JP2001096755A - Ink-jet print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet print head which can easily and stably secure a sealing performance to an ink channel of join members. SOLUTION: An ink pump member 44 is overlapped with an ink nozzle member 42 where a plurality of nozzle holes 54 are formed, thereby forming an ink pressure chamber 46 behind each nozzle hole. The ink pump member 44 is constituted of a ceramics body obtained by layering and integrally baking green sheets of a spacer plate 70 with a plurality of window parts 76, a shutting plate 66 overlapped at one side of the spacer plate to shut the window parts, and a connecting plate 68 overlapped at the other side of the spacer plate and having communication opening parts 72 for shutting the window parts. Moreover, a piezoelectric/electrostrictive element 78 comprising electrodes 75, 77 and a piezoelectric/electrostrictive layer 79 formed by a film form method is set onto an outer face of the shutting plate 66.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet printhead, and more particularly to a novel structure of a low-cost ink-jet printhead capable of improving and stabilizing ink ejection characteristics.

[0002]

2. Description of the Related Art In recent years, in the market of printers used as output devices of computers, demand for inkjet printers that are quiet and have low running costs has been rapidly growing. In general, as an ink jet print head used in such an ink jet printer, the pressure in an ink pressurized chamber filled with ink is increased to eject ink particles (droplets) from nozzle holes. What is printed is used.

As a kind of a mechanism for increasing the pressure in the ink pressurizing chamber, there is known a type in which the volume of the ink pressurizing chamber is changed by displacement of a piezoelectric / electrostrictive element provided on the wall of the ink pressurizing chamber. Have been. This type is characterized in that it consumes less power in principle than other types which generate fine bubbles by heating a heater disposed in the ink pressurizing chamber.

Specifically, an ink jet print head of this type includes, for example, a metal nozzle plate 4 provided with a plurality of nozzle holes 2 as shown in FIGS. By laminating and joining a metal orifice plate 8 provided with a plurality of orifice holes 6 with a flow path plate 10 interposed therebetween, an ink ejection flow path 12 for guiding ink to the nozzle holes 2; The ink supply flow path 14 for guiding the ink to the hole 6 and the ink nozzle member 16 formed therein are respectively formed by a laminate of plates 18 and 20 made of metal or synthetic resin. An ink pump member 24 having a plurality of cavities 22 corresponding to the respective nozzle holes 2 and the orifice holes 6 is overlapped and bonded and integrated to form the nozzle holes 2 and Behind orifice holes 6, respectively,
It is formed by forming the ink pressurizing chamber 26 and fixing the piezoelectric / electrostrictive element 28 to the wall of the ink pressurizing chamber 26.

However, in such an ink jet print head, the ink pressurizing chamber 26
Since the small pieces of the piezoelectric / electrostrictive elements 28 must be bonded one by one to the wall portions, it is extremely difficult to reduce the size of the print head, and the cost due to such bonding is extremely difficult. The problem was that it was inevitable to improve and it was difficult to maintain reliability.

In addition, in such an ink jet print head, it is necessary to bond the ink nozzle member 16 and the ink pump member 24. At this time, the size and space between the adjacent voids 22, 22 are required. That is, since the thickness t of the partition 30 between the adjacent cavities 22 is as small as about 1 mm or less, it is extremely difficult to bond the ink nozzle member 16 and the ink pump member 24. It was.

More specifically, when the ink nozzle member 16 and the ink pump member 24 are bonded together, the adhesive easily protrudes on both sides of the partition wall portion 30. The chamber is deformed, and the ejection characteristics of the ink are hindered, leading to a decrease in product quality and a decrease in yield.

If the amount of the adhesive applied is reduced to prevent such an adhesive from protruding, a portion of the adhesive is likely to be partially defective. For example, adjacent ink pressurizing chambers 26, 26 may be used. The gap between the bonding surfaces may be incomplete due to incomplete sealing, causing a crosstalk, and a gap may remain between the bonding surfaces, causing air to remain, resulting in a pressure loss due to pressurization, resulting in a decrease in ink ejection characteristics. There was a fear of being done.

[0009]

The present invention has been made in view of the above-described circumstances, and a problem to be solved is that the adhesion between an ink nozzle member and an ink pump member is easy, The problems as described above due to the protrusion of the adhesive from the bonding surface or incomplete bonding can be reduced or prevented as much as possible, and excellent ink ejection characteristics can be stably obtained, and the production is easy and An object of the present invention is to provide an ink jet print head that can be advantageously made compact.

[0010]

In order to solve such a problem, a feature of the present invention is to provide an ink nozzle member provided with a plurality of nozzle holes for ejecting ink particles.
By overlapping and joining ink pump members provided with a plurality of cavities corresponding to the nozzle holes, ink pressurizing chambers are respectively formed behind the nozzle holes, and a wall portion of the ink pressurizing chamber is formed. A part of the ink is deformed by a piezoelectric / electrostrictive element to generate pressure in the ink pressurizing chamber, so that the ink supplied to the ink pressurizing chamber is ejected from the nozzle hole. In the head, a spacer plate provided with a plurality of windows forming the space, a closing plate overlaid on one side of the spacer plate to cover the window, and a spacer plate on the other side of the spacer plate. A connection plate, which is overlapped and covers the window, and provided with openings for communicating with the nozzle holes at positions corresponding to the nozzle holes of the ink nozzle member, respectively. And a piezoelectric / electrostrictive layer formed by a film forming method on the outer surface of the closing plate, while forming the ink pump member by a ceramic body which is formed by laminating green sheets and integrally firing. Wherein the piezoelectric / electrostrictive element comprises the piezoelectric / electrostrictive element.

The present invention also provides an ink supply path for supplying ink to the ink pressurizing chamber with respect to the ink nozzle member of the ink jet print head. An orifice hole for guiding ink to the ink pressurizing chamber is provided by opening the overlapping surface of the ink nozzle member with respect to the ink pump member, while an orifice hole corresponding to the orifice hole in the connection plate forming the ink pump member is provided. An ink jet print head having an opening for communicating with the orifice hole at each position is also characterized.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 are schematic structural views of an ink jet print head as an embodiment of the present invention, and FIG. 3 is an exploded perspective view thereof. Such an ink jet print head 40
Is formed by joining and integrating the ink nozzle member 42 and the ink pump member 44. The ink supplied to the ink pressurizing chamber 46 formed in the ink pump member 44 is Is ejected through a nozzle hole 54 provided in the nozzle.

More specifically, the ink nozzle member 42
Is a nozzle plate 4 having a thin plate shape.
The orifice plate 8 and the orifice plate 50 are overlapped with a flow path plate 52 interposed therebetween, and are integrally joined by an adhesive.

The nozzle plate 48 has a plurality of (three in this embodiment) nozzle holes 54 for ejecting ink.
The orifice plate 50 and the flow path plate 52 have through holes 56, 57 penetrating in the plate thickness direction at positions corresponding to the nozzle holes 54, and have inner diameters larger than the nozzle holes 54 by a predetermined dimension. It is formed with.

Further, the orifice plate 50 is provided with a plurality (three in this embodiment) of ink supply orifice holes 58 and a window 60 provided in the flow path plate 52. The nozzle plate 48 and the orifice plate 50 are covered with the nozzle plate 48 and the orifice plate 50 by being covered from both sides.
An ink supply channel 62 communicated with each of the orifice holes 58 is formed between the ink supply channels 62 and 0. The orifice plate 50 is provided with a supply port 64 for supplying ink guided from an ink tank to the ink supply flow path 62.

The material of each of the plates 48, 50, and 52 constituting the ink nozzle member 42 is not particularly limited. However, in forming the nozzle hole 54 and the orifice hole 58 with high dimensional accuracy, Generally, plastics or metals such as nickel and stainless steel are preferably used. Further, the orifice hole 58 is formed, for example, in a tapered shape having a smaller diameter in the ink flowing direction as shown in the drawing, in order to perform an action like a check valve on the supplied ink. It is desirable.

On the other hand, the ink pump member 44 is integrally formed with a structure in which a closing plate 66 and a connection plate 68 each having a thin flat plate shape are overlapped with a spacer plate 70 interposed therebetween.

The connection plate 68 has a first communication opening 72 and a second communication opening 72 at positions corresponding to the through holes 56 and the orifice holes 58 formed in the orifice plate 50 of the ink nozzle member 42. The communication openings 74 are respectively formed. The first communication opening 72 has an inner diameter that is substantially the same as or slightly larger than the through hole 56, while the second communication opening 74 has a larger diameter than the orifice hole 58 by a predetermined dimension. ing.

The spacer plate 70 has a plurality of long rectangular windows 76 formed therein. And
The spacer plate 70 is arranged such that the first communication opening 72 and the second communication opening 74 provided in the connection plate 68 are opened with respect to the respective windows 76. It is superimposed on the connection plate 68.

Further, on the surface of the spacer plate 70 opposite to the side on which the connection plate 68 is overlaid, a closing plate 66 is overlaid. Is covered. Thus, inside the ink pump member 44, the ink pressurizing chamber 46 communicated with the outside through the first and second communication openings 72 and 74 is formed.

By the way, such an ink pump member 4
Numeral 4 is formed as an integrally fired product of ceramics. That is, as a specific manufacturing process, first, from a ceramic slurry prepared from a ceramic raw material and a binder and a liquid medium, using a general device such as a doctor blade device or a reverse roll coater device, a green sheet is formed. Molding. Then, if necessary, the green sheet is subjected to processing such as cutting, cutting, and punching, so that the window 76 and the first and second communication openings 7 are formed.
2, 74, etc., to form precursors for each plate 66, 68, 70. Then, these precursors are laminated and fired, whereby an ink pump member 44 as an integral ceramic substrate is obtained.

The material of the ceramics forming the ink pump member 44 is not particularly limited, but alumina, zirconia, etc. may be used from the viewpoint of moldability.
It is preferably adopted. The plate thickness of the closing plate 66 is preferably 50 μm or less, more preferably 3 to 12 μm.
The thickness of the connection plate 68 is preferably at least 10 μm, more preferably at least 50 μm, and the thickness of the spacer plate 70 is preferably at least 50 μm, more preferably at least 100 μm.

That is, since the ink pump member 44 thus formed is formed as an integrally fired product of ceramics, it is not necessary to add a special bonding process or the like. , On the superposed surfaces of the connection plate 68 and the spacer plate 70, complete sealing can be stably obtained.

In addition, in the ink pump member 44,
The presence of the connection plate 68 also provides an effect of improving manufacturability. That is, in general, a laminated body obtained by laminating thin green sheets having flexibility is difficult to handle.For example, in setting to a firing furnace, etc., distortion is added if the supporting method is not careful, damage or breakage occurs after firing. There is a problem that abnormal deformation easily occurs. However, in the laminate in which the connection plate 68 exists, the rigidity of the laminate is increased, so that the connection plate 6
8 becomes easier to handle than when it does not exist,
The occurrence of defective products due to handling mistakes can be suppressed. Further, in the case of a design in which the ink pressurizing chambers 46 are arranged at a high density in the ink pump member 44, even if the structure using only the closing plate 66 and the spacer plate 70 makes it almost impossible to handle, the connection plate 68
Has the advantage that handling becomes possible.

The shape of the ink pump member 44 slightly varies depending on the manufacturing method.
It is desirable that the bonding surface of the connection plate 68, that is, the outer surface of the connection plate 68 is flat. As the degree of flatness, the maximum undulation with respect to a reference length of 8 mm is 50 μm or less, preferably 25 μm or less, when undulation is measured by a contact type shape measuring instrument.
More preferably, the thickness is 10 μm or less. As one of means for achieving this flatness, it is possible to subject the ceramic substrate after integrally firing to mechanical processing such as polishing or plane cutting.

Further, the ink pump member 44 is provided with a piezoelectric / electrostrictive element 78 at a position corresponding to each ink pressurizing chamber 46 on the outer surface of the closing plate 66. Here, this piezoelectric /
The electrostrictive element 78 is provided on the closing plate 66 on the lower electrode 7.
7, formed by forming a piezoelectric / electrostrictive operating portion including the piezoelectric / electrostrictive layer 79 and the upper electrode 75 by a film forming method. It is particularly preferable to use, as the piezoelectric / electrostrictive element 78, the piezoelectric / electrostrictive element previously proposed by the present applicant in Japanese Patent Application Nos. 3-203831 and 4-94742. Is done.

Specifically, in obtaining the piezoelectric / electrostrictive element 78, the closing plate 66 is mainly composed of zirconium oxide in which a crystal phase is partially or completely stabilized by a predetermined compound. A ceramic substrate is preferably used. Note that "partially stabilized or completely stabilized zirconium oxide" means that when heat or stress is applied, the crystal transformation does not occur partially or at all.
It contains zirconium oxide in which the crystal layer is partially or completely stabilized.

Compounds that stabilize this zirconium oxide include yttrium oxide, cerium oxide, magnesium oxide and calcium oxide. At least one of these compounds is added or contained alone or in combination to form an oxide. Zirconium will be partially or completely stabilized. Furthermore,
The content of each compound is 2 mol% to 7 mol% for yttrium oxide, 6 mol% to 15 mol% for cerium oxide, and 5 mol% to 12 mol% for magnesium oxide and calcium oxide. Among them, it is particularly preferable to use yttrium oxide as a partial stabilizer, in which case 2 mol% to 7 mol%, more preferably 2 mol% to 2 mol%.
Desirably, it is 4 mol%. Zirconium oxide obtained by adding and containing yttrium oxide in such a range has a main crystal phase partially stabilized in a tetragonal crystal or a mixed crystal mainly composed of a cubic crystal and a tetragonal crystal, and provides excellent substrate characteristics. Become. In addition, in order for the tetragonal crystal to be stably present and to obtain a large substrate strength, the average crystal grain size of the substrate is also important. That is, the average particle diameter is preferably 0.05 μm to 2 μm, more preferably 1 μm or less.

On the outer surface of the closing plate 66, predetermined electrode films (upper and lower electrodes) 75 and 77 and a piezoelectric / electrostrictive layer 79 are formed by various known film forming methods such as screen printing and spraying. Thick film forming techniques such as, dipping, coating, ion beam, sputtering, vacuum deposition,
It is formed by a thin film forming technique such as ion plating, CVD, and plating. The film formation can be performed before sintering the closing plate 66 (ink pump member 44) or after sintering. The respective films (electrode films 75, 77 and piezoelectric / electrostrictive layer 79) thus formed on the closing plate 66 are subjected to heat treatment as needed. Each time each film is formed,
It may be performed simultaneously, or may be performed simultaneously after all the films are formed. Further, in order to improve the insulation reliability between the electrode films 75 and 77, if necessary,
An insulating resin film may be formed between the electrostrictive layers 79,79.

The material of the electrode films 75 and 77 constituting such a piezoelectric / electrostrictive operating portion is not particularly limited as long as it is a conductor that can withstand a high-temperature oxidizing atmosphere at about the heat treatment temperature and the firing temperature. For example, a simple metal or an alloy may be used, and a mixture of an insulating ceramic or glass with a metal or an alloy, or a conductive ceramic may be used.
However, preferably, an electrode material mainly containing a high melting point noble metal such as platinum, palladium, and rhodium, or an alloy such as silver-palladium, silver-platinum, and platinum-palladium is suitably used.

Further, the piezoelectric / electrostrictive operating portion comprises
As the material of the electrostrictive layer 79, any material may be used as long as it exhibits an electric field-induced strain such as a piezoelectric or electrostrictive effect. It may be a crystalline material, a semiconductor material,
A dielectric ceramic material or a ferroelectric ceramic material may be used without any problem, and may be a material that requires a polarization treatment or a material that does not require it.

However, the piezoelectric / electrostrictive material used in the present invention is preferably a lead zirconate titanate (PZT).
) -Based material, lead magnesium niobate (P
MN-based material, lead nickel niobate (P
NN-based material, lead manganese niobate-based material, lead antimony stannate-based material, zinc zinc niobate-based material, lead titanate-based material And further, a composite material of these materials and the like are used. In addition, lanthanum,
Materials containing oxides such as barium, niobium, zinc, cerium, cadmium, chromium, cobalt, strontium, antimony, iron, yttrium, tantalum, tungsten, nickel, manganese and other compounds as additives, for example, There is no problem even if the above-mentioned predetermined additive is appropriately added to the above-mentioned material containing PZT as a main component so as to become PLZT.

The electrode film 7 formed as described above
5, 77 and a piezoelectric / electrostrictive film (layer) 79 generally have a thickness of 100 μm or less, and the electrode films 75, 77 generally have a thickness of 2 μm or less.
The thickness of the piezoelectric / electrostrictive film 79 is preferably not more than 50 μm, more preferably not less than 3 μm and not more than 40 μm in order to obtain a large displacement at a low operating voltage. It is desirable that:

That is, in the piezoelectric / electrostrictive element 78 thus formed, the closing plate 66 made of a material containing zirconium oxide as a main component and having a crystal phase partially stabilized is used as a substrate. Therefore, mechanical strength and toughness can be advantageously ensured even at a thin plate thickness, a large displacement can be obtained at a relatively low operating voltage, and a fast response speed and a large generating force can be obtained. You can.

In addition, since the piezoelectric / electrostrictive elements 78 are formed by a film forming method, due to an advantage of the film forming process, a large number of the piezoelectric / electrostrictive elements 78 are formed on the closing plate 66 at a fine interval with an adhesive or the like. Can be formed simultaneously and easily without using a plurality of ink pressurizing chambers 46 formed in the ink pump member 44, as described above. The piezoelectric / electrostrictive element 78 can be easily formed.

Thus, the piezoelectric / electrostrictive element 78 as described above
In the ink pump member 44 as described above, which is provided integrally with the ink nozzle member 42, as shown in FIG. To be joined and integrated. Thereby, based on the operation of the piezoelectric / electrostrictive element 78 provided integrally with the ink pump member 44,
The ink guided through the ink supply channel 62 is supplied to the ink pressurizing chamber 46 from the orifice hole 58,
The ink flows through the nozzle holes 54 through the through holes 56 and 57.
Thus, the target inkjet print head 40 that is ejected to the outside is formed.

Examples of the adhesive that can be used include vinyl, acrylic, polyamide, phenol, resorcinol, urea, melamine, polyester, epoxy, furan, polyurethane, silicone, and rubber. System, polyimide system, polyolefin system, etc. However, a durable adhesive for the ink is selected.

The form of the adhesive is selected from the viewpoint of mass productivity.
A high-viscosity paste type that can be applied by a dispenser, a screen type that can be punched, and a high-viscosity paste type that can be screen-printed are also excellent. desirable. Further, as the high-viscosity paste type, a paste whose viscosity is increased by mixing a filler into an original adhesive can be used.

In view of the above points, and particularly from the viewpoint of durability against ink (aqueous), a screen-printable elastic epoxy adhesive or a silicone-based adhesive, or a sheet-shaped hot-melt type polyolefin-based punchable material. An adhesive, a polyester-based adhesive, or the like is particularly preferably used. In addition, these various adhesives,
For each part of the adhesive surface and the other part,
It is also possible to apply.

As described above, when the ink pump member 44 and the ink nozzle member 42 are bonded to each other, the ink pressurizing chamber 46 provided in the ink pump member 44 is
Ink supply channel 62 provided in ink nozzle member 42
The first communication opening 72 and the second communication opening 74 formed in the connection plate 68 of the ink pump member 44 are connected to the orifice of the ink nozzle member 42. Plate 50
This is accomplished by communicating with the through hole 56 and the orifice hole 58 formed in the hole.

Therefore, the sealing property of the ink flow path between the adhesive surfaces of the ink pump member 44 and the ink nozzle member 42 is ensured only around the first and second communication openings 72 and 74. It is sufficient that the length of the adhesive portion for which the sealing property is to be ensured is short, so that excellent sealing property can be advantageously and stably obtained.

In the present embodiment, the inner diameter of the first and second communication openings 72 and 74 is determined by the inner width of the ink pressurizing chamber 46 (the width of the window 76 formed in the spacer plate 70). (Width dimension), it is also advantageous to ensure a dimension (L in FIG. 2) between the first and second communication openings 72, 74 formed adjacent to each other. Can be.

Thus, the bonding area between the ink pump member 44 and the ink nozzle member 42 around each of the first and second communication openings 72 and 74 can be advantageously and sufficiently secured. Because it is possible, even in the case of adhesion between different kinds of materials, it is possible to more advantageously obtain the sealing property on the adhesion surface.

Depending on the type and application method of the adhesive, there is a possibility that the adhesive protrudes into the first and second communication openings 72 and 74 and closes the openings. In such a case, the inner diameters of the first and second communication openings 72 and 74 formed adjacent to each other are set to be substantially the same as the inner size of the ink pressurizing chamber 46. Thus, it is desirable to prevent the opening from being closed. As shown in FIG. 7, one or both of the first and second communication openings 72 and 74 may be formed in a teardrop shape or an elliptical shape.

Incidentally, the excellent sealing property of the ink flow path as described above, which is exerted on the joint surface between the ink nozzle member 42 and the ink pump member 44 in the ink jet print head 40 of this embodiment, is shown in FIGS. 6, the shape of the bonding surface between the ink nozzle member 16 and the ink pump member 24 required in the ink jet print head having the conventional structure can be easily understood by comparing with the above-mentioned embodiment. Where it is.

Therefore, according to the ink jet print head 40 having such a structure, it is possible to easily and stably obtain the sealing property in the ink flow path, and to prevent the adhesive from protruding into the ink pressurizing chamber 46. It is possible to advantageously prevent the generation of a gap or the like in the bonding surface, and thereby it is possible to stably obtain a product with improved ink ejection characteristics.

In addition, in such an ink jet print head, the piezoelectric / electrostrictive element 7 that deforms the wall of the ink pressurizing chamber 46 to generate an internal pressure in the ink pressurizing chamber 46 is formed.
8 is formed by a film forming method, it can be formed easily and with excellent mass productivity at a portion corresponding to each ink pressurizing chamber 46, and excellent ink ejection characteristics can be obtained. It can be exhibited stably.

Although the embodiment of the present invention has been described in detail above, this is a literal example, and the present invention is not construed as being limited to such a specific example.

For example, in the above embodiment, the ink pressurizing chamber 4
Although the ink supply channel 62 for supplying the ink to the ink nozzle 6 is formed inside the ink nozzle member 42, the ink supply channel 62 may be formed inside the ink pump member 44. One specific example is shown in FIG. In FIG. 4, to facilitate understanding, members and portions corresponding to those in the first embodiment are denoted by the same reference numerals. . The orifice hole 58 in the specific example of FIG. 4 can be formed in the second communication opening 74 of FIG. 1 etc. by appropriately selecting the hole diameter of the second communication opening 74 in the example of FIG. , The function of the orifice hole 58 is integrated. Similarly, it goes without saying that the functions of the first communication opening 72 and the nozzle hole 54 shown in FIG.

The structure and material of the ink nozzle member 42 are not limited to those of the above-described embodiment, and the whole or a part thereof is integrally formed by injection molding of a synthetic resin material or another molding method. It is also possible to use one that has been done.

Further, the nozzle hole 54 and the orifice hole 5
The formation position and the number of the ink pressurizing chambers 46 are not limited to those of the above embodiment.

In addition, the present invention provides on-demand and continuous jet ink jet printheads,
Any of these can be applied to ink jet print heads having various structures belonging to them.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included within the scope of the present invention, without departing from the spirit of the present invention.

[0055]

As is apparent from the above description, in the ink jet print head having the structure according to the present invention, the sealing property of the ink flow path at the joint surface between the ink pump member and the ink nozzle member is dramatically improved. Therefore, the improvement of the product quality and its stabilization can be advantageously achieved.

In addition, in such an ink jet print head, the piezoelectric / electrostrictive element can be easily formed with excellent mass productivity by the film forming method, so that the product quality can be further improved and the productivity can be improved. Can be achieved, and the size of the inkjet print head can be advantageously reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing an ink jet print head as one embodiment of the present invention.

FIG. 2 is an explanatory sectional view taken along the line II-II in FIG.

FIG. 3 is an exploded perspective view illustrating a structure of the inkjet print head illustrated in FIG. 1;

FIG. 4 is an explanatory longitudinal sectional view corresponding to FIG. 1, showing an ink jet print head as another embodiment of the present invention.

FIG. 5 is an explanatory longitudinal sectional view showing a specific example of a conventional ink jet print head.

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5;

FIG. 7 is an explanatory sectional view showing an example in which the shapes of first and second communication openings are changed in FIG. 2;

[Brief description of reference numerals]

 40, 80 Inkjet print head 42 Ink nozzle member 44 Ink pump member 46 Ink pressurizing chamber 48 Nozzle plate 50 Orifice plate 52 Flow path plate 54 Nozzle hole 58 Orifice hole 62 Ink supply flow path 66 Closing plate 68 Connection plate 70 Spacer plate 72 First communication opening 74 Second communication opening 78 Piezoelectric / electrostrictive element

Continued on the front page (72) Inventor Nobuo Takahashi 4-6-6 Toei-cho, Osaka-Asahi City, Aichi Prefecture Toei Park Heights 305 (72) Inventor Hideaki Sonehara 3-5-3 Yamato, Suwa-shi, Nagano Prefecture Seiko Epson Corporation (72) Inventor Kohei Kitahara 150-208 Daimondagawacho, Shiojiri City, Nagano Prefecture

Claims (2)

[Claims] An ink pump member provided with a plurality of cavities corresponding to the nozzle holes is overlapped and joined to an ink nozzle member provided with a plurality of nozzle holes for ejecting ink particles. Forming an ink pressurizing chamber behind each of the nozzle holes, and deforming a part of the wall of the ink pressurizing chamber by a piezoelectric / electrostrictive element to generate pressure in the ink pressurizing chamber. Thus, in the ink jet print head configured to eject the ink supplied to the ink pressurizing chamber from the nozzle hole, a spacer plate provided with a plurality of windows forming the space, A closing plate which is overlaid on one side to cover the window, and an ink cover which is overlaid on the other side of the spacer plate to cover the window. A connection plate provided with an opening for communicating with the nozzle hole at a position corresponding to the nozzle hole of the nozzle member; The piezoelectric / electrostrictive element comprises a member, and the piezoelectric / electrostrictive element is constituted by a piezoelectric / electrostrictive operating portion including an electrode formed on the outer surface of the closing plate by a film forming method and a piezoelectric / electrostrictive layer. Inkjet print head. 2. An ink supply passage for supplying ink to the ink pressurizing chamber is formed in the ink nozzle member, and an orifice hole for guiding ink from the ink supply passage to the ink pressurizing chamber is formed. The ink nozzle member is provided with an opening at the overlapping surface with respect to the ink pump member, while the connection plate forming the ink pump member is provided at a position corresponding to the orifice hole for communicating with the orifice hole. The ink jet print head according to claim 1, further comprising an opening.