JP2988265B2 - Ink jet printer head and driving method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer head for an ink-jet printer, and more particularly to an ink-jet printer head using a piezoelectric element for converting an electric signal into mechanical energy as ink discharging means, and a method of driving the same.

[0002]

2. Description of the Related Art In general, as a printer used as an output device of OA equipment such as a word processor and a personal computer, a drop-on-demand type ink jet printer head using a piezoelectric strain element as a printer head is known. This drop-on-demand type ink jet printer head is provided with a piezoelectric strain element which is deformed by a signal in a container provided with an ink pool, and the pressure generated when the piezoelectric strain element is deformed causes ink in the ink pool to fly by droplets and print. And is widely used in printers of various OA devices. Techniques that employ this type of inkjet printer head include, for example,
There are ink jet heads described in JP-A-5-242189 and JP-A-3-272856.

[0003] A typical drop-on-demand type ink jet printer head of this type will be described below with reference to the drawings. FIG. 6 is a partially sectional perspective view showing a conventional drop-on-demand type ink jet printer head. 7 and 8 are partial sectional views showing the operation of a conventional ink jet printer head.

As shown in these figures, a conventional ink jet printer head has an ink reservoir 11 in which ink is stored, and an ink flow path for independently supplying ink in the ink reservoir 11 to a plurality of nozzles 14. 12,
An ink container 10 comprising a pressurized chamber 13 provided in the middle of the ink flow path 12 and a plurality of nozzles 14 for discharging ink supplied from the ink flow path 12 through the pressurized chamber 13 to the outside. And a vibrating plate 20 that forms one side wall of the ink container 10, and pressurizes a pressurizing chamber 13 that is disposed in contact with the vibrating plate 20 and communicates with each nozzle 14 of the ink container 10 to discharge ink. Discharge, slit 100a
And a comb-shaped piezoelectric strain element 100 formed with.

[0005] Each nozzle 14
Are connected to each other, and each signal line is connected to an electronic device (not shown). Then, the piezoelectric strain element 100 is displaced by the print signal from each signal line, and the pressure due to the displacement is transmitted to the ink via the vibration plate 20 and the pressurizing chamber 13, and the ink is dropletized from each nozzle 14. It is designed to fly.

Next, the operation of the conventional ink jet printer head having such a configuration will be described.
First, as shown in FIG. 7, normally, the ink stored in the ink reservoir 11 is supplied to the nozzle 14 through the ink flow path 12.
Is filled up to the tip. At this time, a print signal from an electronic device (not shown) is transmitted to each signal line 40, 50.
Is sent to the piezoelectric strain element 100 through the piezoelectric strain element 100, a potential is generated between the electrodes of the piezoelectric strain element 100, and the piezoelectric strain element 1
00 is displaced in the direction of arrow A shown in FIG. Then, due to the displacement of the piezoelectric strain element 100, the diaphragm 20 is deformed toward the nozzle 14 as shown in FIG.

As a result, the ink in the pressurizing chamber 13 is pressurized, and the ink is ejected from the tip of the nozzle 14 as an ink droplet in the direction of arrow B shown in FIG. 8 to print one dot. Thereafter, the potential stored in the piezoelectric strain element 100 is discharged, so that the piezoelectric strain element 100 and the diaphragm 20
Returns to the original state, the amount of ink discharged as ink droplets is filled into the pressurizing chamber 13 from the ink reservoir 11 via the ink flow path 12, and returns to the original state (the state of FIG. 7).
As described above, in a conventional ink jet printer head using a piezoelectric strain element, printing is performed by repeating the above-described series of operations at a high speed.

[0008] In addition to the above-described ink discharging method, the piezoelectric strain element 1
00 in the direction opposite to the arrow A direction shown in FIG.
The pressurizing chamber 13 is previously filled with an amount of ink to be ejected as ink droplets from the ink reservoir 11 via the ink flow path 12, and then the piezoelectric strain element 100 is returned to its original state by discharging to discharge the ink. A discharging method (generally called a pulling method) is also employed.

[0009]

In general, in an ink jet printer head using a piezoelectric strain element, it is necessary to increase the pressurizing speed for ink in order to obtain high-speed and stable ink ejection. For this reason, in the conventional ink jet printer head, the length of the piezoelectric strain element 100 in the pressing direction (the value of h shown in FIG. 7A) and the height of the surface perpendicular to the pressing direction of the piezoelectric strain element 100 are determined. Cross-sectional area (cross-sectional area in FIGS. 7A and 7B = t ×
The problem was dealt with by increasing w).

However, with the recent miniaturization of printer heads along with the reduction in size and weight of OA equipment, the cross-sectional area of the surface of the piezoelectric strain element perpendicular to the pressing direction is limited to a certain size. As a result, the force, the piezoelectric strain element and the slit had to be elongated in the pressing direction. As a result, the piezoelectric strain element has a shape that is easily damaged by buckling or bending during manufacture or use, and the life of the printer head itself is shortened, and the reliability of the product is impaired. In addition, since it is generally difficult to process (slit) the piezoelectric strain element into an elongated shape in the pressing direction, there is also a serious problem of causing a defect during processing of the piezoelectric element.

The present invention has been proposed in order to solve the problems of each of the conventional techniques, and can reduce the length of the slit of the piezoelectric strain element in the pressing direction. As a result, an object of the present invention is to provide an inkjet printer head in which slit processing is facilitated and the piezoelectric strain element is less likely to be damaged during use, and a method of driving the inkjet printer head.

[0012]

According to a first aspect of the present invention, there is provided an ink-jet printer head which presses ink in two or more ink flow paths by using a piezoelectric strain element. In an ink jet printer head that discharges as ink droplets from two or more nozzles respectively communicating with the two or more ink flow paths,
At least one wall of the ink flow path is formed as a diaphragm, and the piezoelectric strain element is
Two or more first contacts with the diaphragm of the ink flow path
Piezoelectric element and these two or more first piezoelectric elements
The first piezoelectric element formed with the formed second piezoelectric element.
The element controls each of the diaphragms of the two or more ink flow paths.
Independently displaced and the second piezoelectric element is
All of the two or more first piezoelectric elements are simultaneously displaced .

According to a second aspect of the present invention, there is provided a method of driving an ink jet printer head according to the first aspect, wherein the second piezoelectric element is displaced so that the two or more inks are displaced. Pressurize all the flow paths, and displace the first piezoelectric element corresponding to the ink flow path with which the nozzles that perform ink discharge communicate in the same direction as the second piezoelectric element. A driving method is characterized in that ink is ejected by the sum of the displacement and the displacement of the first piezoelectric element.

Further, a method of driving an ink-jet printer head according to claim 3 is the method of driving an ink-jet printer head according to claim 1, wherein the second piezoelectric element is displaced and the two or more inks are moved. All the flow paths are pressurized, and ink is discharged only by displacement of the second piezoelectric element. The first piezoelectric element corresponding to an ink flow path to which a nozzle that does not discharge ink communicates is used as the second piezoelectric element. Displace in the direction opposite to the displacement direction of the element,
A driving method is characterized in that the displacement of the first piezoelectric element does not cause the displacement of the second piezoelectric element to reach the displacement required for ink ejection, and ink ejection is not performed.

Further, a driving method of an ink jet printer head according to a fourth aspect is the method of driving an ink jet printer head according to the first aspect, wherein the second piezoelectric element is displaced to move the two or more piezoelectric elements. Pressurizing all ink flow paths, and displacing the first piezoelectric element corresponding to the ink flow path to which the nozzle for discharging ink communicates in the same direction as the second piezoelectric element; The ink is ejected by the sum of the displacement of the first piezoelectric element and the displacement of the first piezoelectric element, and the displacement direction of the second piezoelectric element is changed by moving the first piezoelectric element corresponding to the ink flow path to which the nozzle not performing the ink discharge communicates. The ink is not ejected so that the displacement of the first piezoelectric element does not cause the displacement of the second piezoelectric element to reach the displacement required for ink ejection. There the driving method characterized.

According to a fifth aspect of the present invention, there is provided a method of driving an ink jet printer head, wherein the piezoelectric strain element presses the diaphragms of the two or more ink flow paths independently from one side wall, A method for driving an ink jet printer head comprising: a second piezoelectric element that presses the entire vibration plate of the two or more ink flow paths from another wall portion, wherein the second piezoelectric element is displaced to The first piezoelectric element corresponding to the ink flow path to which the nozzles for discharging ink are communicated is displaced in a direction opposite to that of the second piezoelectric element. A driving method is characterized in that ink is ejected by the sum of the displacement of the element and the displacement of the first piezoelectric element.

Further, in the driving method of the ink jet printer head according to the present invention, the piezoelectric strain element presses the diaphragms of the two or more ink flow paths independently from one side wall, A method for driving an ink-jet printer head comprising a second piezoelectric element for pressing the entire vibration plate of the two or more ink channels from another wall portion, the method for driving an ink-jet printer head, The two piezoelectric elements are displaced to pressurize all the two or more ink flow paths, and the ink is discharged only by the displacement of the second piezoelectric element, and the ink flow path corresponding to the ink flow path where the nozzles that do not discharge the ink are connected. The first piezoelectric element is displaced in the same direction as the displacement direction of the second piezoelectric element, and the displacement of the second piezoelectric element is caused by the displacement of the first piezoelectric element. So as not to reach the required displacement to the ink ejection is a driving method characterized in that it does not perform ink ejection.

Further, according to a seventh aspect of the present invention, in the method for driving an ink jet printer head, the piezoelectric strain element comprises:
A first piezoelectric element that independently presses the diaphragm of two or more ink flow paths from one side wall, and a second piezoelectric element that presses the entire diaphragm of the two or more ink flow paths from another wall. A method of driving an ink jet printer head comprising: displacing the second piezoelectric element to pressurize all of the two or more ink flow paths, and corresponding to an ink flow path to which nozzles for discharging ink communicate. The first piezoelectric element is displaced in a direction opposite to that of the second piezoelectric element, and ink is ejected by the sum of the displacement of the second piezoelectric element and the displacement of the first piezoelectric element. The first piezoelectric element corresponding to the ink flow path with which no nozzle communicates is displaced in the same direction as the displacement direction of the second piezoelectric element, and the displacement of the first piezoelectric element causes the displacement of the second piezoelectric element. Displacement is ink Is not performed to the ink discharge so as not to reach the required displacement out there as a driving method, wherein.

[0019]

According to the ink jet printer head according to the first to fourth aspects, a nozzle for discharging ink is
By forming a piezoelectric strain element that pressurizes the ink flow path to which this nozzle communicates, a piezoelectric element that pressurizes each ink flow path and a piezoelectric element that pressurizes the entirety are integrally formed, Displacement can be transmitted without loss. Also, according to the ink jet printer head according to the fifth to seventh aspects, the displacement of the piezoelectric element can be directly transmitted without loss from different directions of the plurality of ink flow paths.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ink jet printer head of the present invention will be described below with reference to the drawings. FIG.
1 is a partially sectional perspective view showing a first embodiment of an ink jet printer head of the present invention. Here, in the ink jet printer head of the present invention, the piezoelectric strain element is a first piezoelectric element that independently pressurizes each of the ink flow paths to which two or more nozzles communicate, and the entire ink flow path is pressurized. It is characterized in that it is constituted by a second piezoelectric element, and the other parts are the same as those of the conventional ink jet printer head shown in FIG. Therefore, the same parts as those in the related art are denoted by the same reference numerals, and detailed description is omitted.

As shown in FIG. 1, the ink jet printer head of this embodiment has an ink reservoir 11 in which ink is stored, and an ink flow which supplies ink in the ink reservoir 11 to a plurality of nozzles 14 independently of each other. Road 12,
An ink container 10 comprising a pressurized chamber 13 provided in the middle of the ink flow path 12 and a plurality of nozzles 14 for discharging ink supplied from the ink flow path 12 through the pressurized chamber 13 to the outside. And a vibration plate 20 that forms one side wall of the ink container 10, is disposed in contact with the vibration plate 20, and is independently supplied from the ink flow path 12 to each nozzle 14 of the ink container 10. And a comb-shaped piezoelectric strain element 30 having a slit 31a formed therein for pressurizing the ink.

The driving piezoelectric strain element 30 for discharging ink in the ink flow path 12 includes a first piezoelectric element 31 that can be driven for each ink flow path 12 and two or more ink flow paths 12. A second piezoelectric element 32 that is driven in common, and one side of the first piezoelectric element 31
A second piezoelectric element 32 is disposed so as to be in contact with the vibration plate 20 forming the wall of “0” and to be connected to the other side. The first piezoelectric element 31 has a comb shape in which a slit 31a is formed, and each end of the comb shape contacts the diaphragm 20 so as to correspond to the position of the plurality of nozzles 14, respectively. The piezoelectric element 32 is formed as a single unit without a slit.

The first piezoelectric element 31 and the second piezoelectric element 32 have independent individual signal lines 40a,
40b and a common signal line 50 are connected, and each signal line is connected to an electronic device (not shown).
The pressurizing energy of the piezoelectric strain element 30 by the print signal from each signal line is transmitted to the diaphragm 20 and the pressurizing chamber 13.
Through each nozzle 14
The ink is made to drop and fly.

Next, an embodiment of a method for driving the ink jet printer head according to the present embodiment having the above-described configuration will be described with reference to FIG. First, since the ink is normally filled from the ink reservoir 11 of the ink container 10 to the nozzle 14 through the ink flow path 12, in this state, each signal line 4 is connected to the piezoelectric strain element 30.
Print signals are input from 0a, 40b and 50. When a print signal is input, a potential difference is generated between each of the first piezoelectric element 31 and the second piezoelectric element 32, and each piezoelectric element generates a displacement according to the potential difference. Pressure is applied via the vibration plate 20, and ink is ejected from the tip of the nozzle 14.

Here, as the driving method of the piezoelectric strain element 30 at the time of printing, there are the following three modes depending on the combination of the displacement amount and the displacement direction of the first piezoelectric element 31 and the second piezoelectric element 32. is there. Driving method 1 A structure in which ink is not ejected only by displacement of the first piezoelectric element 31 or the second piezoelectric element 32 is provided, and a nozzle 14 for ejecting ink corresponds to the pressurizing chamber 13 to which the nozzle 14 communicates. By driving the first piezoelectric element 31 in the same direction as the second piezoelectric element 32, the first piezoelectric element 3
Printing is performed by discharging ink with the sum of the displacement of the first piezoelectric element 32 and the displacement of the second piezoelectric element 32. That is, the second piezoelectric element 32
A bias pressure is applied to all of the plurality of ink flow paths, and the first piezoelectric element 31 corresponding to the ink flow path to which the nozzle for discharging ink communicates is displaced in the same direction as the second piezoelectric element 32. Is performed.

Driving method 2 The ink is ejected only by driving the second piezoelectric element 32, and the nozzle 14 that does not eject ink is
The first piezoelectric element 31 corresponding to the pressurizing chamber 13 with which the nozzle 14 communicates is displaced in the direction opposite to the direction of displacement of the second piezoelectric element 32, and the displacement of the first piezoelectric element 31 and the second piezoelectric element Printing is performed by adopting a configuration in which the sum of the displacements of the elements 32 does not reach the displacement required for ink ejection. That is, the second piezoelectric element 32 applies pressure to all of the plurality of ink flow paths to discharge ink, and the first piezoelectric element 31 corresponding to the ink flow path to which the nozzle not performing ink discharge communicates. The ink is not ejected by being displaced in the direction opposite to that of the second piezoelectric element 32.

Driving method 3 First piezoelectric element 3 corresponding to nozzle for discharging ink
1 is displaced in the same direction as the displacement direction of the second piezoelectric element 32, and ink is ejected by the sum of the displacements of the first piezoelectric element 31 and the second piezoelectric element 32. Further, the first piezoelectric element 31 corresponding to the pressurizing chamber 13 to which the nozzle 14 not performing ink discharge communicates is displaced in the direction opposite to the direction of displacement of the second piezoelectric element 32, and the piezoelectric element 31 Element 32
The printing is performed by a configuration in which the sum of the displacements does not reach the displacement required for ink ejection. That is, the second piezoelectric element 32 applies a bias pressure to all of the plurality of ink flow paths, and replaces the first piezoelectric element 31 corresponding to the ink flow path with which the nozzle for discharging ink communicates with the second piezoelectric element 3.
The ink is ejected while being displaced in the same direction as 2. Then, the first piezoelectric element 31 corresponding to the ink flow path to which the nozzle that does not perform ink discharge communicates is replaced with the second piezoelectric element 3.
No ink is ejected by displacing in the direction opposite to 2.

As described above, according to the ink jet printer head of this embodiment, the displacement of the first piezoelectric element 31 and the displacement of the second piezoelectric element 32 are combined, and the second piezoelectric element 32 is connected to two or more nozzles. In this case, the first piezoelectric element 31 and the slit 31a of the first piezoelectric element 31 are compared with a case where one nozzle is driven by one piezoelectric element by enabling common driving to eject ink. The length in the pressing direction (the value of h shown in FIG. 2B) can be reduced. Thereby, the pressing speed can be increased without making the piezoelectric strain element elongated in the pressing direction as in the related art, and the slit 31a of the piezoelectric strain element 30 can be increased.
Processing becomes easy, and breakage of the piezoelectric strain element during driving or the like can be greatly reduced.

Next, a second embodiment of the ink jet printer head of the present invention will be described with reference to FIG. As shown in the figure, in the present embodiment, opposing walls of the ink container 10 are formed as diaphragms 20 and 21, respectively, and a first piezoelectric element 31 and a second piezoelectric element 32 are The diaphragms 20 and 21 are arranged so as to come into contact with each other.

In this case as well, the ink in the pressurizing chamber 13 is applied by a combination of the displacement amounts of the first piezoelectric element 31 and the second piezoelectric element 32, similarly to the driving method in the first embodiment described above. By applying pressure, ink droplets can be ejected from desired nozzles 14 to perform printing. However, in the case of the present embodiment, since the first piezoelectric element 31 is opposed to the second piezoelectric element 32, the first piezoelectric element 31
Are all opposite to those in the driving method of the first embodiment.

Next, a third embodiment of the present invention will be described with reference to FIG. In the first embodiment described above, the first piezoelectric element 31
And the second piezoelectric element 32 are formed by bonding separately molded parts. In this embodiment, as shown in FIG. 4, the piezoelectric strain elements 30 are stacked (two or more layers). After molding and firing, the first piezoelectric element 31 and the second piezoelectric element 32 are integrally molded by processing a slit 31a having a predetermined length. Accordingly, the piezoelectric strain element 30 can be structured without requiring assembly, and the efficiency of the manufacturing operation of the piezoelectric strain element 30 can be improved.

As shown in FIGS. 4 (a) and 5 (a), the laminating direction of the piezoelectric strain element 30 may be perpendicular to the pressing direction (the state shown in FIG. 4 (a)). Alternatively, it may be parallel to the pressing direction (the state shown in FIG. 5A), but if the number of laminating steps is small (the state shown in FIG. 5A),
This has the effect of keeping costs low. Needless to say, the stacking direction of the piezoelectric strain elements 30 can be appropriately selected for any of the printer heads in the first and second embodiments described above.

[0033]

As described above, according to the ink jet printer head and the method of driving the ink jet printer head of the present invention, the displacement of the first and second piezoelectric elements is transmitted to the vibration plate of the ink flow path without loss. And high-speed and accurate printing can be performed.

[Brief description of the drawings]

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

2A and 2B show a first embodiment of the ink jet printer head of the present invention, wherein FIG. 2A is a side sectional view and FIG. 2B is a front sectional view.

3A and 3B show a second embodiment of the ink jet printer head of the present invention, wherein FIG. 3A is a side sectional view and FIG. 3B is a front sectional view.

4A and 4B show a third embodiment of the ink jet printer head of the present invention, wherein FIG. 4A is a side sectional view and FIG. 4B is a front sectional view.

5 (a) is a side sectional view, and FIG. 5 (b) is a front sectional view showing a third embodiment of the ink jet printer head of the present invention.

FIG. 6 is a partially sectional perspective view showing a conventional ink jet printer head.

7 (a) is a side sectional view and FIG. 7 (b) is a front sectional view showing an operation state of a conventional ink jet printer head.

8 (a) is a side sectional view and FIG. 8 (b) is a front sectional view showing an operation state of a conventional ink jet printer head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Ink container 11 ... Ink pool 12 ... Ink flow path 13 ... Pressurizing chamber 14 ... Nozzle 20 ... Vibrating plate 21 ... Vibrating plate 30 ... Piezoelectric strain element 31 ... First piezoelectric element 31a ... Slit 32 ... Second piezoelectric Element 40: individual signal line 40a: individual signal line 40b: individual signal line 50: common signal line 100: conventional piezoelectric strain element

Claims (7)

(57) [Claims] An ink jet printer that pressurizes ink in two or more ink flow paths by a piezoelectric strain element and discharges the ink as ink droplets from two or more nozzles respectively communicating with the two or more ink flow paths. In the head, at least one wall portion of the ink flow path is formed as a vibration plate, and the piezoelectric strain element is driven by the vibration of the two or more ink flow paths.
Two or more first piezoelectric elements each contacting the plate, and
A second pressure formed integrally with the two or more first piezoelectric elements.
And the first piezoelectric element is configured to vibrate the two or more ink flow paths.
Each of the plates is displaced independently and the second
Of the two or more first piezoelectric elements are the same.
An ink jet printer head that is sometimes displaced . 2. A method for driving an ink jet printer head according to claim 1, wherein said second piezoelectric element is displaced to pressurize all of said two or more ink channels and to discharge ink. The first piezoelectric element corresponding to the ink flow path communicated with the second piezoelectric element is displaced in the same direction as the second piezoelectric element, and the ink ejection is performed by the sum of the displacement of the second piezoelectric element and the displacement of the first piezoelectric element. A method for driving an ink jet printer head. 3. The method of driving an ink jet printer head according to claim 1, wherein the second piezoelectric element is displaced to pressurize all of the two or more ink flow paths. Ink is discharged only by displacement, and the first piezoelectric element corresponding to the ink flow path to which the nozzle not performing ink discharge communicates is displaced in a direction opposite to the displacement direction of the second piezoelectric element. A method for driving the ink jet printer head, wherein the ink is not ejected so that the displacement of the second piezoelectric element does not reach the displacement required for ink ejection due to the displacement of the piezoelectric element. 4. A method for driving an ink jet printer head according to claim 1, wherein said second piezoelectric element is displaced to pressurize all of said two or more ink channels and to discharge ink. The first piezoelectric element corresponding to the ink flow path communicated with the second piezoelectric element is displaced in the same direction as the second piezoelectric element, and the ink ejection is performed by the sum of the displacement of the second piezoelectric element and the displacement of the first piezoelectric element. And displacing the first piezoelectric element corresponding to the ink flow path with which the nozzle not performing ink discharge communicates in a direction opposite to the direction of displacement of the second piezoelectric element, and displacing the first piezoelectric element. The method of driving an ink jet printer head according to claim 1, wherein the ink is not ejected so that the displacement of the second piezoelectric element does not reach the displacement required for ink ejection. 5. A first piezoelectric element in which a piezoelectric strain element independently presses a vibration plate of two or more ink flow paths from one side wall, and a whole of the two or more ink flow path vibration plates in another wall. A method for driving an ink jet printer head comprising: a second piezoelectric element pressurizing from a part, wherein the second piezoelectric element is displaced to pressurize all of the two or more ink flow paths, and discharge ink. The first piezoelectric element corresponding to the ink flow path with which the nozzle to be communicated is displaced in the direction opposite to the second piezoelectric element, and the displacement of the second piezoelectric element and the displacement of the first piezoelectric element are calculated by A method for driving an ink jet printer head, which performs ink discharge. 6. A first piezoelectric element in which a piezoelectric strain element independently presses a vibration plate of two or more ink flow paths from one side wall, and a whole of the two or more ink flow path vibration plates in another wall. And a second piezoelectric element that pressurizes from a part, wherein the second piezoelectric element is displaced to pressurize all of the two or more ink flow paths, and the second piezoelectric element is displaced. While performing ink ejection only by the displacement of the element, the first piezoelectric element corresponding to the ink flow path to which the nozzle that does not perform ink communication communicates is displaced in the same direction as the displacement direction of the second piezoelectric element. An ink jet printer head characterized in that the ink is not ejected so that the displacement of the second piezoelectric element does not reach the displacement required for ink ejection by the displacement of the first piezoelectric element. Dynamic way. 7. A first piezoelectric element in which a piezoelectric strain element independently presses a vibration plate of two or more ink flow paths from one side wall, and a whole of the two or more ink flow path vibration plates in another wall. A method for driving an ink jet printer head comprising: a second piezoelectric element pressurizing from a part, wherein the second piezoelectric element is displaced to pressurize all of the two or more ink flow paths, and discharge ink. The first piezoelectric element corresponding to the ink flow path with which the nozzle to be communicated is displaced in the direction opposite to the second piezoelectric element, and the displacement of the second piezoelectric element and the displacement of the first piezoelectric element are calculated by While discharging ink, the first piezoelectric element corresponding to the ink flow path to which the nozzle not performing ink discharge communicates is displaced in the same direction as the direction of displacement of the second piezoelectric element. Due to the displacement of The driving method of an ink jet printer head, wherein a displacement of the serial second piezoelectric element is not performed to the ink discharge so as not to reach the required displacement to ink ejection.