JP2013071423A - Liquid ejection head and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejection head capable of increasing a displacement quantity of a piezoelectric element by efficiently and simultaneously using a plurality of vibration modes.SOLUTION: A liquid ejection head 110 has an ejection port 102 ejecting a liquid and a pressure chamber 103 communicating with the ejection port 102 and extending in a longitudinal direction. A prescribed part of a sidewall of the pressure chamber 103 is defined with a partition wall 210 formed of a piezoelectric material, and while a first electrode 201 is provided to a surface of the partition wall 210 on the side of the pressure chamber, a second electrode 202 is provided to the opposite surface from the pressure chamber 103 across the first electrode 201, respectively. The partition wall 210 has a first region polarized obliquely to one side in a direction of an electric field generated by application of a voltage between the first electrode 201 and the second electrode 202 and a second region polarized obliquely to the opposite side from the one side in the direction of the electric field.

Description

  The present invention relates to a liquid discharge head using deformation of a piezoelectric element and a method for manufacturing the same.

  As a liquid discharge head using a piezoelectric element, one utilizing each vibration mode of the piezoelectric element is known. As a vibration mode, first, there is a d33 mode which is a strain / stress in a direction parallel to a direction to which an electric field is applied. On the other hand, there is a d31 mode which is a strain / stress in a direction perpendicular to the direction in which an electric field is applied. There is also a d15 mode which is a strain / stress in the shear direction with respect to the direction in which the electric field is applied. A push type is known as a liquid ejection head using the d33 mode, a bend type is known as a liquid ejection head utilizing the d31 mode, and a share mode type is known as a liquid ejection head utilizing the d15 mode. Although these use one vibration mode, the Gould type is known as one using a plurality of vibration modes simultaneously. This is because the displacement in the piezoelectric element is increased by the simultaneous expansion in the radial direction by the d33 mode and the contraction in the circumferential direction by the d31 mode. However, it has been difficult to make a plurality of discharge ports. As a solution to this problem, Patent Document 1 discloses a manufacturing method of a Gould type liquid discharge head capable of creating a large number of discharge ports by connecting piezoelectric elements.

JP 05-254132 A

  The amount of displacement of the piezoelectric element is small, and it is important to displace it efficiently.

  In the push type, the amount of displacement is increased by stacking piezoelectric elements. However, increasing the number of stacked layers not only increases the cost, but also increases the capacitance and makes driving difficult. Further, since only one surface of the pressure chamber can be displaced, the efficiency is low.

  The bend type has a small thickness in the direction in which an electric field is applied, so that the voltage can be lowered, but it is difficult to generate a large pressure. Further, since only one surface of the pressure chamber can be displaced, the efficiency is low.

  In the share mode type, a large number of discharge ports can be easily provided, but the efficiency is low because only two surfaces of the pressure chamber can be displaced. The d15 mode has a lower displacement efficiency than the other vibration modes.

  On the other hand, the Gould type is efficiently displaced by using the d33 mode and the d31 mode simultaneously. However, if a piezoelectric element provided for each discharge port is connected in order to create a plurality of discharge ports, a binding force is generated at the connecting portion, and the d31 mode does not function sufficiently. Therefore, although many discharge ports can be provided by connecting the piezoelectric elements, the vibration mode of the piezoelectric elements cannot be effectively utilized.

  An object of the present invention is to provide a liquid discharge head capable of increasing the amount of displacement of a piezoelectric element by efficiently using a plurality of vibration modes simultaneously, and a method for manufacturing the same.

  The liquid discharge head of the present invention has a discharge port for discharging a liquid and a pressure chamber that communicates with the discharge port and extends in the longitudinal direction, and a predetermined part of the side wall of the pressure chamber is made of a piezoelectric material. The partition is defined by a partition, a first electrode is provided on a surface of the partition on the pressure chamber side, and a second electrode is provided on a surface opposite to the pressure chamber with the first electrode interposed therebetween. A first region polarized to one side with respect to an electric field direction generated by applying a voltage between the first electrode and the second electrode, and the one with respect to the electric field direction. And a second region polarized opposite to the side.

  A method for manufacturing a liquid discharge head according to the present invention is a method for manufacturing a liquid discharge head having a discharge port for discharging a liquid and a pressure chamber communicating with the discharge port. A partition wall forming step for forming a partition wall defining a portion from a piezoelectric material, a polarization step for polarizing the partition wall, a first electrode on the pressure chamber side surface of the partition wall, and the pressure across the first electrode Forming a second electrode on a surface opposite to the chamber, and the polarization step and the electrode forming step include a step in which the partition wall is formed between the first electrode and the second electrode. A first region polarized to one side with respect to the electric field direction generated by applying a voltage therebetween, and a second region polarized to the opposite side to the one side with respect to the electric field direction The polarization direction and the first and second electrodes to have a region It includes adjusting the location.

  In the liquid ejection head according to the present invention, the first region polarized toward one side with respect to the electric field direction and the second region polarized toward the opposite side to the one side are formed in the pressure chamber when a voltage is applied. Is arranged to greatly contract or expand.

  In the present invention, it is possible to provide a liquid discharge head capable of increasing the amount of displacement of a piezoelectric element by efficiently using a plurality of vibration modes simultaneously and a method for manufacturing the same.

1 is a perspective view of a first embodiment of the present invention. It is an enlarged view of the area | region A of FIG. It is a figure which shows the polarization direction and electric field direction in either of area | regions B-E of FIG. It is a figure which shows the manufacturing process regarding the 1st base material of the 1st Embodiment of this invention. It is a figure which shows the manufacturing process regarding the 2nd base material of the 1st Embodiment of this invention. It is a figure which shows the polarization direction and electric field direction of the 1st Embodiment of this invention. It is a figure which shows the manufacturing process regarding the 1st base material of the 2nd Embodiment of this invention. It is a figure which shows the manufacturing process regarding the 1st base material of the 3rd Embodiment of this invention. It is a figure which shows the polarization direction and electric field direction of the 3rd Embodiment of this invention. It is a perspective view of the 4th Embodiment of this invention. It is a figure which shows the polarization direction and electric field direction of the 4th Embodiment of this invention. It is a perspective view of the 5th Embodiment of this invention. It is a figure which shows the polarization direction and electric field direction of the 5th Embodiment of this invention. It is a perspective view of the 6th Embodiment of this invention. It is a figure which shows the polarization direction and electric field direction of the 6th Embodiment of this invention. It is a perspective view of the 7th Embodiment of this invention. It is a figure which shows the polarization direction and electric field direction of the 7th Embodiment of this invention. It is a figure which shows the manufacturing process regarding the piezoelectric base material of the 7th Embodiment of this invention. It is a perspective view of the 8th Embodiment of this invention. It is a figure which shows the manufacturing process regarding the piezoelectric base material of the 8th Embodiment of this invention. It is a figure which shows the polarization direction and electric field direction of 8th-10th embodiment of this invention.

  Hereinafter, an example of an embodiment related to a liquid discharge head and a method of manufacturing the liquid discharge head of the present invention will be described with reference to the drawings. However, this does not limit the present invention.

  FIG. 1 is a perspective view showing the appearance of the liquid discharge head 110 according to the first embodiment of the present invention. The discharge port plate 101 is joined and integrated with a laminated body in which a plurality of first base materials 105 and second base materials 106, both of which are made of a piezoelectric material, are laminated. Yes. As shown in FIG. 1, the discharge port plate 101 has a plurality of discharge ports 102 formed of circular through holes, and these discharge ports 102 are two-dimensionally arranged at a predetermined interval. A pressure chamber 103 extending in the longitudinal direction communicates with the discharge port 102. The cross section orthogonal to the longitudinal direction of the pressure chamber 103 is rectangular. At least a part of the side surface of the pressure chamber 103 is defined by the first substrate 105. The first space portion 104 is provided adjacent to the first base material 105 across the pressure chamber 103 and the partition wall so that at least a part of the side surface 104 is defined by the first base material 105. . Similarly, the second space portion 109 is provided adjacent to the second base material 106 with a partition wall therebetween so that at least a part of the side surface 109 is defined by the second base material 106. It has been. A plurality of layers of the first base material 105 and the second base material 106 are laminated via an adhesive layer to form a laminate. A discharge port plate 101 is joined to the front surface of the laminate, and a rear throttle plate 107 and a common liquid chamber plate 108 are joined to the rear.

  FIG. 2 is an enlarged view of region A shown in FIG. As shown in FIG. 2, a first electrode 201 is formed on the inner wall of the pressure chamber 103. A second electrode 202 is formed on the inner wall of the space 104. Here, the first base material 105 and the second base material 106 are polarized in advance from the inner wall of the pressure chamber 103 to the adjacent first space 104 and second space 109.

  Regions B to E shown in FIG. 2 are partition walls 210 separating the first space portion 104 and the second space portion 109 adjacent to the pressure chamber 103, and are formed of a piezoelectric material. It can be said that the first electrode 201 is provided on the pressure chamber side surface of the partition wall 210 and the second electrode is provided on the opposite surface surface.

  FIG. 3 is an enlarged view of any of the regions B to E shown in FIG. 2 and shows the electric field direction and the polarization direction. In the conventional Gould-type piezoelectric actuator system, the electric field direction 301 and the polarization direction 302 are polarized so as to coincide as shown in FIG. In this case, when a voltage is applied between the electrodes formed on the piezoelectric substrate, the film extends in the direction perpendicular to the electrode surface by the action of expansion and contraction in the direction perpendicular to the electrode surface (hereinafter referred to as d33 mode), and is parallel to the electrode surface. Is contracted in a direction parallel to the electrode surface by the action of expansion and contraction in a specific direction (hereinafter referred to as d31 mode).

  However, in the present invention, as shown in FIG. 3B, the first region 303 and the second region 304 having different electric field directions 301 and polarization directions 302 are provided. In the first region 303, the polarization direction 302 is inclined to one side of the electric field direction 301, and in the second region 304, the polarization direction 302 is inclined to the opposite side of the one side of the electric field direction 301. In this way, when the polarization direction is oblique with respect to the electric field direction, in addition to the action of the d33 mode and the d31 mode, a movement (hereinafter referred to as the d15 mode) occurs in which the polarization direction matches the electric field direction. Therefore, when a positive voltage is applied to the first electrode 201 and the second electrode 202 is set to the ground potential, it expands in a direction perpendicular to the surface of the first electrode 201 and the surface of the second electrode 202 by the action of the d33 mode. To do. At the same time, the action of the d31 mode contracts in a direction parallel to the surface of the first electrode 201 and the surface of the second electrode 202, thereby reducing the circumferential length of the inner wall of the pressure chamber 103. Further, the action of the d15 mode causes a movement in which the polarization direction matches the electric field direction. As described above, since a plurality of modes act simultaneously, the deformation shown by the dotted line 308 in FIG. 3B is performed, so that the amount of displacement can be increased as compared with the conventional case.

  The above-described ejection method is a pushing method in which ink is ejected from the ejection port by contracting the pressure chamber, but the present invention ejects ink from the ejection port by expanding the pressure chamber and returning it to the original position. It can also be applied to the strike method. Specifically, a positive voltage is applied to the second electrode 202, and the first electrode 201 is set to the ground potential. By doing so, the electric field direction becomes the direction of the arrow 301 as shown in FIG. 3C, and the first base material 105 and the second base material 106 face the surface of the first electrode 201 by the action of the d33 mode. And contracts in a direction perpendicular to the surface of the second electrode 202. At the same time, the action of the d31 mode expands in a direction parallel to the surface of the first electrode 201 and the surface of the second electrode 202, and the circumferential length of the inner wall of the pressure chamber 103 extends. Further, the action of the d15 mode causes a movement in which the polarization direction matches the electric field direction. Since a plurality of modes act simultaneously as described above, the deformation as shown by the dotted line 309 in FIG. 3C is performed, so that the amount of displacement can be increased as compared with the conventional case.

  Note that the first base material 105 and the second base material 106 have a third region 305 or a third region 305 or a second region 304 between the first region 303 and the second region 304 as shown in FIGS. Although it is preferable to have the fourth region 306, the first region 303 and the second region 304 may be used alone.

  Next, the manufacturing process of the laminated body of this embodiment is shown using FIG. 4, FIG.

  FIG. 4 shows a manufacturing process of the first base material 105. As shown in FIG. 4A, polarization grooves 402 and first grooves 403 are alternately formed on the piezoelectric substrate 401 by dicing. The piezoelectric substrate 401 is preferably made of lead zirconate titanate or the like. Next, as shown in FIG. 4B, selective plating is performed on the front and back of the piezoelectric substrate 401 to form the polarization electrode 404 and the second electrode 202. Then, a voltage is applied between the polarization electrode 404 and the second electrode 202 to perform polarization processing for aligning the direction of spontaneous polarization. For example, by disposing the piezoelectric substrate 401 in 200 ° C. silicon oil and applying an electric field of 2 kV / mm between the polarization electrode 404 and the second electrode 202, as shown in FIG. Polarized in the direction of arrow 405. After the polarization treatment, as shown in FIG. 4D, the polarization groove 402 is expanded to form a second groove 406 that becomes the pressure chamber 103 by dicing. Then, the first electrode 201 is formed on the inner surface of the second groove 406 as shown in FIG. As a result, the first base material 105 is completed.

  FIG. 5 shows a manufacturing process of the second substrate 106. As shown in FIG. 5A, the front and back surfaces of the piezoelectric substrate 501 are selectively plated to form a third electrode 502 on one surface of the piezoelectric substrate 501 and the third electrode 502 on the other surface. A fourth electrode 503 having a width in a direction perpendicular to the longitudinal direction is narrower than that of the third electrode 502 is formed. The piezoelectric substrate 501 is preferably made of lead zirconate titanate. Then, a polarization process is performed by applying a voltage between the third electrode 502 and the fourth electrode 503. For example, by disposing the piezoelectric substrate 501 in silicon oil at 200 ° C. and applying an electric field of 2 kV / mm between the third electrode 502 and the fourth electrode 503, as shown in FIG. Is polarized in the direction of arrow 504. In order to efficiently use the polarized region, the fourth electrode side of the piezoelectric substrate is removed by grinding as shown in FIG. Next, as shown in FIG. 5D, a fifth groove 506 to be the space 104 is formed by dicing. Then, selective plating is performed as shown in FIG. 5E to form the second electrode 202 on the surface of the piezoelectric substrate 501 on the third electrode side, and the first surface is removed from the surface of the piezoelectric first substrate 501 that has been deleted. The electrode 201 is formed. As a result, the second substrate 106 is completed. A laminated body is completed by laminating and joining a plurality of the first base material 105 and the second base material 106 with an adhesive layer.

  FIG. 6 is a diagram showing the polarization direction and the electric field direction of the present embodiment. When performing polarization, if a positive voltage is applied to the first electrode 201 to bring the second electrode 202 to the ground potential, the polarization direction becomes as indicated by an arrow 601 shown in FIG. On the other hand, the first electrode 201 may be set to the ground potential, and a positive voltage may be applied to the second electrode 202 so that the polarization direction as indicated by an arrow 601 shown in FIG. Even in such a case, the same operation and effect as in FIG.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIG. 6A and FIG. 6B in the cross section in all the regions in the longitudinal direction of the pressure chamber has been described. It is not limited. If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 7 shows a manufacturing process of the first base material 105 according to the second embodiment of the present invention. As shown in FIG. 7A, the first groove 403 that becomes the first space 104 and the second groove 406 that becomes the pressure chamber 103 are alternately formed in the piezoelectric substrate 701 by dicing. Next, as shown in FIG. 7B, selective plating is applied to the front and back of the piezoelectric substrate 701 to form the second electrode 202. Further, a rod-like fourth electrode 702 is installed at the center of the cross section of the second groove 406 by an electrode installation tool. Then, as shown in FIG. 7C, the second through groove 406 is filled with silicon oil 703. The silicon oil 703 is obtained by dispersing ferroelectric powder and preferably has a dielectric constant comparable to that of the piezoelectric substrate 701. Then, a polarization process is performed by applying a high voltage between the second electrode 202 and the fourth electrode 702. By doing so, it is polarized in the direction of the arrow 704 as shown in FIG. After the polarization treatment, as shown in FIG. 7E, the silicon oil 703 in the second groove is removed, and then the first electrode 201 is formed in the second groove. As a result, the first base material 105 is completed. Even if the first base material 105 is manufactured in such a process, the same effects as those of the first embodiment can be obtained.

  FIG. 8 shows a manufacturing process of the first base material 105 according to the third embodiment of the present invention. As shown in FIG. 8A, the first groove 403 serving as the space and the second groove 406 serving as the pressure chamber 103 are alternately formed in the piezoelectric substrate 801 by dicing. The piezoelectric substrate 801 is preferably made of lead zirconate titanate. Next, as shown in FIG. 8B, selective plating is performed on the front and back of the piezoelectric substrate 801 to form the first electrode 201 and the second electrode 202. Then, a polarization process is performed by applying a high voltage between the first electrode 201 and the second electrode 202 to align the direction of spontaneous polarization. By doing so, it is polarized in the direction of the arrow 802 shown in FIG. After the polarization treatment, the electrode in the first groove is removed as shown in FIG. And as shown in FIG.8 (e), selective plating is given to the 1st groove | channel 403, and the 2nd electrode 202 is formed. As a result, the first base material 105 is completed. A second base material 106, which is previously polarized in the thickness direction and has electrodes formed thereon, is joined to the first base material 105 with an adhesive layer as shown in FIG. 8 (f). A laminated body is completed by laminating and joining a plurality of the joined bodies.

  The polarization directions of the first base material 105 and the second base material 106 manufactured in the above process are perpendicular to the surface of the first electrode 201. The cross section perpendicular to the longitudinal direction of the pressure chamber 103 is rectangular, and the length of the direction component parallel to the first electrode 201 of the second electrode 202 is larger than that of the first electrode 201 when viewed in the cross section. And short. Therefore, as shown in FIG. 9, the electric field direction 902 is inclined with respect to the surface of the first electrode 201, and the same operation as in the first embodiment occurs.

  When polarization is performed, if a positive voltage is applied to the first electrode 201 and the second electrode 202 is set to the ground potential, the polarization direction becomes as indicated by an arrow 901 shown in FIG. On the other hand, the first electrode 201 may be set to the ground potential and a positive voltage may be applied to the second electrode 202 so that the polarization direction as indicated by an arrow 901 shown in FIG. Even in such a case, the same effect as in FIG. 9A can be obtained.

  Compared with the first embodiment, the first base material and the second base material have a narrow range in which the electric field is applied and the displacement amount decreases, but the displacement amount can be increased as compared with the first embodiment. .

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIG. 9A and FIG. 9B in the cross section in all the regions in the longitudinal direction of the pressure chamber has been described. It is not limited. If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 10 is a perspective view showing the appearance of a liquid discharge head according to the fourth embodiment of the present invention. The discharge port plate 1006 is joined and integrated with a laminate in which a plurality of first base materials 1001 and second base materials 1005 formed of a piezoelectric material are laminated. Yes. As shown in FIG. 10, the first base material 1001 manufactured by the process of FIG. 4 or 7 is bonded to the surface on which the pressure chamber 1002 and the first space portion 1003 are formed by an adhesive layer. Next, on each surface opposite to the bonded surface, a second base material 1005 having a second space portion 1004 whose center positions are formed at the same interval as the pressure chamber 1002 of the first base material 1001. Are bonded by an adhesive layer. A laminated body is completed by laminating and bonding a plurality of these. In the first embodiment, three sides of the pressure chamber 103 are surrounded by the first base material 105 and the remaining one faces the second base material 106. In this embodiment, all four sides of the pressure chamber 1002 are located. Surrounded by the first substrate 1001.

  FIG. 11 is a diagram illustrating the shape, electric field direction, and polarization direction of the pressure chamber 1002 and the first space portion 1003 of the first base material 1001. As shown in FIGS. 11A to 11C, the first base material 1001 is polarized in the direction of the arrow 1101, and the electric field direction is in the direction of the arrow 1102, which is the same as in the first embodiment. An effect can be obtained. In addition, as shown in FIG. 11A, the first base material 1001 preferably has the same depth of the pressure chamber 1002 and the first space 1003 with respect to the thickness of the first base material 1001. Different depths may be used as shown in (b). Further, as shown in FIG. 11C, the shape is not limited to a square, and the pressure chamber 1002 and the first space portion 1003 may have different shapes and sizes.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIGS. 11A to 11C in the cross sections in all the regions in the longitudinal direction of the pressure chamber has been described. However, the present invention is not limited to this. It is not something. If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 12 is a perspective view of a liquid discharge head according to the fifth embodiment of the present invention. The discharge port plate 1201 is joined to and integrated with a joined body of a piezoelectric base material 1205 formed of a piezoelectric material and a non-piezoelectric base material 1204 formed of a non-piezoelectric material. ing. As shown in FIG. 12, the discharge port plate 1201 is formed with a plurality of discharge ports 1202 each having a circular through hole. Pressure chambers 1203 each having a rectangular through hole are formed at positions corresponding to the respective discharge ports 1202. The pressure chamber 1203 is surrounded by the non-piezoelectric substrate 1204 and the piezoelectric substrate 1205. The non-piezoelectric substrate 1204 can be formed of ceramic, metal, or the like, but it is preferable to use a ceramic having a similar coefficient of thermal expansion in consideration of deformation after bonding with the piezoelectric substrate 1205. In addition, a rear diaphragm plate 1206 and a common liquid chamber plate 1207 are joined to the rear.

  FIG. 13 is an enlarged view of the region F of FIG. 12, showing the electric field direction and the polarization direction. As shown in FIG. 13, a first electrode 1301 is formed on the inner wall of the pressure chamber of the piezoelectric substrate 1205, and a second electrode 1302 is formed on the outer wall facing the piezoelectric substrate 1205.

  This piezoelectric base material 1205 has the electric field direction as shown by arrows 1304 as shown in FIGS. 13 (a) and 13 (b) by taking the manufacturing steps of FIGS. 5 (a) to 5 (c), and the polarization direction. Is set in the direction of the arrow 1303 to make the polarization direction oblique to the electric field direction. And it completes by joining the non-piezoelectric base material 1204 in which the groove | channel was formed by dicing. When a positive voltage is applied to the first electrode 1301 and the second electrode 1302 is set to the ground potential, the piezoelectric substrate 1205 has the same action as in the first embodiment. Specifically, the piezoelectric substrate 1205 expands in a direction perpendicular to the surface of the first electrode 1301 and the surface of the second electrode 1302, and is parallel to the surface of the first electrode 1301 and the surface of the second electrode 1302. Shrink in any direction. At the same time, a movement occurs such that the polarization direction matches the electric field direction, and ink is ejected from the ejection port 1202.

  The above-described ejection method is a pushing method in which ink is ejected from the ejection port by contracting the pressure chamber, but the present invention ejects ink from the ejection port by expanding the pressure chamber and returning it to the original position. It can also be applied to the strike method. Specifically, the first electrode 1301 is set to the ground potential, and a positive voltage is applied to the second electrode 1302. Thus, the piezoelectric substrate 1205 contracts in a direction perpendicular to the surface of the first electrode 1301 and the surface of the second electrode 1302, and is parallel to the surface of the first electrode 1301 and the surface of the second electrode 1302. Swell in any direction. At the same time, a movement occurs such that the polarization direction matches the electric field direction, and the pressure chamber 1203 expands. Ink is ejected from the ejection port 1202 by the contraction force when the inner wall of the pressure chamber 1203 returns to the original position from this state.

  Alternatively, as shown in FIGS. 13C and 13D, the piezoelectric base material 1205 previously polarized in the direction of the arrow 1303 and the non-piezoelectric base material 1204 having grooves formed by dicing are joined. Good. By forming the first electrode 1301 and the second electrode 1302 having a narrower width than the first electrode 1301, the same operation as that of the third embodiment can be obtained. In this case, as compared with FIG. 13A and FIG. 13B, the range in which the electric field is applied to the piezoelectric substrate 1205 is narrowed, so that the amount of displacement is reduced. As a more preferable form, it is a form of FIG. 13 (a) or FIG.13 (b), but all can increase a displacement amount compared with the past.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIGS. 13A to 13D in the cross section in all the regions in the longitudinal direction of the pressure chamber has been described. However, the present invention is not limited to this. It is not something. If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 14 is a perspective view showing an appearance of a liquid discharge head according to the sixth embodiment of the present invention. The discharge port plate 1409 is joined to and integrated with a joined body of a piezoelectric base material 1401 made of a piezoelectric material and a top plate 1405 made of a non-piezoelectric material. . As shown in FIG. 14, the piezoelectric substrate 1401 is formed with a plurality of concave grooves in parallel at predetermined intervals, and each groove is separated by a side wall 1402. The piezoelectric substrate 1401 is preferably made of lead zirconate titanate. This groove is alternately provided with pressure chambers 1403 for discharging ink from the discharge ports and space portions 1404. Each pressure chamber 1403 and the space 1404 are extended from one end surface of the piezoelectric substrate 1401 to the other end surface. Electrodes are formed on both sides of each side wall 1402 in the longitudinal direction. A top plate 1405 is bonded to the upper portion of the groove of the piezoelectric substrate 1401 with an adhesive. The top plate 1405 can be formed of ceramic, metal, or the like, but it is preferable to use a ceramic having a similar coefficient of thermal expansion in consideration of deformation after bonding to the piezoelectric substrate 1401 and the like. A rear diaphragm plate 1406 and a common liquid chamber plate 1407 are joined behind these joined bodies. A discharge port plate 1409 having a discharge port 1408 is joined to the front surface.

  FIG. 15 is an enlarged view of the region G in FIG. 14, showing the electric field direction and the polarization direction. The piezoelectric substrate 1401 is manufactured by the same process as that shown in FIGS. 4 and 7, so that the electric field direction is the direction of the arrow 1504 and the polarization direction is the arrow 1503 as shown in FIGS. 15 (a) and 15 (b). And the polarization direction is inclined with respect to the electric field direction. When a positive voltage is applied to the first electrode 1501 formed on the side wall and the second electrode 1502 is set to the ground potential, the same action as in the first embodiment occurs. The piezoelectric substrate 1401 expands in a direction perpendicular to the surface of the first electrode 1501 and the surface of the second electrode 1502 and contracts in a direction parallel to the surface of the first electrode 1501 and the surface of the second electrode 1502. . At the same time, a movement occurs such that the polarization direction matches the electric field direction, and ink is ejected from the ejection port 1408.

  The above-described ejection method is a pushing method in which ink is ejected from the ejection port by contracting the pressure chamber, but the present invention ejects ink from the ejection port by expanding the pressure chamber and returning it to the original position. It can also be applied to the strike method. Specifically, the first electrode 1501 side is set to the ground potential, and a positive voltage is applied to the second electrode 1502. Thus, the piezoelectric substrate 1401 contracts in a direction perpendicular to the surface of the first electrode 1501 and the surface of the second electrode 1502, and is parallel to the surface of the first electrode 1501 and the surface of the second electrode 1502. Swell in any direction. At the same time, a movement occurs such that the polarization direction matches the electric field direction, and the pressure chamber 1403 expands. Ink is ejected from the ejection port 1408 by the contraction force when the inner wall of the pressure chamber 1403 returns to the original position from this state.

  Further, by producing the piezoelectric substrate 1401 by the same process as in FIG. 8, it is polarized in the direction of the arrow 1503 as shown in FIGS. 15C and 15D, and the width of the second electrode is shortened. Since the electric field direction is the direction of the arrow 1504, the same effect can be obtained. However, compared with FIG. 15A and FIG. 15B, the range in which the electric field is applied to the piezoelectric substrate 1401 becomes narrower, so the amount of displacement decreases. As a more preferable form, FIG. 15 (a) and FIG. 15 (b) can be used, but the displacement amount can be increased as compared with the conventional case.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIGS. 15A to 15D in the cross section in all the regions in the longitudinal direction of the pressure chamber has been described. However, the present invention is not limited thereto. Is not to be done. If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 16 is a perspective view showing an appearance of a liquid discharge head according to the seventh embodiment of the present invention. The discharge port plate 1607 is joined and integrated with a joined body of a piezoelectric base material 1602 formed of a piezoelectric material and a non-piezoelectric base material 1601 formed of a non-piezoelectric material. ing. As shown in FIG. 16, a non-piezoelectric substrate 1601 and a plurality of piezoelectric substrates 1602 arranged on the non-piezoelectric substrate 1601 at equal intervals are provided. The non-piezoelectric substrate 1601 can be formed of ceramic, metal, or the like, but it is preferable to use a ceramic having a similar coefficient of thermal expansion in consideration of deformation after bonding with the piezoelectric substrate 1602 and the like. The piezoelectric substrate 1602 is preferably made of lead zirconate titanate. The piezoelectric base material 1602 is fixed with an adhesive with the groove portion facing the base material 1601, and a space surrounded by the base material 1601 and the piezoelectric base material 1602 is used as a pressure chamber 1603. A rear diaphragm plate 1604 and a common liquid chamber plate 1605 are joined behind these joined bodies. Further, a discharge port plate 1606 in which a discharge port 1607 is formed is joined to the front surface.

  FIG. 17 is an enlarged view of the region H of FIG. 16, showing the electric field direction and the polarization direction. As shown in FIG. 17, a first electrode 1701 is formed on the inner wall on the pressure chamber 1603 side, and a second electrode 1702 is formed on the outer wall facing the pressure chamber 1603. When a positive voltage is applied to the first electrode 1701 and the second electrode 1702 is set to the ground potential, the piezoelectric substrate 1602 has the same action as in the first embodiment. Specifically, the piezoelectric substrate 1602 expands in a direction perpendicular to the surface of the first electrode 1701 and the surface of the second electrode 1702, and at the same time, the surface of the first electrode 1701 and the surface of the second electrode 1702. Shrink in a direction parallel to the. Further, a movement occurs so that the polarization direction matches the electric field direction, and ink is ejected from the ejection port 1607 shown in FIG.

  The above-described ejection method is a pushing method in which ink is ejected from the ejection port by contracting the pressure chamber, but the present invention ejects ink from the ejection port by expanding the pressure chamber and returning it to the original position. It can also be applied to the strike method. Specifically, the first electrode 1701 is set to the ground potential, and a positive voltage is applied to the second electrode 1702. In this way, the piezoelectric substrate 1602 contracts in a direction perpendicular to the surface of the first electrode 1701 and the surface of the second electrode 1702, and at the same time, the surface of the first electrode 1701 and the surface of the second electrode 1702. Expands in a direction parallel to Furthermore, a movement occurs such that the polarization direction matches the electric field direction, and the pressure chamber 1603 expands. Ink is ejected from the ejection port 1607 shown in FIG. 16 by the contraction force when the inner wall of the pressure chamber 1603 returns to the original position from this state.

  FIG. 18 is a view showing a method for manufacturing the piezoelectric substrate 1602. First, steps similar to those in FIGS. 4A to 4D are performed. Then, after all the electrodes are removed, the first electrode 1701 is formed on the inner wall of the second through groove 406 as shown in FIG. Next, as shown in FIG. 18B, the non-piezoelectric substrate 1601 is bonded with an adhesive layer. Then, as shown in FIG. 18C, the first through groove 403 is removed by grinding. Then, a second electrode 1702 is formed as shown in FIG. As a result, the piezoelectric substrate 1602 is completed.

  When polarization is performed, if a positive voltage is applied to the first electrode 201 and the second electrode 201 side is set to the ground potential in the process of FIG. 4, an arrow 1703 is obtained as shown in FIG. Polarized in the direction, the same action as in the first embodiment occurs. At this time, a positive voltage may be applied to the second electrode 202 so that the first electrode 201 side is grounded, and polarization may be performed in the direction of the arrow 1703 as shown in FIG. Even in such a case, the effect is the same.

  Further, in the above steps, the piezoelectric substrate 1602 is manufactured in the same steps as in FIGS. 8A to 8E instead of FIGS. 4A to 4D, so that FIG. Alternatively, as shown in FIG. 17D, the electric field can be polarized in the direction of the arrow 1703 and the electric field direction can be changed to the direction of the arrow 1704. However, compared with FIGS. 17A and 17B, the range in which the electric field is applied to the piezoelectric substrate 1602 becomes narrower, so the amount of displacement decreases. As a more preferable form, it is a form of FIG. 17 (a) or FIG.17 (b), but all can increase a displacement amount compared with the past.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIGS. 17A to 17D in the cross section in all the regions in the longitudinal direction of the pressure chamber has been described. However, the present invention is not limited to this. It is not something. If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 19 is a perspective view showing the appearance of a liquid discharge head according to the eighth embodiment of the present invention. The discharge port plate 1901 is joined and integrated with a piezoelectric base material 1904 made of a piezoelectric material, but is shown in an exploded manner in this drawing. As shown in FIG. 19, the discharge port plate 1901 has a plurality of discharge ports 1902 that are circular through holes, and these discharge ports 1902 are two-dimensionally arranged at a predetermined interval. A rectangular tube-shaped piezoelectric substrate 1904 including a pressure chamber 1903 that is a circular through hole is formed at a position corresponding to each discharge port 1902. The piezoelectric base material 1904 is formed by molding a powder, which is a molding material, using a mold having a predetermined shape and firing it. A rear diaphragm plate 1905 and a common liquid chamber plate 1906 are joined to the rear.

  FIG. 20 is a diagram illustrating the steps of polarization processing and electrode formation of the piezoelectric base material 1904. As shown in FIG. 20A, a second electrode 2001 is formed on the outer wall of the piezoelectric substrate 1904, and a flat plate-like fourth electrode 2002 is installed at the center position of the pressure chamber 1903 using an electrode installation tool. Next, as shown in FIG. 20B, the pressure chamber 1903 is filled with silicon oil 2003. As this silicon oil 2003, it is preferable to use a dispersion of a ferroelectric powder having a dielectric constant comparable to that of the piezoelectric substrate 1904. Then, a polarization process is performed in which a high voltage is applied between the second electrode 2001 and the fourth electrode 2002 to align the direction of spontaneous polarization. By doing so, it is polarized in the direction of arrow 2004 as shown in FIG. After the polarization treatment, the silicon oil 2003 and the fourth electrode 2002 in the pressure chamber are removed, and the first electrode 2005 is formed on the inner wall of the pressure chamber 1903 as shown in FIG. As a result, the piezoelectric substrate 1904 is completed.

  FIG. 21 is an enlarged view of region I in FIG. 19 and shows the electric field direction and the polarization direction. 21A is a view showing the piezoelectric substrate 1904 and the pressure chamber 1903 in FIG. 19, and FIG. 21B is a partial cross-sectional view of the liquid chamber shown in the region I in FIG. In the conventional method, since the piezoelectric substrate 1904 has the same electrode for polarization and drive, it is polarized in a direction perpendicular to the electrode surface, and ink is ejected by the action of the d33 mode and d31 mode. However, in the present embodiment, the piezoelectric substrate 1904 has a region J and a region K in which the polarization direction is oblique with respect to the electric field direction, as shown in FIG. Therefore, when a positive voltage is applied to the first electrode 2005 and the second electrode 2001 side is set to the ground potential, the same action as in the first embodiment occurs. Specifically, the piezoelectric substrate 1904 expands in the radial direction around the pressure chamber 1903 and simultaneously contracts in the circumferential direction. Further, in the region J and the region K, a movement occurs in which the polarization direction matches the electric field direction. Therefore, the ink is deformed as indicated by a dotted line 2111 in FIG. 21B, and the ink in the pressure chamber 1903 is discharged from the discharge port 1902 shown in FIG. By doing in this way, the effect similar to the past is acquired.

  The above-described ejection method is a pushing method in which ink is ejected from the ejection port by contracting the pressure chamber, but the present invention ejects ink from the ejection port by expanding the pressure chamber and returning it to the original position. It can also be applied to the strike method. Specifically, the first electrode 2005 is set to the ground potential, and a positive voltage is applied to the second electrode 2001. By doing so, the piezoelectric substrate 1904 contracts in the radial direction around the pressure chamber 1903 and simultaneously expands in the circumferential direction. Further, in the region J and the region K, a movement in which the polarization direction is aligned with the electric field direction occurs, and the pressure chamber 1903 expands. Ink is ejected from the ejection port 1902 shown in FIG. 19 by the contraction force when the inner wall of the pressure chamber 1903 returns to the original position from this state.

  The shape of the piezoelectric substrate 1904 is preferably a quadrangle as described here, but is not limited thereto, and may be a triangle or a pentagon.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIG. 21B in the cross section in the entire region in the longitudinal direction of the pressure chamber has been described. However, the present invention is not limited to this. . If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 21C is a diagram corresponding to the portion indicated by region I in FIG. 19 of the liquid ejection head according to the ninth embodiment of the present invention. The difference between the present embodiment and the eighth embodiment is the shape of the piezoelectric substrate. In this embodiment, a cylindrical piezoelectric substrate 2103 composed of a pressure chamber 2104 that is a circular through hole is formed. The piezoelectric base material 2103 is formed by molding a powder, which is a molding material, using a mold having a predetermined shape and firing it. A first electrode 2105 is formed on the inner wall of the pressure chamber 2104, and a second electrode 2106 is formed on the outer wall thereof.

  FIG. 21D is an enlarged view of the region L in FIG. 21C, showing the electric field direction and the polarization direction. The piezoelectric substrate 2103 is manufactured using the same process as that in FIG. By doing so, the piezoelectric substrate 2103 has a region J and a region K in which the polarization direction is oblique with respect to the electric field direction, as shown in FIG. 21D, as in the eighth embodiment. Therefore, when a positive voltage is applied to the first electrode 2105 and the second electrode 2106 is set to the ground potential, the piezoelectric substrate 2103 expands in the radial direction around the pressure chamber 2104 and simultaneously contracts in the circumferential direction. Further, in the region J and the region K, a movement occurs in which the polarization direction matches the electric field direction. Accordingly, the tube is crushed as indicated by a dotted line 2112 in FIG. 21D, and the ink in the pressure chamber 2104 is ejected from the ejection port. By doing in this way, the effect similar to the past is acquired.

  The above-described ejection method is a pushing method in which ink is ejected from the ejection port by contracting the pressure chamber, but the present invention ejects ink from the ejection port by expanding the pressure chamber and returning it to the original position. It can also be applied to the strike method. Specifically, the first electrode 2105 is set to the ground potential, and a positive voltage is applied to the second electrode 2106. By doing so, the piezoelectric substrate 2103 contracts in the radial direction around the pressure chamber 2104, and simultaneously expands in the circumferential direction. Further, in the region J and the region K, the pressure chamber 2104 expands by causing a movement in which the polarization direction matches the electric field direction. Ink is ejected from the ejection port by the contraction force when the inner wall of the pressure chamber 2104 returns to the original position from this state.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction as shown in FIG. 21D are shown in the cross section in the entire region in the longitudinal direction of the pressure chamber is not limited to this. . If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  FIG. 21E is a diagram corresponding to the portion indicated by region I in FIG. 19 of the liquid ejection head according to the tenth embodiment of the present invention. The difference between the present embodiment and the eighth embodiment is the shape of the pressure chamber. In the present embodiment, the piezoelectric substrate 2107 is formed in a rectangular tube shape including a pressure chamber 2108 that is a rectangular through hole. The piezoelectric base material 2107 is formed by molding a powder, which is a molding material, using a mold having a predetermined shape and firing it. A second electrode 2109 is formed on the inner wall of the pressure chamber 2108, and a first electrode 2110 is formed on the outer wall thereof.

  FIG. 21F is an enlarged view of the region M in FIG. 21E, showing the electric field direction and the polarization direction. This piezoelectric substrate 2107 is manufactured in the same process as that in FIG. By doing so, the piezoelectric substrate 2107 has a region J and a region K in which the polarization direction is oblique with respect to the electric field direction, as shown in FIG. 21 (f), as in the eighth embodiment. Therefore, when a positive voltage is applied to the first electrode 2109 and the second electrode 2110 is set to the ground potential, the piezoelectric substrate 2107 is in a direction perpendicular to the surface of the first electrode 2109 and the surface of the second electrode 2110. Inflate. At the same time, it contracts in a direction parallel to the surface of the first electrode 2109 and the surface of the second electrode 2110. Further, in the region J and the region K, a movement occurs in which the polarization direction matches the electric field direction. Therefore, since the deformation is performed as shown by the dotted line 2113 in FIG. 21 (f), the displacement amount can be increased as compared with the conventional case.

  The above-described ejection method is a pushing method in which ink is ejected from the ejection port by contracting the pressure chamber, but the present invention ejects ink from the ejection port by expanding the pressure chamber and returning it to the original position. It can also be applied to the strike method. Specifically, the first electrode 2109 is set to the ground potential, and a positive voltage is applied to the second electrode 2110. By doing so, the piezoelectric substrate 2107 contracts in a direction perpendicular to the surface of the first electrode 2109 and the surface of the second electrode 2110. At the same time, it expands in a direction parallel to the surface of the first electrode 2109 and the surface of the second electrode 2110. Furthermore, in the region J and the region K, the pressure chamber 2108 expands by causing a movement in which the polarization direction matches the electric field direction. Ink is ejected from the ejection port by the contraction force when the inner wall of the pressure chamber 2108 returns to the original position from this state.

  Here, if the fourth electrode 2002 of FIG. 20 is a rod-like electrode instead of a flat plate shape, the piezoelectric substrate 2107 can have the same polarization direction as that of the first embodiment. In this case, since the piezoelectric base material 2107 is not connected and no restraining force is generated, the amount of displacement can be increased as compared with the first embodiment. However, it is inferior in terms of robustness as compared with the first embodiment, and it is difficult to provide a large number of discharge ports, so the preferred embodiment is the first embodiment.

  In the present embodiment, the configuration in which the polarization direction and the electric field direction are as shown in FIG. 21 (f) in the cross section in the entire region in the longitudinal direction of the pressure chamber has been described. However, the present invention is not limited to this. . If at least some of the cross sections orthogonal to the longitudinal direction of the pressure chamber have the relationship between the polarization direction and the electric field direction as described above, the same effect can be obtained although the degree is different.

  In the present invention, as described in each embodiment, the amount of displacement of the piezoelectric substrate can be increased as compared with the prior art. Therefore, an equivalent displacement amount can be obtained with a smaller voltage than in the prior art.

103 pressure chamber 105 first base material 106 second base material 201 first electrode 202 second electrode

Claims (20)

A discharge port that discharges the liquid, and a pressure chamber that communicates with the discharge port and extends in the longitudinal direction,
A predetermined part of the side wall of the pressure chamber is defined by a partition made of a piezoelectric material, and a first electrode is opposite to the pressure chamber across the first electrode on the pressure chamber side surface of the partition. A second electrode is provided on each of the first and second surfaces, and the partition wall is polarized while being inclined to one side with respect to an electric field direction generated by applying a voltage between the first electrode and the second electrode. A liquid discharge head comprising: a first region; and a second region polarized in a direction opposite to the one side with respect to the electric field direction.   The cross section perpendicular to the longitudinal direction of the pressure chamber is rectangular, and when viewed in the cross section, the length of the direction component parallel to the first electrode of the second electrode is the length of the first electrode. The liquid discharge head according to claim 1, which is shorter than the length. A first base material formed of the piezoelectric material, and a second base material laminated on the first base material,
The cross section orthogonal to the longitudinal direction of the pressure chamber is rectangular, at least a part of the side surface of the pressure chamber is defined by the first base material, and the first space portion has at least a part of the side surface thereof. As defined by the first substrate, the first substrate is provided adjacent to the pressure chamber with the partition wall therebetween, and the first electrode is provided on an inner wall of the pressure chamber, The liquid ejection head according to claim 1, wherein the second electrode is provided on the pressure chamber side of the inner wall of the first space portion.   The second substrate is formed of the piezoelectric material and is alternately stacked with the first substrate, and the second space is defined by at least a part of the side surface by the second substrate. As described above, the second base material is provided adjacent to the pressure chamber with the partition wall therebetween, and the second electrode is provided on the pressure chamber side of the inner wall of the second space portion, The liquid discharge head according to claim 3.   The liquid ejection head according to claim 4, wherein three sides of the pressure chamber are surrounded by the first base material, and the remaining one of the pressure chambers faces the second base material.   The liquid ejection head according to claim 4, wherein all four sides of the pressure chamber are surrounded by the first base material.   The liquid ejection head according to claim 3, wherein the second substrate is formed of a non-piezoelectric material. A first substrate formed of a non-piezoelectric material, and a second substrate formed of the piezoelectric material and laminated on the first substrate,
The cross section perpendicular to the longitudinal direction of the pressure chamber is rectangular, the pressure chamber is provided on the first base material, and the first electrode is provided on a surface of the second base material that is in contact with the pressure chamber. The liquid discharge head according to claim 1, wherein the second electrode is provided at a position corresponding to a surface opposite to the surface in contact with the pressure chamber of the second base material.   The pressure chambers are arranged at a predetermined interval, each of the pressure chambers is surrounded by a piezoelectric substrate formed of the piezoelectric material, each of the piezoelectric substrates is separated from each other, and the first electrode is The liquid ejection head according to claim 1, wherein the liquid discharge head is provided on an inner wall of the pressure chamber, and the second electrode is provided on an outer wall of the piezoelectric base material.   The liquid discharge head according to claim 9, wherein the pressure chambers are arranged one-dimensionally, and the piezoelectric substrate is supported on a substrate formed of a non-piezoelectric material.   The liquid discharge head according to claim 9, wherein the pressure chambers are two-dimensionally arranged.   The liquid discharge head according to claim 11, wherein the piezoelectric substrate has a rectangular tube shape.   The liquid ejection head according to claim 11, wherein the piezoelectric substrate is cylindrical. A method for manufacturing a liquid discharge head, comprising: a discharge port for discharging liquid; and a pressure chamber communicating with the discharge port,
A partition forming step of forming a partition wall defining a predetermined part of the side wall of the pressure chamber from a piezoelectric material, a polarization step of polarizing the partition wall, and a first electrode on the pressure chamber side surface of the partition wall, An electrode forming step of providing a second electrode on the surface opposite to the pressure chamber across the first electrode, and
In the polarization step and the electrode formation step, the partition wall is polarized while being inclined to one side with respect to an electric field direction generated by applying a voltage between the first electrode and the second electrode. The polarization direction and the arrangement of the first and second electrodes are adjusted so as to have one region and a second region polarized in a direction opposite to the one side with respect to the electric field direction. A method of manufacturing a liquid discharge head.   Alternately forming polarization grooves and first grooves on one surface of the piezoelectric substrate made of the piezoelectric material, forming polarization electrodes on the inner surfaces of the polarization grooves, and the first Forming the second electrode on the inner surface of the groove, and forming the second electrode on a surface of the piezoelectric substrate opposite to the surface on which the polarization groove and the first groove are formed. Performing a polarization process on the piezoelectric substrate between the polarization electrode and the second electrode, expanding the polarization groove after the polarization process, and forming a second groove And a step of forming the first electrode on an inner surface of the second groove.   Forming a third electrode on one surface of the piezoelectric substrate made of the piezoelectric material, and having a width in a direction perpendicular to the longitudinal direction of the third electrode on the other surface of the piezoelectric substrate; Forming a fourth electrode narrower than the third electrode; applying a voltage between the third electrode and the fourth electrode to perform polarization; and Removing the four electrode sides, forming a plurality of grooves on the third electrode side surface of the piezoelectric substrate, forming the second electrode on the inner surface of the grooves, The method of manufacturing a liquid ejection head according to claim 14, further comprising: forming the first electrode on the surface of the piezoelectric substrate that has been deleted.   Forming a first groove and a second groove alternately on one surface of a piezoelectric substrate made of the piezoelectric material; and forming the second electrode on an inner surface of the first groove. And forming the second electrode on a surface of the piezoelectric substrate opposite to the surface on which the first groove and the second groove are formed, and a cross-sectional center position of the second groove A step of installing a rod-like fourth electrode on the substrate, a step of filling the second groove with silicon oil, and a polarization treatment of the piezoelectric substrate between the fourth electrode and the second electrode The liquid ejection head according to claim 14, comprising: a step; a step of removing the silicon oil in the second groove; and a step of forming the first electrode on an inner surface of the second groove. Production method.   A step of alternately forming a first groove and a second groove on one surface of a piezoelectric substrate formed of the piezoelectric material, and a step of forming the first electrode on the inner surface of the first groove; Forming the second electrode on the inner surface of the second groove, and forming the second electrode on a surface of the piezoelectric substrate opposite to the surface on which the first groove and the second groove are formed. Forming a second electrode, performing a polarization treatment of the piezoelectric substrate between the first electrode and the second electrode, and removing the second electrode from the second groove And forming the second electrode in the second groove with a width in a direction perpendicular to the longitudinal direction of the first electrode that is narrower than that of the first electrode. Manufacturing method of liquid discharge head.   Alternately forming polarization grooves and first grooves on one surface of the piezoelectric substrate made of the piezoelectric material, forming polarization electrodes on the inner surfaces of the polarization grooves, and the first Forming a third electrode on the inner surface of the groove, and forming the third electrode on a surface of the piezoelectric substrate opposite to the surface on which the polarization groove and the first groove are formed. A step of performing a polarization treatment of the piezoelectric substrate between the polarization electrode and the third electrode, and a step of expanding the polarization groove after the polarization treatment to form a second groove, A step of removing all electrodes, a step of forming the first electrode on the inner surface of the second groove, and a non-piezoelectric base material formed of a non-piezoelectric material on the opening side of the groove of the piezoelectric substrate Bonding the first electrode, removing the first groove, and attaching the second electrode to the outer wall of each piezoelectric material separated Method for manufacturing a liquid discharge head according to claim 14 comprising the steps of forming a.   Forming the second electrode on an outer wall of the piezoelectric body made of the piezoelectric material, installing a flat fourth electrode at a central position of the pressure chamber, and forming the pressure chamber with silicon oil Filling, a step of applying a voltage between the first electrode and the fourth electrode to perform a polarization treatment, a step of removing the silicon oil and the fourth electrode in the pressure chamber, and an inner wall of the pressure chamber The method of manufacturing a liquid discharge head according to claim 14, further comprising: forming the first electrode.

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