JP2012218252A - Liquid jet head and liquid jet apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize destruction by reducing stress concentration of a piezoelectric element.SOLUTION: The liquid jet head includes: a channel formation substrate 10 where a plurality of pressure generation chambers 12 are juxtaposed; and piezoelectric elements 300 each provided on one side of the channel formation substrate and having a first electrode 60, a piezoelectric layer 70, and a second electrode 80. The first electrode is a discrete electrode which is provided in each pressure generation chamber and whose width in the juxtaposing direction is narrower than that of the pressure generation chamber, and the second electrode is a common electrode which is provided continuously over a plurality of piezoelectric elements. At least on one end in the direction intersecting the juxtaposing direction of the pressure generation chambers, a boundary A between an active part 320 sandwiched by the first and second electrodes and generating an electric field and a non-active part 330 where one of the first and second electrode does not exist is defined by the end 81 of the second electrode. The first electrode in a region corresponding to the boundary A has a part 67 where the width in the juxtaposing direction is larger than that of the pressure generation chamber, and the pressure generation chamber in a region corresponding to the boundary A has a shallower step 110.

Description

  The present invention relates to a liquid ejecting head including a piezoelectric element and a liquid ejecting apparatus.

  The liquid jet head is provided with a piezoelectric element including a first electrode, a piezoelectric layer, and a second electrode on one side of a flow path forming substrate provided with a pressure generation chamber communicating with a nozzle. There is an ink jet recording head that generates a pressure change in a pressure generating chamber and ejects ink droplets from a nozzle. The piezoelectric element employed in such an ink jet recording head has a problem that it is easily destroyed due to an external environment such as moisture. In order to solve this problem, for example, there is a configuration in which the outer peripheral surface of a piezoelectric layer is covered with a second electrode (see, for example, Patent Document 1). In Patent Document 1, the first electrode is a common electrode, and the second electrode is an individual electrode.

  Further, there has been proposed one in which the first electrode of the piezoelectric element is provided for each pressure generation chamber to be an individual electrode, and the second electrode is continuously provided across a plurality of pressure generation chambers to be a common electrode (for example, Patent Document 2). According to this structure, since the second electrode itself contributes as a protective film for the creeping portion of the piezoelectric layer, it is not necessary to provide a separate protective film.

JP 2005-88441 A JP 2009-172878 A (see FIGS. 2 and 4)

  However, in the piezoelectric element as shown in FIG. 2 and FIG. 4 of Patent Document 2, both the first and second electrodes are provided in a direction intersecting the direction in which the pressure generating chambers are juxtaposed (area where the electric field is generated) Part) and a region where no electrode is provided and an electric field is not generated (inactive portion) is provided in a region opposite to the pressure generating chamber, the bending of the boundary portion increases. There was a problem that cracks occurred. In particular, when the second electrode is a common electrode, the first electrode as an individual electrode is drawn from the end in the direction intersecting the juxtaposed direction of the pressure generating chambers to the outside of the pressure generating chambers. This occurs when the ends of the two electrodes are in a region facing the pressure generating chamber. In this case, if the end of the second electrode is positioned in the region outside the pressure generation chamber, an electric field is generated in the region fixed by the flow path forming substrate, so that the end of the second electrode There was a problem that stress was concentrated in the vicinity, causing destruction and burning.

  Such a problem exists not only in the ink jet recording head but also in a liquid ejecting head that ejects liquid other than ink.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting head and a liquid ejecting apparatus that can reduce the stress concentration of the piezoelectric element and suppress the destruction of the piezoelectric element.

An aspect of the present invention that achieves the above object is provided with a flow path forming substrate in which a plurality of pressure generating chambers communicating with the nozzles are arranged in parallel, and provided on one side of the flow path forming substrate corresponding to the pressure generating chamber. A piezoelectric element having a first electrode, a piezoelectric layer provided on the first electrode, and a second electrode provided on the piezoelectric layer, wherein the first electrode of the piezoelectric element comprises: A common electrode provided for each of the pressure generating chambers and having a width in the juxtaposed direction smaller than the width of the pressure generating chamber, and the second electrode being continuously provided across a plurality of piezoelectric elements And at least one end in a direction intersecting with the juxtaposed direction of the pressure generating chambers, and an active part that is sandwiched between both the first and second electrodes of the piezoelectric layer and generates the electric field, An inactive portion in which either one of the first and second electrodes does not exist and no electric field is generated; A boundary is defined by the end of the second electrode, and the first electrode in a region corresponding to the boundary has a portion in which the width in the juxtaposed direction is larger than the width of the pressure generating chamber, and corresponds to the boundary In the liquid generating head, the pressure generating chamber in the region to be formed has a stepped portion in which the thickness of the flow path forming substrate is reduced and the depth of the pressure generating chamber is reduced.
In such an aspect, the boundary between the active portion and the inactive portion is provided in a region facing the relatively thin stepped portion and the first electrode is wide and extends to the partition wall, and is appropriately fixed. Therefore, film peeling due to stress concentration and generation of cracks due to extreme deformation are prevented. That is, the film is completely fixed by the flow path forming substrate, stress concentrates on the boundary portion, and the film is not peeled off and is not burned out.

  Here, it is preferable that the part with the large width | variety of the said 1st electrode is provided in the edge part by which the said 1st electrode is extended to the outside of the direction which cross | intersects the parallel arrangement direction of the said pressure generation chamber. According to this, the problem of the boundary between the active part and the inactive part when the first electrode, which is a common electrode, is extended to the outside of the pressure generating chamber can be solved.

  Further, the position in the direction intersecting the juxtaposed direction of the portion where the width of the first electrode is wide is different from the position of the adjacent portion where the width of the first electrode is wide, and the position in the juxtaposition direction extends. It is arranged in a staggered manner, and the positions of the end portions of the second electrode that define the boundary are different from each other adjacent to the position of the portion where the width of the first electrode is widened. preferable. According to this, since the part where the width | variety of the 1st electrode became wide is more reliably fixed by a partition, the effect which provided the wide part is more reliably exhibited, and the wide parts short-circuit each other. Can be prevented more.

  According to another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to the above aspect. As a result, a liquid ejecting apparatus having a head in which film peeling due to stress concentration and cracks due to extreme deformation are prevented and reliability and durability are improved is realized.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment. FIG. 2 is an enlarged plan view and a cross-sectional view of a main part of the recording head according to the first embodiment. It is a principal part enlarged plan view of the recording head concerning other embodiments. 1 is a schematic diagram of a recording apparatus according to an embodiment.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view of an ink jet recording head that is an example of a liquid jet head according to Embodiment 1 of the present invention. FIG. 2A is a cross-sectional view of the ink jet recording head, and FIG. FIG. 2B is an enlarged sectional view taken along line XX ′ in FIG.

  As shown in the figure, the flow path forming substrate 10 of the present embodiment is made of a silicon single crystal substrate, and an elastic film 50 made of silicon dioxide is formed on one surface thereof.

  A plurality of pressure generation chambers 12 partitioned by a partition wall 11 are arranged in parallel on the flow path forming substrate 10 (referred to as a parallel direction or a first direction). Further, a communication portion 13 is formed in a region outside the direction (also referred to as a second direction) intersecting the direction in which the pressure generation chambers 12 of the flow path forming substrate 10 are juxtaposed, and the communication portion 13 and each pressure generation chamber 12 are formed. Are communicated via an ink supply path 14 provided for each pressure generating chamber 12. The communication part 13 communicates with a manifold part 31 of a protective substrate, which will be described later, and constitutes a part of a manifold that becomes a common ink chamber for each pressure generating chamber 12. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13. In this embodiment, the ink supply path 14 is formed by narrowing the width of the flow path from one side. However, the ink supply path may be formed by narrowing the width of the flow path from both sides. Further, the ink supply path may be formed by narrowing from the thickness direction instead of narrowing the width of the flow path.

  In the present embodiment, the flow path forming substrate 10 is provided with a liquid flow path including the pressure generation chamber 12, the communication portion 13, and the ink supply path 14.

  Further, on the opening surface side of the flow path forming substrate 10, a nozzle plate 20 having a nozzle 21 communicating with the vicinity of the end portion of each pressure generating chamber 12 on the side opposite to the ink supply path 14 is provided with an adhesive or It is fixed by a heat welding film or the like. The nozzle plate 20 is made of, for example, glass ceramics, a silicon single crystal substrate, stainless steel, or the like.

  On the other hand, the elastic film 50 is formed on the side opposite to the opening surface of the flow path forming substrate 10 as described above, and the insulator film 55 is formed on the elastic film 50. On the insulator film 55, the first electrode 60, the piezoelectric layer 70, and the second electrode 80 are laminated to form the piezoelectric element 300. Here, the piezoelectric element 300 refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. A portion where an electric field is generated between the two electrodes of the piezoelectric layer 70 and an electric field is generated in the piezoelectric layer 70 is referred to as an active portion 320. In the present embodiment, the first electrode 60 is provided for each pressure generating chamber 12 to provide an individual electrode of the piezoelectric element 300, and the second electrode 80 is provided to cover the plurality of pressure generating chambers 12 to be a common electrode. . That is, a region that is substantially driven by being sandwiched between the first electrode 60 and the second electrode 80 of the piezoelectric layer 70 is an active portion 320, and one electrode 60, 80 of the piezoelectric layer 70, or both electrodes are provided. In addition, an inactive portion 330 is a region where no electric field is generated and substantially not driven. Here, a device having the displaceable piezoelectric element 300 is referred to as an actuator device. In the above-described example, the elastic film 50, the insulator film 55, and the first electrode 60 function as a diaphragm. However, the present invention is not limited to this. For example, the elastic film 50 and the insulator film 55 are provided. Instead, only the first electrode 60 may act as a diaphragm. Further, the piezoelectric element 300 itself may substantially serve as a diaphragm.

Here, the configuration of the piezoelectric element 300 will be described in detail with reference to FIG.
As shown in FIG. 3, the first electrode 60 constituting the piezoelectric element 300 is provided independently corresponding to each pressure generating chamber 12. Here, that the first electrode 60 is provided independently corresponding to each pressure generating chamber 12 means that the first electrode 60 is separated so as to be discontinuous in the juxtaposition direction of the pressure generating chambers 12. Say that. In the present embodiment, the first electrode 60 is provided so as to be narrower than the width of the pressure generating chambers 12 in the parallel arrangement direction, so that the first electrode 60 is provided independently corresponding to each pressure generating chamber 12. .

  Further, the first electrodes 60 provided independently for each of the pressure generating chambers 12 function as individual electrodes of the piezoelectric element 300 by preventing electrical connection between the first electrodes 60.

  Further, in the second direction intersecting with the direction in which the pressure generation chambers 12 are juxtaposed, the end of the first electrode 60 opposite to the ink supply path 14 extends to the outside of the end of the piezoelectric layer 70. An extended portion 65 that is extended is provided. The end portion of the extended portion 65 is exposed without being covered with the piezoelectric layer 70, and serves as a connection terminal that is electrically connected to a drive circuit 120 described later in detail. That is, the first electrode 60 also functions as a lead-out wiring that is pulled out from the piezoelectric element 300 and connected to the drive circuit 120. Of course, a wiring having conductivity different from that of the first electrode 60 may be separately provided as a lead-out wiring.

  The position corresponding to the end of the pressure generating chamber 12 on the side where the extending portion 65 in the second direction of the first electrode 60 is provided is wider than the width of the pressure generating chamber 12 in the juxtaposed direction. A wide portion 67 is formed. That is, the wide portion 67 extends in the direction in which the pressure generating chambers 12 are arranged side by side, and the tip end portion exists on the partition wall 11.

  The piezoelectric layer 70 is provided so as to be wider than the first electrode 60 in the juxtaposed direction of the pressure generating chambers 12 and narrower than the width of the juxtaposed direction of the pressure generating chambers 12. Covers the end surface of the first electrode 60 in the width direction. In addition, it is preferable that the piezoelectric layer 70 is also formed wide at the portion corresponding to the wide portion 67 of the first electrode 60. In this embodiment, the wide portion 71 that covers the end surface of the wide portion 67 and It has become. The wide portions 71 may be connected to each other because of space.

  In addition, the piezoelectric layer 70 is provided longer than the pressure generation chamber 12 in the second direction intersecting with the parallel direction of the pressure generation chambers 12. In the present embodiment, the piezoelectric layer 70 is provided in a size that covers the end of the first electrode 60 on the ink supply path 14 side in a second direction that intersects the direction in which the pressure generation chambers 12 are juxtaposed. .

  Furthermore, the piezoelectric layer 70 is provided in a second direction that intersects the direction in which the pressure generating chambers 12 are arranged, and is shorter than the end of the first electrode 60 opposite to the communicating portion 13. A part of the lead wiring of one electrode 60 is exposed. The drive circuit 120 is electrically connected to the exposed end of the first electrode 60.

The piezoelectric layer 70 is a piezoelectric material having an electromechanical conversion action, for example, a ferroelectric material having a perovskite structure and containing Zr or Ti as a metal, for example, ferroelectric such as lead zirconate titanate (PZT). It is made of a body material or a material obtained by adding a metal oxide such as niobium oxide, nickel oxide or magnesium oxide to the body material. Specifically, lead zirconate titanate (Pb (Zr, Ti) O ₃ ), barium zirconate titanate (Ba (Zr, Ti) O ₃ ), lead lanthanum zirconate titanate ((Pb, La) ( Zr, Ti) O ₃ ) or lead magnesium niobate zirconium titanate (Pb (Zr, Ti) (Mg, Nb) O ₃ ).

  The thickness of the piezoelectric layer 70 is not particularly limited, but it may be formed thick enough to suppress the thickness to the extent that cracks do not occur in the manufacturing process and exhibit sufficient displacement characteristics. For example, it is easy to obtain a desired crystal structure by forming the piezoelectric layer 70 with a thickness of about 0.2 to 5 μm. In the present embodiment, in order to obtain optimum piezoelectric characteristics, the thickness of the piezoelectric layer 70 is set to 1.2 μm.

  The method for manufacturing the piezoelectric layer 70 is not particularly limited. For example, a piezoelectric layer made of a metal oxide can be obtained by applying and drying a so-called sol in which an organometallic compound is dissolved and dispersed in a solvent, gelling, and baking at a high temperature. The piezoelectric layer 70 can be formed by using a so-called sol-gel method for obtaining the body layer 70. Of course, the manufacturing method of the piezoelectric layer 70 is not limited to the sol-gel method, and for example, a MOD (Metal-Organic Decomposition) method or a sputtering method may be used.

  In the present embodiment, the piezoelectric layer 70 is provided independently for each pressure generation chamber 12, but the present invention is not particularly limited thereto. For example, the piezoelectric layer 70 extends over the plurality of pressure generation chambers 12. You may provide so that it may continue. In the present embodiment, the piezoelectric layer 70 is provided separately for each pressure generation chamber 12, so that the piezoelectric layer 70 does not hinder the displacement of the piezoelectric element 300.

  The second electrode 80 is provided continuously over the parallel arrangement direction of the plurality of pressure generating chambers 12. Here, the second electrode 80 is continuously provided in the plurality of pressure generation chambers 12 as shown in FIG. 3A, which is continuous between adjacent pressure generation chambers 12. Moreover, what is partly divided between adjacent pressure generation chambers 12 is also included.

  The second electrode 80 is provided in a region opposite to the pressure generation chamber 12 in a second direction that intersects the juxtaposed direction of the pressure generation chambers 12. That is, the end of the second electrode 80 in the second direction intersecting the direction in which the pressure generation chambers 12 are arranged is provided so as to be located in the region of the pressure generation chamber 12.

  Further, the second electrode 80 generates pressure on the extended portion 65 side of the first electrode 60, on the inner side of the first electrode 60 (center side of the pressure generating chamber 12), that is, on the end portion of the first electrode 60. The end portion 81 of the second electrode 80 defines the end portion in the second direction of the active portion 320 of the piezoelectric layer 70, and the active portion 320 and the inactive portion are provided. 330 and a boundary A. This boundary A is set so as to exist in a region corresponding to the wide portion 67 of the first electrode 60.

  In such a piezoelectric element 300 including the first electrode 60, the piezoelectric layer 70, and the second electrode 80, the substantial portion of the piezoelectric layer 70 is formed by the end of the first electrode 60 in the direction in which the pressure generating chambers 12 are arranged. The end portion of the active portion 320 that is a typical drive portion is defined in the juxtaposed direction, and is activated by the end portion 81 of the second electrode 80 in the second direction (the direction intersecting the juxtaposed direction of the pressure generating chambers 12). An end of the part 320 is defined. The other region of the piezoelectric layer 70, that is, the region where one or both of the first electrode 60 and the second electrode 80 are not provided is the inactive portion 330, and the end portion 81 is the active portion 320. It is a boundary A with the inactive part 330. Here, in the present embodiment, the boundary between the active part 320 and the inactive part 330 in the second direction of the pressure generating chamber 12 is the boundary A on the opposite side (extension part 65 side) from the ink supply path 14. The ink supply path 14 side is a boundary B.

  A step portion 110 having a thickness smaller than the thickness of the flow path forming substrate 10 is formed at the end of the pressure generating chamber 12 of the flow path forming substrate 10 facing the boundary A of the piezoelectric element 300. The step portion 110 can be formed by performing half etching when the pressure generating chamber 12 is etched.

  In the present embodiment, the boundary A is disposed at a position facing the wide portion 67 of the first electrode 60 and further at a position facing the stepped portion 110, thereby restraining the boundary A when the piezoelectric element 300 is driven. Appropriately, it prevents burnout due to film peeling and cracks due to extreme deformation.

  Here, the thickness of the stepped portion 110 is set in consideration of various requirements such as the driving voltage of the piezoelectric element 300 and the degree of deformation. When forming the stepped portion 110, there may be formed an inclined surface 111 in which the end surface inside the pressure generating chamber 12 expands toward the nozzle 21 side, but the wide portion 67 faces the inclined surface 111. Although it may be located in the region, it is preferable that the boundary A and the wide portion 67 should not be opposed to the inclined surface 111. This is because it is difficult to control the degree of restraint of the boundary A when facing the inclined surface 111. In this embodiment, since the boundary A is arranged in a region facing the stepped portion 110 having a substantially constant thickness, the degree of constraint of the boundary A can be designed with high accuracy, and it can be caused by burnout due to film peeling or extreme deformation. Generation of cracks can be prevented.

  Regarding the boundary B, since the first electrode 60 is not extended to the outside of the pressure generation chamber 12, the occurrence of burnout due to film peeling or the occurrence of cracks due to extreme deformation is less than that on the boundary A side. Although it is not necessary to provide a part and a level | step difference part, it cannot be overemphasized that it may provide similarly.

  On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, that is, on the first electrode 60 and the insulator film 55, the protective substrate 30 having the manifold portion 31 constituting at least a part of the manifold 100 is provided. They are joined via an adhesive 35. In this embodiment, the manifold portion 31 penetrates the protective substrate 30 in the thickness direction and is formed across the width direction of the pressure generating chamber 12. As described above, the communication portion 13 of the flow path forming substrate 10. The manifold 100 is configured as a common ink chamber for the pressure generation chambers 12. Alternatively, the communication portion 13 of the flow path forming substrate 10 may be divided into a plurality of pressure generation chambers 12 and only the manifold portion 31 may be used as a manifold. Further, for example, only the pressure generation chamber 12 is provided in the flow path forming substrate 10, and a manifold and a member (for example, the elastic film 50, the insulator film 55, etc.) interposed between the flow path forming substrate 10 and the protective substrate 30 are provided. An ink supply path 14 that communicates with each pressure generating chamber 12 may be provided.

  A piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region of the protective substrate 30 that faces the piezoelectric element 300. The piezoelectric element holding part 32 only needs to have a space that does not hinder the movement of the piezoelectric element 300, and the space may be sealed or unsealed.

  As such a protective substrate 30, it is preferable to use substantially the same material as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, ceramic material, etc. In this embodiment, the same material as the flow path forming substrate 10 is used. The silicon single crystal substrate was used.

  A drive circuit 120 for driving the piezoelectric elements 300 arranged in parallel is fixed on the protective substrate 30. For example, a circuit board or a semiconductor integrated circuit (IC) can be used as the drive circuit 120. And the drive circuit 120 and the 1st electrode 60 and the 2nd electrode 80 are electrically connected through the connection wiring 121 which consists of electroconductive wires, such as a bonding wire.

  In addition, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility, and one surface of the manifold portion 31 is sealed by the sealing film 41. The fixing plate 42 is formed of a relatively hard material. Since the area of the fixing plate 42 facing the manifold 100 is an opening 43 that is completely removed in the thickness direction, one surface of the manifold 100 is sealed only with a flexible sealing film 41. Has been.

  In such an ink jet recording head of this embodiment, ink is taken in from an ink introduction port connected to an external ink supply means (not shown), and the interior from the manifold 100 to the nozzle 21 is filled with ink, and then the drive circuit 120. In accordance with the recording signal from the first electrode 60 and the second electrode 80 corresponding to the pressure generating chamber 12, the elastic film 50, the insulator film 55, the first electrode 60, and the piezoelectric layer. By bending and deforming 70, the pressure in each pressure generating chamber 12 increases and ink droplets are ejected from the nozzles 21.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

  For example, as shown in FIG. 4, the positions in the second direction intersecting the juxtaposed direction of the wide portions 67 </ b> A of the first electrode 60 may be arranged so as to be different from each other in a staggered manner. Also in this case, the wide portion 71A is also provided in the piezoelectric layer 70 so as to cover the end face of the wide portion 67A. Further, the end portion 81A of the second electrode 80 faces the wide portion 67A arranged in a staggered manner so as to define the boundary A corresponding to each pressure generating chamber 12, that is, corresponds to each pressure generating chamber 12. The boundary A to be bent is formed so as to be arranged in a staggered manner corresponding to each wide portion 67A.

  Also in such an embodiment, since the boundary A is disposed at a position facing the wide portion 67 of the first electrode 60 and further at a position facing the stepped portion 110, the boundary when the piezoelectric element 300 is driven. The restraint of A is moderately performed, and the occurrence of cracks due to film peeling and cracks due to extreme deformation is prevented. In addition, since the wide portion 67A is arranged in a staggered manner, the region fixed by the partition wall 11 is larger than that of the above-described embodiment, and therefore, the wide portion 67A is fixed to the partition wall 11 more reliably. Can be prevented from being deformed.

  Furthermore, in the above-described example, the silicon single crystal substrate is exemplified as the flow path forming substrate 10, but the present invention is not particularly limited thereto, and for example, a material such as an SOI substrate or glass may be used.

  Further, in the above-described example, one end portion in the second direction of the pressure generating chamber 12 of the first electrode 60 is formed by the piezoelectric layer 70 without providing a protective film having moisture resistance on the piezoelectric element 300. Since it is covered, current does not leak between the first electrode 60 and the second electrode 80, and the breakdown of the piezoelectric element 300 can be suppressed. The other end of the first electrode 60 in the second direction of the pressure generating chamber 12 is not covered with the piezoelectric layer 70, but there is a distance between the first electrode 60 and the second electrode 80. There is no particular effect. Of course, by providing a protective film having moisture resistance to the piezoelectric element 300 in the above example, the piezoelectric element 300 can be more reliably protected. However, a protective film is provided as in the piezoelectric element 300 in the above example. By avoiding this, the protective film does not hinder the displacement of the piezoelectric element 300, and a large amount of displacement can be obtained.

  Furthermore, in the above-described example, the piezoelectric layer 70 is cut for each pressure generation chamber 12, but the invention is not particularly limited thereto. For example, the piezoelectric layer is continuous over the direction in which the pressure generation chambers 12 are arranged in parallel. 70 may be provided.

  In addition, the ink jet recording heads of these embodiments constitute a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and are mounted on the ink jet recording apparatus. FIG. 5 is a schematic view showing an example of the ink jet recording apparatus.

  In the ink jet recording apparatus II shown in FIG. 5, the recording head units 1A and 1B having the ink jet recording head I are detachably provided with cartridges 2A and 2B constituting ink supply means, and the recording head units 1A and 1B. Is mounted on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively.

  The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S that is a recording medium such as paper fed by a paper feed roller (not shown) is wound around the platen 8. It is designed to be transported.

  In the ink jet recording apparatus II described above, the ink jet recording head I (head units 1A, 1B) is mounted on the carriage 3 and moves in the main scanning direction. However, the present invention is not particularly limited thereto. The present invention can also be applied to a so-called line recording apparatus in which the ink jet recording head I is fixed and printing is performed simply by moving the recording sheet S such as paper in the sub-scanning direction.

  In the above-described example, the ink jet recording head has been described as an example of the liquid ejecting head. However, the present invention is widely applied to all liquid ejecting heads and ejects liquids other than ink. Of course, it can also be applied. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

  A, B boundary, I Inkjet recording head (liquid ejecting head), II Inkjet recording apparatus (liquid ejecting apparatus), 10 flow path forming substrate, 12 pressure generating chamber, 13 communicating portion, 14 ink supply path, 20 nozzle plate , 21 nozzle, 30 protective substrate, 31 manifold portion, 40 compliance substrate, 50 elastic film, 55 insulator film, 60 first electrode, 65 extended portion, 67, 67A wide portion, 70 piezoelectric layer, 71, 71A wide Part, 80 second electrode, 100 manifold, 110 step part, 111 inclined surface, 120 drive circuit, 300 piezoelectric element, 320 active part, 330 inactive part

Claims (4)

  A flow path forming substrate having a plurality of pressure generating chambers communicating with the nozzle; and a first electrode on the one surface side of the flow path forming substrate corresponding to the pressure generating chamber. And a piezoelectric element having a second electrode provided on the piezoelectric layer, and the first electrode of the piezoelectric element is provided for each of the pressure generating chambers in parallel. The width of the installation direction is an individual electrode smaller than the width of the pressure generation chamber, and the second electrode is a common electrode provided continuously over a plurality of piezoelectric elements, and the pressure generation chambers are arranged side by side. At least one end in the direction intersecting with the active portion where the electric field is generated by being sandwiched between both the first and second electrodes of the piezoelectric layer and either the first or second electrode exists The boundary with the inactive portion where no electric field is generated is formed by the end of the second electrode. The width of the first electrode in a region corresponding to the boundary is larger than the width of the pressure generating chamber, and the flow in the pressure generating chamber in the region corresponding to the boundary is defined. A liquid ejecting head, comprising: a step portion in which the thickness of the path forming substrate is reduced and the depth of the pressure generating chamber is reduced.   The portion where the width of the first electrode is large is provided at an end portion on the side where the first electrode extends to the outside in a direction intersecting the direction in which the pressure generating chambers are arranged side by side. The liquid ejecting head according to 1.   The position in the direction intersecting the juxtaposed direction of the portion where the width of the first electrode is wide is different from the position of the adjacent portion where the width of the first electrode is wide, and is staggered over the juxtaposed direction. The positions of the end portions of the second electrodes that define the boundary are different from each other adjacent to the position of the portion where the width of the first electrode is widened. The liquid jet head according to claim 1.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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