JP2002144559A - Liquid droplet jetting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid droplet jetting device capable of jetting ink droplets efficiently and stably. SOLUTION: A liquid droplet jetting device comprising a groove for providing an ink channel 12 formed in a piezoelectric member 27, a driving electrode formed on the side surface of both side walls of the groove, for having a voltage application for changing the volume of the ink channel 12, a wiring pattern for applying the voltage on the driving electrode, a conductive member 26 provided on one end part of the groove for electrically connecting the driving electrode and the wiring pattern, and a cover plate 3 bonded with the side walls, facing the bottom surface of the groove, for jetting an ink in the ink channel 12 by changing the volume of the ink channel 12, wherein the ink channel 12 direction width (W) of the conductive member 26 is set in a range of 100 μm or more and 2,000 μm or less, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved technique for ejecting ink by changing the volume of an ink flow path formed in a piezoelectric member to eject ink.

[0002]

2. Description of the Related Art Conventionally, as this type of droplet ejecting apparatus,
For example, there are those described in JP-A-63-252750 or JP-A-2-150355.
Hereinafter, the schematic configuration will be described with reference to the drawings. FIG.
As shown in FIG. 1, the inkjet printer head 1 includes a piezoelectric plate 2, a cover plate 3, and a nozzle plate 31.
And a substrate 41.

The piezoelectric plate 2 is made of a lead zirconate titanate (PZT) -based ceramic material having ferroelectricity. The piezoelectric plate 2 is polarized in the polarization direction 5. Next, grooves 8 are formed in the piezoelectric plate 2 by rotation of the diamond cutting disk. Subsequently, the depth of the cutting process is changed to form a shallow groove 16.

As shown in FIG. 10, a plurality of grooves 8 and shallow grooves 16 are formed in the piezoelectric plate 2 thus cut. The grooves 8 are of the same depth and are parallel. These shallow grooves 16 are formed near one end face 15 of the piezoelectric plate 2. The side wall 11 serving as the side surface of the groove 8 is polarized in the direction of the arrow 5 by the above-described polarization processing.

Further, metal electrodes 13 and 9 are formed on the side surface of the groove 8 and the inner surface of the shallow groove 16 by a vapor deposition method. FIG.
As shown in the figure, when the metal electrodes 13 and 9 are formed, the piezoelectric plate 2 is inclined with respect to the direction in which the vapor is emitted from the vapor source (not shown). Then, when the vapor is released, metal electrodes 13, 9, and 10 are formed on the upper half of the side surface of the groove 8, the inner surface of the shallow groove 16, and the upper surface of the side wall 11 due to the shadow effect of the side wall 11.

Next, the piezoelectric plate 2 is rotated by 180 degrees, and metal electrodes 13, 9, and 10 are similarly formed.
Thereafter, the unnecessary metal electrode 1 formed on the upper surface of the side wall 11 is formed.
0 is removed by lapping or the like. In this way,
The metal electrodes 13 formed on both sides of the groove 8 are electrically connected by the metal electrodes 9 formed on the inner surface of the shallow groove 16.

Next, the cover plate 3 shown in FIG.
It is formed from a ceramic material or a resin material. The cover plate 3 is provided with an ink inlet 21 and a manifold 22 by grinding or cutting.
Are formed. Then, the surface of the piezoelectric plate 2 on the processing side of the groove 8 and the surface of the cover plate 3 on the processing side of the manifold 22 are bonded by an adhesive such as an epoxy-based adhesive.

Accordingly, the ink jet printer head 1
, The upper surface of the groove 8 is covered to form a plurality of ink flow paths spaced from each other in the horizontal direction. Then, all the ink flow paths are filled with ink.

The nozzles 32 are provided on the end faces of the piezoelectric plate 2 and the cover plate 3 at positions corresponding to the positions of the respective ink flow paths.
The nozzle plate 31 provided with is bonded. A substrate 41 is bonded to the surface of the piezoelectric plate 2 opposite to the processing side of the groove 8 by an epoxy-based adhesive or the like.

A pattern 42 of a conductive layer is formed on the substrate 41 at a position corresponding to the position of each ink flow path.
The conductive layer pattern 42 and the metal electrode 9 on the bottom surface of the shallow groove 16 are connected to a conductive wire 43 by well-known wire bonding or the like.
Connected by

Thus, in order to eject ink droplets,
The central portions of the side walls 11, which are both side surfaces of the groove 8, are simultaneously deformed toward the inside of the groove 8. For this reason, the metal electrode 13 is formed in the upper half of the side wall 11, and the side walls 11 on both sides of the groove 8 are simultaneously deformed. Side walls 11 that are both side surfaces of groove 8
To simultaneously deform the metal electrodes 1 on both sides of the groove 8.
A metal electrode 9 for electrically connecting 3 is provided, and a voltage is applied to the metal electrode 9. Therefore, a shallow groove 16 is formed to form a metal electrode 9 for electrically connecting the metal electrodes 13 formed on the upper halves of both sides of the groove 8.

The prior art described above is an excellent technique in that an ink jet printer head having a relatively simple structure and high density nozzles can be realized. Since the grooves must be formed at a high density and electrical wiring must be performed from each groove, there is a practical problem in practical use.

Further, in order to form shallow grooves having different depths in the flow path formed by the grooves, the ink flow path needs to have a shape along the circumference of the diamond cutting disk, and the ink flow path length becomes longer. It has been difficult to reduce the size and drive the head at a high speed.

[0014] As a method of solving these problems, there is a method disclosed in
As described in JP-A-307254, JP-A-6-218918 or JP-A-6-218934, one end of a channel formed by a groove is sealed with a solder material, plating or a conductive member. There has been proposed a method of performing electrical wiring using the sealing member.

These conventional techniques will be described with reference to FIGS. As shown in FIG. 12, the inkjet printer head 1 includes a piezoelectric plate 27, a cover plate 3, a nozzle plate 31, and a substrate 41. The piezoelectric plate 27 is formed of a lead zirconate titanate (PZT) -based ceramic material having ferroelectricity. And the piezoelectric plate 27
Are polarized in the direction of the polarization direction 5.

The piezoelectric plate 27 is formed on the piezoelectric plate 27 by cutting or the like by rotating a diamond cutting disk.
As shown in FIG. 8, a plurality of grooves 8 are formed. The grooves 8 are of the same depth and are parallel. The side wall 11 serving as the side surface of the groove 8 is polarized in the direction of the arrow 5 by the above-described polarization processing.

The upper half and the side wall 1 of both sides of the groove 8
Metal electrodes 13 and 10 are formed on the upper surface of 1. Next, as shown in FIG.
Buried in the groove 8. Thereafter, heat is applied to the conductive member 26 by a device (not shown), and the conductive member 26 is solidified by the heat. The conductive member 26 is formed near the end 15 of the piezoelectric plate 27. The conductive member 26 is provided with the groove 8.
Of the full depth. Thereafter, the surplus portion of the conductive member 26 and the metal electrode 10 on the upper surface of the side wall 11 are removed by lapping or the like.

Next, the cover plate 3 shown in FIG.
The ink inlet 21 and the manifold 22 are formed by grinding or cutting. Then, as shown in the cross-sectional shape of the groove 11 in FIG.
Of the groove 8 on the machining side and the manifold 2 of the cover plate 3
(2) The surface on the processing side is bonded with an adhesive 4 such as an epoxy-based material. Accordingly, the ink jet printer head 1 covers the upper surface of the groove 8 and forms a plurality of ink flow paths 12 spaced from each other in the lateral direction. Then, all the ink flow paths 12 are filled with ink.

Nozzles 32 are provided on the end faces of the piezoelectric plate 2 and the cover plate 3 at positions corresponding to the positions of the respective ink flow paths.
The nozzle plate 31 provided with is bonded. The nozzle plate 31 is formed of a plastic such as polyalkyne (eg, ethylene), terephthalate, polyimide, polyetherimide, polyetherketone, polyethersulfone, polycarbonate, or cellulose acetate.

A substrate 41 is bonded to the surface of the piezoelectric plate 27 opposite to the processing side of the groove 8 by an epoxy-based adhesive or the like. The conductive layer pattern 42 is formed on the substrate 41 at a position corresponding to the position of each ink flow path. The conductive layer pattern 42 and the conductive member 26 are electrically connected by wire bonding or the like.

Therefore, the metal electrode 13 on one side of the groove 8 and the metal electrode 13 on the other side are electrically connected by the conductive member 26. Therefore, when a voltage is applied to the conductive member 26, a voltage is simultaneously applied to the metal electrodes 13 on both side surfaces of the groove 8 through the conductive member 26, and at the same time, the side walls 11 that are both side surfaces of the groove 8 The ink droplets are ejected by being deformed inward.

Next, the operation of the ink jet printer head 1 will be described with reference to FIGS. A drive control circuit (not shown) determines that ink is to be ejected from the ink flow path 12b of the inkjet printer head 1 according to required data. Then, the ink flow path 12
A positive drive voltage V is applied to the metal electrodes 13e and 13f via the conductive layer pattern 42 and the conductive member 26 corresponding to b, and the metal electrodes 13d and 13g are grounded.

As shown in FIG. 14, a driving electric field in the direction of arrow 14b is generated on the side wall 11b, and a driving electric field in the direction of arrow 14c is generated on the side wall 11c. Then, since the driving electric field directions 14b and 14c are orthogonal to the polarization direction 5, the side walls 11b and 11c are rapidly deformed in the ink channel 12b in this case due to the piezoelectric thickness-shear effect. Due to this deformation, the volume of the ink flow path 12b decreases, the ink pressure rapidly increases, a pressure wave is generated, and ink droplets are ejected from the nozzles 32 communicating with the ink flow path 12b.

When the application of the driving voltage V is stopped,
Since the side walls 11b and 11c gradually return to the positions before the deformation, the ink pressure in the ink flow path 12b gradually decreases. Then, ink is supplied from the ink supply port 21 through the manifold 22 into the ink flow path 12b.

Thus, in order to eject ink droplets,
The central portions of the two side walls 11 serving as both side surfaces of the groove 8 are simultaneously deformed toward the inside of the groove 8.

[0026]

However, in the above-described ink jet printer head 1, the conductive member 26 covering the end portion 15 has a shear deformation portion of the side wall 11 that actually affects the ejection of ink droplets (the side wall 11 has a shear deformation portion). The upper surface is close to the part that is adhered to the cover plate 3), and
Since the rigidity of the conductive member 26 is lower than that of the piezoelectric member forming the side wall 11, the shape and dimensions of the conductive member 26, the ink supply port, and the ink supply unit have affected the deformation efficiency of the side wall 11.

In particular, when the ink supply port is provided on the surface on the end side where the conductive member is provided, the surface of the conductive member facing the cover plate is completely open, so It was to be affected by shear deformation.

The conductive member 26 needs to transition from a liquid phase state to a solid state state during the formation process. In the process, a change in volume and the generation of voids due to the evaporation of volatile components and the like cause the metal electrode 26 to move. There was a problem with the stable connection with the X.13.

The present invention has been made to solve the above-described problems, and has as its object to provide a droplet ejecting apparatus capable of ejecting ink droplets efficiently and stably.

[0030]

In order to achieve this object, the present invention is configured as follows.

(1) A groove formed in the piezoelectric member and constituting an ink flow path; a drive electrode formed on both sides of the groove and applied with a voltage to change the volume of the ink flow path; A wiring pattern for applying a voltage to the drive electrode, a conductive member provided at one end of the groove to electrically connect the drive electrode and the wiring pattern, and a bottom surface of the groove. An ink supply unit for supplying ink to the ink flow path; and an ink supply unit for supplying ink to the ink supply unit from outside, the cover plate having a cover plate opposed to and bonded to the side wall. A droplet ejecting device, which is provided with a port and configured to eject ink in the ink flow path by changing the volume of the ink flow path, the width of the conductive member in the ink flow direction. (W) , Characterized in that it is set to 2000μm below the range of 100 [mu] m.

According to this structure, a conductive member is provided at the end of the groove formed in the piezoelectric member to electrically connect the driving electrodes formed on both side surfaces of the groove and the wiring pattern. A cover plate opposed to the bottom surface of the groove and bonded to the side wall, wherein the cover plate has an ink supply unit that supplies ink to the ink flow path and an ink supply port that supplies ink to the ink supply unit from outside; In the droplet ejecting apparatus which is provided and ejects ink in the ink flow path by changing the volume of the ink flow path, the width of the conductive member in the ink flow direction is 100 μm or more and 2000 μm or more.
By setting the thickness to the range of μm or less, the conductive member 26 and the metal electrode 13 can be connected with high reliability and uniformly, and stable ink droplet ejection can be performed.

(2) A groove formed in the piezoelectric member and constituting an ink flow path; a drive electrode formed on both sides of the groove and applied with a voltage to change the volume of the ink flow path; A wiring pattern for applying a voltage to the drive electrode, a conductive member provided at one end of the groove to electrically connect the drive electrode and the wiring pattern, and a bottom surface of the groove. An ink supply unit for supplying ink to the ink flow path; and an ink supply unit for supplying ink to the ink supply unit from outside, the cover plate having a cover plate opposed to and bonded to the side wall. A droplet ejecting device which is provided so as to eject ink in the ink flow path by changing the volume of the ink flow path. Long The ratio of (L) and said conductive ink flow path direction of the width of the member (W) (W / L) is characterized in that it is set in the range of 1/5 2/3 of.

According to this configuration, the ratio of the opening length of the ink supply section in the ink flow path direction to the width of the groove is set to １ ／ or more and 2 /
By setting the range to 3 or less, efficient driving of the side wall becomes possible.

(3) The depth (hA) of the ink supply section in the thickness direction in the cover plate direction is at least the depth (hB) of the groove.

According to this configuration, since the ink supply portion of the cover plate has a depth higher than the groove depth, stable ink droplet ejection can be performed. In particular, by combining the above conditions, it has become possible to efficiently and stably eject ink droplets.

[0037]

Embodiments of the present invention will be described below in detail with reference to the drawings. The same members (same portions) and equal members (equal portions) as in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 2, the ink jet printer head 1 includes a piezoelectric plate 27, a cover plate 3, a nozzle plate 31, and a substrate 41.
The piezoelectric plate 27 shown in FIG. 8 is made of a lead zirconate titanate (PZT) -based ceramic material having ferroelectricity.

The piezoelectric plate 27 is a plate having a thickness of about 1 mm, which is polarized in the direction of arrow 5. Further, a plurality of grooves 8 are formed in the piezoelectric plate 27 by a cutting process by rotation of a diamond cutting disk. The grooves 8 are parallel and of the same depth.

Then, the upper half and the side wall 1 of both sides of the groove 8
Metal electrodes 13 and 10 are formed on the upper surface of 1. Aluminum, nickel, copper, gold or the like is used for the metal electrodes 13 and 10. Then, as shown in FIG. 9, the conductive member 26 is filled with the dispenser 25 to substantially the entire depth of the groove 8. Thereafter, heat is applied to the conductive member 26 by a device (not shown), and the conductive member 26 is solidified by the heat.

As the conductive member 26, a gold paste containing an epoxy resin component, a silver paste, a copper paste, gold plating using a plating solution as a base, nickel plating, or the like is used.

As shown in FIG. 3, the conductive member 26 is formed near the end 15 of the piezoelectric plate 27. Thereafter, the surplus portion of the conductive member 26 and the metal electrode 10 on the upper surface of the side wall 11 are removed by lapping or the like.

Next, the cover plate 3 shown in FIG. 4 is formed of a ceramic material or a resin material having a thickness of 3 mm. In the cover plate 3, a concave portion 66 is formed on a surface facing the conductive member 26 by grinding or cutting. The recess 66 is formed with a width that can cover at least the entire groove.

Then, the surface of the piezoelectric plate 27 on the processing side of the groove 8 and the cover plate 3 are bonded to each other with an adhesive such as epoxy.

As shown in the cross-sectional view along the ink flow path 12 of the ink-jet printer head 1 shown in FIG. 4, the ink-jet printer head 1 covers the upper surface of the groove 8 and has a horizontal interval. Number of ink channels 12
When ink is filled, all the ink flow paths 12
The ink passes through the space above the conductive member 26 and is filled with ink.

Next, the substrate 41 on which the conductive layer pattern 42 is formed at a position corresponding to the position of each ink flow path is moved to the conductive member 26 formed on the end 15 of the piezoelectric plate 27.
Connect to The conductive layer pattern 42 and the conductive member 2
6 is formed by forming a bump (not shown) on the anisotropic conductive adhesive or pattern 42 and inserting the bump into a conductive member.

Thereafter, when the conductive ink is used,
The junction is insulated and protected by an organic protective film such as polyparaxylylene (trade name: parylene). However, a protective film is not required depending on the characteristics of the adhesive used for producing the ink jet printer head including the ink used and the anisotropic conductive adhesive.

Next, the nozzles 3 are provided on the end face composed of the piezoelectric plate 27 and the cover plate 3 and on which the conductive member 26 is not provided, at positions corresponding to the positions of the ink flow paths 12.
The nozzle plate 31 provided with 2 is bonded.

With the above configuration, the metal electrode 13 on one side of the groove 8 and the metal electrode 13 on the other side are electrically connected by the conductive member 26. For this reason, when a voltage is applied to the conductive member 26, a voltage is simultaneously applied to the metal electrodes 13 on both side surfaces of the groove 8 through the conductive member 26, and
Are deformed inwardly of the groove 8 to eject ink droplets.

In the above configuration, referring to FIG. 1, when the depth hA of the ink supply portion of the cover plate 3 is 450 μm and the depth hB of the groove 8 of the piezoelectric plate 27 is 300 μm, the width is about 80 μm, and the pitch is In the two cases of 169 μm, the width W of the conductive member 26 in the ink flow direction is 50, 100, 300, 500, 1000,
The initial variation of the connection resistance value between the conductive member 26 and the metal electrode 13 in each groove 8 when 2000, 3000, 4000 μm was set, the voltage was applied to the metal electrode 13, and the side wall 11 was continuously driven for 24 hours. FIG. 6 shows later variations.

In both cases where the dimensions of the groove 8 are changed,
As shown in FIG. 6, when the width of the conductive member 26 is 50 μm, there is a large variation in the connection resistance value in the initial stage, and
When the thickness is 0 μm or more, the connection resistance value after continuous driving greatly varies, so that it is necessary to set the width of the conductive member 26 in the range of 100 μm or more and 2000 μm or less in order to perform stable ink droplet ejection. .

Here, two kinds of materials for the conductive member 26 were used: a gold paste and a silver paste, and the ratio of the resin component to the conductive component was 4: 6 and 3: 7. , There was no difference in the above tendencies.

Next, FIG. 7 shows that the depth hA of the ink supply section of the cover plate 3 is 450 μm, the depth of the groove 8 of the piezoelectric plate 27 is 300 μm, the width is about 70 μm, and the pitch is 1 μm.
40 μm, and the width W of the conductive member 26 is set to 100, 300, 5
The ratio (W / L) of the opening length L of the ink supply unit in the ink flow direction to the width W of the groove 8 is 1/10, 1/5, 1/3. , 1 /
The relationship with the flying speed of the ink droplet when a voltage of 24 V was applied to the side wall 11 when the ratio was set to 2, 2/3, 1/1 was shown. As shown in FIG. 7, the ratio of the opening length of the ink supply unit in the ink flow direction to the width of the groove 8 is 1/5 or more and 2/3.
Otherwise, the flying speed of the ink droplets becomes extremely poor.

This is because when the ratio of the opening length of the ink supply section in the ink flow path direction to the width of the groove 8 is high (1/1), the deformation of the side wall 11 which actually affects the ejection of ink droplets Since the distance between the portion (the portion where the upper surface of the side wall 11 is bonded to the cover plate 3) and the portion buried by the conductive member 26 is short, it is considered that the deformation efficiency of the side wall 11 is affected. .

Conversely, when the ratio of the opening length in the ink flow direction of the ink supply section to the width of the groove 8 is low (1/10), the ink flow path becomes longer and the ink flow path becomes longer. It takes time to propagate the pressure of the ink, and the metal electrode 13
It is considered that the efficiency is deteriorated due to a synergistic effect caused by an increase in the compliance of the ink flow path portion because the length of the ink flow path is increased.

Therefore, when the flying speed is lower than 5 m / s, such as when the ratio of the opening length in the ink flow path direction of the ink supply unit to the width of the groove 8 is 1/10 or 1/1, the air being flying is Disturbance such as resistance deteriorates the landing accuracy of ink droplets, leading to deterioration of print image quality.

When the applied voltage is set high to increase the flying speed, not only does the load on the drive circuit increase, but also the heat generation of the ink jet printer head 1 itself increases, and the viscosity and surface tension of the ink are increased. And the like, the physical property values fluctuate, so that the ejection amount and the flying speed of the ink droplet vary.

The depth hB of the groove 8 of the piezoelectric plate 27 is 300 μm, the width is about 70 μm, and the pitch is 140 μm. The depth hB of the groove 8 is 350 μm and the width is about 80 μm.
m and the pitch were 169 μm, the depth hA of the ink supply portion of the cover plate 3 was 200, 3
Table 1 shows the stability in continuous ejection of ink droplets when the values were set to 00, 400, and 500 μm.

[0059]

[Table 1]

As shown in Table 1, when the depth hA of the ink supply portion of the cover plate 3 is smaller (shallower) than the groove depth hB, it becomes impossible to eject ink droplets in several minutes in continuous ejection of ink droplets. .

As described above, by setting the width of the conductive member 26 in the ink flow direction in the range of 100 μm or more and 2000 μm or less, the conductive member 26 and the metal electrode 1 are formed.
No. 3 was highly reliable, could be connected uniformly, and could stably eject ink droplets.

Further, by setting the ratio of the opening length in the ink flow path direction of the ink supply section to the width of the groove 8 in the range of not less than 1/5 and not more than 2/3, it is possible to drive the side wall 11 efficiently. Become. Further, by making the depth of the ink supply portion of the cover plate 3 higher than the groove depth, stable ejection of ink droplets was achieved.

Here, in the present embodiment, the metal electrode formed on the side wall is formed on the upper half of the side surface. However, after the entire surface of the flow path is formed by metal plating or the like, laser light is irradiated on the upper half. A configuration in which the metal plating is removed and metal electrodes are formed on the lower half and the bottom surface may be used.

In this case, the formation of the metal electrode is complicated, but since the contact area between the conductive member and the metal electrode is large, the electrical resistance of the connection portion can be suppressed and the reliability of the connection portion is improved. . Further, since the filling amount of the conductive member can be suppressed to half or less of the groove depth, the flow path resistance at the ink supply port can be reduced, and the ink supply and the ejection drive can be stabilized.

Similarly, as shown in FIG.
7 is composed of an upper piezoelectric member 61 and a lower piezoelectric member 62, and the polarization directions of the piezoelectric plates are indicated by arrows 63 and 63, respectively.
The adhesive is bonded in the opposite direction in the thickness direction as shown in FIG.
The same effect as above can be obtained by forming an electrode 65 over the entire surface of the groove after forming the electrode 65 at a position about half the height so that the polarization direction is opposite.

Further, in this embodiment, the ink supply port is provided on the end surface on which the conductive member is provided. However, as described in the above conventional example, the ink supply port is provided on the upper surface of the cover plate. A configuration may be used. However, when the surface of the conductive member facing the cover plate is completely released as in the present embodiment, the influence of the shear deformation of the side wall is greater, and the effect is more significant.

[0067]

As is clear from the above description, the present invention has the following effects. According to the first aspect, the width of the conductive member in the ink flow direction is 100 μm or more and 200 μm or more.
When the thickness is within the range of 0 μm or less, the conductive member and the metal electrode can be connected with high reliability and uniformity, and stable ink droplet ejection can be performed.

According to the second aspect, the ratio of the opening length of the ink supply section in the ink flow path direction to the width of the groove is set to １ ／ or more and
By setting the range to 3 or less, it is possible to drive the side wall 11 efficiently.

According to the third aspect, since the depth of the ink supply portion of the cover plate 3 is higher than the depth of the groove, stable ink droplet ejection can be performed. In particular, by combining the above conditions, it is possible to efficiently and stably eject ink droplets.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an inkjet printer head according to an embodiment of the present invention.

FIG. 2 is a perspective view of the same.

FIG. 3 is a perspective view showing the piezoelectric plate after a conductive member is formed.

FIG. 4 is a perspective view showing a configuration of the cover plate.

FIG. 5 is a sectional view showing another configuration example of the piezoelectric plate.

FIG. 6 is a graph showing the relationship between the width of the conductive member and the variation in connection resistance between the conductive member and the metal electrode.

FIG. 7 is a graph showing a relationship between a width of the conductive member, an opening length of an ink ink supply unit, and an ink droplet flying speed.

FIG. 8 is an explanatory view showing a process of forming a piezoelectric plate according to a conventional technique.

FIG. 9 is a cross-sectional view showing the same conductive member applying step.

FIG. 10 is a perspective view showing a configuration of the ink jet printer head.

FIG. 11 is an explanatory view showing an electrode forming step of the piezoelectric plate.

FIG. 12 is a perspective view showing another configuration of the inkjet printer head.

FIG. 13 is a sectional view of the ink jet printer head.

FIG. 14 is an explanatory diagram showing an operation state of the ink jet printer head.

[Explanation of symbols]

 3-cover plate 8-groove 12-ink flow path 26-conductive member 27-piezoelectric member (piezoelectric plate)

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yasuhiro Sakamoto 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 2C057 AF42 AF51 AG45 AG72 AG84 AG89 BA03 BA14

Claims (3)

[Claims] A groove formed on a piezoelectric member and forming an ink flow path; a drive electrode formed on both side surfaces of the groove and applied with a voltage to change a volume of the ink flow path; A wiring pattern for applying a voltage to the driving electrode; a conductive member provided at one end of the groove for electrically connecting the driving electrode and the wiring pattern; and a bottom facing the groove. A cover plate attached to the side wall; an ink supply unit for supplying ink to the ink flow path; and an ink supply port for supplying ink to the ink supply unit from outside. A droplet ejecting apparatus configured to eject ink in the ink flow path by changing the volume of the ink flow path, wherein the width of the conductive member in the ink flow direction ( W) , 100
A droplet ejecting apparatus characterized by being set in a range of not less than μm and not more than 2000 μm. 2. A groove formed in the piezoelectric member and forming an ink flow path; a drive electrode formed on both side surfaces of the groove and applied with a voltage to change the volume of the ink flow path; A wiring pattern for applying a voltage to the driving electrode; a conductive member provided at one end of the groove for electrically connecting the driving electrode and the wiring pattern; and a bottom facing the groove. An ink supply unit for supplying ink to the ink flow path, and an ink supply port for supplying ink to the ink supply unit from outside. A droplet ejecting apparatus configured to eject ink in the ink flow path by changing the volume of the ink flow path, wherein an opening length of the ink supply unit in an ink flow direction is provided. Sa (L) and the width (W) of the conductive member in the ink flow direction (W /
L) is set in the range of 1/5 to 2/3. 3. The method according to claim 1, wherein a depth (hA) of the ink supply section in a thickness direction in the cover plate direction is at least equal to or greater than a depth (hB) of the groove. Droplet ejector.