JP5766464B2 - Ink jet head and recording apparatus - Google Patents

Description

  The present invention relates to an inkjet head and a recording apparatus.

  An inkjet head having an actuator that is displaced in a so-called bending mode is known (for example, Patent Document 1). The ink jet head includes a base body having a recess (pressurizing chamber) that communicates with the ejection hole and an actuator that closes the recess. Then, when the actuator is bent toward the inside of the pressurizing chamber, the volume of the pressurizing chamber is reduced, and the ink filled in the pressurizing chamber is ejected from the ejection holes.

  In a piezoelectric actuator, the above-described bending is realized by utilizing a so-called piezoelectric lateral effect. For example, a unimorph actuator has a diaphragm, a common electrode, a piezoelectric body, and individual electrodes that are sequentially stacked from the substrate side. The piezoelectric body is polarized in the stacking direction of the actuator. When a voltage is applied to the common electrode and the individual electrodes, the piezoelectric body is reduced in the plane (lateral direction) due to the piezoelectric lateral effect. Since this displacement is restrained by the vibration plate, this reduction deformation is converted into a bending deformation with the vibration plate side (pressure chamber side) as a convex.

  In Patent Document 1, when the region immediately below the individual electrode of the piezoelectric body is reduced in the lateral direction, a tensile force is applied to the region around the individual electrode of the piezoelectric body, and the application of the tensile force is repeated. As a result, attention is paid to drive deterioration. In the technique of Patent Document 1, an auxiliary electrode is provided around the individual electrode so as to be separated from the individual electrode. When a voltage is applied between the individual electrode and the common electrode, the auxiliary electrode is disposed between the auxiliary electrode and the common electrode. In addition, a voltage is applied to expand the piezoelectric body in the lateral direction. As a result, the reduction of the area immediately below the individual electrode and the enlargement of the area immediately below the auxiliary electrode are offset, and the tensile force applied to the area around the individual electrode (the area between the individual electrode and the auxiliary electrode) Alleviated.

JP 2010-228145 A

  As described above, conventionally, the deflection of the actuator is realized by the piezoelectric lateral effect, and an object of the present invention is to provide an ink jet head and a recording apparatus that realize the displacement of the actuator based on a new principle. .

  An inkjet head according to an aspect of the present invention includes a base body in which a pressurizing chamber is configured by a recess formed in a predetermined surface, an actuator stacked on the predetermined surface so as to close the pressurizing chamber, and the actuator. A drive signal output unit for applying a voltage, and the actuator includes a diaphragm overlaid on the predetermined surface, a common electrode overlaid on the diaphragm, and a piezoelectric body overlaid on the common electrode, An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in the center of the pressurizing chamber in plan view; and an outer side that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view An outer electrode having an electrode body, a first region of the piezoelectric body overlapping the individual electrode body, and a second region positioned between the individual electrode body and the outer electrode body of the piezoelectric body. Is configured such that the stacking direction of the actuators is a polarization direction, and the drive signal output unit applies a voltage between the individual electrode and the common electrode in the polarization direction of the first region, A deformation addition voltage application is performed, in which a voltage is applied between the individual electrode and the outer electrode in a direction in which shear deformation occurs in a region where the region is closer to the first region.

  Preferably, the first region and the second region have polarization directions opposite to each other, and the outer electrode and the common electrode are set to the same potential when the deformation addition voltage is applied.

  Preferably, the drive signal output unit applies a voltage between the individual electrode and the common electrode in applying the modified addition voltage, and makes the potential of the outer electrode different from the potential of the common electrode. A voltage is applied between the individual electrode and the outer electrode.

  Preferably, the first region and the second region have the same polarization direction.

  Preferably, the drive signal output unit is configured so that the potential of the individual electrode is equal to the potential of the common electrode and the second region is closer to the first region before the deformation addition voltage is applied. A voltage is applied between the individual electrode and the outer electrode in a direction in which shear deformation is located on the opposite side of the chamber.

  Preferably, the drive signal output unit starts voltage application in the polarization direction of the first region when applying the deformation addition voltage, and the second region is positioned closer to the pressurizing chamber as the first region is closer to the first region. It delays with respect to the start of voltage application in the direction in which shear deformation occurs.

  An inkjet head according to an aspect of the present invention includes a base body in which a pressurizing chamber is configured by a recess formed in a predetermined surface, and an actuator that is stacked on the predetermined surface so as to close the pressurizing chamber. The actuator includes a diaphragm overlaid on the predetermined surface, a common electrode overlaid on the diaphragm, a piezoelectric body overlaid on the common electrode, and a piezoelectric body overlaid on the piezoelectric body. An individual electrode having an individual electrode body extending on the center side of the pressure chamber, and an outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view, The first region of the piezoelectric body that overlaps the individual electrode main body has a polarization direction that is the stacking direction of the actuator, and the second region that is located between the individual electrode main body and the outer electrode main body of the piezoelectric body is Is the opposite direction as the polarizing direction of the polarization direction of the first region.

  Preferably, the outer electrode and the common electrode are connected to each other and have the same potential.

  Preferably, the third region of the piezoelectric body overlapping the outer electrode body is not polarized.

  A recording apparatus according to an aspect of the present invention includes a base body in which a pressurizing chamber is configured by a recess formed on a predetermined surface, an actuator stacked on the predetermined surface so as to close the pressurizing chamber, and the actuator. A drive signal output unit for applying a voltage, and the actuator includes a diaphragm overlaid on the predetermined surface, a common electrode overlaid on the diaphragm, and a piezoelectric body overlaid on the common electrode, An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in the center of the pressurizing chamber in plan view; and an outer side that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view A first region that overlaps the individual electrode main body of the piezoelectric body, and a second region that is located between the individual electrode main body and the outer electrode main body of the piezoelectric body. Is the above The stacking direction of the tutor is a polarization direction, and the drive signal output unit applies a voltage between the individual electrode and the common electrode in the polarization direction of the first region, and the second region A voltage is applied between the individual electrode and the outer electrode in a direction in which shear deformation is located closer to the first region toward the pressurizing chamber.

  According to said structure, the displacement of an actuator is realizable based on a new principle.

FIG. 2 is a perspective view schematically illustrating a main part of the recording apparatus according to the first embodiment of the invention. FIG. 2 is a cross-sectional view of a part of an ink jet head of the recording apparatus of FIG. 1. The top view of the actuator of the inkjet head of FIG. 4A and 4B are schematic diagrams for explaining the polarization direction and the voltage application direction in the actuator. FIG. 5A and FIG. 5B are schematic diagrams showing a relationship between a general polarization direction and an electric field direction. Sectional drawing which shows typically the principal part of the recording device which concerns on the 2nd Embodiment of this invention. FIG. 7A to FIG. 7C are views showing pressure and driving signal patterns in the pressurizing chamber in the recording apparatus of FIG. FIG. 8A to FIG. 8D schematically show the displacement of the actuator in the recording apparatus of FIG. Sectional drawing which shows typically the principal part of the recording device which concerns on the 3rd Embodiment of this invention. FIG. 10A to FIG. 10C are diagrams showing the pressure of the pressurizing chamber and the drive signal pattern in the recording apparatus of FIG. Sectional drawing which shows typically the principal part of the recording device which concerns on the 4th Embodiment of this invention. FIG. 12A and FIG. 12B are diagrams showing the displacement of the comparative example. FIG. 13A and FIG. 13B are diagrams showing the displacement of the example in which the area of the second region is changed. FIG. 14A and FIG. 14B are diagrams showing the displacement of the example in which the area of the third region is changed. FIG. 15A and FIG. 15B are diagrams showing the amount of deformation in 15 modes of the embodiment. FIG. 16A and FIG. 16B are diagrams showing the displacement of the embodiment in which the area of the second region is made smaller. FIG. 17A and FIG. 17B are diagrams showing the displacement of the example in which the third region is not polarized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that, in the embodiment to be described, the same or similar configuration as the configuration of the already described embodiment may be denoted by the same reference numeral, and the description may be omitted.

<First Embodiment>
FIG. 1 is a perspective view schematically showing a main part of a recording apparatus 1 according to the first embodiment of the present invention.

  The recording device 1 and the inkjet head 5 to be described later may be either upward or downward, but hereinafter, for convenience, the orthogonal coordinate system xyz is defined and the z-direction normal direction is defined. The term “upper surface” or “lower surface” may be used with the side (upper side in FIG. 1) as the upper side.

  The recording apparatus 1 includes, for example, a transport unit 3 that transports a medium (for example, paper) 101 in a direction indicated by an arrow y1, a head 5 that ejects ink droplets toward the transported medium 101, and the transport unit 3 and the head. 5 and a control unit 7 for controlling the operation of 5.

  For example, the transport unit 3 transports a plurality of media 101 stacked on a supply stack (not shown) one by one to a discharge stack (not shown). The transport unit 3 may have a known appropriate configuration. In FIG. 1, the conveyance path is a straight path, and a conveyance unit provided with a roller 9 that contacts the medium 101 and a motor 11 that rotates the roller 9 is illustrated.

  The head 5 is disposed in the middle of the conveyance path of the medium 101 and faces the medium 101 from the positive side in the z direction. The head 5 may be a serial head that performs a shuttle motion in a direction (main scanning direction, x direction) orthogonal to the printing screen and the conveyance direction of the medium 101, or a line fixed (substantially) in the orthogonal direction. It may be a head. In the present embodiment, the case where the head 5 is a line head will be described as an example.

  The head 5 ejects and attaches ink droplets to the medium 101 at a plurality of positions in the x direction. By repeating this operation as the medium 101 is conveyed, a two-dimensional image is formed on the medium 101.

  The control unit 7 includes, for example, a CPU, a ROM, a RAM, and an external storage device. The controller 7 applies a desired voltage to the motor 11 by outputting a control signal to the motor driver 13 to control the motor 11. Similarly, the control unit 7 outputs a control signal to the head driver 15 to apply a desired voltage to the head 5 to control the head 5.

  The head driver 15 or a part of the head driver 15 and the control unit 7 generates a drive signal (voltage applied to the head 5) according to a drive pattern (waveform) stored in advance and outputs the drive signal to the head 5 The drive signal output unit 8 is configured. The drive signal output unit 8 is configured by, for example, a driver IC or a circuit board.

  In FIG. 1, the drive signal output unit 8 and the head 5 are illustrated as being separate from each other. However, part or all of the drive signal output unit 8 may be mounted on the head 5. In this case, the whole of the head 5 and the part (part or all) of the drive signal output unit 8 mounted on the head 5 may be regarded as constituting the head 6 in a broad sense.

  FIG. 2 is a schematic cross-sectional view (corresponding to the line II-II in FIG. 3) showing a part of the head 5 in an enlarged manner. 2 is the side facing the medium 101. In FIG.

  The head 5 is a piezo-type head that applies pressure to ink by mechanical distortion of a piezoelectric element. The head 5 has a plurality of ejection elements 19 that eject ink droplets, and FIG. 2 shows one ejection element 19. For example, the plurality of ejection elements 19 are arranged in the xy plane, and each ejection element 19 corresponds to one dot on the medium 101.

  In another aspect, the head 5 includes a base 21 that forms a space for storing ink, and an actuator 23 that applies pressure to the ink stored in the base 21. The plurality of ejection elements 19 includes a base 21 and an actuator 23.

  A plurality of individual channels 25 (one is shown in FIG. 2) and a common channel (reservoir) 27 communicating with the plurality of individual channels 25 are formed inside the base 21. The individual flow path 25 is provided for each ejection element 19, and the common flow path 27 is provided in common for the plurality of ejection elements 19.

  Each individual flow path 25 includes a descender (partial flow path) 29 including a discharge hole 29 a facing the medium 101, a pressurization chamber 31 that communicates with the descender 29, and a supply that communicates the pressurization chamber 31 and the common flow path 27. And a path 33.

  The pressurizing chamber 31 is constituted by a recess formed in the upper surface 21 a of the base body 21. The pressurizing chamber 31 has its upper opening blocked by the actuator 23 being superimposed on the upper surface 21a.

  The plurality of individual channels 25 and the common channel 27 are filled with ink. When the volumes of the plurality of pressurizing chambers 31 change and pressure is applied to the ink, the ink is sent from the plurality of pressurizing chambers 31 to the plurality of descenders 29, and a plurality of ink droplets are ejected from the plurality of ejection holes 29a. Is discharged. In addition, the plurality of pressurizing chambers 31 are replenished with ink from a common flow path 27 via a plurality of supply paths 33.

  The cross-sectional shape or planar shape of the plurality of individual channels 25 and the common channel 27 may be set as appropriate. In the present embodiment, the pressurizing chamber 31 is formed to have a constant thickness in the z direction, and is a rhombus (see FIG. 3) having the x direction and the y direction as diagonal directions when viewed in the z direction. One corner of the rhombus in the y direction communicates with the descender 29, and the other corner communicates with the supply path 33.

  A part of the supply path 33 has a smaller cross-sectional area perpendicular to the flow direction than the common flow path 27 and the pressurizing chamber 31. The squeezing suppresses the back flow of the ink so that the vibration flow of the ink becomes stronger on the descender 29 side, or contributes to the attenuation of the ink vibration flow.

  The base body 21 is configured, for example, by stacking a plurality of substrates 35. The substrate 35 is formed with through holes constituting a plurality of individual channels 25 and a common channel 27. The thickness and the number of layers of the plurality of substrates 35 may be appropriately set according to the shapes of the plurality of individual channels 25 and the common channel 27. The plurality of substrates 35 may be formed of an appropriate material, for example, formed of metal, ceramic, or silicon.

  A part of the actuator 23 has a configuration similar to a so-called unimorph type piezoelectric element, and the diaphragm 37, the common electrode 39, the piezoelectric body 41, and a plurality of individual layers stacked in order from the pressurizing chamber 31 side. An electrode 43 is provided. Further, the actuator 23 has a plurality of outer electrodes 45 stacked on the piezoelectric body 41 as a configuration not found in a general unimorph type piezoelectric element.

  The diaphragm 37, the common electrode 39, and the piezoelectric body 41 are provided in common to the plurality of pressurizing chambers 31 so as to cover the plurality of pressurizing chambers 31, for example. On the other hand, the individual electrode 43 and the outer electrode 45 are provided for each pressurizing chamber 31.

  The diaphragm 37, the common electrode 39, the piezoelectric body 41, the individual electrode 43, and the outer electrode 45 may be formed of an appropriate material. For example, the diaphragm 37 is made of ceramic, silicon oxide, or silicon nitride. The common electrode 39, the individual electrode 43, and the outer electrode 45 are made of, for example, platinum or palladium. The piezoelectric body 41 is made of ceramic such as PZT (lead zirconate titanate).

  FIG. 3 is a plan view of the actuator 23.

  The individual electrode 43 has an individual electrode main body 43a having a width extending over a portion of the center side of the pressurizing chamber 31, and an individual electrode lead-out portion 43b that is led out from the individual electrode main body 43a to the outside of the pressurizing chamber 31. ing. The individual electrode body 43a may be regarded as an individual electrode (in a narrow sense).

  The individual electrode main body 43a has, for example, a similar shape (generally a rhombus in this embodiment) having a smaller area than the pressurizing chamber 31. The individual electrode lead-out portion 43b extends, for example, from the diamond-shaped corner of the individual electrode main body 43a in the diagonal direction of the diamond (for example, the direction of the diagonal connecting the descender 29 and the supply path 33), and the area is enlarged at the end. .

  The outer electrode 45 includes an outer electrode main body 45a disposed outside the individual electrode main body 43a, and an outer electrode lead portion 45b extending further outward from the outer electrode main body 45a. The outer electrode main body 45a may be regarded as an outer electrode (in a narrow sense).

  The outer electrode body 45a has a shape surrounding the individual electrode body 43a, for example. When the outer electrode main body 45a surrounds the individual electrode main body 43a, the outer electrode main body 45a only needs to cover a range exceeding 180 ° in total at an angle around the centroid of the individual electrode main body 43a. Preferably, it is 270 degrees or more.

  In the present embodiment, the outer electrode main body 45a has a shape with a cut 45c that allows the individual electrode lead-out portion 43b to be pulled out of the outer electrode main body 45a, and surrounds the entire individual electrode main body 43a. Yes. The width of the cut 45c is, for example, a distance at which the insulation between the individual electrode lead portion 43b and the outer electrode main body 45a is sufficiently and sufficiently ensured from the viewpoint of electrode formation accuracy, dielectric breakdown, and the like.

  The inner edge of the outer electrode main body 45a (the edge on the individual electrode main body 43a side) has, for example, a similar shape to the individual electrode main body 43a. Therefore, the distance between the individual electrode main body 43a and the inner edge of the outer electrode main body 45a is constant over the periphery of the individual electrode main body 43a. Further, the outer edge of the outer electrode body 45a is similar to the inner edge (and the individual electrode body 43a), for example. In other words, the outer electrode body 45a has a constant width. The outer electrode main body 45 a has an outer edge that substantially coincides with the edge of the pressurizing chamber 31 and is accommodated in the pressurizing chamber 31.

  The outer electrode lead part 45b extends, for example, from the rhombus corner of the outer electrode main body 45a in the diagonal direction of the rhombus, and the area is enlarged at the end. Further, the outer electrode lead part 45b extends, for example, in the direction opposite to the individual electrode lead part 43b.

  4A and 4B are schematic diagrams (corresponding to a cross-sectional view taken along the line IV-IV in FIG. 3) for explaining the polarization direction and the voltage application direction in the actuator 23. FIG. In order to make it easy to see the arrows indicating the polarization direction and the voltage application direction, cross-sectional hatching is omitted.

  As shown by arrows a1 and a2 in FIG. 4A, the piezoelectric body 41 includes a first region R1 where the individual electrode main body 43a overlaps, and a second region located between the individual electrode main body 43a and the outer electrode main body 45a. The state of polarization is different between R2 and the third region R3 where the outer electrode body 45a overlaps (for convenience, the terms of the first region R1 to the third region R3 may also be used for the actuator 23 and the like). ). Specifically, it is as follows.

  In the first region R <b> 1, the piezoelectric body 41 has a polarization direction in a stacking direction of members constituting the actuator 23 (thickness direction of the piezoelectric body 41, z direction). The polarization direction may be upward (direction opposite to the pressurizing chamber 31 and positive side in the z direction) or downward (direction toward the pressurizing chamber 31 and negative side in the z direction). In the present embodiment, the downward direction will be described as an example.

  Further, in the piezoelectric region 41, in the second region R2, the direction opposite to the polarization direction of the first region R1 is the polarization direction. That is, in the present embodiment, the direction in which the actuators 23 are stacked and the direction opposite to the pressurizing chamber 31 (the positive side in the z direction) is the polarization direction.

  In addition, in the piezoelectric body 41, the polarization state of the third region R3 may be set as appropriate, but is preferably not polarized. That is, in the third region R3, a plurality of domains having different polarization directions are formed, the polarizations cancel each other, and the piezoelectric effect as a whole is not exhibited.

  Note that the polarization states of the regions other than the above may be set as appropriate, and may be the same as the polarization states of any of the first region R1 to the third region R3, or the first region R1 to the first region. It may be different from all the polarization states of the three regions R3.

  The drive signal output unit 8 can apply a voltage between the individual electrode 43 and the common electrode 39. Therefore, as indicated by an arrow a5 in FIG. 4B, an electric field is formed in the first region R1 of the piezoelectric body 41 with the stacking direction of the actuators 23 as the electric field direction.

  For example, the drive signal output unit 8 applies a voltage between the individual electrode 43 and the common electrode 39 so that the electric field is formed in the same direction as the polarization direction of the piezoelectric body 41 (downward in the present embodiment). . That is, in the present embodiment, the drive signal output unit 8 makes the potential of the individual electrode 43 higher than the potential of the common electrode 39.

  On the other hand, the outer electrode 45 is connected to the common electrode 39 and has the same potential as the common electrode 39. Therefore, as indicated by an arrow a6 in FIG. 4B, due to the potential difference between the individual electrode 43 and the outer electrode 45, in the second region R2 of the piezoelectric body 41, the direction orthogonal to the stacking direction of the actuators 23 ( An electric field having an electric field direction in the direction along the xy plane) is formed. More specifically, in the present embodiment, when the potential of the individual electrode 43 is higher than the potential of the outer electrode 45, an electric field having an electric field direction from the first region R1 side to the outer side is formed. .

  Note that the potential of the common electrode 39 is, for example, a reference potential. The reference potential is 0V, for example. Therefore, applying a voltage between the individual electrode 43 and the common electrode 39 is equivalent to outputting a drive signal (a signal constituted by a potential difference with respect to the reference potential) to the individual electrode 43. In the following, it is assumed that the application of a voltage between electrodes is expressed by the output of a drive signal to the electrodes.

  Further, the connection between the outer electrode 45 and the common electrode 39 may be performed in the drive signal output unit 8 or may be performed in the head 5. When the connection is made in the head 5, the connection is made by, for example, a via conductor penetrating the piezoelectric body 41, a conductor arranged on the surface of the piezoelectric body 41, or a conductive wire arranged around the piezoelectric body.

  FIG. 5A and FIG. 5B are schematic diagrams showing a relationship between a general polarization direction and an electric field direction.

  In FIG. 5A, the polarization direction of the piezoelectric body 141 (arrow a11) and the direction of the voltage applied to the piezoelectric body 141 (electric field direction, arrow a15) are the same direction. In this case, as indicated by the dotted line L1, the piezoelectric body 141 undergoes deformation that expands in the polarization direction and deformation that contracts in the direction orthogonal to the polarization direction. Hereinafter, deformation (spreading vibration) in a direction orthogonal to the polarization direction is referred to as 31-mode deformation.

  In FIG. 5B, the polarization direction (arrow a12) of the piezoelectric body 141 is orthogonal to the direction of the voltage applied to the piezoelectric body 141 (electric field direction, arrow a16). In this case, as indicated by the dotted line L2, the piezoelectric body 141 has small angles at the corners in the positive direction of the polarization direction and the positive direction of the electric field direction, and the corner portions of the negative direction of the polarization direction and the negative direction of the electric field direction. Shear deformation is generated. Hereinafter, shear deformation (thickness shear vibration) in the polarization direction is referred to as 15-mode deformation.

  Here, returning to FIGS. 4A and 4B, in the first region R1 of the piezoelectric body 41, the polarization direction indicated by the arrow a1 and the electric field direction indicated by the arrow a5 are the same direction. The 31-mode deformation shown in FIG. That is, the piezoelectric body 41 shrinks along the xy plane in the first region R1. Since the reduction of the piezoelectric body 41 is constrained by the vibration plate 37, the reduction deformation is converted into bending deformation that causes the actuator 23 to protrude toward the pressurizing chamber 31 as shown by a dotted line L5 in FIG. The

  On the other hand, in the second region R2 of the piezoelectric body 41, the polarization direction indicated by the arrow a2 and the electric field direction indicated by the arrow a6 are orthogonal to each other, so that the 15-mode deformation shown in FIG. 5B occurs. That is, as shown by the dotted line L6 in FIG. 4B, the piezoelectric body 41 undergoes shear deformation such that the first region R1 side and the pressurizing chamber 31 side have an acute angle in the second region R2. As a result, the actuator 23 protrudes toward the pressurizing chamber 31 side.

  The actuator 23 projects into the pressurizing chamber 31 by a displacement obtained by adding the displacement resulting from the 31-mode deformation and the displacement resulting from the 15-mode deformation. As a result, the volume of the pressurizing chamber 31 changes and pressure is applied to the ink in the pressurizing chamber 31.

  The pattern (waveform) of the drive signal output to the individual electrode 43 (potential difference with respect to the potential of the common electrode 39 (reference potential)) may be appropriately selected from known ones. For example, the drive signal may be a signal that realizes a so-called driving method or a signal that realizes a driving method. The drive signal may vary both positively and negatively with respect to the reference potential.

  According to the first embodiment described above, the actuator 23 of the head 6 includes the vibration plate 37, the common electrode 39, the piezoelectric body 41, the individual electrode 43, and the outer electrode 45 that are sequentially stacked on the upper surface 21 a. The first region R1 that overlaps the individual electrode main body 43a of the piezoelectric body 41 and the second region R2 that is located between the individual electrode main body 43a and the outer electrode main body 45a of the piezoelectric body 41 have the stacking direction of the actuator 23 as the polarization direction. ing. The drive signal output unit 8 applies a voltage between the individual electrode 43 and the common electrode 39 in the polarization direction of the first region R1, while the second region R2 is positioned closer to the pressurizing chamber 31 toward the first region R1. A voltage is applied between the individual electrode 43 and the outer electrode 45 in a direction in which shear deformation occurs (hereinafter, such voltage application is referred to as “deformation addition voltage application” for convenience).

  Therefore, the displacement of the actuator 23 can be suitably realized by using the 31-mode deformation and the 15-mode deformation in combination. For example, a high pressure can be applied to the actuator 23 by adding these deformations.

  In the first region R1 and the second region R2, the polarization directions are opposite to each other, and the outer electrode 45 and the common electrode 39 are set to the same potential when the deformation addition voltage is applied. Therefore, the displacement due to the 31-mode deformation and the displacement due to the 15-mode deformation can be added simply by making the potential of the individual electrode 43 higher (or lower) than the potential of the other electrodes. It can be simplified.

  Since the actuator 23 operates as described above, the 15-mode deformation can be increased by making the second region R2 fit in the pressurizing chamber 31 in plan view. Since the electric field generated in the second region R2 and the piezoelectric driving by the electric field are substantially determined by the inner shape of the outer electrode main body 45a and the shape of the individual electrode main body 43a, the outer shape of the outer electrode main body 45a is particularly in this respect. There are no restrictions. However, if the outer electrode main body 45a is made thinner, the presence of the outer electrode main body 45a reduces the influence of the actuator 23 becoming difficult to deform, so that the displacement can be increased. Further, if the outer position of the outer electrode body 45 a is the same position as the end of the pressurizing chamber 31, the outer position of the outer electrode body 45 a is set to the inner side with respect to the end of the pressurizing chamber 31 due to manufacturing variations. Therefore, the outer electrode body 45a may have a shape that can be accommodated in the pressurizing chamber 31 in a plan view, or conversely, the outer electrode body 45a. The shape of the outer side of the main body 45a is preferably large enough to accommodate the pressurizing chamber 31 in plan view.

  The third region R3 overlapping the outer electrode body 45a of the piezoelectric body 41 is not polarized. Accordingly, it is possible to suppress an unexpected operation due to the deformation of the third region R3 and its change with time.

<Second Embodiment>
FIG. 6 is a cross-sectional view (corresponding to FIG. 4A) schematically showing the main part of the recording apparatus 201 according to the second embodiment of the present invention.

  Compared to the configuration of the recording apparatus 1 of the first embodiment, the configuration of the recording apparatus 201 is such that the drive signal output unit 208 can individually output a drive signal to the individual electrode 43 and the outer electrode 45. Only the difference.

  That is, the drive signal output unit 208 can apply a voltage between the individual electrode 43 and the common electrode 39 using the common electrode 39 as a reference potential, and independently of this, the outer electrode 45 and the common electrode 39 A voltage can be applied with the common electrode 39 as a reference potential.

  The drive signal output unit 208 can apply a voltage between the individual electrode 43 and the outer electrode 45 by making the potential of the individual electrode 43 and the potential of the outer electrode 45 different from each other.

  In other words, the drive signal output unit 208 can apply a voltage between the individual electrode 43 and the common electrode 39, and makes the potential of the outer electrode 45 different from the potential of the common electrode 39 (the first electrode In the embodiment, the potential of the outer electrode 45 remains the same as the potential of the common electrode 39). A voltage can be applied between the individual electrode 43 and the outer electrode 45.

  Note that the drive signal output unit 208 may be mounted on the head 5, and that when mounted, the head 5 and the drive signal output unit 208 may be regarded as the head 206 in a broad sense. It is the same.

  Hereinafter, an example of the drive signal output from the drive signal output unit 208 and the operation of the actuator 23 based on the drive signal will be described. As described in the first embodiment, the polarization direction of the piezoelectric body 41 may be opposite to the direction shown in FIG. 6, but will be described below according to the polarization direction in FIG. In the case where the polarization direction is opposite to that in FIG. 6, the sign of the drive signal (potential) described below may be reversed.

  FIG. 7A is a diagram showing a pressure change in the pressurizing chamber 31, FIG. 7B is a diagram showing a drive signal output to the individual electrode 43, and FIG. It is a figure which shows the drive signal output to the electrode. In these drawings, the horizontal axis indicates time t. In FIG. 7A, the vertical axis indicates the pressure P in the pressurizing chamber 31. In the vertical axis, the pressure in the standby state where the actuator 23 is not driven (strictly, it is a negative pressure) is approximately zero. 7B and 7C, the vertical axis indicates the signal level (voltage V, potential difference with respect to the potential of the common electrode 39).

  8A to 8D are diagrams schematically showing displacement of the actuator 23. FIG. The bold lines indicate the first region R1 and the second region R2 of the actuator 23. The lower side of the drawing in these drawings is the pressurizing chamber 31 side.

  Time points t0 to t1 in FIGS. 7A to 7C are in a standby state. That is, the individual electrode 43 and the outer electrode 45 are set to the reference potential, and the actuator 23 is not displaced (FIG. 8A). Therefore, no pressure fluctuation occurs in the pressurizing chamber 31.

  From time t1 to t2, the individual electrode 43 is maintained at the reference potential (FIG. 7B), and a positive pulse is output to the outer electrode 45 (FIG. 7C). Therefore, the potential of the outer electrode 45 is higher than that of the individual electrode 43, and the actuator 23 is displaced to the opposite side of the pressurizing chamber 31 by the 15-mode deformation in the second region R2, as shown in FIG. 8B. To do. As a result, the pressure in the pressurizing chamber 31 becomes a negative pressure (FIG. 7A). The pulse width (the time from the time point t1 to the time point t2) is, for example, about the time AL (Acoustic Length) in which the pressure wave is transmitted from the discharge hole 29a to the supply passage 33.

  At time t2, a negative pulse is output to the outer electrode 45 (FIG. 7C). Therefore, contrary to the time points t1 to t2, the potential of the outer electrode 45 is lower than that of the individual electrode 43. As shown in FIG. 8C, the actuator 23 is deformed by the 15-mode deformation in the second region R2. Displacement toward the pressurizing chamber 31 side. As a result, the pressure in the pressurizing chamber 31 is positive (FIG. 7A). The pulse width (time from time t2 to time t4) is, for example, about AL.

  When the pressure in the pressurizing chamber 31 becomes positive, the ink in the pressurizing chamber 31 flows toward the ejection holes 29a. Further, since the positive pressure is applied to the ink in the pressurizing chamber 31 in accordance with the phase in which the negative pressure wave (t1 to t2) in the pressurizing chamber 31 is reversed, the amplitude of the ink flow is doubled.

  At time t3, a positive pulse is output to the individual electrode 43 (FIG. 7B). Therefore, as shown in FIG. 8D, the actuator 23 is displaced (bends) toward the pressurizing chamber 31 due to the 31-mode deformation in the first region R1. Then, the displacement due to the 31-mode deformation is added to the displacement due to the 15-mode deformation, and the pressure applied to the pressurizing chamber 31 increases (FIG. 7A). The pulse width (time from the time point t3 to the time point t4) is, for example, an appropriate size less than AL.

  Thereafter, at time t4, the potentials of the individual electrode 43 and the outer electrode 45 are set to the reference potential (FIGS. 7A and 7B). As a result, the actuator 23 returns to the state shown in FIG. Further, the pressure in the pressurizing chamber 31 also returns to the standby pressure (FIG. 7A, time point t5).

  The time point t4 may be an arbitrary time point after the pressure in the pressurizing chamber 31 reaches the maximum. In the present embodiment, since the time t4 is before the time t5 when the pressure returns to the standby pressure, the trailing edge of the pressure wave in which the falling portion of the pulse proceeds toward the discharge hole 29a It is preferable that it functions as a cancel pulse for pulling back. The timing at which the individual electrode 43 and the outer electrode 45 are set to the reference potential may be shifted from each other.

  Note that, as indicated by a dotted line L11 in FIG. 7C, the absolute value of the potential of the outer electrode 45 may be lowered from time t3 to time t4. For example, the absolute value of the potential of the outer electrode 45 may be lowered so that the potential difference between the individual electrode 43 and the outer electrode 45 becomes equal at the time points t3 to t4 and the time points t2 to t3.

  In this case, since the voltage applied to 2nd area | region R2 can be lowered | hung, it is suppressed that the polarization state in 2nd area | region R2 changes. In addition, the aspect in which the absolute value of the potential of the outer electrode 45 shown by the solid line is not lowered is preferable from the viewpoint of increasing the deformation amount of the 15 mode.

  According to the second embodiment described above, the drive signal output unit 208 applies a voltage between the individual electrode 43 and the common electrode 39 in the polarization direction of the first region R1, while the second region R2 is the first region R1. A voltage is applied between the individual electrode 43 and the outer electrode 45 in a direction in which shear deformation is located closer to the region R1 toward the pressurizing chamber 31 (deformation addition voltage application is performed, t3 to t4). The same effect as in the embodiment can be obtained. That is, the displacement of the actuator 23 can be suitably realized by using the 31-mode deformation and the 15-mode deformation in combination.

  The drive signal output unit 208 can apply a voltage between the individual electrode 43 and the common electrode 39, and makes the potential of the outer electrode 45 different from the potential of the common electrode 39. Since it is possible to apply a voltage during this period, as illustrated in the embodiment, it is more preferable to drive only one of the 31-mode deformation and the 15-mode deformation, or to shift the timing of these deformations. A driving method can be realized.

  Prior to the application of the modified addition voltage, the drive signal output unit 208 makes the potential of the individual electrode 43 equal to the potential of the common electrode 39, while the second region R2 is closer to the first region R1 side than the pressurizing chamber 31. A voltage is applied between the individual electrode 43 and the outer electrode 45 in the direction in which shear deformation is located (t1 to t2).

  Therefore, the volume of the pressurizing chamber 31 can be reduced following the expansion of the volume, and the vibration of the ink flow can be increased as in the so-called pulling type. In addition, the following advantageous effects can be obtained as compared with a pulling type in an actuator that uses only general 31-mode deformation.

  In a general pulling type, application of a voltage in the polarization direction to the first region R1 is continued in a standby state until the discharge timing comes. That is, the actuator stands by in a state of being bent toward the pressurizing chamber 31 side. When the discharge timing arrives, the application of voltage is stopped and the volume of the pressurizing chamber 31 is expanded, and then the volume of the pressurizing chamber 31 is reduced by applying the voltage again in the polarization direction. Therefore, the time during which the voltage is applied is long, the power consumption is likely to increase, and the deterioration is likely to be accelerated.

  On the other hand, in the present embodiment, since it is not necessary to stand by in a state where a voltage is applied as described above, it is expected that power consumption can be suppressed and the life of the actuator can be extended.

  Further, in a method similar to another punching method using only the 31-mode deformation, no voltage is applied to the first region R1 in the standby state. When the discharge timing arrives, a voltage is applied to the first region R1 in the direction opposite to the polarization direction to increase the volume of the pressurizing chamber 31, and then the voltage in the polarization direction to the first region R1. Is applied or voltage application is stopped, and the volume of the pressurizing chamber 31 is reduced. Therefore, a voltage is applied in the direction opposite to the polarization direction, which may cause deterioration of the polarization state.

  On the other hand, in this embodiment, since it is not necessary to apply a voltage to the first region R1 in the direction opposite to the polarization direction, deterioration of the polarization state is suppressed.

  The drive signal output unit 208 applies a deformation addition voltage to start the voltage application in the polarization direction of the first region R1 (t3), and shear the second region R2 closer to the pressurizing chamber 31 as the first region R1 side. Delay with respect to the start of voltage application (t2) in the direction in which deformation occurs.

  Therefore, the discharge speed is improved as compared with the case where both start timings are set at the same time. Specifically, it is as follows. Considering only the propagation of the pressure wave, it is ideal that both start timings be the same. However, in actuality, the pressure wave is transmitted, and at the same time, the ink flows toward the ejection holes 29a. Therefore, when pressure is applied to match the flow, the pressure transmission becomes smoother and the discharge speed increases. In other words, when ink flows, new ink is drawn into the pressurizing chamber 31, but this amount of ink slows the flow of ink toward the ejection holes 29a. Therefore, the ink flow can be made faster by delaying the 31-mode deformation start timing with respect to the 15-mode deformation start timing so as to apply pressure to the newly introduced liquid.

<Third Embodiment>
FIG. 9 is a cross-sectional view (corresponding to FIG. 4A) schematically showing the main part of the recording apparatus 301 according to the third embodiment of the present invention.

  The head 305 of the recording apparatus 301 is different from the head 5 of the first embodiment only in the polarization direction of the second region R2. That is, in the piezoelectric body 341 of the actuator 323 of the head 305, the polarization direction (arrow a1) in the first region R1 and the polarization direction (arrow a2) in the second region R2 are the same (downward in this embodiment). Yes.

  The drive signal output unit 208 of the recording apparatus 301 can output drive signals individually to the individual electrode 43 and the outer electrode 45 as in the second embodiment. However, the pattern of the drive signal is different from that of the second embodiment as will be described later.

  It should be noted that the drive signal output unit 208 may be mounted on the head 305, and in that case, the head 305 and the drive signal output unit 208 may be regarded as the head 306 in a broad sense, as in other embodiments. It is the same.

  Hereinafter, an example of the drive signal output by the drive signal output unit 208 in the third embodiment and the operation of the actuator 323 according to the drive signal will be described. As in the other embodiments, the polarization direction of the piezoelectric body 341 may be opposite to the direction shown in FIG. 9, but the following description will be made according to the polarization direction of FIG. Note that when the polarization direction is opposite to that in FIG. 9, the sign of the drive signal (potential) described below may be reversed.

  FIGS. 10A to 10C are diagrams showing patterns of pressure and drive signals in the pressurizing chamber 31 in the third embodiment (FIGS. 7A to 7C of the second embodiment). Equivalent to)).

  As understood from the comparison between FIG. 10A and FIG. 7A, the operation of the actuator 423 of the third embodiment is the same as the operation of the actuator 23 of the second embodiment. However, the signal level of the drive signal differs depending on the polarization direction of the second region R2. In addition, since the figure which showed the displacement of the actuator 423 typically is the same as FIG. 8 (a)-FIG.8 (d), illustration is abbreviate | omitted and refer FIG.8 (a)-FIG.8 (d). I decided to.

  Times t0 to t1 are the same as in the second embodiment. That is, the potentials of the individual electrode 43 and the outer electrode 45 are set to the reference potential, and the actuator 423 is not deformed (FIG. 8A).

  At time points t1 to t2, the drive signal output unit 208 outputs a pulse to the outer electrode 45 so that the 15-mode deformation occurs in the direction in which the volume of the pressurizing chamber 31 increases as in the second embodiment. (FIG. 7 (c), FIG. 8 (b)). However, in correspondence with the polarization direction of the second region R2 being opposite to that of the second embodiment, the positive / negative of the signal level (voltage) of the pulse is negative opposite to the positive / negative of the second embodiment. .

  At time t2, the drive signal output unit 208 outputs a pulse to the outer electrode 45 so that the 15-mode deformation occurs in the direction in which the volume of the pressurizing chamber 31 decreases as in the second embodiment (see FIG. 7 (c), FIG. 8 (c)). However, like the time points t1 to t2, in correspondence with the polarization direction of the second region R2 being opposite to that of the second embodiment, the positive / negative of the signal level (voltage) of the pulse is the same as that of the second embodiment. It is the opposite of positive and negative.

  At time t3, the drive signal output unit 208 outputs a pulse to the individual electrode 43 so that the 31-mode deformation occurs in the direction of reducing the volume of the pressurizing chamber 31 as in the second embodiment (see FIG. 7 (b), FIG. 8 (d)).

  However, the pulse at this time is set so that the electric field direction in the first region R1 is the same as that in the second embodiment, and the electric field direction in the second region R2 is opposite to that in the second embodiment. Specifically, the pulse potential applied to the individual electrode 43 is set to be higher than the potential of the common electrode 39 (reference potential) and lower than the potential of the outer electrode 45. In other words, the potential of the pulse is on the positive side and the absolute value is lower than the absolute value of the potential of the outer electrode 45.

  At the time point t3, as indicated by the solid line L12 in FIG. 7C, the potential of the outer electrode 45 may also be changed to be high. For example, the potential of the outer electrode 45 is increased by the increase in the potential of the individual electrode 43 so that the potential difference between the outer electrode 45 and the individual electrode 43 is equal between the time points t2 to t3 and the time points t3 to t4. Good. Further, as indicated by a dotted line L13 in FIG. 7C, the potential of the outer electrode 45 may be constant over a period of time t2 to t4.

  In the case of the potential indicated by the solid line L12, the 15-mode deformation amount at the time points t3 to t4 is ensured. In the case of the potential indicated by the dotted line L13, since a high voltage is not applied to the third region R3, changes such as the displacement amount in the subsequent drive, which are caused by the change in the polarization state of the third region R3, are suppressed.

  According to the third embodiment described above, the drive signal output unit 208 applies a voltage between the individual electrode 43 and the common electrode 39 in the polarization direction of the first region R1, while the second region R2 is the first region R2. A voltage is applied between the individual electrode 43 and the outer electrode 45 in a direction in which shear deformation is located closer to the region R1 toward the pressurizing chamber 31 (deformation addition voltage application is performed). The same effect as in the embodiment can be obtained. That is, the displacement of the actuator 23 can be suitably realized by using the 31-mode deformation and the 15-mode deformation in combination.

  Since the first region R1 that overlaps the individual electrode 43 of the piezoelectric body 341 and the second region R2 that is positioned between the individual electrode 43 and the outer electrode 45 of the piezoelectric body 341 have the same polarization direction. The polarization process is easy.

<Fourth Embodiment>
FIG. 11 is a cross-sectional view (corresponding to FIG. 4B) schematically showing the main part of a recording apparatus 401 according to the fourth embodiment of the present invention.

  The configuration itself of the recording apparatus 401 (head 406) may be the same as the configuration of the recording apparatus 201 of the second embodiment or the recording apparatus 301 of the third embodiment. However, the recording device 401 is different from the second and third embodiments in the drive signal pattern.

  Specifically, as shown by the thin dotted line L21 and the thick dotted line L22, when the volume of the pressurizing chamber 31 is reduced and ink is ejected, the 31-mode deformation in the first region R1 causes the first region R1 to change. The deformation is to be displaced toward the pressurizing chamber 31, and the 15-mode deformation in the second region R <b> 2 is a deformation that displaces the first region R <b> 1 to the side opposite to the pressurizing chamber 31. By performing the 31-mode deformation and the 15-mode deformation by appropriately setting the timing of the deformation and the like, it is possible to suitably form ink droplets.

<Comparative example and Example>
Regarding the head 6 of the first embodiment, simulation calculation is performed by changing the ratio of the first region R1, the second region R2, and the third region R3 to the area of the pressurizing chamber 31, and the pressurizing chamber 31 of the actuator 23 is calculated. The displacement at the center of was investigated.

  However, the polarization state of the third region R3 is assumed to be polarized in the stacking direction of the actuator 23 except for FIG. The voltage applied to the individual electrode 43 was 20V.

  12 to 17 show simulation results. Each figure (a) is a graph showing a simulation result, and the horizontal axis represents the area ratio of the area where the area is changed to the pressurizing chamber 31 (hereinafter simply referred to as the area ratio, the area relative to the pressurizing chamber 31). The vertical axis represents the displacement z of the actuator 23. Each figure (b) has shown the combination of the area ratio of each area | region corresponding to each plot of each figure (a), and the displacement z in the said combination.

  12 (a) and 12 (b) show the displacement of the comparative example. That is, the displacement z when the outer electrode 45 is not provided is shown. In FIG. 12B, the column R2 indicates the area between the individual electrode 43 and the edge of the pressurizing chamber 31 in plan view.

  12A and 12B, the area ratio of the first region R1 is changed. As a result, in the comparative example, when the area ratio of the first region R1 is 0.4, the displacement z is 75.5 nm, which is the maximum.

  FIGS. 13A and 13B show the displacement z of the embodiment when the area ratio of the second region R2 is changed. The area ratio of the first region R1 was set to 0.4 at which the displacement z was maximum in the comparative example (FIG. 12). The total area of the first region R1 to the third region R3 is equal to the total area of the pressurizing chamber 31.

  From FIG. 13, it is confirmed that the displacement z is increased as compared with the comparative example by adding the 15-mode deformation to the 31-mode deformation in the area ratio of the second region R2 of 0.1 to 0.4. It was done.

  FIGS. 14A and 14B show the displacement z of the embodiment when the area ratio of the third region R3 is changed. The area ratio of the first region R1 was set to 0.4 at which the displacement z was maximum in the comparative example (FIG. 12). Further, the area ratio of the second region R2 was set to 0.1 at which the displacement z was maximum in FIG.

  From FIG. 14, it is confirmed that when the area ratio of the third region R3 is in the range of 0.1 to 0.5, the displacement z is increased as compared with the comparative example by adding the 15-mode deformation to the 31-mode deformation. It was done.

  FIGS. 15A and 15B show only the contribution of 15 modes in the displacement z. In FIG. 15A and FIG. 15B, the area ratio of the second region R2 is made constant, and the total area of the first region R1 to the third region R3 is taken as the total area of the pressurizing chamber 31. The area ratio of the first region R1 (third region R3) was changed. The area ratio of the second region R2 was set to 0.1 at which the displacement z was maximum in FIG.

  In FIG. 15, when the area ratio of the first region R1 is 0.4, the maximum contribution of 15 modes in the displacement z is 63.5 nm. The area ratio 0.4 of the first region R1 is a condition that the contribution of the 31 modes in the displacement z is also maximized (FIG. 12).

  FIGS. 16A and 16B are obtained by changing the area ratio of the second region R2 as in FIG. 13, but the area ratio of the second region R2 is smaller than that of FIG. Other conditions are the same as in FIG.

  In FIG. 16, it was confirmed that even if the area ratio of the second region R2 is small (0.01), the effect of adding the 31-mode deformation and the 15-mode deformation is exerted.

  FIGS. 17A and 17B show the displacement z when the third region R3 is not polarized. Other conditions are the same as in FIG.

  From comparison between FIG. 17 and FIG. 14, in the state where the third region R3 is not polarized, the 31-mode deformation and the 15-mode deformation are added stably and preferably regardless of the area ratio of the third region R3. It was confirmed that the effect of

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The planar shapes of the pressurizing chamber, the individual electrode (main body), and the outer electrode (main body) may be set as appropriate, and are not limited to those exemplified in the embodiment. For example, the planar shape of the pressurizing chamber and the individual electrode may be a circle, an ellipse, or an oval.

  The outer electrode may not be provided for each pressurizing chamber. For example, as in the first embodiment, when the outer electrode is set to the same potential as the common electrode, a plurality of openings corresponding to the arrangement positions of the plurality of individual electrodes have the same width as the common electrode. An outer electrode (for example, a net-like electrode) formed with may be provided. In other words, a plurality of outer electrodes may be connected to each other, and the boundary may be ambiguous.

  The outer electrode (main body) may not surround the individual electrode (main body). For example, a non-frame-shaped outer electrode that is positioned only in a predetermined direction with respect to an individual electrode in a plan view is provided to cause anisotropy in displacement, or anisotropy of displacement caused by 31-mode deformation May be compensated.

  In the case where the outer electrode (main body) surrounds the individual electrode (main body), the outer electrode may not be continuous. That is, the outer electrode may be composed of a plurality of electrodes arranged around the individual electrode.

  In a plan view, the outer electrode (main body) (which surrounds or does not surround the individual electrode (main body)) may not have an inner edge and / or outer edge similar to the individual electrode (and / or pressure chamber), and may have a width. May not be constant. By making these different shapes with respect to the individual electrodes, anisotropy may be generated in the displacement, or the anisotropy of the displacement due to the 31-mode deformation may be compensated.

  In plan view, the positions of the inner and outer edges of the outer electrode (main body) (which surrounds or does not surround the individual electrode (main body)) may be set appropriately with respect to the pressurizing chamber, and the outer electrode is pressed in plan view. It doesn't have to be in the room. For example, the inner edge of the outer electrode may be aligned with the edge of the pressurizing chamber, and a region where bending deformation by the individual electrode and shear deformation by the outer electrode occur may be ensured to the maximum with respect to the area of the pressurizing chamber.

  The third region overlapping the outer electrode (main body) of the piezoelectric body may be polarized. The polarization direction may be the same as or opposite to the first region and / or the second region.

  The pattern of the drive signal is not limited to that exemplified in the embodiment. For example, as in the third embodiment, when the polarization direction is the same in the first region and the second region, the displacement to the pressurizing chamber due to the 31-mode deformation and the 15-mode deformation are caused. A pulling type or a pushing type, in which the displacement to the pressurizing chamber side is always simply added, may be performed. In addition, for example, in the second and third embodiments, prior to the application of the modified addition voltage that adds the deformation of the 31 mode and the deformation of the 15 mode, the volume of the pressurizing chamber is increased using the deformation of the 15 mode. However, the volume of the pressurizing chamber may be reduced by using 15-mode deformation, and the volume may be increased by releasing the 15-mode deformation at the time of discharge. For example, in the second and third embodiments, the 31-mode deformation start is delayed from the 15-mode deformation start, but these may be performed simultaneously.

DESCRIPTION OF SYMBOLS 5 ... Head, 6 ... Head (a drive signal output part is included), 8,208 ... Drive signal output part, 21 ... Base | substrate, 21a ... Upper surface, 23 ... Actuator, 31 ... Pressurization chamber, 37 ... Diaphragm, 39 ... Common Electrode, 41 ... piezoelectric body, 43 ... individual electrode, 45 ... outer electrode, R1 ... first region, R2 ... second region.

Claims (11)

A base body in which a pressurizing chamber is constituted by a recess formed on a predetermined surface;
An actuator overlaid on the predetermined surface so as to close the pressurizing chamber;
A drive signal output unit for applying a voltage to the actuator;
Have
The actuator is
A diaphragm overlaid on the predetermined surface;
A common electrode overlaid on the diaphragm;
A piezoelectric body overlaid on the common electrode;
An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in a center side of the pressurizing chamber in a plan view;
An outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view;
Have
The first region of the piezoelectric body that overlaps with the individual electrode body and the second region of the piezoelectric body that is located between the individual electrode body and the outer electrode body have a polarization direction that is a stacking direction of the actuator. And
The drive signal output unit applies the voltage between the individual electrode and the common electrode in the polarization direction of the first region, and overlaps the period in which the voltage is maximum . An ink jet head that performs deformation addition voltage application in which a voltage is applied between the individual electrode and the outer electrode in a direction in which shear deformation occurs in a region where the region is closer to the first region toward the pressurizing chamber. A base body in which a pressurizing chamber is constituted by a recess formed on a predetermined surface;
An actuator overlaid on the predetermined surface so as to close the pressurizing chamber;
A drive signal output unit for applying a voltage to the actuator;
Have
The actuator is
A diaphragm overlaid on the predetermined surface;
A common electrode overlaid on the diaphragm;
A piezoelectric body overlaid on the common electrode;
An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in a center side of the pressurizing chamber in a plan view;
An outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view;
Have
The first region of the piezoelectric body that overlaps with the individual electrode body and the second region of the piezoelectric body that is located between the individual electrode body and the outer electrode body have a polarization direction that is a stacking direction of the actuator. And
The drive signal output unit applies a voltage between the individual electrode and the common electrode in the polarization direction of the first region, and the second region is located closer to the pressurizing chamber side toward the first region side. A voltage is applied between the individual electrode and the outer electrode in a direction in which shear deformation occurs, and a deformation addition voltage is applied,
In the first region and the second region, the polarization directions are opposite to each other,
In applying the modified addition voltage, the outer electrode and the common electrode are set to the same potential.
Lee ink jet head. The drive signal output unit applies a voltage between the individual electrode and the common electrode in applying the modified addition voltage, and makes the potential of the outer electrode different from the potential of the common electrode. The inkjet head according to claim 1, wherein a voltage is applied between the outer electrode and the outer electrode. The inkjet head according to claim 3, wherein the first region and the second region have the same polarization direction. A base body in which a pressurizing chamber is constituted by a recess formed on a predetermined surface;
An actuator overlaid on the predetermined surface so as to close the pressurizing chamber;
A drive signal output unit for applying a voltage to the actuator;
Have
The actuator is
A diaphragm overlaid on the predetermined surface;
A common electrode overlaid on the diaphragm;
A piezoelectric body overlaid on the common electrode;
An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in a center side of the pressurizing chamber in a plan view;
An outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view;
Have
The first region of the piezoelectric body that overlaps with the individual electrode body and the second region of the piezoelectric body that is located between the individual electrode body and the outer electrode body have a polarization direction that is a stacking direction of the actuator. And
The drive signal output unit is
While applying a voltage between the individual electrode and the common electrode in the polarization direction of the first region, the second region is in a direction in which shear deformation is generated such that the second region is closer to the pressurizing chamber. Applying a voltage between the individual electrode and the outer electrode, applying a modified addition voltage,
In the deformation addition voltage application, while applying a voltage between the individual electrode and the common electrode, the potential of the outer electrode is made different from the potential of the common electrode, so that the potential between the individual electrode and the outer electrode is different. Apply voltage,
Prior to applying the deformation addition voltage, shear deformation is performed such that the potential of the individual electrode is equal to the potential of the common electrode, and the second region is located closer to the first region than the pressurizing chamber. A voltage is applied between the individual electrode and the outer electrode in the direction in which it occurs
Lee ink jet head. The drive signal output unit starts the voltage application in the polarization direction of the first region in the deformation addition voltage application, and performs shear deformation in which the second region is positioned closer to the pressurizing chamber side toward the first region side. The inkjet head according to claim 5, wherein the inkjet head is delayed with respect to a voltage application start in a direction in which the voltage occurs. A base body in which a pressurizing chamber is constituted by a recess formed on a predetermined surface;
An actuator overlaid on the predetermined surface so as to close the pressurizing chamber;
Have
The actuator is
A diaphragm overlaid on the predetermined surface;
A common electrode overlaid on the diaphragm;
A piezoelectric body overlaid on the common electrode;
An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in a center side of the pressurizing chamber in a plan view;
An outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view;
Have
The first region of the piezoelectric body that overlaps the individual electrode body has a polarization direction that is a stacking direction of the actuator,
The inkjet head according to claim 2, wherein the second region of the piezoelectric body positioned between the individual electrode main body and the outer electrode main body has a polarization direction opposite to a polarization direction of the first region. The inkjet head according to claim 7, wherein the outer electrode and the common electrode are connected to each other and have the same potential. A base body in which a pressurizing chamber is constituted by a recess formed on a predetermined surface;
An actuator overlaid on the predetermined surface so as to close the pressurizing chamber;
Have
The actuator is
A diaphragm overlaid on the predetermined surface;
A common electrode overlaid on the diaphragm;
A piezoelectric body overlaid on the common electrode;
An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in a center side of the pressurizing chamber in a plan view;
An outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view;
Have
The first region of the piezoelectric body that overlaps with the individual electrode body and the second region of the piezoelectric body that is located between the individual electrode body and the outer electrode body have a polarization direction that is a stacking direction of the actuator. And
The third region overlapping the outer electrode body of the piezoelectric body is not polarized
Lee ink jet head. A base body in which a pressurizing chamber is constituted by a recess formed on a predetermined surface;
An actuator overlaid on the predetermined surface so as to close the pressurizing chamber;
A drive signal output unit for applying a voltage to the actuator;
Have
The actuator is
A diaphragm overlaid on the predetermined surface;
A common electrode overlaid on the diaphragm;
A piezoelectric body overlaid on the common electrode;
An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in a center side of the pressurizing chamber in a plan view;
An outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view;
Have
The first region of the piezoelectric body that overlaps with the individual electrode body and the second region of the piezoelectric body that is located between the individual electrode body and the outer electrode body have a polarization direction that is a stacking direction of the actuator. And
The drive signal output unit applies the voltage between the individual electrode and the common electrode in the polarization direction of the first region, and overlaps the period in which the voltage is maximum . A recording apparatus that applies a voltage between the individual electrode and the outer electrode in a direction in which shear deformation occurs in a region where the region is closer to the first region and closer to the pressurizing chamber. A base body in which a pressurizing chamber is constituted by a recess formed on a predetermined surface;
An actuator overlaid on the predetermined surface so as to close the pressurizing chamber;
A drive signal output unit for applying a voltage to the actuator;
Have
The actuator is
A diaphragm overlaid on the predetermined surface;
A common electrode overlaid on the diaphragm;
A piezoelectric body overlaid on the common electrode;
An individual electrode having an individual electrode body that is superimposed on the piezoelectric body and spreads in a center side of the pressurizing chamber in a plan view;
An outer electrode having an outer electrode body that is superimposed on the piezoelectric body and is located outside the individual electrode body in plan view;
Have
The first region of the piezoelectric body that overlaps with the individual electrode body and the second region of the piezoelectric body that is located between the individual electrode body and the outer electrode body have a polarization direction that is a stacking direction of the actuator. And
The driving signal output unit, the potential of the individual electrode while the equivalent potential of the common electrode, the direction resulting in shear deformation the second region is located to the opposite side of the pressure chamber as the first region side An inkjet head that applies a voltage between the individual electrode and the common electrode in the polarization direction of the first region after applying a voltage between the individual electrode and the outer electrode.

Images