Liquid ejection head and liquid ejection device

Abstract

To solve the problem in that, in a case where an adhesive bonding a pressure chamber substrate and another member extrudes onto an inner wall of each pressure chamber and there is a variation in the state of the extruding adhesive, the variation may adversely affect the ejection characteristics of the liquid.SOLUTION: A liquid ejection head 1 has: a pressure chamber substrate 23 provided with a plurality of pressure chambers CV and bonded to another member with adhesive GL; and a piezoelectric element PZ including: a piezoelectric body Qm; individual electrodes Qc individually provided in at least some of the plurality of pressure chambers CV; and the common electrodes Qb commonly provided in at least some of the plurality of pressure chambers CV. The plurality of pressure chambers CV includes a first pressure chamber CV1 used for ejecting a liquid and a second pressure chamber DCV1 not used for ejecting the liquid. Both the individual electrodes Qc and the common electrodes Qb are disposed in correspondence with the first pressure chamber. At least one of the individual electrodes Qc and the common electrodes Qb is not disposed in correspondence with the second pressure chamber DCV1.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a liquid ejection device.

Background Art

[0002] In recent years, liquid ejection devices that form an image on a medium by ejecting liquid in a pressure chamber from a nozzle have become widespread.

[0003] For example, Patent Document 1 describes a liquid ejection device including a nozzle substrate provided with nozzles, a pressure chamber substrate provided with a plurality of pressure chambers and connected to other members by an adhesive, individual electrodes provided individually for each of the plurality of pressure chambers, and a common electrode provided commonly for the plurality of pressure chambers.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a liquid ejection device, an adhesive that connects a pressure chamber substrate and other members may protrude into the pressure chamber. And depending on the degree of protrusion of the adhesive that connects the pressure chamber substrate and other members into the pressure chamber, the ejection characteristics of the liquid in the pressure chamber may vary. However, according to the conventional technology, since individual electrodes and a common electrode that do not transmit infrared rays are provided corresponding to the pressure chambers, it has been difficult to observe the degree of protrusion of the adhesive into the pressure chamber using infrared rays or the like.

Means for Solving the Problems

[0006] A liquid ejection head according to an aspect of the present invention includes a nozzle substrate provided with nozzles for ejecting a liquid, a plurality of first pressure chambers filled with the liquid inside and applying pressure to the liquid to eject the liquid, a second pressure chamber not used for ejecting the liquid, a pressure chamber substrate bonded to other members with an adhesive, a piezoelectric body, individual electrodes provided individually in the plurality of first pressure chambers, and a common electrode provided in the plurality of first pressure chambers. The liquid ejection head having a piezoelectric element is characterized in that both the individual electrode and the common electrode are arranged corresponding to the first pressure chamber, and at least one of the individual electrode and the common electrode is not arranged corresponding to the second pressure chamber.

[0007] A liquid ejection device according to an aspect of the present invention includes the above-described liquid ejection head and a control unit that controls the ejection operation from the liquid ejection head.

Brief Description of Drawings

[0008]

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Mode for Carrying Out the Invention

[0009] 1: First Embodiment Hereinafter, with reference to FIGS. 1 to 8, the liquid ejection device 100 according to the first embodiment will be described.

[0010] 1-1: Outline of the Liquid Ejection Device FIG. 1 is an explanatory diagram showing the liquid ejection device 100 according to the present embodiment.

[0011] The liquid ejection device 100 is an inkjet printing device that ejects ink onto the medium PP. The medium PP is typically printing paper, but any printing target such as a resin film or fabric can be used as the medium PP.

[0012] The liquid ejection device 100 includes a liquid container 93 that stores ink. As the liquid container 93, for example, a cartridge detachable from the liquid ejection device 100, a bag-shaped ink pack formed of a flexible film, an ink tank capable of refilling ink, or the like can be adopted. A plurality of types of inks with different colors are stored in the liquid container 93.

[0013] The liquid ejection device 100 includes a plurality of liquid ejection heads 1, a control device 7, a conveyance mechanism 91, a movement mechanism 92, and a supply mechanism 94.

[0014] The control device 7 includes a processing circuit such as a CPU or an FPGA, and a storage circuit such as a semiconductor memory, and controls each element of the liquid ejection device 100. Here, CPU is an abbreviation for Central Processing Unit, and FPGA is an abbreviation for Field Programmable Gate Array.

[0015] The conveyance mechanism 91 conveys the medium PP in the Y1 direction along the Y axis under the control of the control device 7. Hereinafter, the Y1 direction and the Y2 direction opposite to the Y1 direction are collectively referred to as the Y-axis direction. Further, hereinafter, the X1 direction along the X axis intersecting the Y axis and the X2 direction opposite to the X1 direction are collectively referred to as the X-axis direction. Further, hereinafter, the Z1 direction along the Z axis intersecting the X axis and the Y axis and the Z2 direction opposite to the Z1 direction are collectively referred to as the Z-axis direction. In the present embodiment, as an example, the case where the X axis, the Y axis, and the Z axis are orthogonal to each other will be assumed and described. However, the present invention is not limited to such a mode. The X axis, the Y axis, and the Z axis only need to intersect each other. Note that the X-axis direction is an example of the "first direction". The Y-axis direction is an example of the "second direction".

[0016] Under the control of the control device 7, the moving mechanism 92 reciprocates a plurality of liquid ejection heads 1 in the X1 direction and the X2 direction. The moving mechanism 92 includes a storage case 921 that houses the plurality of liquid ejection heads 1 and an endless belt 922 to which the storage case 921 is fixed. Note that the liquid container 93 may be stored in the storage case 921 together with the liquid ejection head 1.

[0017] Under the control of the control device 7, the supply mechanism 94 supplies the ink stored in the liquid container 93 to the liquid ejection head 1. Note that the supply mechanism 94 may further recover the ink stored in the liquid ejection head 1 under the control of the control device 7 and reflux the recovered ink to the liquid ejection head 1.

[0018] The control device 7 supplies a drive signal Com for driving the liquid ejection head 1 and a control signal SI for controlling the liquid ejection head 1 to the liquid ejection head 1. Then, the liquid ejection head 1 is driven by the drive signal Com under the control of the control signal SI, and ejects ink in the Z1 direction from some or all of the plurality of nozzles N provided in the liquid ejection head 1. That is, the liquid ejection head 1 ejects ink from some or all of the plurality of nozzles N in conjunction with the conveyance of the medium PP by the conveyance mechanism 91 and the reciprocating movement of the liquid ejection head 1 by the moving mechanism 92, and lands the ejected ink on the surface of the medium PP, thereby forming a desired image on the surface of the medium PP. Note that the nozzles N will be described later with reference to FIGS. 2 and 3.

[0019] 1-2: Outline of the liquid ejection head Hereinafter, the outline of the liquid ejection head 1 will be described with reference to FIGS. 2 and 3.

[0020] FIG. 2 is an exploded perspective view of the liquid ejection head 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2.

[0021] As shown in FIGS. 2 and 3, the liquid ejection head 1 includes a nozzle substrate 21, compliance sheets CS1 and CS2, a communication plate 22, a pressure chamber substrate 23, a diaphragm 24, a sealing substrate 25, a flow path forming substrate 26, and a wiring substrate 4.

[0022] As shown in FIG. 2, the nozzle substrate 21 is a plate-like member that is long in the Y-axis direction and extends substantially parallel to the XY plane. Here, "substantially parallel" is a concept that includes cases where, in addition to being completely parallel, it can be regarded as parallel considering errors. In the present embodiment, "substantially parallel" is a concept that includes cases where it can be regarded as parallel considering an error of about 10%. The nozzle substrate 21 is manufactured, for example, by processing a single crystal silicon substrate using semiconductor manufacturing techniques such as etching, but known materials and manufacturing methods may be arbitrarily adopted for the manufacture of the nozzle substrate 21.

[0023] A plurality of nozzles N are formed in the nozzle substrate 21. Here, the nozzle N is a through hole provided in the nozzle substrate 21. In the present embodiment, it is assumed that the plurality of nozzles N formed in the nozzle substrate 21 include a plurality of nozzles N1 arranged to extend in the Y-axis direction and a plurality of nozzles N2 arranged to extend in the Y-axis direction at positions in the X2 direction when viewed from the plurality of nozzles N1. Hereinafter, the plurality of nozzles N1 extending in the Y-axis direction are referred to as nozzle row Ln1, and the plurality of nozzles N2 extending in the Y-axis direction are referred to as nozzle row Ln2. Further, hereinafter, the nozzle row Ln1 and the nozzle row Ln2 may be collectively referred to as the nozzle row Ln.

[0024] As shown in FIGS. 2 and 3, a communication plate 22 is provided at a position in the Z2 direction when viewed from the nozzle substrate 21. The communication plate 22 is a plate-like member that is long in the Y-axis direction and extends substantially parallel to the XY plane. The communication plate 22 is manufactured, for example, by processing a single crystal silicon substrate using semiconductor manufacturing techniques, but known materials and manufacturing methods may be arbitrarily adopted for the manufacture of the communication plate 22.

[0025] An ink flow path is formed in the communication plate 22. Specifically, in the communication plate 22, one supply flow path BA1 provided so as to extend in the Y-axis direction (the Y-axis direction is the longitudinal direction) and one supply flow path BA2 provided so as to extend in the Y-axis direction at a position in the X2 direction when viewed from the supply flow path BA1 are formed. Further, in the communication plate 22, a plurality of connection flow paths BK1, a plurality of connection flow paths BK2, a plurality of communication flow paths BR1, and a plurality of communication flow paths BR2 are formed.

[0026] Among these, some of the plurality of connection flow paths BK1 communicate with the supply flow path BA1 and are provided so as to extend in the Z-axis direction (the Z-axis direction is the longitudinal direction) at a position in the X2 direction when viewed from the supply flow path BA1. The communication flow path BR1 is provided so as to extend in the Z-axis direction at a position in the X2 direction when viewed from the connection flow path BK1. Some of the plurality of communication flow paths BR1 communicate with the nozzle N1 corresponding to the communication flow path BR1. Some of the plurality of connection flow paths BK2 communicate with the supply flow path BA2 and are provided so as to extend in the Z-axis direction at a position in the X1 direction when viewed from the supply flow path BA2. The communication flow path BR2 is provided so as to extend in the Z-axis direction at a position in the X1 direction when viewed from the connection flow path BK2 and at a position in the X2 direction when viewed from the communication flow path BR1. Some of the plurality of communication flow paths BR2 communicate with the nozzle N2 corresponding to the communication flow path BR2. In the following, the supply flow path BA1 and the supply flow path BA2 may be collectively referred to as the supply flow path BA. Also, in the following, the connection flow path BK1 and the connection flow path BK2 may be collectively referred to as the connection flow path BK. Further, in the following, the communication flow path BR1 and the communication flow path BR2 may be collectively referred to as the communication flow path BR.

[0027] As shown in FIGS. 2 and 3, a pressure chamber substrate 23 is provided at a position in the Z2 direction when viewed from the communication plate 22. The pressure chamber substrate 23 is a plate-like member that is long in the Y-axis direction and extends substantially parallel to the XY plane. The pressure chamber substrate 23 is manufactured, for example, by processing a single-crystal silicon substrate using semiconductor manufacturing technology, but known materials and manufacturing methods may be arbitrarily adopted for the manufacture of the pressure chamber substrate 23.

[0028] An ink flow path is formed in the pressure chamber substrate 23. Specifically, a plurality of pressure chambers CV1 and a plurality of pressure chambers CV2 are formed in the pressure chamber substrate 23. Among these, when viewed in the Z-axis direction, the pressure chamber CV1 connects the end portion in the X2 direction of the connection flow path BK1 and the end portion in the X1 direction of the communication flow path BR1, and is provided so as to extend in the X-axis direction (the X-axis direction is the longitudinal direction). The pressure chamber CV2 connects the end portion in the X1 direction of the connection flow path BK2 and the end portion in the X2 direction of the communication flow path BR2 when viewed in the Z-axis direction, and is provided so as to extend in the X-axis direction. Hereinafter, the pressure chamber CV1 and the pressure chamber CV2 may be collectively referred to as the pressure chamber CV.

[0029] The plurality of pressure chambers CV1 include a plurality of normal pressure chambers SCV1 and a plurality of dummy pressure chambers DCV1. The plurality of normal pressure chambers SCV1 correspond one-to-one with the plurality of nozzles N1. However, it is also possible that one nozzle N1 is shared by a plurality of normal pressure chambers SCV1, or a plurality of nozzles N1 are provided in one normal pressure chamber SCV1. In FIG. 2, the plurality of normal pressure chambers SCV1 are arranged in the Y-axis direction. A part of the plurality of dummy pressure chambers DCV1 is installed on the Y1 side of the plurality of normal pressure chambers SCV1. The remaining part of the plurality of dummy pressure chambers DCV1 is installed on the Y2 side of the plurality of normal pressure chambers SCV1. That is, the plurality of dummy pressure chambers DCV1 are installed at both ends of the arrangement of the plurality of normal pressure chambers SCV1. As will be described later, a piezoelectric element PZ1 is installed on the diaphragm 24 corresponding to the normal pressure chamber SCV1. When the diaphragm 24 vibrates due to the deformation of the piezoelectric element PZ1, ink is ejected from the normal pressure chamber SCV1. On the other hand, no piezoelectric element PZ1 corresponding to the dummy pressure chamber DCV1 is installed on the diaphragm 24. As a result, the diaphragm 24 does not vibrate corresponding to the dummy pressure chamber DCV1, and ink is not discharged from the dummy pressure chamber DCV1 to the communication flow path BR1. Similarly, the plurality of pressure chambers CV2 include a plurality of normal pressure chambers SCV2 and a plurality of dummy pressure chambers DCV2. The plurality of normal pressure chambers SCV2 correspond one-to-one with the plurality of nozzles N2. In FIG. 2, the plurality of normal pressure chambers SCV2 are arranged in the Y-axis direction. A part of the plurality of dummy pressure chambers DCV2 is installed on the Y1 side of the plurality of normal pressure chambers SCV2. The remainder of the plurality of dummy pressure chambers DCV2 is installed on the Y2 side of the plurality of normal pressure chambers SCV2. That is, the plurality of dummy pressure chambers DCV2 are installed at both ends of the arrangement of the plurality of normal pressure chambers SCV2. Piezoelectric elements PZ2 are installed on the diaphragm 24 corresponding to the normal pressure chambers SCV2. When the diaphragm 24 vibrates due to the deformation of the piezoelectric elements PZ2, ink is ejected from the normal pressure chambers SCV2. On the other hand, piezoelectric elements PZ2 corresponding to the dummy pressure chambers DCV2 are not installed on the diaphragm 24. As a result, the diaphragm 24 does not vibrate corresponding to the dummy pressure chambers DCV2, and ink is not discharged from the dummy pressure chambers DCV2 to the communication flow path BR2. In addition, each of the plurality of pressure chambers CV1 including the plurality of normal pressure chambers SCV1 and the plurality of dummy pressure chambers DCV1 may be installed at equal intervals from each other. Specifically, in this embodiment, it is assumed that the interval in the Y-axis direction between two adjacent normal pressure chambers SCV1 among the plurality of normal pressure chambers SCV1 in the Y-axis direction is equal to the interval in the Y-axis direction between two adjacent dummy pressure chambers DCV1 among the plurality of dummy pressure chambers DCV1 in the Y-axis direction. Also, in this embodiment, it is assumed that the interval between the normal pressure chamber SCV1 provided at the end on the Y1 side of the plurality of normal pressure chambers SCV1 and the dummy pressure chamber DCV1 adjacent to the normal pressure chamber SCV1 on the Y1 side is equal to the interval in the Y-axis direction between two adjacent normal pressure chambers SCV1 among the plurality of normal pressure chambers SCV1 in the Y-axis direction. Further, in this embodiment, it is assumed that the interval between the normal pressure chamber SCV1 provided at the end on the Y2 side of the plurality of normal pressure chambers SCV1 and the dummy pressure chamber DCV1 adjacent to the normal pressure chamber SCV1 on the Y2 side is equal to the interval in the Y-axis direction between two adjacent normal pressure chambers SCV1 among the plurality of normal pressure chambers SCV1 in the Y-axis direction. Similarly, each of the plurality of pressure chambers CV2 including a plurality of normal pressure chambers SCV2 and a plurality of dummy pressure chambers DCV2 may be installed at equal intervals from each other.

[0030] Further, the normal pressure chamber SCV1 and the normal pressure chamber SCV2 may be collectively referred to as a normal pressure chamber SCV. Similarly, the dummy pressure chamber DCV1 and the dummy pressure chamber DCV2 may be collectively referred to as a dummy pressure chamber DCV. The normal pressure chamber SCV is an example of a "first pressure chamber". The dummy pressure chamber DCV is an example of a "second pressure chamber".

[0031] As shown in FIGS. 2 and 3, a diaphragm 24 is provided at a position in the Z2 direction as viewed from the pressure chamber substrate 23. The diaphragm 24 is a plate-like member that is long in the Y-axis direction and extends substantially parallel to the XY plane, and is an elastically vibratable member. In the present embodiment, of the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, the surface in the Z2 direction is formed of a non-conductive member. For example, the diaphragm 24 may include an elastic film made of silicon oxide and an insulator film made of zirconium oxide provided at a position in the Z2 direction as viewed from the elastic film.

[0032] As shown in FIGS. 2 and 3, at a position in the Z2 direction as viewed from the diaphragm 24, a plurality of piezoelectric elements PZ1 corresponding to the plurality of normal pressure chambers SCV1 and a plurality of piezoelectric elements PZ2 corresponding to the plurality of normal pressure chambers SCV2 are provided. Hereinafter, the piezoelectric element PZ1 and the piezoelectric element PZ2 may be collectively referred to as a piezoelectric element PZ. The piezoelectric element PZ is a passive element that deforms in response to a potential change in the drive signal Com. In other words, the piezoelectric element PZ is an example of an energy conversion element that converts the electrical energy of the drive signal Com into kinetic energy. Specifically, the piezoelectric element PZ is driven and deformed in response to a potential change in the drive signal Com. The diaphragm 24 vibrates in conjunction with the deformation of the piezoelectric element PZ. When the diaphragm 24 vibrates, the pressure in the normal pressure chamber SCV fluctuates. Then, due to the fluctuation of the pressure in the normal pressure chamber SCV, the ink filled inside the normal pressure chamber SCV is ejected from the nozzle N via the communication flow path BR.

[0033] As described below, the piezoelectric element PZ1 corresponding to a plurality of normal pressure chambers SCV1 is a laminate in which a normal piezoelectric body SQm1 is interposed between a common electrode Qb set to a reference potential VBS and an individual electrode Qc to which a drive signal Com is supplied. Similarly, the piezoelectric element PZ2 corresponding to a plurality of normal pressure chambers SCV2 is a laminate in which a normal piezoelectric body SQm2 is interposed between a common electrode Qb set to a reference potential VBS and an individual electrode Qc to which a drive signal Com is supplied. Hereinafter, the normal piezoelectric body SQm1 and the normal piezoelectric body SQm2 may be collectively referred to as the normal piezoelectric body SQm. When the liquid ejection head 1 is viewed in a plan view in the Z1 direction, the overlapping portion of the normal piezoelectric body SQm, the common electrode Qb, and the individual electrode Qc corresponding to one normal pressure chamber SCV corresponds to the active part of the piezoelectric element PZ corresponding to one normal pressure chamber SCV. At the position of the piezoelectric element PZ in the Z1 direction, a normal pressure chamber SCV corresponding to the piezoelectric element PZ is provided.

[0034] Also, as shown in FIG. 2, at positions in the Z2 direction as viewed from the diaphragm 24, a plurality of dummy piezoelectric bodies DQm1 corresponding to a plurality of dummy pressure chambers DCV1 and a plurality of dummy piezoelectric bodies DQm2 corresponding to a plurality of dummy pressure chambers DCV2 are provided. Hereinafter, the dummy piezoelectric body DQm1 and the dummy piezoelectric body DQm2 may be collectively referred to as the dummy piezoelectric body DQm. Different from the normal piezoelectric body SQm, the dummy piezoelectric body DQm is not a piezoelectric body disposed between the common electrode Qb and the individual electrode Qc. For this reason, since the dummy piezoelectric body DQm is not driven in response to the potential change of the drive signal Com, the pressure in the dummy pressure chamber DCV does not fluctuate. Note that hereinafter, the normal piezoelectric body SQm and the dummy piezoelectric body DQm may be collectively referred to as the piezoelectric body Qm.

[0035] As shown in FIGS. 2 and 3, a sealing substrate 25 for protecting a plurality of piezoelectric elements PZ and a plurality of dummy piezoelectric bodies DQm is provided at a position in the Z2 direction when viewed from the pressure chamber substrate 23. The sealing substrate 25 seals the piezoelectric elements PZ and the dummy piezoelectric bodies DQm. The sealing substrate 25 is an example of a "sealing plate". The sealing substrate 25 is a plate-shaped member that is long in the Y-axis direction and extends substantially parallel to the XY plane. The sealing substrate 25 is manufactured, for example, by processing a single-crystalline silicon substrate using semiconductor manufacturing technology, but known materials and manufacturing methods may be arbitrarily adopted for the manufacture of the sealing substrate 25.

[0036] On the surface in the Z1 direction among the two surfaces of the sealing substrate 25 having the Z-axis direction as the normal direction, there are provided a recess for covering a plurality of piezoelectric elements PZ1 and a plurality of dummy piezoelectric bodies DQm1, and a recess for covering a plurality of piezoelectric elements PZ2 and a plurality of dummy piezoelectric bodies DQm2. Hereinafter, the sealing space formed between the diaphragm 24 and the sealing substrate 25 that covers the plurality of piezoelectric elements PZ1 and the plurality of dummy piezoelectric bodies DQm1 is referred to as a sealing space SP1, and the sealing space formed between the diaphragm 24 and the sealing substrate 25 that covers the plurality of piezoelectric elements PZ2 and the plurality of dummy piezoelectric bodies DQm2 is referred to as a sealing space SP2. Also, hereinafter, the sealing spaces SP1 and SP2 may be collectively referred to as a sealing space SP. The sealing space SP is a space for sealing the piezoelectric elements PZ and preventing the piezoelectric elements PZ from deteriorating due to the influence of moisture or the like. Also, hereinafter, when the sealing substrate 25 is viewed in plan in the Z1 direction, the portion that becomes the side wall of the sealing space SP1 is referred to as a side wall WL1, and the portion that becomes the side wall of the sealing space SP2 is referred to as a side wall WL2. Also, hereinafter, the side walls WL1 and WL2 may be collectively referred to as a side wall WL.

[0037] A through hole 250 is provided in the sealing substrate 25. The through hole 250 is a hole that is located between the sealing spaces SP1 and SP2 when the sealing substrate 25 is viewed in the Z1 direction and penetrates from the surface of the sealing substrate 25 in the Z1 direction to the surface of the sealing substrate 25 in the Z2 direction. A wiring substrate 4 is inserted into the through hole 250.

[0038] As shown in FIGS. 2 and 3, a flow path forming substrate 26 is provided at a position in the Z2 direction when viewed from the communication plate 22. The flow path forming substrate 26 is a plate-like member that is long in the Y-axis direction and extends substantially parallel to the XY plane. The flow path forming substrate 26 is formed, for example, by injection molding of a resin material, but known materials and manufacturing methods may be arbitrarily adopted for the manufacture of the flow path forming substrate 26.

[0039] In the flow path forming substrate 26, ink flow paths are formed. Specifically, one supply flow path BB1 and one supply flow path BB2 are formed in the flow path forming substrate 26. Among these, the supply flow path BB1 communicates with the supply flow path BA1 and is provided so as to extend in the Y-axis direction at a position in the Z2 direction when viewed from the supply flow path BA1. The supply flow path BB2 communicates with the supply flow path BA2 and is provided so as to extend in the Y-axis direction at a position in the Z2 direction when viewed from the supply flow path BA2 and at a position in the X2 direction when viewed from the supply flow path BB1. Hereinafter, the supply flow path BB1 and the supply flow path BB2 may be collectively referred to as the supply flow path BB.

[0040] The flow path forming substrate 26 is provided with an inlet HL1 communicating with the supply flow path BB1 and an inlet HL2 communicating with the supply flow path BB2. Then, ink is supplied from the liquid container 93 to the supply flow path BB1 through the inlet HL1. The ink supplied from the liquid container 93 to the supply flow path BB1 through the inlet HL1 flows into the supply flow path BA1. A part of the ink that has flowed into the supply flow path BA1 is filled into the normal pressure chamber SCV1 via the connection flow path BK1. When the piezoelectric element PZ1 is driven by the drive signal Com, a part of the ink filled in the normal pressure chamber SCV1 is discharged from the nozzle N1 via the communication flow path BR1. In addition, ink is supplied from the liquid container 93 to the supply channel BB2 through the inlet HL2. The ink supplied from the liquid container 93 to the supply channel BB2 through the inlet HL2 flows into the supply channel BA2. A part of the ink that has flowed into the supply channel BA2 is filled into the normal pressure chamber SCV2 via the connection channel BK2. When the piezoelectric element PZ2 is driven by the drive signal Com, a part of the ink filled in the normal pressure chamber SCV2 is discharged from the nozzle N2 via the communication channel BR2.

[0041] On the other hand, the dummy pressure chamber DCV1 communicates with the connection channel BK1, but the connection channel BK1 does not communicate with the supply channel BA1. Therefore, a part of the ink that has flowed into the supply channel BA1 will not be filled into the dummy pressure chamber DCV1 via the connection channel BK1. However, the connection channel BK1 and the supply channel BA1 may communicate with each other and the dummy pressure chamber DCV1 may be filled with liquid. Also, the dummy pressure chamber DCV1 communicates with the communication channel BR1, but no nozzle N1 is provided in the communication channel BR1.

[0042] Similarly, the dummy pressure chamber DCV2 communicates with the connection channel BK2, but the connection channel BK2 does not communicate with the supply channel BA2. Therefore, a part of the ink that has flowed into the supply channel BA2 will not be filled into the dummy pressure chamber DCV2 via the connection channel BK2. However, the connection channel BK2 and the supply channel BA2 may communicate with each other and the dummy pressure chamber DCV2 may be filled with liquid. Also, the dummy pressure chamber DCV2 communicates with the communication channel BR2, but no nozzle N2 is provided in the communication channel BR2.

[0043] The flow path forming substrate 26 is provided with a through hole 260. The through hole 260 is located between the supply channel BB1 and the supply channel BB2 when the flow path forming substrate 26 is viewed in the Z1 direction, and is a hole that penetrates from the surface of the flow path forming substrate 26 in the Z1 direction to the surface of the flow path forming substrate 26 in the Z2 direction. The wiring substrate 4 is inserted into the through hole 260.

[0044] As shown in FIGS. 2 and 3, a wiring board 4 is mounted on the surface of the diaphragm 24 in the Z2 direction. The wiring board 4 is a component for electrically connecting the liquid ejection head 1 to the control device 7. As the wiring board 4, for example, a flexible wiring board such as an FPC or an FFC is preferably adopted. Here, FPC is an abbreviation for Flexible Printed Circuit, and FFC is an abbreviation for Flexible Flat Cable. An integrated circuit 40 is mounted on the wiring board 4. The integrated circuit 40 is an electric circuit that switches whether to supply a drive signal Com to the piezoelectric element PZ under the control of a control signal SI.

[0045] As shown in FIGS. 2 and 3, at a position in the Z1 direction when viewed from the communication board 22, a compliance sheet CS1 is provided so as to block the supply flow path BA1 and the connection flow path BK1, and a compliance sheet CS2 is provided so as to block the supply flow path BA2 and the connection flow path BK2. Hereinafter, the compliance sheet CS1 and the compliance sheet CS2 may be collectively referred to as the compliance sheet CS. The compliance sheet CS is a plate-like member that is long in the Y-axis direction and extends substantially parallel to the XY plane. The compliance sheet CS is formed of an elastic material and absorbs pressure fluctuations of the ink in the supply flow path BA and the connection flow path BK.

[0046] 1-3: Structure of Electrodes Hereinafter, with reference to FIG. 4, the structures of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1 according to the first embodiment will be described.

[0047] FIG. 4 is a plan view of the liquid ejection head 1 when the liquid ejection head 1 is viewed in plan in the Z1 direction.

[0048] As shown in FIG. 4, in a position overlapping with a sealing space SP1 which is a space located inside a side wall WL1 of a sealing substrate 25 when the liquid ejection head 1 is viewed in a plan view in the Z1 direction, a plurality of normal pressure chambers SCV1, a plurality of dummy pressure chambers DCV1, a plurality of individual electrodes Qc, and a common electrode Qb are provided. The plurality of normal pressure chambers SCV1 correspond one-to-one with the plurality of nozzles N1. Also, the plurality of normal pressure chambers SCV1 correspond one-to-one with the plurality of individual electrodes Qc. The normal pressure chamber SCV1 is used for ink ejection. On the other hand, the dummy pressure chamber DCV1 is not used for ink ejection. The sealing substrate 25 is provided so as to overlap both the plurality of normal pressure chambers SCV1 and the plurality of dummy pressure chambers DCV1 when viewed in the Z-axis direction.

[0049] In the present embodiment, the common electrode Qb is provided in common for the plurality of normal pressure chambers SCV1. More specifically, the common electrode Qb is provided so as to overlap the plurality of normal pressure chambers SCV1 when the liquid ejection head 1 is viewed in a plan view in the Z1 direction. However, the common electrode Qb may be provided so that each of the plurality of normal pressure chambers SCV1 has a portion that does not overlap the common electrode Qb when the liquid ejection head 1 is viewed in a plan view in the Z1 direction. In the present embodiment, the common electrode Qb is not provided for the plurality of dummy pressure chambers DCV1.

[0050] The common electrode Qb is connected to a wiring provided on the wiring substrate 4 and set to a reference potential VBS. For this reason, the potential of the common electrode Qb is set to the reference potential VBS.

[0051] Note that the common electrode Qb is formed of a conductive material. Specifically, as the material of the common electrode Qb, for example, a metal such as platinum, iridium, gold, or titanium, or a conductive material such as indium tin oxide abbreviated as ITO can be adopted.

[0052] Generally, the normal piezoelectric body SQm1 is provided so as to overlap with the normal pressure chamber SCV1 when the liquid ejection head 1 is viewed in plan in the Z1 direction. However, when the liquid ejection head 1 is viewed in plan in the Z1 direction, a part of the normal pressure chamber SCV1 may be provided so as not to overlap with the normal piezoelectric body SQm1. In the example shown in FIG. 4, the normal piezoelectric body SQm1 is provided so that when the liquid ejection head 1 is viewed in plan in the Z1 direction, all of the normal piezoelectric body SQm1 is included in the normal pressure chamber SCV1 corresponding to the normal piezoelectric body SQm1.

[0053] Similarly, the dummy piezoelectric body DQm1 is provided so as to overlap with the dummy pressure chamber DCV1 when the liquid ejection head 1 is viewed in plan in the Z1 direction. However, when the liquid ejection head 1 is viewed in plan in the Z1 direction, a part of the dummy pressure chamber DCV1 may be provided so as not to overlap with the dummy piezoelectric body DQm1. In the example shown in FIG. 4, the dummy piezoelectric body DQm1 is provided so that when the liquid ejection head 1 is viewed in plan in the Z1 direction, all of the dummy piezoelectric body DQm1 is included in the dummy pressure chamber DCV1 corresponding to the dummy piezoelectric body DQm1.

[0054] Note that the normal piezoelectric body SQm1 and the dummy piezoelectric body DQm1 are formed of, for example, a perovskite-structured crystal film made of a ferroelectric ceramic material exhibiting electromechanical conversion action, that is, a so-called perovskite-type crystal. Specifically, as the materials of the normal piezoelectric body SQm1 and the dummy piezoelectric body DQm1, for example, ferroelectric piezoelectric materials such as lead zirconate titanate, or those obtained by adding metal oxides such as niobium oxide, nickel oxide, or magnesium oxide to ferroelectric piezoelectric materials such as lead zirconate titanate can be adopted. More specifically, as the materials of the normal piezoelectric body SQm1 and the dummy piezoelectric body DQm1, for example, lead titanate, lead zirconate titanate, lead zirconate, lanthanum lead titanate, lanthanum lead zirconate titanate, or lead magnesium niobate zirconate titanate can be adopted.

[0055] As described above, the liquid ejection head 1 is provided with a plurality of individual electrodes Qc so as to correspond one-to-one with the plurality of normal pressure chambers SCV1. A drive signal Com is supplied from the control device 7 to each individual electrode Qc via wiring provided on the wiring substrate 4. In the present embodiment, no individual electrode Qc is provided for the plurality of dummy pressure chambers DCV1.

[0056] Further, the individual electrode Qc is formed of a conductive material. Specifically, as the material of the individual electrode Qc, for example, a conductive material such as a metal such as platinum, iridium, gold, or titanium, or a conductive metal oxide such as indium tin oxide abbreviated as ITO can be adopted.

[0057] In FIG. 4, the configuration of the portion corresponding to the sealing space SP1 located in the X1 direction with respect to the wiring substrate 4 in the liquid ejection head 1 has been illustrated and described. However, the same description as in FIG. 4 also applies to the configuration of the portion corresponding to the sealing space SP2 located in the X2 direction with respect to the wiring substrate 4. The same also applies to FIGS. 5 and 6 described later.

[0058] 1-4: Configuration near the pressure chamber CV1 FIG. 5 is a cross-sectional view taken along the line e-E in FIG. 4.

[0059] As shown in FIG. 5, among the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, on the surface in the Z2 direction, a common electrode Qb, an individual electrode Qc, a normal piezoelectric body SQm1, and a sealing substrate 25 are formed.

[0060] Further, an orientation control layer SD for controlling the orientation of the normal piezoelectric body SQm1 is provided on the surface of the normal piezoelectric body SQm1 in the Z1 direction. The orientation control layer SD is provided so as to cover the surface of the normal piezoelectric body SQm1 in the Z1 direction. The orientation control layer SD is a composite oxide containing at least titanium (Ti). Alternatively, the orientation control layer SD is a composite oxide containing at least lead (Pb), bismuth (Bi), iron (Fe), and titanium (Ti).

[0061] Hereinafter, among the two surfaces of the normal piezoelectric body SQm1 with the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface PL1. Also, among the two surfaces of the orientation control layer SD with the Z-axis direction as the normal direction, the surface in the Z1 direction is referred to as surface PL2. Further, among the inclined surfaces of the normal piezoelectric body SQm1, the surface in the X1 direction is referred to as surface PL3, and the surface in the X2 direction is referred to as surface PL4. Also, among the two surfaces of the diaphragm 24 with the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface QL1.

[0062] An individual electrode Qc is formed on the surface PL2 of the orientation control layer SD. The end portion of the individual electrode Qc in the X1 direction is located in the X2 direction with respect to the surface PL3. Also, the individual electrode Qc extends in the X2 direction to the outside of the sealing substrate 25.

[0063] A common electrode Qb is formed on the surface PL1 and the surface PL3 of the normal piezoelectric body SQm1, and the surface QL1 of the diaphragm 24. The end portion of the common electrode Qb in the X2 direction is on the surface PL1 and is located in the X1 direction with respect to the surface PL4. Also, the end portion of the common electrode Qb in the X1 direction is on the surface QL1 and is located inside the sealing substrate 25.

[0064] The pressure chamber substrate 23 and the diaphragm 24 are joined by an adhesive GL. Also, the pressure chamber substrate 23 and the communication plate 22 are joined by the adhesive GL. At the interface between the pressure chamber substrate 23 and the diaphragm 24, at the corner CN1 in the X2 direction and the Z2 direction of the normal pressure chamber SCV1, there is a facing portion PT1 of the adhesive GL facing the normal pressure chamber SCV1. At the interface between the pressure chamber substrate 23 and the diaphragm 24, at the corner CN2 in the X1 direction and the Z2 direction of the normal pressure chamber SCV1, there is a facing portion PT2 of the adhesive GL facing the normal pressure chamber SCV1. Also, at the interface between the pressure chamber substrate 23 and the communication plate 22, at the end CN3 in the X2 direction of the normal pressure chamber SCV1, there is a facing portion PT3 of the adhesive GL facing the normal pressure chamber SCV1. At the interface between the pressure chamber substrate 23 and the communication plate 22, at the end CN4 in the X1 direction of the normal pressure chamber SCV1, there is a facing portion PT4 of the adhesive GL facing the normal pressure chamber SCV1. Note that the diaphragm 24 is an example of "other member". Also, the communication plate 22 is another example of "other member".

[0065] As described above, the adhesive GL that connects the pressure chamber substrate 23 and other members may protrude into the normal pressure chamber SCV1. And depending on the degree of protrusion of the adhesive GL into the normal pressure chamber SCV1, the ejection characteristics of the ink in the normal pressure chamber SCV1 may vary. Whether between the diaphragm 24 and the pressure chamber substrate 23 or between the pressure chamber substrate 23 and the communication plate 22, when the adhesive GL protrudes, the volume of the normal pressure chamber SCV1 becomes smaller by that amount, thus affecting the ejection characteristics. In particular, the protrusion of the adhesive GL between the diaphragm 24 and the pressure chamber substrate 23 results in substantial hardening of the diaphragm 24, so the influence on the ejection characteristics is particularly large. In order to inspect whether the degree of variation in the ejection characteristics of the ink exceeds the allowable limit, it is conceivable to confirm the degree of protrusion of the adhesive GL into the normal pressure chamber SCV1.

[0066] In order to check the state of the facing portion PT1 of the adhesive GL, as shown by the arrow IA1, even when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT1, since the metal individual electrode Qc exists and the infrared rays do not pass through the individual electrode Qc, the state of the facing portion PT1 of the adhesive GL could not be confirmed. Furthermore, as shown by the arrow IA3, even when infrared rays are projected in the Z2 direction from the nozzle substrate 21 side, since the facing portion PT3 exists, the state of the facing portion PT1 could not be confirmed. Also, in order to check the state of the facing portion PT2 of the adhesive GL, as shown by the arrow IA2, even when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT2, since the metal common electrode Qb exists and the infrared rays do not pass through the common electrode Qb, the state of the facing portion PT2 of the adhesive GL could not be confirmed. Furthermore, as shown by the arrow IA4, even when infrared rays are projected in the Z2 direction from the nozzle substrate 21 side, since the facing portion PT4 exists, the state of the facing portion PT2 could not be confirmed.

[0067] FIG. 6 is a cross-sectional view of the f-F line in FIG. 5.

[0068] As shown in FIG. 6, among the inclined surfaces of the normal piezoelectric body SQm1, the surface in the Y1 direction is referred to as surface PL5, and the surface in the Y2 direction is referred to as surface PL6.

[0069] A common electrode Qb is formed on the surface PL5, surface PL1, and PL6 of the normal piezoelectric body SQm1 and the surface QL1 of the diaphragm 24.

[0070] As described above, an individual electrode Qc is formed on the surface PL2 of the normal piezoelectric body SQm1. The end portion of the individual electrode Qc in the Y1 direction is located in the Y2 direction with respect to the surface PL5. The end portion of the individual electrode Qc in the Y2 direction is located in the Y1 direction with respect to the surface PL6.

[0071] At the interface between the pressure chamber substrate 23 and the diaphragm 24, on the corner portion CN5 in the Y2 direction and Z2 direction of the normal pressure chamber SCV1, there is a facing portion PT5 of the adhesive GL. At the interface between the pressure chamber substrate 23 and the diaphragm 24, on the corner portion CN6 in the Y1 direction and Z2 direction of the normal pressure chamber SCV1, there is a facing portion PT6 of the adhesive GL. Also, at the interface between the pressure chamber substrate 23 and the communication plate 22, on the corner portion CN7 in the Y2 direction and Z1 direction of the normal pressure chamber SCV1, there is a facing portion PT7 of the adhesive GL. At the interface between the pressure chamber substrate 23 and the communication plate 22, on the corner portion CN8 in the Y1 direction and Z1 direction of the normal pressure chamber SCV1, there is a facing portion PT8 of the adhesive GL.

[0072] In order to check the state of the facing portion PT5 of the adhesive GL, as shown by the arrow IA5, even when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT5, since the metal common electrode Qb exists and the infrared rays do not pass through the common electrode Qb, the state of the facing portion PT5 of the adhesive GL could not be confirmed. Furthermore, as shown by the arrow IA7, even when infrared rays are projected in the Z2 direction from the nozzle substrate 21 side, since the facing portion PT7 exists, the state of the facing portion PT5 could not be confirmed. Also, in order to check the state of the facing portion PT6 of the adhesive GL, as shown by the arrow IA6, even when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT6, since the common electrode Qb made of metal exists and the infrared rays do not pass through the common electrode Qb, the state of the facing portion PT6 of the adhesive GL could not be checked. Furthermore, as shown by the arrow IA8, even when infrared rays are projected in the Z2 direction from the nozzle substrate 21 side, since the facing portion PT8 exists, the state of the facing portion PT6 could not be checked.

[0073] As described above, since the states of the facing portions PT1, PT2, PT5, and PT6 cannot be checked, depending on the method of checking the degree of protrusion of the adhesive GL into the normal pressure chamber SCV1, it is not possible to inspect whether the degree of variation in the ink ejection characteristics exceeds the allowable limit.

[0074] In addition, as another method of inspecting whether the degree of variation in the ink ejection characteristics exceeds the allowable limit, a method of checking the resonance frequency of the diaphragm 24 is also conceivable. Specifically, the resonance frequency of the diaphragm 24 changes depending on the degree to which the facing portions PT1, PT2, PT5, and PT6 climb up onto the diaphragm 24. Conventionally, for each product, there has been variation in the degree to which the facing portions PT1, PT2, PT5, and PT6 climb up onto the diaphragm 24, but since the defects caused by such climbing in each product have been evaluated at the resonance frequency of the diaphragm 24 after attaching the case head to the liquid ejection head 1, until that process, it has not been possible to detect defects caused by the states of the facing portions PT1, PT2, PT5, and PT6. Also, since defects are discovered in a state where a plurality of expensive parts are joined, the influence on the increase in manufacturing cost and the delay of the manufacturing schedule due to the delay in defect detection has been significant.

[0075] Therefore, in the present embodiment, as shown in FIG. 4, a dummy pressure chamber DCV1 and a dummy pressure chamber DCV2 are provided in the pressure chamber substrate 23, and for the dummy pressure chamber DCV1 and the dummy pressure chamber DCV2, a common electrode Qb and an individual electrode Qc that do not transmit infrared rays are not provided.

[0076] 1-5: Configuration near the dummy pressure chamber DCV1 Figure 7 is a cross-sectional view of the g-G line in Figure 4.

[0077] As shown in Figure 7, among the two surfaces of the diaphragm 24 with the Z-axis direction as the normal direction, on the surface in the Z2 direction, a dummy piezoelectric body DQm1 and a sealing substrate 25 are formed.

[0078] In Figure 7, the dummy pressure chamber DCV1 communicates with the connection flow path BK1, but since the connection flow path BK1 does not communicate with the supply flow path BA1, the dummy pressure chamber DCV1 is not filled with ink. Also, the dummy pressure chamber DCV1 flows through the communication flow path BR1, but nozzles N1 are not provided in the communication flow path BR1.

[0079] As described above, the orientation control layer SD is provided on the surface in the Z1 direction of the normal piezoelectric body SQm1, but the orientation control layer SD is not provided on the surface in the Z1 direction of the dummy piezoelectric body DQm1. Note that, as described above, the shape of the dummy piezoelectric body DQm1 is the same as the shape of the normal piezoelectric body SQm.

[0080] Similar to the vicinity of the normal pressure chamber SCV1 shown in Figure 5, also in the vicinity of the dummy pressure chamber DCV1 shown in Figure 7, the pressure chamber substrate 23 and the diaphragm 24 are joined by an adhesive GL. Also, the pressure chamber substrate 23 and the communication plate 22 are joined by the adhesive GL. At the interface between the pressure chamber substrate 23 and the diaphragm 24, at the corners CN1' in the X2 and Z2 directions of the dummy pressure chamber DCV1, there is a facing portion PT1' of the adhesive GL facing the dummy pressure chamber DCV1. At the interface between the pressure chamber substrate 23 and the diaphragm 24, at the corners CN2' in the X1 and Z2 directions of the dummy pressure chamber DCV1, there is a facing portion PT2' of the adhesive GL facing the dummy pressure chamber DCV1. Also, at the interface between the pressure chamber substrate 23 and the communication plate 22, at the end portion CN3' in the X2 direction of the dummy pressure chamber DCV1, there is a facing portion PT3' of the adhesive GL that faces the dummy pressure chamber DCV1. At the interface between the pressure chamber substrate 23 and the communication plate 22, at the end portion CN4' in the X1 direction of the dummy pressure chamber DCV1, there is a facing portion PT4' of the adhesive GL that faces the dummy pressure chamber DCV1.

[0081] Also, as described above, a common electrode Qb and an individual electrode Qc are provided corresponding to the normal pressure chamber SCV1, but neither the common electrode Qb nor the individual electrode Qc is provided corresponding to the dummy pressure chamber DCV1.

[0082] Therefore, in order to check the state of the facing portion PT1' of the adhesive GL, as shown by the arrow IA1, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT1', since there is no metal electrode, the state of the facing portion PT1' of the adhesive GL can be checked. Also, in order to check the state of the facing portion PT2' of the adhesive GL, as shown by the arrow IA2, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT2', since there is no metal electrode, the state of the facing portion PT2' of the adhesive GL can be checked.

[0083] Figure 8 is a cross-sectional view of the h-H line in Figure 7.

[0084] At the interface between the pressure chamber substrate 23 and the diaphragm 24, at the corner portions CN5' in the Y2 and Z2 directions of the dummy pressure chamber DCV1, there is a facing portion PT5' of the adhesive GL. At the interface between the pressure chamber substrate 23 and the diaphragm 24, at the corner portions CN6' in the Y1 and Z2 directions of the dummy pressure chamber DCV1, there is a facing portion PT6' of the adhesive GL. Also, at the interface between the pressure chamber substrate 23 and the communication plate 22, on the corners CN7' in the Y2 direction and Z1 direction of the dummy pressure chamber DCV1, there are facing portions PT7' of the adhesive GL. At the interface between the pressure chamber substrate 23 and the communication plate 22, on the corners CN8' in the Y1 direction and Z1 direction of the dummy pressure chamber DCV1, there are facing portions PT8' of the adhesive GL.

[0085] As described above, corresponding to the dummy piezoelectric body DQm, neither the common electrode Qb nor the individual electrode Qc is formed.

[0086] Therefore, in order to check the state of the facing portion PT5' of the adhesive GL, as shown by the arrow IA5, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT5', since there is no metal electrode, the state of the facing portion PT5' of the adhesive GL can be checked. Also, in order to check the state of the facing portion PT6' of the adhesive GL, as shown by the arrow IA6, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT6', since there is no metal electrode, the state of the facing portion PT6' of the adhesive GL can be checked.

[0087] As a result, it becomes possible to check the degree to which the facing portions PT1', PT2', PT5', and PT6' climb up onto the diaphragm 24 at a stage prior to attaching the case head to the liquid ejection head 1. Subsequently, in the manufacturing process of the liquid ejection head 1, it becomes possible to check the states of the facing portions PT1', PT2', PT5', and PT6' of the adhesive GL at a stage prior to attaching the case head to the liquid ejection head 1, and an effective 100% inspection of the liquid ejection head 1 is achieved.

[0088] Also, in the plan view shown in FIG. 4, in the arrangement of the pressure chambers CV1 and CV2 in the Y-axis direction, as the facing portions PT1', PT2', PT5', and PT6' move away from the center in the Y1 or Y2 direction, the degree of crawling onto the diaphragm 24 increases. Therefore, by arranging the dummy pressure chambers DCV1 and DCv2 outside the normal pressure chambers CV1 and CV2 in the Y-axis direction, it becomes possible to check the states of the facing portions PT1', PT2', PT5', and PT6' with a greater degree of crawling.

[0089] 1-6: Effects achieved by the first embodiment The liquid ejection head 1 according to the present embodiment includes a nozzle substrate 21 provided with nozzles N for ejecting ink as a liquid, a plurality of normal pressure chambers SCV1 filled with ink therein and applying pressure to the ink to eject the ink, a dummy pressure chamber DCV1 not used for ink ejection, a pressure chamber substrate 23 adhered to other members with an adhesive GL, a normal piezoelectric body SQm1, individual electrodes Qc provided individually for the plurality of normal pressure chambers SCV1, and a common electrode Qb provided for the plurality of normal pressure chambers SCV1, and a piezoelectric element PZ1 composed of these. Corresponding to the normal pressure chambers SCV1, both the individual electrode Qc and the common electrode Qb are arranged. Corresponding to the dummy pressure chamber DCV1, at least one of the individual electrode Qc and the common electrode Qb is not arranged.

[0090] In the dummy pressure chamber DCV1, at least one of the individual electrode Qc and the common electrode Qb that does not transmit infrared rays is not arranged. As a result, in the dummy pressure chamber DCV1, the state in which the adhesive GL joining the pressure chamber substrate 23 and other members protrudes from the interface between the pressure chamber substrate 23 and other members can be confirmed by an infrared camera via a location where neither the individual electrode Qc nor the common electrode Qb is arranged.

[0091] The state of the adhesive GL protruding from the interface between the pressure chamber substrate 23 and other members may have an adverse effect on the ink ejection characteristics. By being able to confirm the state of the adhesive GL protruding from the interface between the pressure chamber substrate 23 and other members with an infrared camera, it becomes possible to detect defects in the liquid ejection head 1 at an early stage during the manufacturing process of the liquid ejection head 1.

[0092] Also, in the liquid ejection head 1, a normal piezoelectric body SQm1 is disposed corresponding to the normal pressure chamber SCV1, and a dummy piezoelectric body DQm1 is disposed corresponding to the dummy pressure chamber DCV1.

[0093] By disposing not only the normal piezoelectric body SQm1 corresponding to the normal pressure chamber SCV1 but also the dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1, compared to the case where only the diaphragm 24 is provided corresponding to the dummy pressure chamber DCV1, the substantial thickness of the diaphragm 24 is increased by the amount of the dummy piezoelectric body DQm1 to prevent cracks, and the manufacturing process of the liquid ejection head 1 can be facilitated.

[0094] Also, in the liquid ejection head 1, on the normal pressure chamber SCV1 side of the normal piezoelectric body SQm1 corresponding to the normal pressure chamber SCV1, an orientation control layer SD for controlling the orientation of the normal piezoelectric body SQm1 is provided. On the dummy pressure chamber DCV1 side of the dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1, an orientation control layer SD for controlling the orientation of the dummy piezoelectric body DQm1 is not provided.

[0095] By providing the orientation control layer SD on the normal piezoelectric body SQm1, the piezoelectric characteristics of the normal piezoelectric body SQm1 are improved. On the other hand, since the dummy piezoelectric body DQm1 is not driven, the orientation control layer SD is not provided on the dummy piezoelectric body DQm1. As a result, it becomes possible to reduce the manufacturing cost of the liquid ejection head 1.

[0096] Also, in the liquid ejection head 1, corresponding to the dummy pressure chamber DCV1, neither the individual electrode Qc nor the common electrode Qb is disposed.

[0097] Corresponding to the dummy pressure chamber DCV1, by not arranging both the individual electrode Qc and the common electrode Qb through which infrared rays do not pass, it becomes possible to confirm with an infrared camera a state in which the adhesive GL that joins the pressure chamber substrate 23 and another member protrudes from the interface between the pressure chamber substrate 23 and the other member.

[0098] Also, in the liquid ejection head 1, a diaphragm 24 that vibrates by driving the piezoelectric element PZ is provided between the pressure chamber substrate 23 and the piezoelectric element PZ. The pressure chamber substrate 23 and the diaphragm 24 are adhered with an adhesive GL.

[0099] As a result, it becomes possible to confirm with an infrared camera a state in which the adhesive GL that joins the pressure chamber substrate 23 and the diaphragm 24 protrudes from the interface between the pressure chamber substrate 23 and the diaphragm 24 and climbs onto the diaphragm 24. Subsequently, by confirming the state of the adhesive GL climbing onto the diaphragm 24 at a stage before detecting the resonance frequency of the diaphragm 24, it becomes possible to detect a defect in the liquid ejection head 1.

[0100] Also, in the liquid ejection head 1, a communication plate 22 provided with a communication flow path BR1 for ink to flow from the pressure chamber CV1 toward the nozzle N is provided between the pressure chamber substrate 23 and the nozzle substrate 21. The pressure chamber substrate 23 and the communication plate 22 are adhered with an adhesive GL.

[0101] As a result, it becomes possible to confirm with an infrared camera a state in which the adhesive GL that joins the pressure chamber substrate 23 and the communication plate 22 protrudes from the interface between the pressure chamber substrate 23 and the diaphragm 24.

[0102] Also, the liquid ejection head 1 includes a sealing substrate 25 that seals the piezoelectric element PZ1. The sealing substrate 25 is provided so as to overlap the dummy pressure chamber DCV1 when viewed in the Z-axis direction, which is the stacking direction of the pressure chamber substrate 23 and the piezoelectric element PZ1. Corresponding to the dummy pressure chamber DCV1, neither the individual electrode Qc nor the common electrode Qb is arranged.

[0103] Corresponding to the dummy pressure chamber DCV1, since neither the individual electrode Qc that does not transmit infrared rays nor the common electrode Qb is disposed, the adhesive GL that joins the pressure chamber substrate 23 and another member can be confirmed from the outside of the sealing substrate 25 by an infrared camera in a state of protruding from the interface between the pressure chamber substrate 23 and the other member.

[0104] Further, the liquid ejection device 100 according to the present embodiment includes the above-described liquid ejection head 1 and a control device 7 that controls the ejection operation from the liquid ejection head 1.

[0105] In the dummy pressure chamber DCV1, at least one of the individual electrode Qc that does not transmit infrared rays and the common electrode Qb is not disposed. As a result, in the dummy pressure chamber DCV1, the adhesive GL that joins the pressure chamber substrate 23 and another member can be confirmed by an infrared camera through a location where neither the individual electrode Qc nor the common electrode Qb is disposed in a state of protruding from the interface between the pressure chamber substrate 23 and the other member.

[0106] The state of the adhesive GL protruding from the interface between the pressure chamber substrate 23 and another member may adversely affect the ejection characteristics of the ink. By being able to confirm the state of the adhesive GL protruding from the interface between the pressure chamber substrate 23 and another member by an infrared camera, it becomes possible to detect a defect in the liquid ejection head 1 at an early stage during the manufacturing process of the liquid ejection device 100.

[0107] 2: Second Embodiment Hereinafter, the liquid ejection device 100 according to the second embodiment will be described with reference to FIGS. 9 to 11. For the sake of simplicity of explanation, hereinafter, mainly, the points in which the liquid ejection device 100 according to the second embodiment differs from the liquid ejection device 100 according to the first embodiment will be described. Further, among the components provided in the liquid ejection device 100 according to the second embodiment, for the components that are the same as those in the liquid ejection device 100 according to the first embodiment, the same reference numerals may be used and the description of their functions may be omitted.

[0108] 2-1: Structure of Electrodes The liquid ejection device 100 according to the second embodiment includes a liquid ejection head 1A instead of the liquid ejection head 1 provided in the liquid ejection device 100 according to the first embodiment. Hereinafter, with reference to FIG. 9, the structures of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1A according to the second embodiment will be described.

[0109] FIG. 9 is a plan view of the liquid ejection head 1A when viewed in a plan view in the Z1 direction.

[0110] In the liquid ejection head 1A, unlike the liquid ejection head 1, an individual electrode DQc is provided corresponding to the dummy pressure chamber DCV. The shape of the individual electrode DQc may be substantially the same as or different from the shape of the individual electrode Qc. Also, the material of the individual electrode DQc may be the same as the material of the individual electrode Qc. Specifically, for the material of the individual electrode DQc, similar to the individual electrode Qc, for example, metals such as platinum, iridium, gold, or titanium, or conductive materials such as indium tin oxide abbreviated as ITO, a conductive metal oxide, may be employed. However, the material of the individual electrode DQc does not have to be the same as the material of the individual electrode Qc. Also, different from the individual electrode Qc, the individual electrode DQc is not connected to the wiring for supplying the drive signal Com provided on the wiring substrate 4. For this reason, the drive signal Com is not supplied from the control device 7 to the individual electrode DQc. On the other hand, in the liquid ejection head 1A, similar to the liquid ejection head 1, the common electrode Qb is commonly provided for the normal pressure chamber SCV. On the other hand, the common electrode Qb is not provided for the dummy pressure chamber DCV.

[0111] 2-2: Configuration near the dummy pressure chamber DCV1 FIG. 10 is a cross-sectional view of the g-G line in FIG. 9.

[0112] In FIG. 10, of the two surfaces of the dummy piezoelectric body DQm1 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface PL1', and the surface in the Z1 direction is referred to as surface PL2'. Also, of the inclined surfaces of the dummy piezoelectric body DQm1, the surface in the X1 direction is referred to as surface PL3', and the surface in the X2 direction is referred to as surface PL4'. Further, of the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface QL1.

[0113] Corresponding to the dummy pressure chamber DCV1, an individual electrode DQc is provided. The end portion of the individual electrode DQc in the X1 direction is located in the X2 direction with respect to the surface PL3'. Also, the individual electrode DQc extends in the X2 direction to the outside of the sealing substrate 25.

[0114] On the other hand, corresponding to the dummy pressure chamber DCV1, a common electrode Qb is not provided. Therefore, in order to check the state of the facing portion PT2' of the adhesive GL, as shown by the arrow IA2, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT2', since there is no metal electrode, the state of the adhesive GL climbing up to the diaphragm 24 at the facing portion PT2' can be checked.

[0115] When comparing the vicinity of the dummy pressure chamber DCV1 shown in FIG. 10 with the vicinity of the normal pressure chamber SCV1 shown in FIG. 5, the dummy piezoelectric body DQm1 provided corresponding to the dummy pressure chamber DCV1 has a shorter length in the X-axis direction than the length in the X-axis direction of the normal piezoelectric body SQm provided corresponding to the normal pressure chamber SCV1. However, the length of the dummy piezoelectric body DQm1 in the X-axis direction may be equal to the length of the normal piezoelectric body SQm1 in the X-axis direction. Also, the length of the dummy piezoelectric body DQm1 in the Z-axis direction is shorter than the length of the normal piezoelectric body SQm1 in the Z-axis direction. However, the length of the dummy piezoelectric body DQm1 in the Z-axis direction may be equal to the length of the normal piezoelectric body SQm1 in the Z-axis direction.

[0116] FIG. 11 is a cross-sectional view of the h-H line in FIG. 10.

[0117] As shown in FIG. 11, among the inclined surfaces of the dummy piezoelectric body DQm1, the surface in the Y1 direction is referred to as surface PL5', and the surface in the Y2 direction is referred to as surface PL6'.

[0118] As described above, an individual electrode DQc is formed on the surface PL2' of the dummy piezoelectric body DQm1. The end portion of the individual electrode DQc in the Y1 direction is located in the Y2 direction with respect to the surface PL5'. The end portion of the individual electrode DQc in the Y2 direction is located in the Y1 direction with respect to the surface PL6'.

[0119] On the other hand, a common electrode Qb is not provided corresponding to the dummy pressure chamber DCV1. For this reason, in order to check the state of the facing portion PT5' of the adhesive GL, as shown by the arrow IA5, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT5', since there is no metal electrode, the state of the facing portion PT5' of the adhesive GL climbing up to the diaphragm 24 can be checked.

[0120] When comparing the vicinity of the dummy pressure chamber DCV1 shown in FIG. 11 with the vicinity of the normal pressure chamber SCV1 shown in FIG. 6, the length of the dummy piezoelectric body DQm1 in the Y-axis direction provided corresponding to the dummy pressure chamber DCV1 is shorter than the length of the normal piezoelectric body SQm1 in the Y-axis direction provided corresponding to the normal pressure chamber SCV1. However, the length of the dummy piezoelectric body DQm1 in the Y-axis direction may be equal to the length of the normal piezoelectric body SQm1 in the Y-axis direction.

[0121] 2-3: Effects of the Second Embodiment In the liquid ejection head 1A according to the present embodiment, the thickness of the normal piezoelectric body SQm1 corresponding to the normal pressure chamber SCV1 is thicker than the thickness of the dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1.

[0122] In addition to the normal piezoelectric body SQm1 corresponding to the normal pressure chamber SCV1, a dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1 is provided, so that the rigidity of the liquid ejection head 1A is maintained higher than when the dummy piezoelectric body DQm1 is not provided. By making the thickness of the normal piezoelectric body SQm1 thicker than the thickness of the dummy piezoelectric body DQm1, the normal piezoelectric body SQm1 can secure a higher driving force as compared with the case where its thickness is equal to the thickness of the dummy piezoelectric body DQm1. Conversely, by making the thickness of the dummy piezoelectric body DQm1 thinner than the thickness of the normal piezoelectric body SQm1, it is possible to reduce the manufacturing cost of the liquid ejection head 1A. Further, since the dummy piezoelectric body DQm1 may slightly block infrared rays, it is preferable to keep the thickness of the dummy piezoelectric body DQm1 at a level where the effect of preventing cracks can be obtained.

[0123] Also, in the liquid ejection head 1A, when the X-axis direction, which is the extending direction of the pressure chamber CV, is defined as the first direction, the length of the normal piezoelectric body SQm corresponding to the normal pressure chamber SCV in the first direction is longer than the length of the dummy piezoelectric body DQm corresponding to the dummy pressure chamber DCV in the first direction.

[0124] In addition to the normal piezoelectric body SQm1 corresponding to the normal pressure chamber SCV1, a dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1 is provided, so that the rigidity of the liquid ejection head 1A is maintained higher than when the dummy piezoelectric body DQm1 is not provided. Also, by making the length of the normal piezoelectric body SQm1 in the extending direction longer than the length of the dummy piezoelectric body DQm1 in the extending direction, the normal piezoelectric body SQm1 can secure a higher driving force as compared with the case where its length in the extending direction is equal to the length of the dummy piezoelectric body DQm1. Conversely, by making the length of the dummy piezoelectric body DQm1 in the extending direction shorter than the length of the normal piezoelectric body SQm1 in the extending direction, it is possible to reduce the manufacturing cost of the liquid ejection head 1A. Further, since the dummy piezoelectric body DQm1 may slightly block infrared rays, it is preferable to keep the length of the dummy piezoelectric body DQm1 in the first direction at a level where the effect of preventing cracks can be obtained.

[0125] Further, in the liquid ejection head 1A, when the Y-axis direction, which is the arrangement direction of the plurality of pressure chambers CV, is defined as the second direction, the length of the normal piezoelectric body SQm1 corresponding to the normal pressure chamber SCV1 in the second direction is longer than the length of the dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1 in the second direction.

[0126] In addition to the normal piezoelectric body SQm1 corresponding to the normal pressure chamber SCV1, the provision of the dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1 enables the rigidity of the liquid ejection head 1A to be maintained higher than when the dummy piezoelectric body DQm1 is not provided. Also, by making the length of the normal piezoelectric body SQm1 in the arrangement direction longer than the length of the dummy piezoelectric body DQm1 in the arrangement direction, the normal piezoelectric body SQm1 can secure a higher driving force compared to the case where the length in its arrangement direction is equal to the length of the dummy piezoelectric body DQm1 in the arrangement direction. Conversely, by making the length of the dummy piezoelectric body DQm1 in the arrangement direction shorter than the length of the normal piezoelectric body SQm1 in the arrangement direction, it is possible to reduce the manufacturing cost of the liquid ejection head 1A. Further, since the dummy piezoelectric body DQm1 may slightly block infrared rays, it is preferable to keep the length of the dummy piezoelectric body DQm1 in the second direction at a thickness sufficient to obtain the effect of preventing cracks.

[0127] Further, in the liquid ejection head 1A, an individual electrode Qc is arranged corresponding to the dummy pressure chamber DCV1, and a common electrode Qb is not arranged.

[0128] As a result, it becomes possible to confirm, by means of an infrared camera, a state in which the adhesive GL joining the pressure chamber substrate 23 and another member protrudes from the interface between the pressure chamber substrate 23 and the other member via a location where the common electrode Qb is not arranged. Furthermore, the arrangement of the individual electrode Qc maintains the rigidity of the liquid ejection head 1A.

[0129] 3: Third Embodiment Hereinafter, with reference to FIGS. 12 to 14, the liquid ejection device 100 according to the third embodiment will be described. For the sake of simplicity of explanation, hereinafter, mainly, the points in which the liquid ejection device 100 according to the third embodiment differs from the liquid ejection device 100 according to the first embodiment will be described. In addition, among the components provided in the liquid ejection device 100 according to the third embodiment, for the same components as those in the liquid ejection device 100 according to the first embodiment, the same reference numerals are used, and the description of their functions may be omitted.

[0130] 3-1: Structure of Electrodes The liquid ejection device 100 according to the third embodiment includes a liquid ejection head 1B instead of the liquid ejection head 1 provided in the liquid ejection device 100 according to the first embodiment. Hereinafter, with reference to FIG. 12, the structures of the individual electrodes Qc and the common electrode Qb in the liquid ejection head 1B according to the second embodiment will be described.

[0131] FIG. 12 is a plan view of the liquid ejection head 1B when viewed in a plan view in the Z1 direction.

[0132] In the liquid ejection head 1B, unlike the liquid ejection head 1, the common electrode Qb is commonly provided for the plurality of normal pressure chambers SCV1 and the plurality of dummy pressure chambers DCV1. More specifically, the common electrode Qb is provided so as to overlap the plurality of normal pressure chambers SCV1 and the plurality of dummy pressure chambers DCV1 when the liquid ejection head 1 is viewed in a plan view in the Z1 direction. However, the common electrode Qb may be provided so that each of the plurality of normal pressure chambers SCV1 and each of the plurality of dummy pressure chambers DCV1 has a portion that does not overlap the common electrode Qb when the liquid ejection head 1 is viewed in a plan view in the Z1 direction. On the other hand, in the liquid ejection head 1B, similar to the liquid ejection head 1, the plurality of individual electrodes Qc are not provided for the plurality of dummy pressure chambers DCV1.

[0133] 3-2: Configuration Near the Dummy Pressure Chamber DCV1 FIG. 13 is a cross-sectional view taken along line g-G in FIG. 12.

[0134] Similar to FIG. 10, in FIG. 13, of the two surfaces of the dummy piezoelectric body DQm1 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface PL1', and the surface in the Z1 direction is referred to as surface PL2'. Also, of the inclined surfaces of the dummy piezoelectric body DQm1, the surface in the X1 direction is referred to as surface PL3', and the surface in the X2 direction is referred to as surface PL4'. Also, of the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface QL1.

[0135] As shown in FIG. 13, a common electrode Qb is formed on the surface PL1' and surface PL3' of the dummy piezoelectric body DQm1 and on the surface QL1 of the diaphragm 24. The end portion of the common electrode Qb in the X2 direction is on the surface PL1' and is located in the X1 direction with respect to the surface PL4'. Also, the end portion of the common electrode Qb in the X1 direction is on the surface QL1 and is located inside the sealing substrate 25.

[0136] On the other hand, corresponding to the dummy pressure chamber DCV1, an individual electrode Qc is not provided. For this reason, in order to check the state of the facing portion PT1' of the adhesive GL, as shown by the arrow IA1, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT1, since there is no metal electrode, the state of the facing portion PT1' of the adhesive GL can be checked.

[0137] When comparing the vicinity of the dummy pressure chamber DCV1 shown in FIG. 13 with the vicinity of the normal pressure chamber SCV1 shown in FIG. 5, the dummy piezoelectric body DQm1 provided corresponding to the dummy pressure chamber DCV1 has a shorter length in the X-axis direction than the length in the X-axis direction of the normal piezoelectric body SQm1 provided corresponding to the normal pressure chamber SCV1. However, the length in the X-axis direction of the dummy piezoelectric body DQm1 may be equal to the length in the X-axis direction of the normal piezoelectric body SQm1. Also, the length of the dummy piezoelectric body DQm1 in the Z-axis direction is shorter than the length of the normal piezoelectric body SQm1 in the Z-axis direction. However, the length of the dummy piezoelectric body DQm1 in the Z-axis direction may be equal to the length of the normal piezoelectric body SQm1 in the Z-axis direction.

[0138] FIG. 14 is a cross-sectional view of the h-H line in FIG. 13.

[0139] Similar to FIG. 11, among the inclined surfaces of the dummy piezoelectric body DQm1, the surface in the Y1 direction is referred to as surface PL5', and the surface in the Y2 direction is referred to as surface PL6'.

[0140] A common electrode Qb is formed on the surface PL5', surface PL1', and PL6' of the dummy piezoelectric body DQm1 and the surface QL1 of the diaphragm 24.

[0141] On the other hand, corresponding to the dummy pressure chamber DCV1, the individual electrode Qc is not provided.

[0142] When comparing the vicinity of the dummy pressure chamber DCV1 shown in FIG. 14 with the vicinity of the normal pressure chamber SCV1 shown in FIG. 6, the length of the dummy piezoelectric body DQm1 provided corresponding to the dummy pressure chamber DCV1 in the Y-axis direction is shorter than the length of the normal piezoelectric body SQm1 provided corresponding to the normal pressure chamber SCV1 in the Y-axis direction. However, the length of the dummy piezoelectric body DQm1 in the Y-axis direction may be equal to the length of the normal piezoelectric body SQm1 in the Y-axis direction.

[0143] 3-3: Effects of the Third Embodiment In the liquid ejection head 1B according to the present embodiment, corresponding to the dummy pressure chamber DCV1, the individual electrode Qc is not arranged, and the common electrode Qb is arranged.

[0144] As a result, it becomes possible to confirm, by means of an infrared camera, a state in which the adhesive GL joining the pressure chamber substrate 23 and other members protrudes from the interface between the pressure chamber substrate 23 and other members via a location where the individual electrode Qc is not arranged. Furthermore, by arranging the common electrode Qb, the rigidity of the liquid ejection head 1B is maintained higher than when the common electrode Qb is not arranged.

[0145] 4: Fourth Embodiment Hereinafter, the liquid ejection device 100 according to the fourth embodiment will be described with reference to FIGS. 15 and 16. For the sake of simplicity of explanation, hereinafter, mainly, the differences between the liquid ejection device 100 according to the fourth embodiment and the liquid ejection device 100 according to the third embodiment will be described. In addition, among the components provided in the liquid ejection device 100 according to the fourth embodiment, for the components that are the same as those in the liquid ejection device 100 according to the third embodiment, the same reference numerals will be used, and the description of their functions may be omitted.

[0146] 4-1: Structure of Electrodes The liquid ejection device 100 according to the fourth embodiment includes a liquid ejection head 1C instead of the liquid ejection head 1B provided in the liquid ejection device 100 according to the third embodiment. Hereinafter, with reference to FIG. 15, the structures of the individual electrodes Qc and the common electrode Qb in the liquid ejection head 1C according to the fourth embodiment will be described.

[0147] FIG. 15 is a plan view of the liquid ejection head 1C when viewed in a plan view in the Z1 direction.

[0148] In the liquid ejection head 1C, similar to the liquid ejection head 1B, the common electrode Qb is commonly provided for the plurality of normal pressure chambers SCV1 and the plurality of dummy pressure chambers DCV1. However, a plurality of opening portions OPy1 are provided in the common electrode Qb. Each of the plurality of opening portions OPy1 is elongated in the Y-axis direction and commonly overlaps a part of each of the plurality of dummy pressure chambers DCV1. In addition, the plurality of opening portions OPy1 are arranged in the X-axis direction. Therefore, when viewed in the Z-axis direction, a part of the plurality of opening portions OPy1 overlaps each of the plurality of dummy pressure chambers DCV1 in a striped manner. On the other hand, in the liquid ejection head 1C, similar to the liquid ejection head 1B, the plurality of individual electrodes Qc are not provided for the plurality of dummy pressure chambers DCV1.

[0149] 4-2: Configuration Near the Dummy Pressure Chamber DCV1 FIG. 16 is a cross-sectional view taken along the g-G line in FIG. 15.

[0150] Similar to FIG. 10, in FIG. 13, of the two surfaces of the dummy piezoelectric body DQm1 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface PL1', and the surface in the Z1 direction is referred to as surface PL2'. Also, of the inclined surfaces of the dummy piezoelectric body DQm1, the surface in the X1 direction is referred to as surface PL3', and the surface in the X2 direction is referred to as surface PL4'. Further, of the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface QL1.

[0151] As shown in FIG. 16, a common electrode Qb is formed on a part of the surface PL1' of the dummy piezoelectric body DQm1 and a part of the surface QL1 of the diaphragm 24. Note that a common electrode Qb may also be formed on a part of the surface PL3'. The common electrode Qb is formed in a scattered manner on the surfaces PL1', PL3', and QL1 with the opening portion OPy1 interposed therebetween. As a result, when viewed in the Z-axis direction, since the opening portion OPy1 exists in the Z2 direction of the facing portions PT1' to PT4', the common electrode Qb is not formed.

[0152] In other words, the opening portion OPy1 is provided so as to overlap at least a part of the facing portions PT1' to PT4' which are the facing portions of the adhesive GL between the other members facing the dummy pressure chamber DCV1 when viewed in the stacking direction of the pressure chamber substrate 23 and the piezoelectric element PZ1 including the dummy piezoelectric body DQm1.

[0153] Therefore, in order to check the state of the facing portion PT1' of the adhesive GL, as shown by the arrow IA1, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT1', since there is no metal electrode, the state of the facing portion PT1' of the adhesive GL can be checked. Also, in order to check the state of the facing portion PT2' of the adhesive GL, as shown by the arrow IA2, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT2', since there is no metal electrode, the state of the facing portion PT2' of the adhesive GL can be checked.

[0154] Note that since the cross-sectional view of the h-H line in FIG. 16 is the same as the cross-sectional view of FIG. 8, the description thereof is omitted.

[0155] 4-3: Effects Exhibited by the Fourth Embodiment In the liquid ejection head 1C according to the present embodiment, the common electrode Qb includes an opening portion OPy1. The opening portion OPy1 is provided so as to overlap at least a part of facing portions PT1' to PT4' of the adhesive GL between the other members facing the dummy pressure chamber DCV1 when viewed in the stacking direction of the pressure chamber substrate 23 and the piezoelectric element PZ including the normal piezoelectric body SQm1.

[0156] As a result, it becomes possible to confirm, by means of an infrared camera via the opening portion OPy1, a state in which the adhesive GL joining the pressure chamber substrate 23 and the other member protrudes from the interface between the pressure chamber substrate 23 and the other member. Further, by arranging the common electrode Qb, the rigidity of the liquid ejection head 1C is maintained higher than in the case where the common electrode Qb is not arranged.

[0157] 5: Fifth Embodiment Hereinafter, with reference to FIGS. 17 and 18, the liquid ejection device 100 according to the fifth embodiment will be described. For the sake of simplicity of explanation, hereinafter, mainly, the differences between the liquid ejection device 100 according to the fifth embodiment and the liquid ejection device 100 according to the third embodiment will be described. Also, among the components provided in the liquid ejection device 100 according to the fifth embodiment, for the components identical to those of the liquid ejection device 100 according to the third embodiment, the same reference numerals may be used and the description of their functions may be omitted.

[0158] 5-1: Structure of Electrodes The liquid ejection device 100 according to the fifth embodiment includes a liquid ejection head 1D instead of the liquid ejection head 1B provided in the liquid ejection device 100 according to the third embodiment. Hereinafter, while referring to FIGS. 17 and 18, the structures of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1D according to the fifth embodiment will be described.

[0159] FIG. 17 is a plan view of the liquid ejection head 1D when viewed in a plan view in the Z1 direction.

[0160] In the liquid ejection head 1D, similarly to the liquid ejection head 1B, the common electrode Qb is commonly provided for the plurality of normal pressure chambers SCV1 and the plurality of dummy pressure chambers DCV1. However, a plurality of opening portions OPx1 are provided in the common electrode Qb. Each of the plurality of opening portions OPx1 is elongated in the X-axis direction and overlaps a part of each of the plurality of dummy pressure chambers DCV1. Further, the plurality of opening portions OPx1 are arranged in the Y-axis direction. For this reason, a part of the plurality of opening portions OPx1 overlaps each of the plurality of dummy pressure chambers DCV1 in a striped pattern. More specifically, when viewed in the Z-axis direction, each of the plurality of opening portions OPx1 is arranged so as to include a part of the outer periphery extending in the X-axis direction among the outer peripheries of the dummy pressure chamber DCV1. Also, in the liquid ejection head 1D, similarly to the liquid ejection head 1B, the plurality of individual electrodes Qc are not provided for the plurality of dummy pressure chambers DCV1.

[0161] 5-2: Configuration near the dummy pressure chamber DCV1 Since the cross-sectional view of the g-G line in FIG. 17 is the same as the cross-sectional view shown in FIG. 13, the description thereof is omitted. FIG. 18 is a cross-sectional view similar to the cross-sectional view of the h-H line in FIG. 13.

[0162] Similar to FIG. 11, in FIG. 18, of the two surfaces of the dummy piezoelectric body DQm1 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface PL1', and the surface in the Z1 direction is referred to as surface PL2'. Also, of the inclined surfaces of the dummy piezoelectric body DQm1, the surface in the Y1 direction is referred to as surface PL5', and the surface in the Y2 direction is referred to as surface PL6'. Further, of the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, the surface in the Z2 direction is referred to as surface QL1.

[0163] As shown in FIG. 18, a common electrode Qb is formed on a part of the surface PL1' of the dummy piezoelectric body DQm and a part of the surface QL1 of the diaphragm 24. The common electrode Qb is formed in a scattered manner on the surfaces PL1' and QL1 with the opening portion OPx1 interposed therebetween. As a result, when viewed in the Z-axis direction, since the opening portion OPx1 exists in the Z2 direction of the facing portions PT1' to PT4', the common electrode Qb is not formed.

[0164] In other words, the opening portion OPx1 is provided so as to overlap at least a part of the facing portions PT5' to PT8' which are the facing portions of the adhesive GL between the other members facing the dummy pressure chamber DCV1 when viewed in the stacking direction of the pressure chamber substrate 23 and the piezoelectric element PZ including the normal piezoelectric body SQm.

[0165] Therefore, in order to check the state of the facing portion PT5' of the adhesive GL, as shown by the arrow IA5, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT5', since there is no metal electrode, the state of the facing portion PT5' of the adhesive GL can be checked. Also, in order to check the state of the facing portion PT6' of the adhesive GL, as shown by the arrow IA6, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT6', since there is no metal electrode, the state of the facing portion PT6' of the adhesive GL can be checked.

[0166] 5-3: Effects of the Fifth Embodiment In the liquid ejection head 1D according to the present embodiment, the common electrode Qb includes the opening portion OPx1. The opening portion OPx1 is provided so as to overlap at least a part of the facing portions PT5' to PT8' which are the facing portions of the adhesive GL between the other members facing the dummy pressure chamber DCV1 when viewed in the stacking direction of the pressure chamber substrate 23 and the piezoelectric element PZ including the normal piezoelectric body SQm1.

[0167] As a result, it becomes possible to confirm, via the opening portion OPx1, with an infrared camera, a state in which the adhesive GL that joins the pressure chamber substrate 23 and other members protrudes from the interface between the pressure chamber substrate 23 and the other members. Furthermore, by arranging the common electrode Qb, the rigidity of the liquid ejection head 1D is maintained higher than in the case where the common electrode Qb is not arranged.

[0168] 6: Sixth Embodiment Hereinafter, with reference to FIGS. 19 to 21, the liquid ejection device 100 according to the sixth embodiment will be described. For the sake of simplicity of explanation, hereinafter, mainly, the points in which the liquid ejection device 100 according to the sixth embodiment differs from the liquid ejection device 100 according to the first embodiment will be described. In addition, among the components provided in the liquid ejection device 100 according to the sixth embodiment, for the same components as those in the liquid ejection device 100 according to the first embodiment, the same reference numerals may be used and the description of their functions may be omitted.

[0169] 6-1: Structure of Electrodes The liquid ejection device 100 according to the sixth embodiment includes a liquid ejection head 1E instead of the liquid ejection head 1 provided in the liquid ejection device 100 according to the first embodiment. Hereinafter, while referring to FIGS. 19 to 21, the structures of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1E according to the sixth embodiment will be described.

[0170] FIG. 19 is a plan view of the liquid ejection head 1E when viewed in plan in the Z1 direction. The structures of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1E are the same as the structures of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1 shown in FIGS. 4 to 6.

[0171] However, in the liquid ejection head 1E, as shown in FIG. 19, when viewed in plan in the Z1 direction, it is different from the liquid ejection head 1 according to the first embodiment in that a dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1 is not provided.

[0172] 6-2: Configuration in the Vicinity of the Dummy Pressure Chamber DCV1 Figure 20 is a cross-sectional view of the g-G line in Figure 19.

[0173] The cross-sectional view shown in Figure 20 is the same as the cross-sectional view shown in Figure 7 in the first embodiment, except that the dummy piezoelectric body DQm1 is not laminated in the Z2 direction of the diaphragm 24. More specifically, as shown in Figure 20, among the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, although the sealing substrate 25 is formed on the surface in the Z2 direction, the dummy piezoelectric body DQm1 is not laminated.

[0174] Also in the liquid ejection head 1E, similar to the liquid ejection head 1, in order to check the state of the facing portion PT1' of the adhesive GL, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT1' as shown by the arrow IA1, since there is no metal electrode, the states of the facing portions PT1' and PT3' of the adhesive GL can be checked. Further, in order to check the state of the facing portion PT2' of the adhesive GL, when infrared rays are projected in the Z1 direction from an infrared camera located in the Z2 direction with respect to the facing portion PT2' as shown by the arrow IA2, since there is no metal electrode, the state of the facing portion PT2' of the adhesive GL can be checked.

[0175] Figure 21 is a cross-sectional view of the h-H line in Figure 20.

[0176] The cross-sectional view shown in Figure 21 is the same as the cross-sectional view shown in Figure 8 in the first embodiment, except that the dummy piezoelectric body DQm1 is not laminated in the Z2 direction of the diaphragm 24. More specifically, as shown in Figure 21, among the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, although the sealing substrate 25 is formed on the surface in the Z2 direction, the dummy piezoelectric body DQm1 is not laminated.

[0177] Also in the liquid ejection head 1E, similar to the liquid ejection head 1, in order to check the state of the facing portion PT5' of the adhesive GL, as shown by the arrow IA5, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT5', since there is no metal electrode, the state of the facing portion PT5' of the adhesive GL can be checked. Further, in order to check the state of the facing portion PT6' of the adhesive GL, as shown by the arrow IA6, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT6', since there is no metal electrode, the state of the facing portion PT6' of the adhesive GL can be checked.

[0178] 6-3: Effects Exhibited by the Sixth Embodiment In the liquid ejection head 1E according to the present embodiment, a dummy piezoelectric body DQm1 is not arranged corresponding to the dummy pressure chamber DCV1.

[0179] As a result, the manufacturing cost of the liquid ejection head 1E can be reduced.

[0180] 7: Seventh Embodiment Hereinafter, with reference to FIGS. 22 to 24, the liquid ejection device 100 according to the seventh embodiment will be described. For the sake of simplicity of explanation, hereinafter, mainly, the differences between the liquid ejection device 100 according to the seventh embodiment and the liquid ejection device 100 according to the first embodiment will be described. Also, among the components provided in the liquid ejection device 100 according to the seventh embodiment, for the components identical to those in the liquid ejection device 100 according to the first embodiment, the same reference numerals will be used and the description of their functions may be omitted.

[0181] 7-1: Structure of Electrodes The liquid ejection device 100 according to the seventh embodiment includes a liquid ejection head 1F instead of the liquid ejection head 1 provided in the liquid ejection device 100 according to the first embodiment. Hereinafter, while referring to FIGS. 22 to 24, the structures of the individual electrodes Qc and the common electrode Qb in the liquid ejection head 1F according to the seventh embodiment will be described.

[0182] FIG. 22 is a plan view of the liquid ejection head 1F when viewed in a plan view in the Z1 direction. The structure of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1F is the same as the structure of the individual electrode Qc and the common electrode Qb in the liquid ejection head 1 shown in FIGS. 4 to 6.

[0183] However, in the liquid ejection head 1F, as shown in FIG. 22, when viewed in a plan view in the Z1 direction, it is different from the liquid ejection head 1 according to the first embodiment in that the dummy piezoelectric body DQm1 corresponding to the dummy pressure chamber DCV1 is not provided. On the other hand, when viewed in a plan view in the Z1 direction, the sealing substrate 25 overlaps the dummy pressure chamber DCV1.

[0184] 7-2: Configuration near the dummy pressure chamber DCV1 FIG. 23 is a cross-sectional view of the g-G line in FIG. 22.

[0185] The cross-sectional view shown in FIG. 23 is different from the cross-sectional view shown in FIG. 7 in the first embodiment in that the dummy piezoelectric body DQm1 is not laminated in the Z2 direction of the diaphragm 24. Further, when viewed in the Z-axis direction, the diaphragm 24 and the sealing substrate 25 are in contact with each other at a portion overlapping the dummy pressure chamber DCV1. Furthermore, when viewed in the Z-axis direction, the sealing substrate 25 has no internal space at a portion overlapping the dummy pressure chamber DCV1.

[0186] The infrared rays pass through the sealing substrate 25. Therefore, also in the liquid ejection head 1F, as in the liquid ejection head 1, in order to confirm the state of the facing portion PT1' of the adhesive GL, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT1' as shown by the arrow IA1, since there is no metal electrode, the state of the facing portion PT1' of the adhesive GL can be confirmed. Also, in order to confirm the state of the facing portion PT2' of the adhesive GL, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT2' as shown by the arrow IA2, since there is no metal electrode, the state of the facing portion PT2' of the adhesive GL can be confirmed.

[0187] FIG. 24 is a cross-sectional view of the h-H line in FIG. 23.

[0188] The cross-sectional view shown in FIG. 24 is different from the cross-sectional view shown in FIG. 8 in the first embodiment in that the dummy piezoelectric body DQm1 is not laminated in the Z2 direction of the diaphragm 24. More specifically, as shown in FIG. 24, of the two surfaces of the diaphragm 24 having the Z-axis direction as the normal direction, although the sealing substrate 25 is formed on the surface in the Z2 direction, the dummy piezoelectric body DQm1 is not laminated. Further, when viewed in the Z-axis direction, the diaphragm 24 and the sealing substrate 25 are in contact with each other at a portion overlapping the dummy pressure chamber DCV1. Furthermore, when viewed in the Z-axis direction, the sealing substrate 25 has no internal space at a portion overlapping the dummy pressure chamber DCV1.

[0189] Also in the liquid ejection head 1E, similarly to the liquid ejection head 1, in order to check the state of the facing portion PT5' of the adhesive GL, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT5' as shown by the arrow IA5, since there is no metal electrode, the state of the facing portion PT5' of the adhesive GL can be checked. Also, in order to check the state of the facing portion PT6' of the adhesive GL, when infrared rays are projected in the Z1 direction from an infrared camera positioned in the Z2 direction with respect to the facing portion PT6' as shown by the arrow IA6, since there is no metal electrode, the state of the facing portion PT6' of the adhesive GL can be checked.

[0190] 7-3: Effects Exhibited by the Seventh Embodiment In the liquid ejection head 1F according to the present embodiment, a diaphragm 24 that vibrates by driving the piezoelectric element PZ is provided between the pressure chamber substrate 23 and the piezoelectric element PZ. When viewed in the Z-axis direction, which is the stacking direction, the diaphragm 24 and the sealing substrate 25 are in contact with each other at a portion overlapping the dummy pressure chamber DCV1.

[0191] When the diaphragm 24 and the sealing substrate 25 are in contact with each other, the rigidity of the diaphragm 24 is maintained higher than when the diaphragm 24 and the sealing substrate 25 are not in contact with each other. Consequently, the rigidity of the liquid ejection head 1F is maintained higher than when the diaphragm 24 and the sealing substrate 25 are not in contact with each other.

[0192] 8: Modification Each of the above forms can be variously modified. Specific modification modes are exemplified below. The modes exemplified below and the modes shown in the above embodiments can be appropriately combined within a range not conflicting with each other. In the modification examples exemplified below, for elements whose actions and functions are equivalent to those in the embodiments, the reference numerals referred to in the above description are reused, and the detailed description of each is appropriately omitted.

[0193] 8-1: Modification 1 In the above embodiment, the shapes of the plurality of dummy pressure chambers DCV1 may be different from each other. More specifically, when viewed in the Z-axis direction, the shape of the above-mentioned "second pressure chamber" included in the plurality of dummy pressure chambers DCV1 and the shape of the "third pressure chamber" different from the "second pressure chamber" included in the plurality of dummy pressure chambers DCV1 may be different from each other. This is because the shape of the plurality of dummy pressure chambers DCV1 affects the ease of the adhesive GL protruding between the pressure chamber substrate 23 and other members. By forming a plurality of types of dummy pressure chambers DCV1 from the dummy pressure chamber DCV1 with a shape where the adhesive GL easily protrudes to the dummy pressure chamber DCV1 with a shape where the adhesive GL hardly protrudes, it is possible to ensure against the influence of manufacturing variations for each product.

[0194] 8-2: Modification 2 When the liquid ejection head 1 is viewed in plan in the Z1 direction, all of the dummy piezoelectric body DQm is provided so as to be included in the dummy pressure chamber DCV corresponding to the dummy piezoelectric body DQm. However, when the liquid ejection head 1 is viewed in plan in the Z1 direction, at least a part of the dummy piezoelectric body DQm may be provided so as to protrude from the dummy pressure chamber DCV corresponding to the dummy piezoelectric body DQm.

[0195] 8-3: Modification 3 In the above embodiment, when viewed from the Z1 direction from the dummy pressure chamber DCV, there is no nozzle N on the nozzle substrate 21, but when viewed from the Z1 direction from the dummy pressure chamber DCV, the nozzle N may be present. In this case, since the connection flow path BK communicating with the dummy pressure chamber DCV does not communicate with the supply flow path BA, the dummy pressure chamber DCV is not filled with ink. As a result, even if the nozzle N is provided in the communication flow path BR communicating from the dummy pressure chamber DCV, no ink is ejected from the nozzle N.

[0196] 8-4: Modification Example 4 In the above embodiment, the connection flow path BK communicating with the dummy pressure chamber DCV does not communicate with the supply flow path BA, but the connection flow path BK may communicate with the supply flow path BA. As a result, the dummy pressure chamber DCV is filled with ink. However, since the nozzle N is not provided in the communication flow path BR communicating with the dummy pressure chamber DCV, no ink is ejected from the nozzle N.

[0197] 8-5: Modification Example 5

[0198] In the first embodiment, as exemplified in FIGS. 2 and 4, for example, a plurality of dummy pressure chambers DCV and a plurality of dummy piezoelectric bodies DQm corresponding one-to-one to the plurality of dummy pressure chambers DCV are installed in the liquid ejection head 1. However, only one dummy pressure chamber DCV and one dummy piezoelectric body DQm corresponding to the one dummy pressure chamber DCV may be installed in the liquid ejection head 1. The same applies to other embodiments.

[0199] 8-6: Modification Example 6 In the first embodiment, a plurality of normal piezoelectric elements SQm corresponding one-to-one to a plurality of normal pressure chambers SCV are installed. Also, a plurality of dummy piezoelectric elements DQm corresponding one-to-one to a plurality of dummy pressure chambers DCV are installed. However, one normal piezoelectric element SQm corresponding commonly to a plurality of normal pressure chambers SCV may be installed. Similarly, one dummy piezoelectric element DQm corresponding commonly to a plurality of dummy pressure chambers DCV may be installed. Alternatively, one piezoelectric element Qm corresponding commonly to both a plurality of normal pressure chambers SCV and a plurality of dummy pressure chambers DCV may be installed. The same applies to other embodiments.

Explanation of Reference Numerals

[0200] 1, 1A, 1B, 1C, 1D, 1E, 1F: Liquid ejection head, 4: Wiring board, 7: Control device, 21: Nozzle board, 22: Communication board, 23: Pressure chamber board, 24: Diaphragm, 25: Sealing board, 26: Flow path forming board, 40: Integrated circuit, 100: Liquid ejection device, BA, BA1, BA2, BB1, BB2: Supply flow path, BK, BK1, BK2: Connection flow path, BR, BR1, BR2: Communication flow path, CV, CV1, CV2, DCV, DCV1, DCV2: Pressure chamber, DQc: Individual electrode, DQm, DQm1, DQm2: Piezoelectric element, GL: Adhesive, N, N1, N2: Nozzle, OPx1, OPy1: Opening portion, PT1, PT1', PT2, PT2', PT3, PT3', PT4, PT4', PT5, PT5', PT6, PT6', PT7, PT7', PT8, PT8': Opposing portion, PZ, PZ1, PZ2: Piezoelectric element, Qb: Common electrode, Qc: Individual electrode, Qm: Piezoelectric element, SCV, SCV1, SCV2: Pressure chamber, SD: Orientation control layer, SQm, SQm1, SQm2: Piezoelectric element, SV1, SV2: Pressure chamber

Claims

1. a nozzle substrate provided with nozzles for ejecting liquid; a pressure chamber substrate provided with a plurality of first pressure chambers which are filled with liquid and which eject the liquid by applying pressure to the liquid, and second pressure chambers which are not used for ejecting the liquid, and which is bonded to another member with an adhesive; a piezoelectric element including a piezoelectric body, individual electrodes provided in the first pressure chambers, and a common electrode provided in the first pressure chambers; A liquid ejection head having Both the individual electrode and the common electrode are disposed corresponding to the first pressure chamber, A liquid ejection head, wherein at least one of the individual electrodes and the common electrode is not disposed in correspondence with the second pressure chamber.

2. The piezoelectric element is disposed in correspondence with the first pressure chamber, 2. The liquid ejection head according to claim 1, wherein the piezoelectric element is disposed in correspondence with the second pressure chamber.

3. 3. The liquid ejection head according to claim 2, wherein a thickness of the piezoelectric element corresponding to the first pressure chamber is greater than a thickness of the piezoelectric element corresponding to the second pressure chamber.

4. When the extension direction of the pressure chamber is defined as a first direction, 3. The liquid ejection head according to claim 2, wherein a length in the first direction of the piezoelectric element corresponding to the first pressure chamber is longer than a length in the first direction of the piezoelectric element corresponding to the second pressure chamber.

5. When the arrangement direction of the plurality of pressure chambers is a second direction, 3. The liquid ejection head according to claim 2, wherein a length in the second direction of the piezoelectric element corresponding to the first pressure chamber is longer than a length in the second direction of the piezoelectric element corresponding to the second pressure chamber.

6. an orientation control layer for controlling an orientation of the piezoelectric body is provided on a side of the piezoelectric body corresponding to the first pressure chamber, the side of the piezoelectric body being adjacent to the first pressure chamber; 3. The liquid ejection head according to claim 2, wherein the orientation control layer is not provided on the second pressure chamber side of the piezoelectric body corresponding to the second pressure chamber.

7. 7. The liquid ejection head according to claim 1, wherein neither the individual electrode nor the common electrode is disposed in correspondence with the second pressure chamber.

8. 7. The liquid ejection head according to claim 1, wherein the individual electrodes are arranged in correspondence with the second pressure chambers, and the common electrode is not arranged.

9. 7. The liquid ejection head according to claim 1, wherein the individual electrode is not provided in correspondence with the second pressure chamber, and the common electrode is provided in correspondence with the second pressure chamber.

10. the plurality of pressure chambers further includes a third pressure chamber that is not used for ejecting liquid, At least one of the individual electrode and the common electrode is not disposed corresponding to the third pressure chamber, 7. The liquid ejection head according to claim 1, wherein the second pressure chamber and the third pressure chamber have different shapes.

11. a vibration plate that vibrates when driven by the piezoelectric element is provided between the pressure chamber substrate and the piezoelectric element; 7. The liquid ejection head according to claim 1, wherein the pressure chamber substrate and the diaphragm are bonded with an adhesive.

12. a communication plate having a communication flow path for liquid to flow from the pressure chamber to the nozzle is provided between the pressure chamber substrate and the nozzle substrate; 7. The liquid ejection head according to claim 1, wherein the pressure chamber substrate and the communication plate are bonded with an adhesive.

13. the common electrode has an opening; The liquid ejection head according to claim 1, characterized in that the opening portion is arranged to overlap at least a portion of a facing portion of the adhesive between the pressure chamber substrate and the other member that faces the second pressure chamber, when viewed in the stacking direction of the pressure chamber substrate and the piezoelectric element.

14. a sealing plate for sealing the piezoelectric element, the sealing plate is provided so as to overlap the second pressure chamber when viewed in a stacking direction of the pressure chamber substrate and the piezoelectric element, 12. The liquid ejection head according to claim 11, wherein neither the individual electrode nor the common electrode is disposed in correspondence with the second pressure chamber.

15. a vibration plate that vibrates when driven by the piezoelectric element is provided between the pressure chamber substrate and the piezoelectric element; The liquid ejection head according to claim 14 , wherein the vibration plate and the sealing plate are in contact with each other in a portion overlapping with the second pressure chamber when viewed in the stacking direction.

16. A liquid ejection head according to any one of claims 1 to 15, a control unit for controlling a discharge operation from the liquid discharge head.

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