5 made of resin, there is no need to position each actuator part 4.

Further, since the connection between the flexible printed circuit board 41 connected to the LSI chip 51 and the metal electrodes 61 and 62 is made on the upper surface 30c of the actuator member 30, the connection is easy.

Further, in the method of manufacturing the ink jet head, since the master 10 is manufactured from the master 10 by the lithography technique, the mask 1 used when manufacturing the master 10 is used.
The layout and shape of the ink chamber 1 are determined by the design of the third pattern 13b. Since the mask 13 is usually formed by freely drawing with an electron beam, the degree of freedom in the arrangement of the ink chambers is very high. Looking at the manufacturing process, the rigging technology for producing the master 10 is an extension of the semiconductor technology and is suitable for mass production. In addition, both plating and vapor deposition are already stable technologies and the yield is high. In addition, the formation of the piezoelectric ceramic layer 2 by the sol-gel liquid can be mass-produced. Further, the piezoelectric ceramic layer 2 can be formed to a predetermined thickness.

In the first embodiment, the actuator member 30 and the manifold member 17 are separate bodies, but they may be integrated. An example thereof will be described below as a second embodiment with reference to the drawings. FIG. 12 is a structural perspective view of the inkjet head. The ink jet head 140 includes an actuator member 130, a cover member 117, and a flexible printed board 141. Actuator member 130 includes a plurality of hollow cylindrical actuator units 104, a resin holding unit 105 that holds the plurality of actuator units 104, and a cylindrical actuator unit 1.
And a manifold 122 that communicates with the hollow portion 04.

As shown in FIG. 14, the actuator 1
Reference numeral 04 denotes a structure in which a plurality of conductive layers 103 and piezoelectric ceramic layers 102 are alternately stacked. In the second embodiment, four conductive layers 103 are stacked, and three piezoelectric ceramic layers 102 are stacked. The actuator section 104 is formed with a plurality of columnar first hollow portions and a second hollow portion communicating with each of the first hollow portions.

A conductive layer 103a is formed on the inner surface of the piezoelectric ceramic layer 102a corresponding to the first and second hollow portions, and a conductive layer 103b is formed on the outer surface corresponding to the first hollow portion. A piezoelectric ceramic layer 102b is formed at a portion corresponding to the first and second hollow portions from the outside, and a conductive layer 103c is formed at a portion corresponding to the first and second hollow portions on the outer surface of the piezoelectric ceramic layer 102b. Piezoelectric ceramic layer 102c from outside of layer 103c
Are formed in portions corresponding to the first and second hollow portions, and a conductive layer 103d is formed in a portion corresponding to the first hollow portion on the outer surface of the piezoelectric ceramic layer 102c. Conductive layer 103
a and 103c are exposed on the end face 130b side, and the end face 13c
It is not exposed on the 0a side. The conductive layers 103b, 10b
3d is exposed on the end face 130a side and is not exposed on the end face 130b side.

Therefore, the conductive layers 103a and 103c are connected to the metal electrode 162 formed on the end face 130b of the actuator member 130, and the conductive layers 103b and 103d are connected to the metal electrode 161 formed on the end face 130a. The metal electrodes 162 connect the conductive layers 103a and 103c of all the actuator units 104 in common, and the metal electrodes 161 are separated by the grooves 109. Therefore, each metal electrode 162 is formed corresponding to each actuator unit 104. , The conductive layers 103b, 1
03d.

The piezoelectric ceramic layers 102a, 102b,
The polarization direction of 102c is the same as the polarization directions A, B, and C of the piezoelectric ceramic layers 2a, 2b, and 2c of the first embodiment shown in FIG. That is, the piezoelectric ceramic layer 102a is polarized in the direction from the conductive layer 103b to the conductive layer 103a, the piezoelectric ceramic layer 102b is polarized in the direction from the conductive layer 103b to the conductive layer 103c, and the piezoelectric ceramic layer 102c is From the conductive layer 103c
Polarized in the direction to.

The first hollow portion of the actuator section 104 serves as an ink chamber 1 filled with ink, and is opened at the opposite end face 130 a of the actuator member 130. The opening on the end face 130a side is the nozzle 106 from which ink is ejected. In addition, the second hollow portion of the actuator section 104 becomes a manifold 122.

As shown in FIG. 13, the lid member 117 is adhered to the end face 130b of the actuator member 130 to cover the manifold 122. An ink supply port 123 communicating with an ink tank (not shown) is formed in the lid member 117, and ink is supplied to the manifold 122 from the ink tank via the ink supply port 123.

The flexible printed board 141 is provided on the surface 130c of the actuator member 130 (the upper surface in FIG. 13).
Adhered to. On the flexible printed board 141, contact electrodes 143 and 144 are formed, each contact electrode 144 is arranged corresponding to each metal electrode 161, and the contact electrode 143 is arranged corresponding to the metal electrode 162. . Each contact electrode 141 is connected to each pattern 142,
The contact electrode 143 is connected to the pattern 145.

Each of the patterns 142 and 145 is connected to the LSI chip 151 as shown in FIG. 15, and the clock line 152, the data line 153, the voltage line 154, and the ground line 155 are also connected to the LSI chip 1.
51. The LSI chip 151 determines from the data appearing on the data line 153 which nozzle 106 should eject an ink droplet based on the continuous clock pulse supplied from the clock line 152, and drives the ink chamber 101 to be driven. The voltage V of the voltage line 154 is applied to the pattern 142 conducting to the metal electrode 131 corresponding to. The pattern 142 connected to the metal electrode 161 other than the ink chamber 101 to be driven and the pattern 145 connected to the metal electrode 162 are connected to the ground line 15.
Connect to 5.

As in the first embodiment, the ink-jet head 140 is driven by deforming the portions of the piezoelectric ceramic layers 102a, 102b and 102c corresponding to the ink chamber 1 (see FIGS. 4 and 5).

Next, a method of manufacturing the ink jet head 140 will be described. First, in the same manner as in the first embodiment, a master 10 in which a plurality of cylinders 21 shown in FIG.

Subsequently, a 1 μm conductive layer 103 a made of titanium is formed on the cylinder 21 of the master 10 and the conductive substrate 11. This is formed as follows. As shown in FIG. 16A, a shielding plate 13 is provided at a portion corresponding to the tip of the cylinder 21.
2 is set, and vapor deposition is performed from two directions (arrows 15 and 16), and as shown in FIG.
Then, a conductive layer 103a is formed on the conductive substrate 11.

Next, a piezoelectric ceramic layer 102a is placed on the cylinder 21 and the conductive substrate 11 from above the conductive layer 103a, as shown in FIG.
As shown in (b), it is manufactured by the same method as in the first embodiment.

Next, as shown in FIG. 17 (c), a titanium 1 μm
Of the conductive layer 103b is formed. This is formed as follows. As shown in FIG. 16B, a shielding plate 132 is set on the base end of the cylinder 21 and a portion corresponding to the conductive substrate 11, and the conductive layer 103b is deposited by vapor deposition from two directions (arrows 15 and 16). Form.

Next, as shown in FIG. 17D, a piezoelectric ceramic layer 102b is formed in the same manner as the piezoelectric ceramic layer 102a. Subsequently, a 1 μm conductive layer 103c made of titanium is formed on the piezoelectric ceramic layer 102b in the same manner as the conductive layer 103a, and the piezoelectric ceramic layer 102c is formed in the same manner as the piezoelectric ceramic layer 102a. 1 μm conductive layer 1 made of titanium
03d is formed in a manner similar to that of the conductive layer 103b.

As described above, the conductive layers 103a, 103b, 1
03c, 103d and piezoelectric ceramic layers 102a,
The master 10 on which the layers 02b and 102c were formed was heated at about 600 ° C.
For about 30 minutes to form a piezoelectric ceramic layer 102 having excellent piezoelectric characteristics.

In this way, a PZT structure 133 having a laminated cylinder (FIG. 18) is obtained. The PZT structure 133 is made into a block shape by covering a plurality of laminated cylinders with an epoxy resin or the like (FIG. 19). The resin becomes the holding portion 105. And it cut | disconnects by the XX line of the front-end | tip part side of the cylinder 21,
The conductive substrate 11 is cut along the line ZZ. The conductive layers 103b and 103d are exposed on the XX line cut surface, and the conductive layers 103a and 103c are exposed on the ZZ line cut surface.

Next, the master disk 10 made of nickel is eluted by wet etching with a ferric chloride solution. Then, a portion corresponding to the cylinder 21 and the conductive substrate 11 becomes hollow. Then, as shown in FIG.
A two-layer film of chromium and nickel is formed by vapor deposition from the direction of arrow 19 on the entire end face where 3a and 103c are exposed. Subsequently, over the entire end face where the conductive layers 103b and 103d are exposed,
A two-layer film of chromium and nickel is formed by vapor deposition in the direction of arrow 18. At this time, the conductive layer 103 is formed inside the ink chamber 1.
a and a two-layer film of chromium and nickel formed on the exposed side of the conductive layer 103b and a two-layer film of chromium and nickel formed on the exposed side of the conductive layer 103b. Distance between (in FIG. 20, distance between upper conductive layer 103b and lower conductive layer 103b)
A shield plate 136 slightly smaller than that shown in FIG. 20 is installed, and vapor deposition is performed from the direction of arrow 18 so that the two-layer film formed on the exposed side of the conductive layer 103 b does not enter the ink chamber 1. . Then, the conductive layers 103b, 103
The two-layer film on the end face side where d is exposed is mechanically cut using a diamond blade to form a groove 109 shown in FIG. The separated two-layer film is the metal electrode 161, and the two-layer film on the end face side where the conductive layers 103 a and 103 c are exposed is the metal electrode 162.

Then, the metal electrode 162 is grounded, and a high voltage is applied to all the metal electrodes 161. That is, all the conductive layers 103a and 103c are grounded, and a high voltage is applied to all the conductive layers 103b and 103d to polarize the piezoelectric ceramic layers 102a, 102b and 102c.

As described above, the actuator member 130 thus manufactured is provided with the lid member 11 on the end face 130b.
7 and the flexible printed circuit board 141 on the upper surface 130c to complete the inkjet head 140.

In the method of manufacturing the ink jet head 140 according to the second embodiment described above, the same effects as those of the first embodiment are obtained, and the manifold 122 and the ink chamber 101 are formed at the same time.
There is no adhesive portion between the ink chamber 101 and the ink chamber 101. For this reason,
The positioning between the manifold 122 and the ink chamber 101 is easy, and no ink leakage occurs between the manifold 122 and the ink chamber 101.

In the first and second embodiments, the actuators 4 and 104 have a cylindrical shape, but may have a polygonal cylindrical shape instead of a circle.

In the first and second embodiments, the opening ends of the ink chambers 1 and 101 are the nozzles 6 and 106.
A nozzle plate formed with a plurality of nozzles may be joined to the opening end. Further, a nozzle plate in which one nozzle communicates with a plurality of ink chambers, for example, two ink chambers may be used.

Further, in the first and second embodiments, the shape of the ink chambers 1 and 101 is cylindrical. However, the shape of the ink chamber 1 may be funnel-shaped or tapered. .

In the first and second embodiments, when the conductive layer 3 is formed, the vapor deposition is performed in two directions (arrows 15 and 16). However, the vapor deposition may be performed in three or more directions. The conductive layer may be formed at a predetermined position by turning over the master by vapor deposition from one direction.

Further, in the first and second embodiments, three piezoelectric ceramic layers 2 are laminated, but the number of piezoelectric ceramic layers 2 may be any number.

Further, in the first and second embodiments, the master 1
0 is formed of nickel, but may be chromium.

In the first and second embodiments, the metal electrodes 61 and 162 common to all the ink chambers 1 and 101 are grounded, and the metal electrodes 62 and
161 has been selected to apply ink or to ground by selecting whether to apply voltage or to ground.
By changing the structure of the I chip, applying a voltage to the metal electrodes 61 and 162 and selecting whether to eject the ink by selecting whether the metal electrodes 62 and 161 are grounded or set to a high impedance state. Good.

In the second embodiment, the lid member 11 having the actuator member 130 and the ink supply port 123 is provided.
Although the ink supply port is provided separately from the actuator member 7, the ink supply port may be provided integrally with the actuator member. This eliminates the need for the cover member 117 and reduces the cost.

[0082]

As is apparent from the above description, according to the ink ejecting apparatus of the present invention, the actuator section is configured such that the plurality of electrodes and the plurality of piezoelectric ceramics are alternately stacked, and a hollow center is formed at the center of the stack. The actuator has a high rigidity because it has a cylindrical shape with a portion. For this reason, the driving voltage value for ejecting ink from the ink chamber can be reduced. Therefore, the distance between the portions of the electrodes connected to the power supply circuit can be made shorter than before. Therefore, the size of the ink ejecting apparatus can be reduced, and the degree of nozzle integration can be improved. Further, the cost of the driving circuit is reduced. Further, the plurality of actuator units are provided with the plurality of actuators.
The unit is integrated by the holding part provided over the tutor.
A plurality of ink chambers.
Can be In addition, one electrode is
Connected to the common electrode formed on one end face of the
Each electrode is connected to each drive electrode formed on each other end face.
The common electrode and each drive electrode are connected to each contact on the printed circuit board.
Easily connected to the electrodes, and easily to the power supply circuit.
Continued. In the ink ejecting apparatus according to the second aspect, a plurality of
One end of each actuator section
Each ink chamber is connected to the piezoelectric ceramic
A plurality of cylindrical manifolds are formed in communication with the manifold.
An ink ejecting device having an integral actuator
Can be. In addition, the second electrode is
Not reach any, any cylindrical actuator
Only the part can be deformed to eject the ink .

[Brief description of the drawings]

FIG. 1 is a perspective view showing an inkjet head according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the actuator member of the first embodiment.

FIG. 3 is a block diagram showing a control unit of the first embodiment.

FIG. 4 is a sectional view of the ink jet head of the first embodiment.

FIG. 5 is an explanatory diagram showing an operation of the ink jet head of the first embodiment.

FIG. 6 is a perspective view showing a master for producing the actuator member of the first embodiment.

FIG. 7 is an explanatory view showing a step of producing the master of the first embodiment.

FIG. 8 is an explanatory view showing a step of forming a conductive layer of the actuator member of the first embodiment.

FIG. 9 is an explanatory view showing a step of stacking a conductive layer and a piezoelectric ceramic layer of the actuator member of the first embodiment.

FIG. 10 is a sectional view showing a PZT structure of the first embodiment.

FIG. 11 is an explanatory view showing a manufacturing process of the actuator member of the first embodiment.

FIG. 12 is an explanatory view showing a step of forming a metal electrode on an end face of the actuator member of the first embodiment.

FIG. 13 is a perspective view showing an ink jet head according to a second embodiment of the present invention.

FIG. 14 is a sectional view of the actuator member of the second embodiment.

FIG. 15 is a block diagram showing a control unit of the second embodiment.

FIG. 16 is an explanatory view showing a step of forming a conductive layer of the actuator member of the second embodiment.

FIG. 17 is an explanatory view showing a step of stacking a conductive layer and a piezoelectric ceramic layer of the actuator member of the second embodiment.

FIG. 18 is a sectional view showing a PZT structure according to the second embodiment.

FIG. 19 is an explanatory view showing a manufacturing process of the actuator member of the second embodiment.

FIG. 20 is an explanatory view showing a step of forming a metal electrode on an end face of the actuator member of the second embodiment.

FIG. 21 is a perspective view showing a conventional ink jet head.

FIG. 22 is a cross-sectional view illustrating a conventional inkjet head.

[Explanation of symbols]

 Reference Signs List 1, 1 Ink chamber 2, 102 Piezoelectric ceramic layer 3, 103 Conductive layer 4, 104 Actuator section 5, 105 Holder 6, 106 Nozzle 17 Manifold member 22, 122 Manifold 40, 140 Ink jet head 41, 141 Flexible printed circuit board 43, 143 contact electrode 44,144 contact electrode 61,161 metal electrode 62,162 metal electrode

Claims (2)

(57) [Claims] 1. An ink chamber to which ink is supplied from an ink supply source, an actuator section that changes the volume of the ink chamber to eject ink, and a voltage is applied from a power supply circuit formed in the actuator section. In the ink ejecting apparatus having an electrode, the actuator section is configured such that the plurality of electrodes and the plurality of piezoelectric ceramics are alternately stacked in a cylindrical shape, a hollow portion is provided at a stacking center, and the hollow portion forms the ink chamber. and, a plurality of the actuator portion, the plurality of actuator
A plurality of first electrodes of the plurality of electrodes in the stacking direction.
An electrode is provided for each of the plurality of integrated actuator units.
Exposed on one end and formed on each end
Connected to the common electrode, and every other second electrode is
The one end faces of the plurality of integrated actuator units
Exposed on the other end face different from that formed on each other end face
It is connected to the drive electrodes, along the outer surface of the integrated multiple actuators
The common electrode and the plurality of
With contact electrodes connected to the drive electrodes
A pattern to connect the contact electrode to the power supply circuit
The ink jet apparatus characterized by a. 2. A plurality of ink chambers to which ink is supplied from an ink supply source, a plurality of actuator units for changing the volume of each ink chamber by applying a voltage to an electrode to eject ink, and It is supplied from the supply source
An ink ejecting apparatus having a manifold for supplying the separated ink to each of the ink chambers , wherein each of the actuator units has the electrode and the piezoelectric ceramic laminated in a cylindrical shape, and has a hollow portion at the center of the lamination, and the hollow portion has a hollow portion. forms the ink chamber, the one end of the plurality of the actuator portion, the continuous layer piezoelectric ceramics of each of the actuator elements, the manifold communicating with the respective ink chambers are formed, the plurality of electrodes Every other first in the stacking direction
Electrodes are placed along the manifold along the perimeter of the manifold.
Exposed on one end of the field, every other second electrode is
And does not reach the outer periphery of the manifold.
On the other end face different from the one end face of the plurality of actuator portions
The contact electrodes that are exposed and connected to the first electrode and the second electrode, respectively.
The printed circuit board with the poles and the contact electrodes for the power circuit
An ink ejecting device comprising a connecting pattern .