JP2000343691A - Ink jet printer head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ejection quantity and speed of ink drop from lowering by preventing the state of crystal composing the side face or the top face of a polarized piezoelectric ceramics from being varied due to cutting or blasting for forming a channel in the channel member of a head or laser machining for forming the lead wire of a driving electrode on the top face of the barrier wall thereby ensuring the essential displacement of the barrier wall. SOLUTION: The ink jet print head 40 is constituted by setting the ratio B/A of peak intensities B and A between tetragonal 002 diffraction and tetragonal 200 diffraction at 1.5 or below when the side face of a piezoelectric ceramics barrier wall 1 defining an ink channel 2 is measured by X-ray diffraction, or setting the ratio A/B of peak intensities A and B between tetragonal 200 diffraction and tetragonal 002 diffraction at 1.5 or below when the top face of the barrier wall 1 is measured by X-ray diffraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer head mounted on a high precision ink jet printer used for printing characters and images.

[0002]

2. Description of the Related Art In recent years, with the spread of personal computers and the development of multimedia, the use of ink jet printers as image forming apparatuses for outputting information to recording media has been rapidly expanding.

As an ink jet printer head (hereinafter, referred to as a head) mounted on an ink jet printer, a fine heater is provided in a flow path filled with ink, and the ink is heated and boiled by the heater, so that the ink flows in the flow path. The thermal jet method in which the ink in the flow path is pressurized by bubbles generated in the ink to discharge ink droplets from the ink discharge holes, and the partition wall forming the flow path filled with ink is bent and displaced by a piezoelectric element to mechanically flow the ink. In general, a piezoelectric method in which ink in a path is pressurized and ink droplets are ejected from an ink ejection hole is used. Among these, the piezoelectric method has excellent durability and responsiveness, and does not directly heat the ink. There is an advantage that the type is not limited.

As shown in FIG. 8, such a piezoelectric type head has a plurality of partition walls 51 installed in parallel, and a lead zircon titanate or the like which serves as an ink flow path 52 between the partition walls 51. A top plate 55 having an ink supply hole 56 that is joined to the top of each partition wall 51 and that introduces ink into each flow passage 52; Nozzle plate 5 having an ink discharge hole 57 connected to one end of
In some cases, drive electrodes 54 were formed on both side surfaces of the partition wall 51 along the longitudinal direction thereof (see Japanese Patent Application Laid-Open No. 7-101506).

The other end of the flow path member 53 has a closed structure, and each partition wall 51 is polarized in the direction of the arrow. Reference numeral 59 denotes a lead line of the driving electrode 54 formed on the top surface of the partition wall 51.

In order to manufacture the head 50, a plurality of grooves are formed at equal intervals by, for example, a rotary blade called a dicing saw in a piezoelectric ceramic body mainly composed of lead zircon titanate or the like that has been polarized in the thickness direction in advance. Or blasting to form multiple grooves by spraying powder of sand, glass, ceramics, etc.
Each groove is used as an ink flow path 52, and a flow path member 53 is manufactured in which a wall constituting the flow path 52 is used as a partition wall 51.
Next, the top and side surfaces of the partition wall 51 are coated with a metal film by a film forming means such as a vapor deposition method, a sputtering method, or a plating method, and the metal film coated on the side surface of the partition wall 51 is coated with a driving electrode 54.
After removing the center of the metal film formed on the top surface of the partition wall 51 by laser processing along the longitudinal direction to form the lead wire 59 of each driving electrode 54, the ink is formed on the top of the partition wall 51. The top plate 55 provided with the supply holes 56 is bonded with an adhesive or glass, and the nozzle plate 58 provided with the ink discharge holes 57 is bonded to the open end of the flow path member 53 with an adhesive or glass. It was produced by.

In order to print on a recording medium using the head 50, a current is applied between a driving electrode 54 formed on both side surfaces of a partition wall 51 made of piezoelectric ceramics polarized in a height direction. When an electric field is applied in the horizontal direction, a shear vibration occurs in the piezoelectric ceramics in a shearing mode, and the partition wall 51 is bent and displaced in the horizontal direction. This phenomenon is used to pressurize the ink in each flow path 52. As a result, ink droplets are ejected from the ink ejection holes 57 and printing is performed on a recording medium.

[0008]

However, in forming the flow path 52 of the flow path member 53, if cutting or blasting is performed with a dicing saw or the like, heat is generated due to the action of the processing pressure, and the piezoelectric element is pressed. Distortion is generated in the crystal constituting the side surface of the partition wall 51 made of ceramics, and the crystal axis expands and contracts. The piezoelectric characteristic of the portion where the electric field acts is deteriorated by the expansion and contraction of the crystal axis. There was a problem that was not obtained.

Further, a partition wall 51 made of piezoelectric ceramics
The crystal forming the top surface of the partition wall is distorted by the polarization treatment, and the crystal axis expands and contracts. However, since the lead wire 59 of the driving electrode 54 is formed on the top surface of the partition wall 51, When the center of the metal film formed on the top surface of the partition 51 is removed by laser processing, the distortion of the crystal constituting the top surface of the partition 51 is eliminated by the heat of the laser beam, and the degree of polarization is reduced. However, even if a current is applied between the drive electrodes 54 formed on both side surfaces of the partition wall 51, the original displacement amount of the partition wall 51 cannot be obtained.

Therefore, in any case, the flow path 52
A predetermined pressure cannot be generated with respect to the ink in the ink, and the ejection amount and ejection speed of ink droplets ejected from the ink ejection holes 57 are reduced, so that accurate characters and images based on information cannot be printed. Was.

[0011]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention has a plurality of partition walls made of piezoelectric ceramics arranged in parallel, and a flow path member having a flow path for ink between the partition walls. A top plate that is joined to the top of the partition wall and closes each flow path; and a driving electrode is provided on both side surfaces of each of the partition walls. In an ink jet printer head that pressurizes ink in a passage and ejects ink droplets from ink discharge holes communicating with each flow passage, the peak intensity B of tetragonal 002 diffraction when the side surface of the partition is measured by X-ray diffraction. And the ratio (B / A) of the peak intensity A of tetragonal 200 diffraction to 1.5 or less.

Further, the present invention has a plurality of partition walls made of piezoelectric ceramics arranged side by side, a flow path member serving as an ink flow path between the partition walls, and joined to a top of the partition walls,
A top plate that closes each flow path, a drive electrode is provided on both side surfaces of each partition, and a lead wire of the drive electrode is provided on a top surface of each partition, and the drive electrode In the ink jet printer head which pressurizes the ink in each flow path by applying a current to cause the partition walls to bend and displace, thereby ejecting ink droplets from ink ejection holes communicating with the respective flow paths, the top surface of the partition walls is subjected to X-ray diffraction. The ratio (A / B) of the peak intensity A of the tetragonal 200 diffraction and the peak intensity B of the tetragonal 002 diffraction measured by the above is set to 1.5 or less.

[0013]

According to the present invention, the peak intensity B of tetragonal 002 diffraction and the peak intensity of tetragonal 002 are measured when the side surface of the partition wall made of piezoelectric ceramics polarized in the height direction is measured by X-ray diffraction.
The ratio (B / A) to the peak intensity A of the 0 diffraction is set to 1.5 or less, and the crystal forming the side surface of the partition wall is distorted by the heat generated at the time of forming the flow path by cutting or blasting. Since the original displacement amount of the partition wall is obtained as much as possible, it is possible to prevent a decrease in the ejection amount and the ejection speed of the ink droplet.

According to the present invention, when the top surface of the partition wall made of piezoelectric ceramics polarized in the height direction is measured by X-ray diffraction, the peak intensity A of tetragonal 200 diffraction and the tetragonal 002 diffraction are obtained. And the ratio (A / B) to the peak intensity B is set to 1.5 or less, and the heat generated when forming the lead line of the driving electrode by laser processing on the top surface of the partition wall causes the top surface of the partition wall to rise. Since the distortion of the constituent crystals is suppressed as much as possible and the original amount of displacement of the partition is obtained, it is possible to prevent a decrease in the ejection amount and ejection speed of ink droplets.

[0015]

Embodiments of the present invention will be described below.

FIG. 1 is a partially cutaway perspective view showing an example of the ink jet printer head of the present invention, and FIG.
(B) is a partial cross-sectional view for explaining the driving principle of the ink jet printer head of the present invention.

In this ink jet printer head, a plurality of partition walls 1 made of piezoelectric ceramics are arranged in parallel at equal intervals, and a flow path member 3 serving as an ink flow path 2 between the partition walls 1 is provided at the top of the partition wall 1. A top plate 5 having an ink supply hole 6 for introducing ink into each flow path 2 and an ink discharge hole 7 being connected to one end of the flow path member 3 and communicating with each flow path 2; The partition wall 1
Drive electrodes 4 are respectively formed on the upper halves of both side surfaces along the longitudinal direction. Each partition 1 is polarized in the direction of the arrow in the figure in order to bend in the horizontal direction due to shear mode deformation when current is applied between the driving electrodes 4 on both side surfaces.

The other end of the flow path member 3 has a closed structure, and a driving electrode 4 formed on the partition wall 1 is formed.
Is electrically connected to a driving circuit (not shown) via a lead wire 9 extending to the end of the flow path member 3 beyond the flow path 2.

According to the head 10 of the present invention, the side surface of the partition wall 1, particularly the side surface on which the drive electrode 4 which affects the displacement characteristics of the partition wall 1, is formed by tetragonal crystal as measured by X-ray diffraction. The ratio (B / A) of the peak intensity B of the 002 diffraction and the peak intensity A of the tetragonal 200 diffraction is set to 1.5 or less, preferably 1.0 or less.

In order to print on a recording medium (not shown) using the head 10, first, an ink such as a pigment type oil-based ink, a water-based dye ink, or an ultraviolet curable ink is supplied from the ink supply holes 6 through the respective ink supply holes 6. 2 and drive electrodes 4b, 4c and drive electrodes 4h, 4i, respectively, to apply negative voltages to the drive electrodes 4a, 4d, 4g, 4j, for example.
When the voltage of the positive electrode is applied, the partition walls 1a and 1b are bent and displaced toward the flow path 2a as shown in FIG. 2A, and the partition walls 1d and 1e are bent and displaced toward the flow path 2d.
The ink filled in the flow paths 2a and 2d can be pressurized to eject ink droplets from the ink ejection holes 7. Next, when the power supply to the driving electrodes 4a to 4d and 4g to 4j is cut off, the partition walls 1a, 1b, 1d, and 1e that have been bent and displaced.
Is returned to the original shape by the elastic action, and as a result, the inside of the flow paths 2a and 2d is decompressed, so that the introduction of ink from the ink supply hole 6 is started.
When voltage is applied to 4d, 4g to 4j with the sign reversed,
As shown in FIG. 2B, the partition walls 1a and 1b bend outwardly with respect to the flow path 2a, and the partition walls 1d and 1e bend outwardly with respect to the flow path 2d.
The inside of d is further reduced in pressure, and the ink is filled. When the drive electrodes 4a to 4d and 4g to 4j are cut off, the partition walls 1a, 1b,
1d and 1e return to the original shape by the elastic action and enter the ejection stage of the next ink droplet. By repeating these operations sequentially, the ejection of the ink droplet can be performed continuously. Has become.

According to the present invention, as described above, the tetragonal 002 when the side surface of the partition wall 1 is measured by X-ray diffraction.
Peak intensity B of diffraction and peak intensity A of tetragonal 200 diffraction
The ratio (B / A) is set to 1.5 or less, and the crystal constituting the side surface of the partition 1 has almost no distortion. Since the bending displacement can be performed by the displacement amount originally possessed by 1, it is possible to prevent a decrease in the ejection amount and the ejection speed of the ink droplet, and to print an accurate character or image according to the information.

That is, when forming the flow path 2 of the flow path member 3, cutting or blasting of a dicing saw or the like is usually performed in consideration of mass productivity, workability, and the like. In some cases, the crystal forming the side surface of the partition wall 1 is distorted by heat generated by the application of the processing pressure, and the crystal axis may expand and contract, and the degree of expansion and contraction of the crystal axis may be large. If the proportion of the expanding and contracting crystals is large, large shear vibrations cannot be generated in the piezoelectric ceramics due to the shear mode.
The present inventor has found that the original displacement amount of the partition wall 1 cannot be obtained.

The reason for this is that the displacement of the piezoelectric ceramics is obtained by extending or contracting the crystal axis given by the polarization process by applying or applying an electric field, and the heat is dissipated. It is considered that the expansion and contraction of the crystal axis caused by the crystal distortion caused by the crystal acts to reduce the slip vibration of the piezoelectric ceramic. And, as the piezoelectric ceramic used for the partition 1,
Piezoelectric ceramics mainly composed of lead zircon titanate (PZT), piezoelectric ceramics mainly composed of lead magnesium niobate (PMN), lead nickel niobate (P
NN-based piezoelectric ceramics, as well as piezoelectric ceramics in which these main components are compounded, are generally used because their crystals mainly consist of two crystal phases of tetragonal and rhombohedral. When the side surface of the partition wall 1 made of the piezoelectric ceramics polarized in the height direction is measured by X-ray diffraction, the peak intensity A of the tetragonal 200 diffraction and the tetragonal 002 diffraction as shown in the chart shown in FIG. Is found, and the ratio (B / A) of those peak intensities located in the range of the diffraction angle of 40 ° to 50 ° is obtained to determine the degree of expansion and contraction of the crystal axis constituting the side surface of the partition wall 1. As a result, the expansion / contraction of the crystal axis is suppressed by suppressing the ratio (B / A) to 1.5 or less.
It has been found that the original displacement amount of has been obtained.

The ratio (B / A) between the peak intensity B of the tetragonal 002 diffraction and the peak intensity A of the tetragonal 200 diffraction.
In the measurement, the X-ray source was Cu, the tube voltage of the X-ray source was 50, using Rigaku RINT1400V type X-ray diffraction.
kV, a tube current of 200 mA, a biaxial vertical goniometer with a step width of 0.020 °, a peak intensity A of tetragonal 200 diffraction and a peak of tetragonal 002 diffraction appearing in a diffraction angle range of 40 ° to 50 °. What is necessary is just to measure and calculate the intensity B.

The X-ray diffraction is obtained by measuring 30 minutes from the surface of the object.
Since the crystal state up to a depth of about μm can be confirmed, if the thickness of the driving electrode 4 formed on the side surface of the partition wall 1 is less than 30 μm, the measurement may be performed directly on the driving electrode 4. In this case, X-ray diffraction information at a diffraction angle of 40 ° to 50 ° of the metal film forming the driving electrode 4 may be measured in advance, and the peak intensity may be corrected.

Next, a method of manufacturing the head 10 shown in FIG. 1 will be described.

First, in order to form the flow path member 3, the above-described piezoelectric ceramic body is prepared, polarized in its thickness direction, and then cut or blasted with a dicing saw or the like to form a plurality of grooves in the thickness direction. Are arranged at equal intervals,
These grooves are used as ink flow paths 2 and each of the flow paths 2
Is formed as the partition wall 1 using the wall constituting the above.

At this time, the partition 1 made of piezoelectric ceramics
The peak intensity B of the tetragonal 002 diffraction measured by X-ray diffraction and the tetragonal 2
It is necessary that the ratio (B / A) to the peak intensity A of the 00 diffraction be 1.5 or less. For example, when groove processing is performed with a dicing saw, a diamond grinder of # 1000 to # 2000 is used. Using a rotary blade to which grains are fixed, the processing speed is 15 mm / sec or less, preferably 5 mm / sec.
When grooving is performed by blasting, since the processing pressure applied to the side surface of the partition wall 1 is relatively small, 4 kg of particles such as sand, glass, and ceramics are used.
/ Cm ² may be applied.

The groove processing is not limited to the method and conditions described above, and any method and condition may be used as long as the ratio (B / A) can be set to 1.5 or less.

Next, after masking necessary portions of the flow path member 3, the driving electrodes 4 are applied along the longitudinal direction of both side surfaces of each partition 1 from the rear end of the flow path 2. Lead wires 9 are continuously connected to the end, respectively, by a film forming means such as a vapor deposition method, a sputtering method, and a plating method, by using metals such as platinum, gold, palladium, rhodium, nickel, and aluminum, or platinum-gold, palladium-silver, It is coated and formed using an alloy mainly composed of platinum-palladium or the like.

As means for energizing the driving electrode 4, a through-hole conductor is formed on the top plate 5, which will be described later, and a conductor film communicating with the driving electrode 4 is formed on the top surface of the partition wall 1. In addition, when the top plate 5 is joined to the top surface of the partition 1, conduction may be achieved by directly contacting the through-hole conductor of the top plate 5 and the conductor film on the top surface of the partition.

Thereafter, a top plate 5 made of an insulating material such as ceramics, glass, or silicon and provided with ink supply holes 6 for introducing ink into each flow path 2 is attached to the top of each partition 1 with an adhesive or the like. A nozzle plate 8 made of ceramics, glass, silicon, resin, or the like, provided with an ink discharge hole 7 communicating with each flow path 2 is attached to an open end of the flow path member 3 with an adhesive or glass. By joining them, the head 10 shown in FIG. 1 can be obtained.

By the way, in the head 10 shown in FIG. 1, an example is shown in which the entire flow path member 3 constituting the partition 1 is integrally formed of piezoelectric ceramics, but only the partition 1 is formed of piezoelectric ceramics. Needless to say, it may be.

Regarding the structure and shape of the head 10,
Needless to say, improvements and modifications can be made without departing from the scope of the present invention. For example, although not shown, the nozzle plate 8 in FIG. As shown in FIG. 4, a head having an ink ejection hole at the bottom of the flow path 2, or a nozzle plate 8 shown in FIG. The head 20 in which the ink supply holes 16 are provided in the flow path member 3 or, as shown in FIG. 5, the top of the partition walls 1 in FIG. Of the tetragonal 002 diffraction peak B measured by X-ray diffraction
Another partition member 11 made of piezoelectric ceramics having a ratio (B / A) to the peak intensity A of zero diffraction of 1.5 or less is joined with an adhesive such as epoxy, and the joined partition 1
It is also possible to provide the head 30 in which the driving electrode 14 is formed on the side surface of the partition member 11 along the longitudinal direction thereof. In particular, when a voltage is applied to the driving electrode 14, the head 30 shown in FIG. 5 can be bent and displaced in a large U-shape around the joint between the partition 1 and the partition member 11. The ejection characteristics (ejection speed and ejection amount) of ink droplets can be improved as compared with the head 10 shown in FIG.

Next, another embodiment of the present invention will be described.

FIG. 6 shows a structure similar to that of FIG. 1 except that the top surface of the partition wall 1 is provided with a lead wire 19 which communicates with the driving electrodes 4 provided on both side surfaces of the partition wall 1 and extends to the end of the flow path member 3. When the ratio (B / A) of the peak intensity B of the tetragonal 002 diffraction and the peak intensity A of the tetragonal 200 diffraction when the side surface of the partition wall 1 is measured by X-ray diffraction is 1.5 or less. And a tetragonal crystal 2 when the top surface of the partition wall 1 is measured by X-ray diffraction.
The ratio (A / B) of the peak intensity A of the 00 diffraction and the peak intensity B of the tetragonal 002 diffraction is 1.5 or less.

According to the head 40, not only does the crystal axis forming the side surface of the partition wall 1 made of piezoelectric ceramics expand and contract, but also the crystal forming the top surface of the partition wall 1 has no distortion and the degree of polarization is reduced. When the partition wall 1 is bent and displaced, the original displacement amount of the partition wall 1 is obtained. As with the head 10 shown in FIG. It is possible to prevent a decrease in speed, and to print accurate characters and images according to information.

That is, the expansion and contraction of the crystal axis on the side surface of the partition wall 1 is as described above, but the head 4 shown in FIG.
In the case where the lead wire 19 is formed on the top surface of the partition wall 1 as in the case of 0, the distortion of the crystal constituting the top surface of the partition wall 1 that has been distorted due to the polarization treatment may be removed. This is because when the driving electrode 4 and the lead wire 19 are formed on the partition 1, the partition 1
Is covered with a metal film from the side surface to the top surface, and the metal film located on the side surface of the partition 1 is used as the driving electrode 4, and the center of the metal film located on the top surface of the partition 1 is set along the longitudinal direction thereof. For example, the lead wire 19 is formed by removal by laser processing, but the heat of this laser beam eliminates the expansion and contraction of the crystal axis constituting the top surface of the partition wall 1. Is small or the proportion of crystals that expand and contract is small, the degree of polarization treatment is small, and the original displacement amount of the partition wall 1 cannot be obtained. Since the above-described piezoelectric ceramic having two crystal phases of tetragonal and rhombohedral is used for the partition 1, the partition 1 made of the piezoelectric ceramic polarized in the height direction is used.
Is measured by X-ray diffraction, the peak intensity A of the tetragonal 200 diffraction shown in the chart of FIG.
And the peak intensity B of the tetragonal 002 diffraction are observed, and the ratio (A / B) of those peak intensities located in the range of the diffraction angle of 40 ° to 50 ° is obtained, whereby the crystal constituting the top surface of the partition wall 1 is obtained. The degree of expansion and contraction of the axis can be confirmed, and by setting the ratio (A / B) to 1.5 or less, the expansion and contraction of the crystal axis can be prevented from being removed, and the original displacement amount of the partition wall 1 can be obtained. .

The partition 1 of the head 20 shown in FIG.
To make the ratio (A / B) of the peak intensity A of the tetragonal 200 diffraction and the peak intensity B of the tetragonal 002 diffraction when the top surface of the sample is measured by X-ray diffraction 1.5 or less As a type of laser for removing the metal film, a YAG laser, an excimer laser, or the like may be used. For example, when a xima laser is used, 400 mJ of 20 to 50 pulses is used.
/ Cm ² energy may be output. Note that the means for forming the lead wire 19 is not limited to the above-described means, and any means may be used as long as the ratio (A / B) can be set to 1.5 or less.

As in these embodiments, according to the present invention, when the side surface of the partition wall 1 which is polarized in the height direction and the electric field is formed in the thickness direction by the driving electrode 4 is measured by X-ray diffraction. 002 diffraction peak intensity B and tetragonal 20
The ratio (B / A) to the peak intensity A of the zero diffraction is set to 1.5 or less to suppress expansion and contraction of the crystal constituting the side surface of the partition 1,
The peak intensity A of the tetragonal 200 diffraction and the peak of the tetragonal 002 diffraction when the top surface of the partition wall 1 polarized in the height direction and an electric field is formed in the thickness direction by the driving electrode 4 are measured by X-ray diffraction. The ratio (A / B) to the strength B is 1.5 or less,
By preventing the distortion of the crystal constituting the top surface of the partition 1 from being removed, a predetermined amount of displacement can be obtained by bending and displacing the partition 1, and the discharge characteristics (discharge amount and discharge speed) of the ink droplet can be improved. The drop can be prevented.

[0041]

(Example 1) A piezoelectric ceramic body containing lead zircon titanate as a main component was prepared, polarized in advance in the thickness direction, and then a dicing saw was used to form a groove having a groove width of 70 μm, a groove depth of 400 μm, and a pitch of 141 μm. A groove was formed, and a plurality of grooves formed by the groove processing were used as ink flow paths, and a flow path member was formed in which a wall constituting the flow path was used as a partition.

However, in the groove processing, the degree of expansion and contraction of the crystal axis constituting the side surface of the partition is changed by changing the type of the rotary blade and the processing speed, and the side surface of the partition is measured by X-ray diffraction. 002 diffraction peak intensity B of
Fourteen flow path members having different ratios (B / A) between the peak intensity A and the peak intensity A of tetragonal 200 diffraction were prepared.

In measuring the ratio (B / A) between the peak intensity B of the tetragonal 002 diffraction and the peak intensity A of the tetragonal 200 diffraction, Rigaku RINT1400V type X-ray diffraction was used, and the X-ray source was Cu. X-ray tube voltage of 50 kV, tube current of 200 mA, biaxial vertical goniometer with step width of 0.020 °, peak intensity of tetragonal 200 diffraction appearing in the range of diffraction angle 40 ° to 50 ° A and peak intensity B of tetragonal 002 diffraction were measured and calculated.

Next, on both side surfaces of the partition wall of each flow path member, drive electrodes made of Au were formed by a sputtering method along the longitudinal direction. The size of the driving electrode is 200 μm in the depth direction of the flow channel, and 1 μm in the longitudinal direction of the flow channel.
It was a 0 mm strip shape.

Thereafter, an alumina ceramic top plate having an ink supply hole is joined to the top of the partition wall of the flow path member with an epoxy-based adhesive, and each flow path member is attached to the open end of the flow path member. An ink jet printer head was obtained by joining a nozzle plate made of a polyimide resin having an ink discharge hole communicating with the path with an epoxy adhesive.

Then, each of the manufactured heads is cut in parallel with the flow path by a dicing saw so that the partition walls can be observed, and the drive electrodes of these heads are energized to bend and displace the partition walls. The displacement was measured.

The driving frequency for the partition is a sine wave 120.
kHz, the input on the negative electrode side was cut off, a voltage of 30 V was applied only to the positive electrode side, and the displacement at the center of the side wall of the partition at this time was measured using a laser displacement meter.

The results are as shown in Table 1.

[0049]

[Table 1]

As a result, as can be seen from Table 1, the tetragonal crystal 0
When the ratio (B / A) of the peak intensity B of the 02 diffraction and the peak intensity A of the tetragonal 200 diffraction is 1 or less, a large displacement is obtained. However, when the ratio (B / A) exceeds 1, the displacement gradually increases. The amount of displacement decreased, and when the ratio (B / A) exceeded 1.5, the amount of displacement decreased to less than 30 nm.

The required 6 m / s for the head
In order to satisfy the ejection speed of the ink droplets equal to or higher than ec, the displacement amount of the partition wall needs to be 30 nm or more. Therefore, the ratio of the peak intensity B of the tetragonal 002 diffraction to the peak intensity A of the tetragonal 200 diffraction ( B / A) may be set to 1.5 or less,
Preferably, by setting the ratio (B / A) to 1 or less, the partition wall 1
As a result, the original displacement amount of the ink droplet was obtained, the ejection amount and ejection speed of ink droplets could be increased, and the reliability of the head could be improved.

(Example 2) Next, a piezoelectric ceramic body containing lead zircon titanate as a main component was prepared, polarized in advance in the thickness direction, and the groove width was set to 70 μm with a dicing saw.
m, a groove depth of 400 μm, and a pitch of 141 μm were processed, and a plurality of grooves formed by the groove processing were used as ink flow paths, and a flow path member having walls constituting the flow paths as partition walls was manufactured.

In the groove processing, however, the type of the rotary blade and the processing speed were adjusted, and the peak intensity B of the tetragonal 002 diffraction and the tetragonal 002 diffraction when the side surfaces of the partition were measured by X-ray diffraction.
The ratio (B / A) to the peak intensity A of the zero diffraction was set to 0.981.

Next, a metal film made of Au is coated on the side surface and the top surface of the partition wall of the obtained flow path member by a sputtering method, and the metal film formed on the side surface of the partition wall is used as a driving electrode and the partition wall is formed. The center of the metal film formed on the top surface was removed with an excimer laser to form a lead line.

However, in forming the lead line, the degree of expansion and contraction of the crystal axis constituting the top surface of the partition is changed by changing the output value of the excimer laser, and the top surface of the partition is measured by X-ray diffraction. Of the peak intensity A of the tetragonal 200 diffraction and the peak intensity B of the tetragonal 002 diffraction (A
Fourteen kinds of flow path members having different / B) were prepared.

Thereafter, an alumina ceramic top plate having an ink supply hole is joined to the top of the partition wall of the flow path member with an epoxy-based adhesive, and each flow path member is attached to the open end of the flow path member. An ink jet printer head was obtained by joining a nozzle plate made of a polyimide resin having an ink discharge hole communicating with the path with an epoxy adhesive.

Then, each of the manufactured heads is cut in parallel with the flow path by a dicing saw so that the partition walls can be observed, and the drive electrodes of these heads are energized to bend and displace the partition walls. The displacement was measured under the same conditions as in Example 1.

The results are as shown in Table 2.

[0059]

[Table 2]

As a result, as can be seen from Table 2, the tetragonal crystal 2
When the ratio (A / B) between the peak intensity A of the 00 diffraction and the peak intensity B of the tetragonal 002 diffraction (A / B) is 1 or less, a large displacement is obtained, but when the ratio (A / B) exceeds 1, the displacement gradually increases. The amount of displacement decreased, and when the ratio (A / B) exceeded 1.5, the amount of displacement decreased to less than 30 nm.

Therefore, the required 6 m / s for the head
In order to satisfy the ink droplet ejection speed of ec or more, the ratio (A / B) between the peak intensity A of the tetragonal 200 diffraction and the peak intensity B of the tetragonal 002 diffraction may be 1.5 or less, which is preferable. By setting the ratio (A / B) to 1.0 or less, the displacement originally possessed by the partition can be obtained, the ejection amount and ejection speed of ink droplets can be increased, and the reliability of the head can be improved. did it.

[0062]

As described above, according to the present invention, there are provided a plurality of partition walls made of piezoelectric ceramics arranged side by side, and a flow path member which serves as an ink flow path between the partition walls, and a top portion of the partition walls. And a top plate closing each flow path, and in an ink jet printer head provided with driving electrodes on both side surfaces of each of the partition walls, a square when measuring the side surfaces of the partition walls by X-ray diffraction. 002 diffraction peak intensity B and tetragonal 2
The ratio (B / A) to the peak intensity A of the 00 diffraction is set to 1.5 or less, or the peak intensity A of the tetragonal 200 diffraction and the tetragonal crystal when the top surface of the partition is measured by X-ray diffraction. 00
By setting the ratio (A / B) to the peak intensity B of the two diffractions to 1.5 or less, when the head is driven, a large slip vibration is generated in the partition by the shear mode, and the original displacement of the partition , It is possible to prevent a decrease in the ejection amount and ejection speed of the ink droplets, thereby printing accurate characters and images according to the information.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing an example of an ink jet printer head according to the present invention.

FIGS. 2A and 2B are partial cross-sectional views for explaining a driving principle of an ink jet printer head according to the present invention.

FIG. 3 is a chart of a side surface of a partition wall made of piezoelectric ceramics polarized in a height direction when measured by X-ray diffraction.

FIG. 4 is a partially cutaway perspective view showing another example of the ink jet printer head according to the present invention.

FIG. 5 is a partially cutaway perspective view showing still another example of the ink jet printer head according to the present invention.

FIG. 6 is a partially cutaway perspective view showing an inkjet printer head according to another embodiment of the present invention.

FIG. 7 is a chart when the top surface of a partition wall made of piezoelectric ceramics polarized in a height direction is measured by X-ray diffraction.

FIG. 8 is a partially cutaway perspective view showing a conventional inkjet printer head.

[Explanation of symbols]

1, 51: partition wall 2, 52: flow path 3, 53: flow path member 4, 14, 54: drive electrode 5, 55: top plate 6, 16, 56: ink supply hole 7, 17, 57: ink discharge Holes 8, 18, 58: Nozzle plate 9, 19, 59: Leader
11: cover plate 10, 20, 30, 40, 50: inkjet printer head

Claims (2)

[Claims] 1. A flow path member having a plurality of partition walls made of piezoelectric ceramics arranged side by side, the flow path member serving as an ink flow path between the partition walls, and a top plate joined to the top of the partition walls to close each flow path. Having a drive electrode on both sides of each partition,
In the ink jet printer head which pressurizes the ink in each flow path by applying a current to the driving electrode to bend and displace the partition, and ejects ink droplets from the ink discharge holes communicating with the respective flow paths, the side face of the partition is Peak intensity B of tetragonal 002 diffraction measured by X-ray diffraction and tetragonal 200
An ink jet printer head, wherein the ratio (B / A) to the diffraction peak intensity A is 1.5 or less. 2. A flow path member having a plurality of partition walls made of piezoelectric ceramics arranged side by side, the flow path member serving as an ink flow path between the partition walls, and a top plate joined to the top of the partition walls to close each flow path. And a driving electrode provided on both side surfaces of each partition, and a lead wire of the driving electrode provided on a top surface of each partition, and a current is supplied to the driving electrode to bend the partition. In an ink jet printer head that pressurizes ink in each flow path by displacing and ejects ink droplets from ink ejection holes communicating with each flow path, a square when the top surface of the partition is measured by X-ray diffraction An inkjet printer head, wherein the ratio (A / B) between the peak intensity A of 200-crystal diffraction and the peak intensity B of tetragonal 002 diffraction is 1.5 or less.