Patent Description:
The present disclosure relates to a liquid ejecting head and a liquid ejecting apparatus.

There is known a liquid ejecting head including a pressure chamber plate provided with pressure chambers, a vibration plate for generating a pressure in the pressure chamber, and a piezoelectric actuator including a piezoelectric element provided on the vibration plate. For example, <CIT> discloses that a piezoelectric actuator is covered with a case portion and a humidity sensor is provided in a space inside the case portion. <CIT> is an example of the related art.

Performance of the piezoelectric actuator or a member in the vicinity of the piezoelectric actuator may be deteriorated because of an influence of humidity. The technique in the related art does not propose, for example, a specific structure for adopting a humidity sensor, such as a structure of the humidity sensor itself, a disposition position of the humidity sensor with respect to the piezoelectric actuator and the member in the vicinity of the piezoelectric actuator, and the like. As a result, in the technique in the related art, there is a possibility that information on humidity in the piezoelectric actuator or the member in the vicinity of the piezoelectric actuator cannot be appropriately acquired.

<CIT> discloses a liquid jet head in which a detection circuit includes, on a head substrate a set of detection wiring formed along an array of piezoelectric elements; and plural resistors located at a position previously set on the head substrate and serially connected by the detection wiring. The detection circuit includes, on the head substrate, detection wiring that is divided into plural zones by the plural resistors, detects a resistance value of the detection wiring, where the resistance value differs depending on a zone that is attached with moisture, thus determining a zone attached with moisture from the moisture attached zone.

<CIT> discloses an ink jet recording head in which a substrate <NUM> comprises a piezoelectric vibrator consisting of a vibration plate that forms a part of a pressurizing chamber with a nozzle, which can be capped. An environment detecting means is provided for detecting the change in environment of the space in a cap member <NUM>.

<CIT> discloses an ink-jet recording head in which rigidity of a compartment wall is improved and pressure generating chambers are arranged in a high density. Pressure generating chambers communicate with a nozzle orifice. A piezoelectric element generates a pressure change in the pressure generating chamber, the piezoelectric element being provided in a region opposite the pressure generating chamber via a vibration plate, which constitutes a portion of the pressure generating chamber.

According to an aspect of the present disclosure, a liquid ejecting head is provided. A liquid ejecting head includes: a piezoelectric element that includes a first drive electrode, a second drive electrode, and a piezoelectric body, the piezoelectric body being provided between the first drive electrode and the second drive electrode in a lamination direction in which the first drive electrode, the second drive electrode, and the piezoelectric body are laminated; a vibration plate that is provided on one side of the lamination direction with respect to the piezoelectric element and is deformed by driving of the piezoelectric element; a pressure chamber substrate that is provided on the one side of the lamination direction with respect to the vibration plate and is provided with a plurality of pressure chambers; an interlayer that is laminated on at least one of the piezoelectric body, the vibration plate, or the pressure chamber substrate and of which capacitance changes according to humidity; a first detection electrode that is in contact with the interlayer; and a second detection electrode that is in contact with the interlayer and is disposed to be separated from the first detection electrode.

<FIG> is an explanatory diagram illustrating a schematic configuration of a liquid ejecting apparatus <NUM> as a first embodiment of the present disclosure. In the present embodiment, the liquid ejecting apparatus <NUM> is an ink jet printer that forms an image by ejecting ink as an example of a liquid onto printing paper P. The liquid ejecting apparatus <NUM> may use any kind of medium, such as a resin film or a cloth, as a target on which ink is to be ejected, instead of the printing paper P. X, Y, and Z illustrated in <FIG> and each of the drawings subsequent to <FIG> represent three spatial axes orthogonal to each other. In the present specification, directions along the axes are also referred to as an X-axis direction, a Y-axis direction, and a Z-axis direction. When specifying the direction, a positive direction is "+" and a negative direction is "-" so that positive and negative signs are used together in the direction notation, and description will be given when a direction to which an arrow faces in each of the drawings is the + direction and an opposite direction thereof is the - direction. In the present embodiment, the Z-axis direction coincides with a vertical direction, the +Z direction indicates vertically downward, and the -Z direction indicates vertically upward. Further, when the positive direction and the negative direction are not limited, the three X, Y, and Z will be described as the X-axis, the Y-axis, and the Z-axis.

The liquid ejecting apparatus <NUM> includes a liquid ejecting head <NUM>, an ink tank <NUM>, a transport mechanism <NUM>, a moving mechanism <NUM>, and a control device <NUM>. The liquid ejecting head <NUM> is configured with a plurality of nozzles, ejects inks of a total of four colors, for example, black, cyan, magenta, and yellow in the +Z direction to form an image on a printing paper P. The liquid ejecting head <NUM> is mounted on a carriage <NUM> and reciprocates in a main scanning direction with the movement of the carriage <NUM>. In the present embodiment, the main scanning directions are the +X direction and the -X direction. The liquid ejecting head <NUM> may further eject ink of a random color such as light cyan, light magenta, or clear white, in addition to the four colors.

The ink tank <NUM> accommodates the ink to be ejected to the liquid ejecting head <NUM>. The ink tank <NUM> is coupled to the liquid ejecting head <NUM> by a resin tube <NUM>. The ink in the ink tank <NUM> is supplied to the liquid ejecting head <NUM> via the tube <NUM>. Instead of the ink tank <NUM>, a bag-shaped liquid pack formed of a flexible film may be provided.

The transport mechanism <NUM> transports the printing paper P in a sub-scanning direction. The sub-scanning direction is a direction that intersects with the X-axis direction, which is a main scanning direction, and is the +Y direction and the -Y direction in the present embodiment. The transport mechanism <NUM> includes a transport rod <NUM>, on which three transport rollers <NUM> are mounted, and a transport motor <NUM> for rotatably driving the transport rod <NUM>. When the transport motor <NUM> rotatably drives the transport rod <NUM>, the printing paper P is transported in the +Y direction, which is the sub-scanning direction. The number of the transport rollers <NUM> is not limited to three and may be a random number. Further, a configuration in which a plurality of transport mechanisms <NUM> are provided may be provided.

The moving mechanism <NUM> includes a carriage <NUM>, a transport belt <NUM>, a moving motor <NUM>, and a pulley <NUM>. The carriage <NUM> mounts the liquid ejecting head <NUM> in a state where the ink can be ejected. The carriage <NUM> is fixed to the transport belt <NUM>. The transport belt <NUM> is bridged between the moving motor <NUM> and the pulley <NUM>. When the moving motor <NUM> is rotatably driven, the transport belt <NUM> reciprocates in the main scanning direction. Thereby, the carriage <NUM> fixed to the transport belt <NUM> also reciprocates in the main scanning direction.

<FIG> is a block diagram illustrating a functional configuration of the liquid ejecting apparatus <NUM>. In <FIG>, a partial configuration of the liquid ejecting apparatus <NUM> such as the ink tank <NUM>, the transport mechanism <NUM>, and the moving mechanism <NUM> is omitted. As illustrated in <FIG>, the liquid ejecting head <NUM> includes a piezoelectric element <NUM>, a humidity detection mechanism <NUM>, and a temperature detection mechanism <NUM>.

The piezoelectric element <NUM> causes a pressure change in the ink in the pressure chamber of the liquid ejecting head <NUM>. The humidity detection mechanism <NUM> functions as a so-called electric humidity sensor, and acquires information on humidity in a member included in the liquid ejecting head <NUM>, such as the piezoelectric element <NUM>, or a member on the periphery of the humidity detection mechanism <NUM>. "Information on humidity" includes, for example, an amount of moisture absorbed or dehumidified from a member, relative humidity and absolute humidity which indicate an amount of moisture contained in the air, a degree of an influence on performance of a member because of moisture absorption or dehumidification, and information used to acquire such information, such as a resistance value or a capacitance value. The "degree of an influence on performance of a member" may include the presence or absence of a failure of the member, a temporal change in the performance of the member, and the like.

As illustrated in <FIG>, the humidity detection mechanism <NUM> includes a humidity detection section <NUM>, a humidity-detection power supply section <NUM>, and a capacitance measurement section <NUM>. In the present embodiment, the humidity detection section <NUM> is configured with a capacitance type humidity sensor, and utilizes a property that the dielectric constant changes and the capacitance changes because of moisture absorption of the measurement target. The humidity-detection power supply section <NUM> applies a predetermined voltage to the humidity detection section <NUM> under a control of the humidity management section <NUM>. The capacitance measurement section <NUM> detects capacitance of the humidity detection section <NUM> by using a method of measuring a time until a voltage value of the voltage applied to the humidity detection section <NUM> by the humidity-detection power supply section <NUM> reaches a predetermined reference voltage. A detection result by the capacitance measurement section <NUM> is output to the humidity management section <NUM>. The capacitance may be measured by using various general methods such as a constant current discharge method. The humidity-detection power supply section <NUM> and the capacitance measurement section <NUM> may be provided in the control device <NUM>.

The temperature detection mechanism <NUM> functions as a temperature sensor that detects a temperature of the ink in a pressure chamber to be described later. Specifically, the temperature detection mechanism <NUM> detects a temperature of a resistance wiring by using a characteristic that a resistance value of a resistance wiring of a metal, a semiconductor, or the like changes depending on a temperature, and estimates the detected temperature of the resistance wiring as a temperature of the ink in the pressure chamber.

The temperature detection mechanism <NUM> includes a temperature detection section <NUM>, a temperature-detection power supply section <NUM>, and a temperature-detection resistance measurement section <NUM>. The temperature detection section <NUM> is configured with a conductor wiring including a resistor for temperature detection. The temperature-detection power supply section <NUM> is, for example, a constant current circuit, and causes a predetermined current to flow through the temperature detection section <NUM> under a control of a temperature management section <NUM>. The temperature-detection resistance measurement section <NUM> acquires a resistance value of a temperature detection resistor of the temperature detection section <NUM> based on a current value of a current flowing through the temperature detection section <NUM> by the temperature-detection power supply section <NUM> and a voltage value of a voltage generated in the temperature detection section <NUM>. A detection result by the temperature-detection resistance measurement section <NUM> is output to the temperature management section <NUM>. The temperature-detection power supply section <NUM> and the temperature-detection resistance measurement section <NUM> may be provided in the control device <NUM>.

As illustrated in <FIG>, the control device <NUM> is configured as a microcomputer including a CPU <NUM> and a storage section <NUM>. The control device <NUM> is mounted on, for example, a wiring substrate <NUM> or a circuit substrate directly or indirectly coupled to the wiring substrate <NUM>. As the storage section <NUM>, for example, a non-volatile memory such as EEPROM in which data can be erased by an electrical signal, a non-volatile memory such as One-Time-PROM or EPROM in which data can be erased by ultraviolet rays, a non-volatile memory such as PROM in which data cannot be erased, and the like can be used. The storage section <NUM> stores various programs for realizing functions provided in the present embodiment. The CPU <NUM> functions as a head control section <NUM>, a humidity management section <NUM>, and a temperature management section <NUM> by developing and executing a program stored in the storage section <NUM>. The control device <NUM> may further include a communication section for transmitting and receiving a humidity detection result or a temperature detection result to and from a predetermined server.

The head control section <NUM> collectively performs a control of each section of the liquid ejecting head <NUM>, such as an ejecting operation. The head control section <NUM> may control, for example, a reciprocating operation of the carriage <NUM> along the main scanning direction, and a transport operation of the printing paper P along the sub-scanning direction, in addition to the control of the liquid ejecting head <NUM>. As an ejecting operation of the liquid ejecting head <NUM>, the head control section <NUM> can control ejection of the ink onto the printing paper P by, for example, outputting a drive signal to the liquid ejecting head <NUM> to drive the piezoelectric element <NUM>, the drive signal being a signal based on the temperature of the ink in the pressure chamber that is acquired from the temperature management section <NUM>.

The humidity management section <NUM> derives information on the humidity of the detection target by using the capacitance of the humidity detection section <NUM> that is acquired from the capacitance measurement section <NUM> and a humidity calculation equation stored in the storage section <NUM> in advance. The humidity calculation equation indicates a correspondence relationship between the capacitance of the detection target and the humidity. Instead of the humidity calculation equation, a conversion table indicating a correspondence relationship between the capacitance of the detection target and the humidity may be used. In addition, the storage section <NUM> may store a correspondence relationship between the capacitance of the detection target and a temporal change in performance of the detection target.

The temperature management section <NUM> derives the temperature of the ink in the pressure chamber <NUM> by using the resistance value of the temperature detection resistor of the temperature detection section <NUM> that is acquired from the temperature-detection resistance measurement section <NUM> and a temperature calculation equation stored in the storage section <NUM> in advance. The temperature calculation equation indicates a correspondence relationship between the resistance value of the temperature detection resistor and the temperature. Instead of the temperature calculation equation, a conversion table indicating a correspondence relationship between the resistance value of the temperature detection resistor and the temperature may be used. The temperature management section <NUM> outputs the derived temperature of the ink in the pressure chamber <NUM> to the head control section <NUM>.

A detailed configuration of the liquid ejecting head <NUM> will be described with reference to <FIG>. <FIG> is an exploded perspective view illustrating the configuration of the liquid ejecting head <NUM>. <FIG> is an explanatory diagram illustrating the configuration of the liquid ejecting head <NUM> in plan view. In the present disclosure, the "plan view" means a state in which an object is viewed along a lamination direction to be described later. <FIG> illustrates the configuration around a pressure chamber substrate <NUM> and a vibration plate <NUM> in the liquid ejecting head <NUM>. In order to facilitate understanding of the technique, a protective film <NUM>, a sealing substrate <NUM>, a case member <NUM>, and the like are not illustrated. <FIG> is a cross-sectional view illustrating a V-V position of <FIG>.

The liquid ejecting head <NUM> includes a pressure chamber substrate <NUM>, a communication plate <NUM>, a nozzle plate <NUM>, a compliance substrate <NUM>, a vibration plate <NUM>, a sealing substrate <NUM>, a case member <NUM>, a wiring substrate <NUM>, which are illustrated in <FIG>, and a piezoelectric element <NUM> illustrated in <FIG>. The liquid ejecting head <NUM> is configured by laminating these laminated members. In the present disclosure, a direction in which the laminated members of the liquid ejecting head <NUM> are laminated is also referred to as a "lamination direction". In the present embodiment, the lamination direction coincides with the Z-axis direction. In the present disclosure, the +Z direction side with respect to a predetermined reference position is also referred to as "one side of the lamination direction" or "lower side", and the -Z direction side with respect to a predetermined reference position is also referred to as "the other side of the lamination direction" or "upper side".

The pressure chamber substrate <NUM> is configured by using, for example, a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, and the like. As illustrated in <FIG>, a plurality of pressure chambers <NUM> are provided on the pressure chamber substrate <NUM>. An ink flow path provided on the pressure chamber substrate <NUM>, such as the pressure chamber <NUM>, is formed by anisotropically etching the pressure chamber substrate <NUM> from the surface on the +Z direction side. The pressure chamber <NUM> is formed in a substantially rectangular shape in which a length in the X-axis direction is longer than a length in the Y-axis direction in plan view. On the other hand, the shape of the pressure chamber <NUM> is not limited to the rectangular shape, and may be a parallelogram shape, a polygonal shape, a circular shape, an oval shape, or the like. The oval shape means a shape in which both end portions in a longitudinal direction are semicircular based on a rectangular shape, and includes a rounded rectangular shape, an elliptical shape, an egg shape, and the like.

As illustrated in <FIG>, a plurality of pressure chambers <NUM> are arranged along a predetermined direction in the pressure chamber substrate <NUM>. In plan view of the liquid ejecting head <NUM> along the lamination direction, a direction in which the plurality of pressure chambers <NUM> are arranged is also referred to as an "arrangement direction". In the present embodiment, the plurality of pressure chambers <NUM> are arranged in two rows parallel to each other with the Y-axis direction as the arrangement direction. In the example of <FIG>, the pressure chamber substrate <NUM> is provided with two pressure chamber rows, that is, a first pressure chamber row L1 having a first arrangement direction parallel to the Y-axis direction and a second pressure chamber row L2 having a second arrangement direction parallel to the Y-axis direction. The first pressure chamber row L1 and the second pressure chamber row L2 are disposed on both sides with the wiring substrate <NUM> interposed therebetween. Specifically, the second pressure chamber row L2 is disposed on the opposite side of the first pressure chamber row L1 with the wiring substrate <NUM> interposed therebetween in the direction that intersects with the arrangement direction of the first pressure chamber row L1. The direction orthogonal to both the arrangement direction and the lamination direction is also referred to as an "intersection direction". In the example of <FIG>, the intersection direction is the X-axis direction, and the second pressure chamber row L2 is disposed in the -X direction with respect to the first pressure chamber row L1 with the wiring substrate <NUM> interposed between the first pressure chamber row L1 and the second pressure chamber row L2. In the plurality of pressure chambers <NUM>, all the pressure chambers <NUM> do not necessarily have to be arranged in a straight line. For example, the plurality of pressure chambers <NUM> may be arranged along the Y-axis direction according to so-called staggered arrangement in which every other pressure chamber <NUM> is alternately disposed in the intersection direction.

As illustrated in <FIG>, the communication plate <NUM>, the nozzle plate <NUM>, and the compliance substrate <NUM> are laminated on the +Z direction side of the pressure chamber substrate <NUM>. The communication plate <NUM> is, for example, a flat plate member using a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, a metal substrate, or the like. Examples of the metal substrate include a stainless steel substrate or the like. The communication plate <NUM> is provided with a nozzle communication path <NUM>, a first manifold portion <NUM>, a second manifold portion <NUM> illustrated in <FIG>, and a supply communication path <NUM>. Preferably, the communication plate <NUM> is formed by using a material having a thermal expansion coefficient substantially the same as a thermal expansion coefficient of the pressure chamber substrate <NUM>. Thereby, when the temperatures of the pressure chamber substrate <NUM> and the communication plate <NUM> change, warpage of the pressure chamber substrate <NUM> and the communication plate <NUM> because of a difference in the thermal expansion coefficient can be suppressed.

As illustrated in <FIG>, the nozzle communication path <NUM> is a flow path that communicates the pressure chamber <NUM> and a nozzle <NUM>. The first manifold portion <NUM> and the second manifold portion <NUM> function as a part of a manifold <NUM> which is a common liquid chamber in which a plurality of pressure chambers <NUM> communicate with each other. The first manifold portion <NUM> is provided to penetrate the communication plate <NUM> in the Z-axis direction. Further, as illustrated in <FIG>, the second manifold portion <NUM> is provided on a surface of the communication plate <NUM> on the +Z direction side without penetrating the communication plate <NUM> in the Z-axis direction.

As illustrated in <FIG>, the supply communication path <NUM> is a flow path coupled to a pressure chamber supply path <NUM> provided on the pressure chamber substrate <NUM>. The pressure chamber supply path <NUM> is a flow path coupled to one end portion of the pressure chamber <NUM> in the X-axis direction via a throttle portion <NUM>. The throttle portion <NUM> is a flow path provided between the pressure chamber <NUM> and the pressure chamber supply path <NUM>. The throttle portion <NUM> is a flow path in which an inner wall protrudes from the pressure chamber <NUM> and the pressure chamber supply path <NUM> and which is formed narrower than the pressure chamber <NUM> and the pressure chamber supply path <NUM>. Thereby, the throttle portion <NUM> is set such that the flow path resistance is higher than those of the pressure chamber <NUM> and the pressure chamber supply path <NUM>. With the configuration, even when pressure is applied to the pressure chamber <NUM> by the piezoelectric element <NUM> when the ink is ejected, the ink in the pressure chamber <NUM> can be suppressed or prevented from flowing back to the pressure chamber supply path <NUM>. A plurality of supply communication paths <NUM> are arranged along the Y-axis direction, that is, the arrangement direction, and are individually provided for each of the pressure chambers <NUM>. The supply communication path <NUM> and the pressure chamber supply path <NUM> communicate the second manifold portion <NUM> with each pressure chamber <NUM>, and supply the ink in the manifold <NUM> to each pressure chamber <NUM>.

The nozzle plate <NUM> is provided on a side opposite to the pressure chamber substrate <NUM>, that is, on a surface of the communication plate <NUM> on the +Z direction side with the communication plate <NUM> interposed between the nozzle plate <NUM> and the pressure chamber substrate <NUM>. A material of the nozzle plate <NUM> is not particularly limited, and for example, a silicon substrate, a glass substrate, an SOI substrate, various ceramic substrates, and a metal substrate can be used. Examples of the metal substrate include a stainless steel substrate or the like. As the material of the nozzle plate <NUM>, an organic substance, such as a polyimide resin, can also be used. On the other hand, it is preferable to use a material for the nozzle plate <NUM> that has substantially the same thermal expansion coefficient as the thermal expansion coefficient of the communication plate <NUM>. Thereby, when the temperatures of the nozzle plate <NUM> and the communication plate <NUM> change, warpage of the nozzle plate <NUM> and the communication plate <NUM> because of the difference in the thermal expansion coefficient can be suppressed.

A plurality of nozzles <NUM> are provided on the nozzle plate <NUM>. Each nozzle <NUM> communicates with each pressure chamber <NUM> via the nozzle communication path <NUM>. As illustrated in <FIG>, the plurality of nozzles <NUM> are arranged along the arrangement direction of the pressure chambers <NUM>, that is, the Y-axis direction. The nozzle plate <NUM> is provided with two nozzle rows in which the plurality of nozzles <NUM> are arranged in a row. The two nozzle rows respectively correspond to the first pressure chamber row L1 and the second pressure chamber row L2.

As illustrated in <FIG>, the compliance substrate <NUM> is provided together with the nozzle plate <NUM> on the side opposite to the pressure chamber substrate <NUM> with the communication plate <NUM> interposed therebetween, that is, on a surface of the communication plate <NUM> on the +Z direction side. The compliance substrate <NUM> is provided on the periphery of the nozzle plate <NUM>, and covers openings of the first manifold portion <NUM> and the second manifold portion <NUM> provided in the communication plate <NUM>. The compliance substrate <NUM> includes, for example, a sealing film <NUM> made of a flexible thin film and a fixed substrate <NUM> made of a hard material such as a metal. As illustrated in <FIG>, a region of the fixed substrate <NUM> facing the manifold <NUM> is completely removed in a thickness direction, and thus an opening portion <NUM> is defined. Therefore, one surface of the manifold <NUM> is a compliance portion <NUM> sealed only by the sealing film <NUM>.

As illustrated in <FIG>, the vibration plate <NUM> and the piezoelectric element <NUM> are laminated on a side opposite to the communication plate <NUM> or the like, that is, on a surface of the pressure chamber substrate <NUM> on the -Z direction side with the pressure chamber substrate <NUM> interposed therebetween. The piezoelectric element <NUM> bends and deforms the vibration plate <NUM> to cause a pressure change in the ink in the pressure chamber <NUM>. In <FIG>, illustration of the piezoelectric element <NUM> is simplified.

The vibration plate <NUM> is provided between the piezoelectric element <NUM> and the pressure chamber substrate <NUM>. The vibration plate <NUM> is provided at a position closer to the pressure chamber substrate <NUM> side than the piezoelectric element <NUM>, and includes an elastic film <NUM> containing silicon oxide (SiO<NUM>) and an insulator film <NUM> that is provided on the elastic film <NUM> and contains a zirconium oxide film (ZrO<NUM>). The elastic film <NUM> constitutes a surface of the flow path, such as the pressure chamber <NUM>, on the -Z direction side. The vibration plate <NUM> may be configured with, for example, either the elastic film <NUM> or the insulator film <NUM>, and may further include another film other than the elastic film <NUM> and the insulator film <NUM>. Examples of the material of the other film include silicon, silicon nitride, and the like.

As illustrated in <FIG>, the sealing substrate <NUM> having substantially the same size as the pressure chamber substrate <NUM> in plan view is further bonded to the surface of the pressure chamber substrate <NUM> on the -Z direction side by an adhesive or the like. The sealing substrate <NUM> may be bonded to a protective film <NUM> to be described later by an adhesive. As illustrated in <FIG>, the sealing substrate <NUM> includes a ceiling portion 30T, a wall portion 30W, a holding portion <NUM>, and a through hole <NUM>. The holding portion <NUM> is a space defined by the ceiling portion 30T and the wall portion 30W, and protects an active portion of the piezoelectric element <NUM> by accommodating the piezoelectric element <NUM>. In the present embodiment, the holding portions <NUM> are provided for each row of the piezoelectric elements <NUM>. More specifically, two holding portions <NUM> corresponding to the first pressure chamber row L1 and the second pressure chamber row L2 are formed to be adjacent to each other. The through hole <NUM> penetrates the sealing substrate <NUM> along the Z-axis direction. The through hole <NUM> is disposed between the two holding portions <NUM> in plan view, and is formed in a long rectangular shape along the Y-axis direction.

As illustrated in <FIG>, the case member <NUM> is fixed on the sealing substrate <NUM>. The case member <NUM> forms the manifold <NUM> that communicates with the plurality of pressure chambers <NUM>, together with the communication plate <NUM>. The case member <NUM> has substantially the same outer shape as the communication plate <NUM> in plan view, and is bonded to cover the sealing substrate <NUM> and the communication plate <NUM>.

The case member <NUM> includes an accommodation section <NUM>, a supply port <NUM>, a third manifold portion <NUM>, and a coupling port <NUM>. The accommodation section <NUM> is a space having a depth in which the pressure chamber substrate <NUM>, the vibration plate <NUM>, and the sealing substrate <NUM> can be accommodated. The third manifold portion <NUM> is a space provided in the vicinity of both ends of the accommodation section <NUM> in the X-axis direction in the case member <NUM>. The manifold <NUM> is formed by coupling the third manifold portion <NUM> to the first manifold portion <NUM> and the second manifold portion <NUM> provided in the communication plate <NUM>. The manifold <NUM> has a long shape in the Y-axis direction. The supply port <NUM> communicates with the manifold <NUM> to supply ink to each manifold <NUM>. The coupling port <NUM> is a through hole that communicates with the through hole <NUM> of the sealing substrate <NUM>, and the wiring substrate <NUM> is inserted to the coupling port <NUM>.

In the liquid ejecting head <NUM>, the ink supplied from the ink tank <NUM> illustrated in <FIG> is taken from the supply port <NUM> illustrated in <FIG>, and an internal flow path from the manifold <NUM> to the nozzle <NUM> is filled with ink. Thereafter, a voltage based on the drive signal is applied to each of the piezoelectric elements <NUM> corresponding to the plurality of pressure chambers <NUM>. Thereby, the vibration plate <NUM> bends and deforms together with the piezoelectric element <NUM>, and thus the internal pressure of each pressure chamber <NUM> increases because of a change in volume of each pressure chamber <NUM>. Therefore, ink droplets are ejected from each nozzle <NUM>.

Configurations of the piezoelectric element <NUM>, the humidity detection section <NUM>, and the temperature detection section <NUM> will be described with reference to <FIG> as appropriate together with reference to <FIG> and <FIG>. <FIG> is an enlarged explanatory diagram illustrating a partial range AR of <FIG>. <FIG> is a cross-sectional view illustrating a VII-VII position of <FIG>.

As illustrated in <FIG>, the piezoelectric element <NUM> includes a first drive electrode <NUM>, a piezoelectric body <NUM>, and a second drive electrode <NUM>. The first drive electrode <NUM>, the piezoelectric body <NUM>, and the second drive electrode <NUM> are laminated in this order in the -Z direction of the lamination direction. The piezoelectric body <NUM> is provided between the first drive electrode <NUM> and the second drive electrode <NUM> in the lamination direction.

As illustrated in <FIG>, the first drive electrode <NUM> and the second drive electrode <NUM> are electrically coupled to the wiring substrate <NUM> illustrated in <FIG> via a first drive wiring <NUM> and a second drive wiring <NUM>. The first drive electrode <NUM> and the second drive electrode <NUM> apply a drive voltage according to the drive signal to the piezoelectric body <NUM>. The drive voltage is a voltage applied to the piezoelectric element <NUM> from the first drive electrode <NUM> and the second drive electrode <NUM> to drive the piezoelectric element <NUM> by the head control section <NUM>. When a voltage is applied between the first drive electrode <NUM> and the second drive electrode <NUM>, a part, at which piezoelectric distortion occurs in the piezoelectric body <NUM>, in the piezoelectric element <NUM> is also referred to as an active portion.

A different drive voltage is applied to the first drive electrode <NUM> according to an ejection amount of ink, and a predetermined reference voltage is applied to the second drive electrode <NUM> regardless of the ejection amount of ink. When a voltage difference occurs between the first drive electrode <NUM> and the second drive electrode <NUM> because of the application of the drive voltage and the reference voltage, the piezoelectric body <NUM> of the piezoelectric element <NUM> is deformed. Because of the deformation of the piezoelectric body <NUM>, the vibration plate <NUM> is deformed or vibrated, and thus the volume of the pressure chamber <NUM> changes. Because of the change in the volume of the pressure chamber <NUM>, pressure is applied to the ink accommodated in the pressure chamber <NUM>, and thus the ink is ejected from the nozzle <NUM> via the nozzle communication path <NUM>.

In the present embodiment, the first drive electrode <NUM> is an individual electrode individually provided for the plurality of pressure chambers <NUM>. As illustrated in <FIG>, the first drive electrode <NUM> is a lower electrode provided on a side opposite to the second drive electrode <NUM> with the piezoelectric body <NUM> interposed therebetween, that is, on a lower side of the piezoelectric body <NUM>. A thickness of the first drive electrode <NUM> is formed to be, for example, approximately <NUM> nanometers. For example, the first drive electrode <NUM> is formed of a conductive material including a metal, such as platinum (Pt), iridium (Ir), gold (Au), titanium (Ti), and a conductive metal oxide such as indium tin oxide abbreviated as ITO. The first drive electrode <NUM> may be formed by laminating a plurality of materials such as platinum (Pt), iridium (Ir), gold (Au), and titanium (Ti). In the present embodiment, platinum (Pt) is used for the first drive electrode <NUM>.

As illustrated in <FIG>, the piezoelectric body <NUM> has a predetermined width in the X-axis direction, and has a long rectangular shape along the arrangement direction of the pressure chambers <NUM>, that is, the Y-axis direction. The thickness of the piezoelectric body <NUM> is formed, for example, from approximately <NUM> nanometers to <NUM> nanometers. Examples of the piezoelectric body <NUM> include a crystal film having a perovskite structure provided on the first drive electrode <NUM> and made of a ferroelectric ceramic material exhibiting an electromechanical conversion action, that is, a so-called perovskite type crystal. As the material of the piezoelectric body <NUM>, for example, a ferroelectric piezoelectric material such as lead zirconate titanate (PZT) or a material to which a metal oxide, such as niobium oxide, nickel oxide, or magnesium oxide, is added can be used. Specifically, lead titanate (PbTiO<NUM>), lead zirconate titanate (Pb(Zr,Ti)O<NUM>), lead zirconate (PbZrO<NUM>), lead lanthanum titanate ((Pb,La),TiO<NUM>), lead lanthanum zirconate titanate ((Pb,La)(Zr,Ti)O<NUM>), lead magnesium niobate zirconate (Pb(Zr,Ti)(Mg,Nb)O<NUM>), or the like can be used. In the present embodiment, lead zirconate titanate (PZT) is used for the piezoelectric body <NUM>.

The material of the piezoelectric body <NUM> is not limited to the lead-based piezoelectric material containing lead, and a non-lead-based piezoelectric material containing no lead can also be used. Examples of the non-lead-based piezoelectric material include bismuth iron acid ((BiFeO<NUM>), abbreviated to "BFO"), barium titanate ((BaTiO<NUM>), abbreviated to "BT"), potassium sodium niobate ((K,Na)(NbO<NUM>), abbreviated to "KNN"), potassium sodium lithium niobate ((K,Na,Li) (NbO<NUM>)), potassium sodium lithium tantalate niobate ((K,Na,Li)(Nb,Ta)O<NUM>), bismuth potassium titanate ((Bi<NUM>/<NUM>K<NUM>/<NUM>)TiO<NUM>, abbreviated to "BKT"), bismuth sodium titanate ((Bi<NUM>/<NUM>Na<NUM>/<NUM>)TiO<NUM>, abbreviated to "BNT"), bismuth manganate (BiMnO<NUM>, abbreviated to "BM"), a composite oxide containing bismuth, potassium, titanium, and iron and having a perovskite structure (x[(BixK<NUM>-x)TiO<NUM>]-(<NUM>-x)[BiFeO<NUM>], abbreviated to "BKT-BF"), a composite oxide containing bismuth, iron, barium, and titanium and having a perovskite structure ((<NUM>-x)[BiFeO<NUM>]-x[BaTiO<NUM>], abbreviated to "BFO-BT"), and a material ((<NUM>-x)[Bi(Fe<NUM>-yMy)O<NUM>]-x[BaTiO<NUM>], M being Mn, Co, or Cr), which is obtained by adding metals such as manganese, cobalt, and chromium to the composite oxide.

As illustrated in <FIG>, the second drive electrode <NUM> is a common electrode that is commonly provided for the plurality of pressure chambers <NUM>. The second drive electrode <NUM> has a predetermined width in the X-axis direction, and is provided to extend along the arrangement direction of the pressure chambers <NUM>, that is, the Y-axis direction. As illustrated in <FIG>, the second drive electrode <NUM> is an upper electrode provided on a side opposite to the first drive electrode <NUM> with the piezoelectric body <NUM> interposed therebetween, that is, on an upper side of the piezoelectric body <NUM>. As a material of the second drive electrode <NUM>, similar to the first drive electrode <NUM>, for example, metals, such as platinum (Pt), iridium (Ir), gold (Au), and titanium (Ti), and conductive materials including conductive metal oxides, such as indium tin oxide abbreviated as ITO, are used. The second drive electrode <NUM> may be formed by laminating a plurality of materials such as platinum (Pt), iridium (Ir), gold (Au), and titanium (Ti). In the present embodiment, iridium (Ir) is used for the second drive electrode <NUM>.

As illustrated in <FIG>, a protective film <NUM> is provided on an end portion 80b of the second drive electrode <NUM> on the -X direction side. As a material of the protective film <NUM>, a material having an electrical insulating property and a moisture barrier property is used. For the protective film <NUM>, for example, an oxide insulating film such as aluminum oxide or hafnia, a polymer material film such as polyimide, or the like can be adopted. When the protective film <NUM> is a photosensitive resin such as polyimide, a resist layer used in a manufacturing process can be used. When the protective film <NUM> is made of a resin material, the surface resistance easily changes depending on the humidity, and thus the protective film <NUM> can be suitably used for an interlayer <NUM>. In the present embodiment, polyimide is used for the protective film <NUM>.

As illustrated in <FIG>, the protective film <NUM> is disposed at a drive electrode end portion position that overlaps the end portion of the second drive electrode <NUM> in plan view of the liquid ejecting head <NUM>, and is formed to cover the end portion 80b of the second drive electrode <NUM> and the surface of the piezoelectric body <NUM>, as illustrated in <FIG>. By covering the surface of the piezoelectric body <NUM> with the protective film <NUM>, the piezoelectric body <NUM> can be protected from moisture in the outside air and the air. Therefore, the protective film <NUM> is preferably made of a material having low water vapor permeability. Further, by covering the end portion 80b with the protective film <NUM>, peeling of the second drive electrode <NUM> from the end portion 80b can be suppressed or prevented. Further, by covering the end portion 80b, driving of the piezoelectric element <NUM> in the vicinity of the end portion of the active portion of the piezoelectric element <NUM> can be suppressed. As a result, for example, occurrence of a physical damage such as a crack in a member in the vicinity of the end portion of the active portion, such as a joint portion between the vibration plate <NUM> and the pressure chamber substrate <NUM> and the vibration plate <NUM>, can be suppressed. For this reason, the protective film <NUM> is preferably made of, for example, a material having a high elastic modulus or a high Young's modulus. For example, the Young's modulus is preferably equal to or higher than <NUM> GPa from a viewpoint of suitable driving suppression. Further, the protective film <NUM> has an insulating property, and thus a progress of migration between wirings such as wirings between the end portion 80b and the first drive wiring <NUM> or the like can be suppressed or prevented. When the second drive electrode <NUM> is disposed on the lower side of the piezoelectric body <NUM> as a lower electrode and the first drive electrode <NUM> is disposed on the upper side of the piezoelectric body <NUM> as an upper electrode, the drive electrode end portion position means a position overlapping the end portion of the first drive electrode <NUM> on the -X direction side. On the other hand, the drive electrode end portion position is not limited to only the end portion of the first drive electrode <NUM> on the -X direction side, and may be set by using an end portion of the first drive electrode <NUM> or an end portion of the second drive electrode <NUM> located in the X-axis direction and the Y-axis direction, or by using a plurality of end portions obtained by combining end portions of the first drive electrode <NUM> and the second drive electrode <NUM>.

As illustrated in <FIG>, a wiring portion <NUM> is provided on the further -X direction side of the end portion 80b of the second drive electrode <NUM> in the -X direction. In <FIG> and <FIG>, the wiring portion <NUM> is not illustrated. The wiring portion <NUM> is in the same layer as the second drive electrode <NUM>, but is electrically discontinuous with the second drive electrode <NUM>. The wiring portion <NUM> is formed from the end portion 70b of the piezoelectric body <NUM> in the -X direction to the end portion 60b of the first drive electrode <NUM> in the -X direction in a state of being spaced from the end portion 80b of the second drive electrode <NUM>. The end portion 60b of the first drive electrode <NUM> in the -X direction is pulled out from the end portion 70b of the piezoelectric body <NUM> to the outside. The wiring portion <NUM> is provided for each piezoelectric element <NUM>, and a plurality of wiring portions <NUM> are disposed at predetermined intervals along the Y-axis direction. Preferably, the wiring portion <NUM> is formed in the same layer as the second drive electrode <NUM>. Thereby, a manufacturing process of the wiring portion <NUM> can be simplified and the cost can be reduced. Here, the wiring portion <NUM> may be formed in a layer different from the layer of the second drive electrode <NUM>.

As illustrated in <FIG> and <FIG>, the first drive wiring <NUM> is electrically coupled to the first drive electrode <NUM> which is an individual electrode, and an extension portion 92a and an extension portion 92b of the second drive wiring <NUM> are electrically coupled to the second drive electrode <NUM> which is a common electrode. The first drive wiring <NUM> and the second drive wiring <NUM> function as drive wirings for applying a voltage for driving the piezoelectric body <NUM> from the wiring substrate <NUM>.

The materials of the first drive wiring <NUM> and the second drive wiring <NUM> are conductive materials. For example, gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), aluminum (Al), and the like can be used. In the present embodiment, gold (Au) is used for the first drive wiring <NUM> and the second drive wiring <NUM>. The first drive wiring <NUM> and the second drive wiring <NUM> are formed in the same layer in a state of being electrically discontinuous with each other. Thereby, a process of forming the first drive wiring <NUM> can be shared with a process of forming the second drive wiring <NUM>. Therefore, as compared with when the first drive wiring <NUM> and the second drive wiring <NUM> are individually formed, the manufacturing process can be simplified and productivity of the liquid ejecting head <NUM> can be improved. Here, the first drive wiring <NUM> and the second drive wiring <NUM> may be formed in different layers from each other. The first drive wiring <NUM> and the second drive wiring <NUM> may include an adhesion layer for improving adhesion to the first drive electrode <NUM>, the second drive electrode <NUM>, and the vibration plate <NUM>.

The first drive wiring <NUM> is individually provided for each first drive electrode <NUM>. As illustrated in <FIG>, the first drive wiring <NUM> is coupled to the vicinity of the end portion 60b of the first drive electrode <NUM> via the wiring portion <NUM>, and is pulled out in the -X direction to reach a top of the vibration plate <NUM>. The first drive wiring <NUM> is electrically coupled to the end portion 60b of the first drive electrode <NUM> in the -X direction, the end portion 60b being pulled out from the end portion 70b of the piezoelectric body <NUM> to the outside. The wiring portion <NUM> may be omitted, and the first drive wiring <NUM> may be directly coupled to the end portion 60b of the first drive electrode <NUM>.

As illustrated in <FIG>, the second drive wiring <NUM> extends along the Y-axis direction, bends at both ends in the Y-axis direction, and is pulled out along the X-axis direction. The second drive wiring <NUM> includes an extension portion 92a extending along the Y-axis direction and an extension portion 92b. As illustrated in <FIG> and <FIG>, the end portions of the first drive wiring <NUM> and the second drive wiring <NUM> are extended so as to be exposed to the through hole <NUM> of the sealing substrate <NUM>, and are electrically coupled to the wiring substrate <NUM> in the through hole <NUM>.

The wiring substrate <NUM> is configured with, for example, a flexible printed circuit (FPC). The wiring substrate <NUM> is provided with a plurality of wirings for coupling to the control device <NUM> and a power supply circuit (not illustrated). In addition, the wiring substrate <NUM> may be configured with any flexible substrate, such as flexible flat cable (FFC), instead of FPC. An integrated circuit <NUM> including a switching element and the like is mounted at the wiring substrate <NUM>. A command signal or the like for driving the piezoelectric element <NUM> is input to the integrated circuit <NUM>. The integrated circuit <NUM> controls a timing at which a drive signal for driving the piezoelectric element <NUM> is supplied to the first drive electrode <NUM> based on the command signal.

As illustrated in <FIG>, the temperature detection section <NUM> includes a temperature detection resistor <NUM> and temperature detection wirings <NUM>. The temperature detection resistor <NUM> is a resistance wiring used for detecting the temperature of the ink in the pressure chamber. The temperature detection wiring <NUM> electrically couples the wiring substrate <NUM> and the temperature detection resistor <NUM>. More specifically, the temperature detection wirings <NUM> include a first temperature detection wiring <NUM> coupled to one end of the temperature detection resistor <NUM> and a second temperature detection wiring <NUM> coupled to the other end of the temperature detection resistor <NUM>. The temperature detection wirings <NUM> are formed in the same layer as, for example, layers of the first drive wiring <NUM>, the second drive wiring <NUM>, and a humidity detection wiring <NUM> to be described later, and are formed so as to be electrically discontinuous with each other. An end portion of the temperature detection wiring <NUM> extends so as to be exposed to the through hole <NUM> of the sealing substrate <NUM>, and is electrically coupled to the wiring substrate <NUM> in the through hole <NUM>.

A material of the temperature detection resistor <NUM> is a material of which the resistance value is temperature dependent. For example, gold (Au), platinum (Pt), iridium (Ir), aluminum (Al), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), or the like can be used. Here, platinum (Pt) can be preferably used as a material of the temperature detection resistor <NUM> from a viewpoint that the change in resistance with temperature is large and stability and accuracy are high.

As illustrated in <FIG>, the temperature detection resistor <NUM> is formed in the same layer as, for example, the layer of the first drive electrode <NUM> in the lamination direction, and is formed so as to be electrically discontinuous with the first drive electrode <NUM>. In the present embodiment, the temperature detection resistor <NUM> is formed together with the first drive electrode <NUM> in a process of forming the first drive electrode <NUM>. As a result, the temperature detection resistor <NUM> is formed of platinum (Pt), which is the same material as the first drive electrode <NUM>, and a thickness of the temperature detection resistor <NUM> is approximately <NUM> nanometers similar to the first drive electrode <NUM>. Here, the temperature detection resistor <NUM> is not limited thereto, may be individually formed separately from the process of forming the first drive electrode <NUM>, or may be formed together with a conductor wiring different from the conductor wiring of the first drive electrode <NUM>.

A material of the temperature detection wiring <NUM> is a conductive material. For example, gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), aluminum (Al), and the like can be used. The material of the temperature detection wiring <NUM> is gold (Au) that is the same as the materials of the first drive wiring <NUM>, the second drive wiring <NUM>, and the humidity detection wiring <NUM> to be described later. Here, any material other than gold (Au) may be used for the temperature detection wiring <NUM>, and the material may be different from the materials of the first drive wiring <NUM>, the second drive wiring <NUM>, and the humidity detection wiring <NUM>.

As illustrated in <FIG>, in the present embodiment, the temperature detection resistor <NUM> is continuously formed so as to surround the vicinities of the first pressure chamber row L1 and the second pressure chamber row L2 in plan view. More specifically, the temperature detection resistor <NUM> includes a first extension portion 415A electrically coupled to the first temperature detection wiring <NUM>, a third extension portion 415C electrically coupled to the second temperature detection wiring <NUM>, and second extension portions 415B between the first extension portion 415A and the third extension portion 415C.

The first extension portion 415A extends along the X-axis direction, which is the intersection direction, on one side in the arrangement direction of the plurality of pressure chambers <NUM>, specifically, on the -Y direction side. The second extension portion 415B is further disposed on an outer side with respect to the first pressure chamber row L1 and the second pressure chamber row L2 in the liquid ejecting head <NUM>, and extends along the Y-axis direction which is the arrangement direction. The third extension portion 415C extends along the X-axis direction, at a position on the other side in the arrangement direction of the plurality of pressure chambers <NUM>, specifically, the +Y direction side. In this way, the temperature detection resistor <NUM> is disposed so as to surround the vicinities of the first pressure chamber row L1 and the second pressure chamber row L2. By widening a region in which the temperature detection resistor <NUM> is disposed, the temperature of the entire ink of the liquid ejecting head <NUM> can be detected.

As illustrated in <FIG> and <FIG>, the temperature detection resistor <NUM> is disposed so as to pass the vicinity of the ink flow path in the pressure chamber substrate <NUM>. In the present embodiment, the second extension portion 415B of the temperature detection resistor <NUM> is disposed so as to pass the throttle portion <NUM> in the vicinity of each pressure chamber <NUM>. In addition, as illustrated in <FIG>, the second extension portion 415B is formed as a so-called zigzag pattern to be reciprocated a plurality of times along the arrangement direction. By lengthening a wiring length of the portion of the temperature detection resistor <NUM> that passes the vicinity of the pressure chamber <NUM> and is likely to contribute to the temperature detection of the ink, accuracy in detection of the temperature of the ink in the pressure chamber <NUM> can be improved. Here, the second extension portion 415B may be formed in any shape, may be formed, for example, in a zigzag pattern to be reciprocated a plurality of times along the intersection direction instead of the arrangement direction, or may be formed, for example, in any shape such as a linear shape or a wave shape instead of the zigzag pattern. Further, the disposition position of the temperature detection resistor <NUM> is not limited to the position on the throttle portion <NUM>, and may be any position on the pressure chamber <NUM>. When the temperature detection resistor <NUM> cannot be disposed on the pressure chamber <NUM>, the temperature detection resistor <NUM> may be disposed at a position close to the pressure chamber <NUM>.

As illustrated in <FIG>, in plan view, the humidity detection sections <NUM> are disposed at total four positions including positions adjacent to both sides of the first pressure chamber row L1 along the first arrangement direction and positions adjacent to both sides of the second pressure chamber row L2 along the second arrangement direction. The humidity detection sections <NUM> are individually provided for each of the holding portions <NUM> of the sealing substrate <NUM> corresponding to the first pressure chamber row L1 and the holding portion <NUM> of the sealing substrate <NUM> corresponding to the second pressure chamber row L2. Thereby, information on the humidity of each pressure chamber row can be acquired with high accuracy. Here, the positions of the humidity detection sections <NUM> are not limited to the four positions. The humidity detection sections <NUM> may be disposed at any one position of positions adjacent to the first pressure chamber row L1 on the +Y direction side and the -Y direction side and positions adjacent to the second pressure chamber row L2 on the +Y direction side and the -Y direction side in the second arrangement direction, and may be disposed in any positions obtained by combining a plurality of these positions. Here, preferably, the humidity detection sections <NUM> are formed in a number corresponding to the number of the holding portions <NUM>.

As illustrated in <FIG>, the humidity detection section <NUM> includes humidity detection wirings <NUM>, a first detection electrode <NUM>, a second detection electrode <NUM>, and an interlayer <NUM>. The humidity detection wirings <NUM> include a first humidity detection wiring <NUM> that electrically couples the wiring substrate <NUM> and the first detection electrode <NUM> and a second humidity detection wiring <NUM> that electrically couples the wiring substrate <NUM> and the second detection electrode <NUM>. End portions of the first humidity detection wiring <NUM> and the second humidity detection wiring <NUM> extend so as to be exposed to the through hole <NUM> of the sealing substrate <NUM>, and are electrically coupled to the wiring substrate <NUM> in the through hole <NUM>.

The interlayer <NUM> is a humidity detection target, and functions as a so-called humidity-sensitive film. The interlayer <NUM> is formed of a material of which the capacitance changes with humidity. For the interlayer <NUM>, among the members included in the liquid ejecting head <NUM>, as a member of which the performance may deteriorate because of the influence of the humidity, a member to be laminated on at least one of the piezoelectric body <NUM>, the vibration plate <NUM>, or the pressure chamber substrate <NUM> can be adopted. In the present embodiment, the same material as the material of the protective film <NUM> is used for the interlayer <NUM>. In the present embodiment, in the process of forming the protective film <NUM>, the interlayer <NUM> is formed by using the same material as the material of the protective film <NUM> at the same time as the protective film <NUM>, and thus the interlayer <NUM> is provided on the surface of the piezoelectric body <NUM>. By sharing the process of forming the interlayer <NUM> with the process of forming the protective film <NUM>, productivity of the liquid ejecting head <NUM> can be improved. In the present embodiment, the material of the interlayer <NUM> is not limited to the same material as the material of the protective film <NUM>. For example, a material suitable as a humidity-sensitive film, such as a polymer material such as a cellulose compound, a polyvinyl compound, or an aromatic polymer, or a metal oxide such as aluminum oxide (Al<NUM>O<NUM>) or silicon oxide (SiO<NUM>), may also be used.

A material of the humidity detection wiring <NUM> is a conductive material. For example, gold (Au), copper (Cu), titanium (Ti), tungsten (W), nickel (Ni), chromium (Cr), platinum (Pt), aluminum (Al), and the like can be used. The material of the humidity detection wiring <NUM> is gold (Au) that is the same as the materials of the first drive wiring <NUM>, the second drive wiring <NUM>, and the temperature detection wiring <NUM>. Here, any material other than gold (Au) may be used for the humidity detection wiring <NUM>, and the material may be different from the materials of the first drive wiring <NUM>, the second drive wiring <NUM>, and the temperature detection wiring <NUM>.

<FIG> is a cross-sectional view illustrating a VIII-VIII position of <FIG>. As illustrated in <FIG>, the first detection electrode <NUM> and the second detection electrode <NUM> are formed in different layers, and are electrically discontinuous with each other. The first detection electrode <NUM> and the second detection electrode <NUM> are both in contact with the interlayer <NUM>, are disposed so as to face each other with the interlayer <NUM> interposed therebetween, and apply a voltage from the humidity-detection power supply section <NUM> to the interlayer <NUM>. Specifically, the first detection electrode <NUM> is disposed on one side of the lamination direction, that is, on a lower side of the interlayer <NUM>, and the second detection electrode <NUM> is disposed on the other side of the lamination direction, that is, on an upper side of the interlayer <NUM>. With the configuration, the change in the capacitance between the first detection electrode <NUM> and the second detection electrode <NUM> can be detected, and a temporal change in the moisture absorption state of the protective film <NUM> which serves as the interlayer <NUM> can be managed. Thus, a temporal change in the performance of the protective film <NUM> because of humidity can be managed.

The first detection electrode <NUM> and the second detection electrode <NUM> can be formed in any shape. In the present embodiment, the first detection electrode <NUM> is formed in a flat plate shape. A so-called comb shape is adopted for the second detection electrode <NUM>. More specifically, as illustrated in <FIG>, the second detection electrode <NUM> includes a first electrode portion 212P1 extending along a certain first direction and a plurality of second electrode portions 212P2 coupled to the first electrode portion 212P1. The plurality of second electrode portions 212P2 extend along a second direction intersecting with the first direction, and are arranged to be separated from each other. In the example of <FIG>, the first direction coincides with the X-axis direction, and the second direction coincides with the Y-axis direction.

Since the second detection electrode <NUM> is formed to cover the upper surface of the interlayer <NUM>, an exposed area of the interlayer <NUM> is reduced. As a result, moisture absorption and dehumidification of the interlayer <NUM> may be inhibited, and detection accuracy may be lowered. From a viewpoint of suppressing inhibition of moisture absorption of the interlayer <NUM>, preferably, the second detection electrode <NUM> is formed in a shape with an area smaller than an area of a flat plate shape, such as a through-hole shape or a comb shape, such that the upper surface of the interlayer <NUM> can be exposed.

The first detection electrode <NUM> and the second detection electrode <NUM> can be formed of any conductive material, and can be formed of, for example, a conductive material such as a metal, such as platinum (Pt), iridium (Ir), gold (Au), and titanium (Ti), or a conductive metal oxide such as indium tin oxide which is abbreviated as ITO. The first detection electrode <NUM> and the second detection electrode <NUM> may be made of the same material or different materials from each other. For the first detection electrode <NUM> and the second detection electrode <NUM>, for example, copper (Cu), tungsten (W), nickel (Ni), chromium (Cr), aluminum (Al), or the like can also be used. The materials of the first detection electrode <NUM> and the second detection electrode <NUM> can be the same as the materials of the first drive wiring <NUM>, the second drive wiring <NUM>, the temperature detection wiring <NUM>, and the humidity detection wiring <NUM>.

In the present embodiment, for example, the process of forming the first detection electrode <NUM> is shared with the process of forming the second drive electrode <NUM>, and the first detection electrode <NUM> is provided on the piezoelectric body <NUM>. Therefore, the material of the first detection electrode <NUM> is the same iridium (Ir) as the material of the second drive electrode <NUM>. By sharing the process of forming the first detection electrode <NUM> with the process of forming the second drive electrode <NUM>, productivity of the liquid ejecting head <NUM> can be improved. The process of forming the first detection electrode <NUM> may be shared with the process of forming the first drive electrode <NUM>.

In the present embodiment, the process of forming the second detection electrode <NUM> is shared with the process of forming the first drive wiring <NUM>, the second drive wiring <NUM>, the temperature detection wiring <NUM>, or the humidity detection wiring <NUM>, and the second detection electrode 212a2 is provided on the interlayer <NUM>. Therefore, the material of the second detection electrode <NUM> is the same gold (Au) as the material of the first drive wiring <NUM> or the like. By sharing the process of forming the second detection electrode <NUM> with the process of forming the first drive wiring <NUM> and the like, productivity of the liquid ejecting head <NUM> can be improved. As an example of a specific process order, after the piezoelectric body <NUM> is coated, the first detection electrode <NUM> is formed in the same process as the process of forming the second drive electrode <NUM>, and then the interlayer <NUM> is formed using the same material as the material of the protective film <NUM>. Thereafter, the second detection electrode <NUM>, the first drive wiring <NUM>, the second drive wiring <NUM>, the temperature detection wiring <NUM>, and the humidity detection wiring <NUM> are formed in the same process, and then the protective film <NUM> is formed at the drive electrode end portion position. The process of forming the second detection electrode <NUM> may be shared with the process of forming the first drive electrode <NUM> or the second drive electrode <NUM>.

As described above, the liquid ejecting head <NUM> of the present embodiment includes the interlayer <NUM> which is laminated on the piezoelectric body <NUM> and of which the capacitance changes according to humidity, the first detection electrode <NUM> which is in contact with the interlayer <NUM>, and the second detection electrode <NUM> which is in contact with the interlayer <NUM>, the second detection electrode <NUM> being disposed on the opposite side of the first detection electrode <NUM> with the interlayer <NUM> interposed therebetween. With the liquid ejecting head <NUM> configured as described above, by using the capacitance between the first detection electrode <NUM> and the second detection electrode <NUM>, the information on the humidity of the interlayer <NUM>, which is laminated on the piezoelectric body <NUM> among the component members of the liquid ejecting head <NUM>, can be detected with high accuracy. Therefore, the influence of the humidity on the piezoelectric element <NUM> or the member in the vicinity of the piezoelectric element <NUM> can be appropriately managed.

The liquid ejecting apparatus <NUM> of the present embodiment includes, in addition to the liquid ejecting head <NUM>, a capacitance measurement section <NUM> that measures capacitance between the first detection electrode <NUM> and the second detection electrode <NUM>, and a humidity management section <NUM> that acquires information on humidity of the interlayer <NUM> by using the capacitance measured by the capacitance measurement section <NUM>. Therefore, the liquid ejecting apparatus <NUM> that can appropriately manage the information on the humidity in the member in the liquid ejecting head <NUM> can be provided.

With the liquid ejecting head <NUM> of the present embodiment, the first detection electrode <NUM> is formed of the same material as the material of the second drive electrode <NUM>. The process of forming the first detection electrode <NUM> can be shared with the process of forming the second drive electrode <NUM>, and thus productivity of the liquid ejecting head <NUM> can be improved.

The liquid ejecting head <NUM> of the present embodiment further includes the protective film <NUM> that is disposed on an upper side of the pressure chamber substrate <NUM>, more specifically, at the end portion 80b of the second drive electrode <NUM> and on the surface of the piezoelectric body <NUM>, and is formed using a resin material. The interlayer <NUM> is formed of the same material as the material of the protective film <NUM>. By forming the interlayer <NUM> using a resin material of which the capacitance is likely to change according to humidity, accuracy of detection of the information on humidity can be improved. Further, by sharing the process of forming the interlayer <NUM> with the process of forming the protective film <NUM>, productivity of the liquid ejecting head <NUM> can be improved.

With the liquid ejecting head <NUM> of the present embodiment, the first detection electrode <NUM> is disposed on the lower side of the interlayer <NUM>, and the second detection electrode <NUM> is disposed on the upper side of the interlayer <NUM>. As compared with when the first detection electrode <NUM> and the second detection electrode <NUM> are formed in the same layer on the upper side or the lower side of the interlayer <NUM>, the capacitance of the interlayer <NUM> can be detected with high accuracy.

With the liquid ejecting head <NUM> of the present embodiment, the second detection electrode <NUM> includes the first electrode portion 212P1 extending along the first direction on the surface of the interlayer <NUM> and the plurality of second electrode portions 212P2 coupled to the first electrode portion 212P1 on the surface of the interlayer <NUM>. The second electrode portions 212P2 extend in the second direction intersecting with the first direction and are arranged to be separated from each other. By forming the second detection electrode <NUM> in a comb shape with an area smaller than an area in a flat plate shape, an exposed area on the upper surface of the interlayer <NUM> can be increased, and thus inhibition of moisture absorption and dehumidification of the interlayer <NUM> by the second detection electrode <NUM> can be suppressed or prevented.

With the liquid ejecting head <NUM> of the present embodiment, in plan view, the humidity detection sections <NUM> are disposed at positions adjacent to both sides of the first pressure chamber row L1 along the first arrangement direction and positions adjacent to both sides of the second pressure chamber row L2 along the second arrangement direction. With the liquid ejecting head <NUM> configured as described above, by individually providing the humidity detection sections <NUM> for each of the holding portions <NUM> of the first pressure chamber row L1 and the second pressure chamber row L2, the information on humidity for each pressure chamber row can be acquired with high accuracy.

<FIG> is an explanatory diagram illustrating the humidity detection section 210a2 included in the liquid ejecting head of another embodiment. The first embodiment describes an example in which the second detection electrode <NUM> has a comb shape. On the other hand, various shapes can be adopted for the first detection electrode and the second detection electrode. In the example of <FIG>, both the first detection electrode 211a2 and the second detection electrode 212a2 are formed in a flat plate shape. In addition to the flat plate shape, the second detection electrode 212a2 may have, for example, a shape in which a certain number of through holes having a certain shape are provided in a comb shape. In addition to the comb shape, a so-called zigzag shape in which the conductor zigzags may be adopted. Further, although not illustrated, the first detection electrode 211a2 may have a comb shape similar to the shape of the second detection electrode 212a2. For example, the first detection electrode 211a2 may have a shape in which a certain number of through holes having a certain shape are provided in a comb shape. In addition to the comb shape, a zigzag shape in which the conductor zigzags may be adopted.

<FIG> is an explanatory diagram illustrating a configuration of a liquid ejecting head 510b according to a second embodiment of the present disclosure in plan view. The liquid ejecting head 510b of the present embodiment is different in that a humidity detection section 210b is provided instead of the humidity detection section <NUM>, and the other configurations are the same as the configurations of the liquid ejecting head <NUM> of the first embodiment.

<FIG> is an enlarged explanatory diagram illustrating a partial range AR of <FIG>. The humidity detection section 210b is different from the humidity detection section <NUM> described in the first embodiment in that the material used for the interlayer is different. More specifically, in the first embodiment, the same material as the material of the protective film <NUM> is used for the interlayer <NUM>. On the other hand, the present embodiment is different from the first embodiment in that the same material as the material of the piezoelectric body <NUM> is used for the interlayer 215b. As illustrated in <FIG>, the disposition position of the humidity detection section 210b and the shapes of the first detection electrode 211b and the second detection electrode 212b in plan view are the same as those in the first embodiment.

<FIG> is a cross-sectional view illustrating an XII-XII position of <FIG>. As illustrated in <FIG>, the first detection electrode 211b2 has a flat plate shape, and is disposed on the lower side of the piezoelectric body <NUM> which serves as the interlayer <NUM>. More specifically, the first detection electrode 211b is provided on the vibration plate <NUM>, and is disposed between the vibration plate <NUM> and the piezoelectric body <NUM>. By disposing the first detection electrode 211b on the lower side of the piezoelectric body <NUM>, the process of forming the first detection electrode 211b can be easily shared with the process of forming the first drive electrode <NUM>. In the present embodiment, the first detection electrode 211b is formed together with the first drive electrode <NUM> in the process of forming the first drive electrode <NUM>, and the first detection electrode 211b and the first drive electrode <NUM> are formed of the same material.

The second detection electrode 212b2 has the same comb shape as the shape of the second detection electrode <NUM> described in the first embodiment, and is exposed and disposed on the upper side of the piezoelectric body <NUM>. By disposing the second detection electrode 212b2 on the upper side of the piezoelectric body <NUM>, the process of forming the second detection electrode 212b2 can be shared with the process of forming the second drive electrode <NUM> after the piezoelectric body <NUM> is coated. From a viewpoint of suppressing inhibition of moisture absorption and dehumidification of the piezoelectric body <NUM> which serves as the interlayer 215b, preferably, the second detection electrode 212b2 is formed in a shape with an area smaller than an area of a flat plate shape, such as a comb shape, such that the upper surface of the piezoelectric body <NUM> is exposed. Further, in the present embodiment, the second detection electrode 212b is formed together with the second drive electrode <NUM> in the process of forming the second drive electrode <NUM>. Therefore, the second detection electrode 212b and the second drive electrode <NUM> are formed of the same material.

<FIG> is an explanatory diagram illustrating an example of a hysteresis loop which is a characteristic of the piezoelectric body <NUM>. As illustrated in <FIG>, when the electric field applied to the piezoelectric body <NUM> increases, the polarization becomes zero, and the positive and negative of the polarization are reversed. A magnitude of the electric field when the polarization is reversed is also called a "coercive electric field". <FIG> illustrates a positive coercive electric field +Ec and a negative coercive electric field -Ec. In the present embodiment, the head control section <NUM> applies a drive voltage to the piezoelectric body <NUM>, the drive voltage being adjusted to be in, for example, a range RG in which the polarization is equal to or higher than a first polarization value P1 and is equal to or lower than a second polarization value P2.

The humidity management section <NUM> applies a detection voltage to the first detection electrode 211b and the second detection electrode 212b, the detection voltage being a voltage for generating a second electric field E2 closer to the negative coercive electric field -Ec of the piezoelectric body <NUM> than a first electric field E1 which is the minimum electric field in the range RG of the electric fields generated in the piezoelectric element <NUM> by the drive voltage. Since the electric field is proportional to an amount of charge, capacitance can be obtained by differentiating the electric field. As the capacitance increases, a current flowing through the piezoelectric body <NUM> greatly changes with respect to the applied voltage. Therefore, by using, as the detection voltage, a voltage for generating the second electric field E2 in the vicinity of the negative coercive electric field -Ec at which the capacitance is substantially maximum, a change in the current value when the detection voltage is applied can be increased, and thus sensitivity of humidity measurement can be improved.

As described above, the liquid ejecting head 510b of the second embodiment includes the piezoelectric body <NUM> which is laminated on the vibration plate <NUM>, of which the capacitance changes according to humidity, and which serves as the interlayer 215b. With the liquid ejecting head 510b configured as described above, the information on humidity of the piezoelectric body <NUM> can be detected with high accuracy, and thus an influence of the humidity on the piezoelectric element <NUM> can be appropriately managed.

With the liquid ejecting head 510b of the present embodiment, the first detection electrode 211b is formed of the same material as the material of the first drive electrode <NUM>. With the configuration, the process of forming the first detection electrode 211b can be shared with the process of forming the first drive electrode <NUM>, and thus productivity of the liquid ejecting head 510b can be improved.

With the liquid ejecting head 510b of the present embodiment, the first detection electrode 211b is disposed on the lower side of the piezoelectric body <NUM> which serves as the interlayer 215b, and the second detection electrode 212b is disposed on the upper side of the piezoelectric body <NUM>. As compared with when the first detection electrode <NUM> and the second detection electrode <NUM> are formed in the same layer, the capacitance of the piezoelectric body <NUM> can be detected with high accuracy.

The liquid ejecting head 510b of the present embodiment includes a capacitance measurement section <NUM> that measures capacitance between the first detection electrode 211b and the second detection electrode 212b, and a humidity management section <NUM> that acquires information on humidity of the interlayer 215b by using the capacitance measured by the capacitance measurement section <NUM>. Therefore, the liquid ejecting apparatus <NUM> that can appropriately manage the information on the humidity of the piezoelectric body <NUM> can be provided.

With the liquid ejecting head 510b of the present embodiment, the humidity management section <NUM> applies a detection voltage to the first detection electrode 211b and the second detection electrode 212b, the detection voltage being a voltage for generating a second electric field E2 closer to the negative coercive electric field -Ec of the piezoelectric body <NUM> than a first electric field E1 generated in the piezoelectric body <NUM> by the drive voltage applied to the piezoelectric body <NUM> from the first drive electrode <NUM> and the second drive electrode <NUM> to drive the piezoelectric element <NUM>. By using the detection voltage for generating the second electric field E2 in the vicinity of the negative coercive electric field -Ec at which the capacitance is substantially maximum, a change in the current value when the detection voltage is applied can be increased, and thus sensitivity of humidity measurement can be improved.

(C1) <FIG> is a first explanatory diagram illustrating another disposition example of the humidity detection section. Each of the embodiments describes an example in which, in plan view, the humidity detection sections are disposed at total four positions including positions adjacent to both sides of the first pressure chamber row L1 along the first arrangement direction and positions adjacent to both sides of the second pressure chamber row L2 along the second arrangement direction. On the other hand, as illustrated in <FIG>, for example, the humidity detection sections <NUM> may be disposed at positions adjacent to both sides of the wiring substrate <NUM> along the Y-axis direction which is the first arrangement direction. Alternatively, the humidity detection sections <NUM> may be disposed only at a position adjacent to any one side of the wiring substrate <NUM> along the Y-axis direction. With the liquid ejecting head <NUM> configured as described above, by disposing the humidity detection section <NUM> at a position separated from the piezoelectric element <NUM>, an influence of noise of the drive signal of the piezoelectric element <NUM> on the humidity detection section <NUM> can be reduced. Further, for example, when one holding portion <NUM> common to a plurality of pressure chamber rows such as the first pressure chamber row L1 and the second pressure chamber row L2 is provided, the number of the humidity detection sections <NUM> can be reduced, and thus information on humidity can be efficiently acquired.

(C2) <FIG> is a second explanatory diagram illustrating another disposition example of the humidity detection section. As illustrated in <FIG>, the humidity detection section 210c may be formed with respect to the protective film <NUM> that is disposed to cover the end portion 80b and the surface of the piezoelectric body <NUM> at the drive electrode end portion position overlapping the end portion 80b of the second drive electrode <NUM>. In this case, the protective film <NUM> functions as the interlayer 215c. As illustrated in <FIG>, in plan view, the first humidity detection wiring <NUM> and the second humidity detection wiring <NUM> are disposed at positions that face each other with the plurality of first drive wirings <NUM> interposed therebetween and are disposed on the inner side of the liquid ejecting head 510c with respect to the second drive wiring <NUM>, the plurality of first drive wirings <NUM> being arranged in the Y-axis direction.

<FIG> is an enlarged explanatory diagram illustrating a partial range AR of <FIG>. As illustrated in <FIG>, the first detection electrode 211c is disposed on a lower side of the protective film <NUM> that is at the drive electrode end portion position and serves as the interlayer 215c, and the second detection electrode 212c is disposed on an upper side of the protective film <NUM>. That is, the first detection electrode 211c and the second detection electrode 212c are disposed so as to face each other with the protective film <NUM> interposed therebetween. With the liquid ejecting head 510c configured as described above, the same effect as that of the first embodiment can be obtained, and by using the existing protective film <NUM> as the interlayer 215c, an increase in the number of components because of installation of the humidity detection section 210c can be suppressed. Although detailed illustration of the shapes of the first detection electrode 211c and the second detection electrode 212c is omitted, any shape such as a linear shape, a flat plate shape, and a comb shape described above can be used.

(C3) The first embodiment describes an example in which the same material as the material of the protective film <NUM> is used for the interlayer <NUM>, and the second embodiment describes an example in which the same material as the material of the piezoelectric body <NUM> is used for the interlayer 215b. On the other hand, the same material as the material of the vibration plate <NUM> may be used for the interlayer. In this case, the first detection electrode <NUM> may be disposed on an upper side of the vibration plate <NUM>, specifically, an upper side of the insulator film <NUM>, and the second detection electrode <NUM> may be disposed on a lower side of the vibration plate <NUM>, specifically, a lower side of the elastic film <NUM>. With the liquid ejecting head <NUM> according to the form, by detecting the capacitance of the vibration plate <NUM>, information on humidity of the vibration plate <NUM> can be detected with high accuracy. The first detection electrode <NUM> may be disposed on the upper side of the insulator film <NUM>, and the second detection electrode <NUM> may be disposed between the insulator film <NUM> and the elastic film <NUM>. The first detection electrode <NUM> may be disposed between the insulator film <NUM> and the elastic film <NUM>, and the second detection electrode <NUM> may be disposed on the lower side of the elastic film <NUM>.

(C4) The first embodiment describes an example in which the first detection electrode <NUM> and the second detection electrode <NUM> are disposed so as to face each other with the interlayer <NUM> that is interposed therebetween and is formed of the same material as the material of the protective film. In addition, the second embodiment describes an example in which the first detection electrode 211b is disposed on the lower side of the piezoelectric body <NUM> which serves as the interlayer 215b and the second detection electrode 212b is disposed on the upper side of the piezoelectric body <NUM>. On the other hand, the first detection electrode and the second detection electrode may be provided on the same layer on the upper side or the lower side of the interlayer in a state where the first detection electrode and the second detection electrode are separated from each other and are electrically discontinuous with each other. In the example of <FIG>, the first detection electrode <NUM> and the second detection electrode <NUM> may be exposed and disposed on the upper side of the interlayer <NUM>, or may be disposed between the piezoelectric body <NUM> and the interlayer <NUM>. In the example of <FIG>, the first detection electrode 211b and the second detection electrode 212b may be exposed and disposed on the upper side of the interlayer 215b which serves as the piezoelectric body <NUM>, and may be disposed between the piezoelectric body <NUM> and the vibration plate <NUM>. Even in the liquid ejecting head configured as described above, as in the first embodiment and the second embodiment, by using the capacitance between the first detection electrode and the second detection electrode, information on humidity of the interlayer can be detected with high accuracy.

The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the scope of the present invention as defined by the claims.

With the liquid ejecting head according to the aspect, by using the capacitance between the first detection electrode and the second detection electrode, information on humidity of the interlayer provided in the piezoelectric element or a member in the vicinity of the piezoelectric element can be detected with high accuracy. Therefore, an influence of humidity on the piezoelectric element or the member in the vicinity of the piezoelectric element can be appropriately acquired.

(<NUM>) According to another aspect of the present disclosure, a liquid ejecting apparatus is provided. A liquid ejecting apparatus includes: the liquid ejecting head according to the aspect; a capacitance measurement section that measures capacitance between the first detection electrode and the second detection electrode; and a humidity management section that acquires information on humidity of the interlayer by using the capacitance which is measured by the capacitance measurement section.

With the liquid ejecting head according to the aspect, the liquid ejecting apparatus that can appropriately manage information on the humidity in the member in the liquid ejecting head can be provided.

(<NUM>) In the liquid ejecting head according to the aspect, at least one of the first detection electrode or the second detection electrode may be formed of the same material as a material of the first drive electrode.

With the liquid ejecting head according to the aspect, the process of forming at least one of the first detection electrode or the second detection electrode can be shared with the process of forming the first drive electrode, and thus productivity of the liquid ejecting head can be improved.

(<NUM>) In the liquid ejecting head according to the aspect, at least one of the first detection electrode or the second detection electrode may be formed of the same material as a material of the second drive electrode.

With the liquid ejecting head according to the aspect, the process of forming at least one of the first detection electrode or the second detection electrode can be shared with the process of forming the second drive electrode, and thus productivity of the liquid ejecting head can be improved.

(<NUM>) The liquid ejecting head according to the aspect may further include at least a protective film that is disposed on another side of the lamination direction with respect to the pressure chamber substrate and contains a resin material, the other side of the lamination direction being a side of the lamination direction opposite to the one side on which the vibration plate is provided. The interlayer may be formed of the same material as a material of the protective film.

With the liquid ejecting head according to the aspect, by forming the interlayer using a resin material of which the capacitance is likely to change according to humidity, accuracy of detection of the information on humidity can be improved.

(<NUM>) In the liquid ejecting head according to the aspect, the first detection electrode may be disposed on one side of the lamination direction with respect to the interlayer, and the second detection electrode may be disposed on the other side of the lamination direction with respect to the interlayer.

With the liquid ejecting head according to the aspect, as compared with when the first detection electrode and the second detection electrode are formed in the same layer on the upper side or the lower side of the interlayer, the capacitance of the interlayer can be detected with high accuracy.

(<NUM>) In the liquid ejecting head according to the aspect, the second detection electrode may include a first electrode portion that extends along a first direction on a surface of the interlayer and a plurality of second electrode portions that are coupled to the first electrode portion on the surface of the interlayer, the plurality of second electrode portions extending in a second direction intersecting with the first direction and arranged to be separated from each other.

With the liquid ejecting head according to the aspect, by forming the second detection electrode with an area smaller than an area of a flat plate, an exposed area of the upper surface of the interlayer can be increased, and thus inhibition of moisture absorption of the interlayer by the second detection electrode can be suppressed or prevented.

(<NUM>) In the liquid ejecting head according to the aspect, in plan view of the liquid ejecting head in the lamination direction, the protective film may be disposed at a drive electrode end portion position overlapping an end portion of the first drive electrode or an end portion of the second drive electrode. The first detection electrode may be disposed on the one side of the lamination direction with respect to the protective film that is disposed at the drive electrode end portion position and serves as the interlayer. The second detection electrode may be disposed on the other side of the lamination direction with respect to the protective film that is disposed at the drive electrode end portion position and serves as the interlayer.

With the liquid ejecting head according to the aspect, by using, as the interlayer, the protective film disposed at the drive electrode end portion position, an increase in the number of components because of installation of the humidity detection section can be suppressed.

(<NUM>) In the liquid ejecting head according to the aspect, the interlayer may be formed of the same material as a material of the piezoelectric body.

With the liquid ejecting head according to the aspect, information on humidity of the piezoelectric body can be detected with high accuracy, and thus an influence of the humidity on the piezoelectric body can be appropriately acquired.

(<NUM>) In the liquid ejecting head according to the aspect, the first detection electrode may be disposed on the one side of the lamination direction with respect to the interlayer. The second detection electrode may be disposed on another side of the lamination direction with respect to the interlayer, the other side of the lamination direction being a side of the lamination direction opposite to the one side.

With the liquid ejecting head according to the aspect, by detecting the capacitance of the piezoelectric body, information on humidity of the piezoelectric body can be detected with high accuracy.

(<NUM>) According to still another aspect of the present disclosure, a liquid ejecting apparatus including the liquid ejecting head according to (<NUM>) is provided. A liquid ejecting apparatus includes: a capacitance measurement section that measures capacitance between the first detection electrode and the second detection electrode; and a humidity management section that acquires information on humidity of the interlayer by using the capacitance which is measured by the capacitance measurement section. With the liquid ejecting head according to the aspect, the liquid ejecting apparatus that can appropriately manage information on the humidity of the piezoelectric body can be provided.

(<NUM>) In the liquid ejecting apparatus according to the aspect, the humidity management section may apply, to the first detection electrode and the second detection electrode, a voltage for generating an electric field closer to a negative coercive electric field of the piezoelectric body than an electric field generated in the piezoelectric body by a drive voltage applied to the piezoelectric body from the first drive electrode and the second drive electrode to drive the piezoelectric element.

With the liquid ejecting head according to the aspect, by using, as the detection voltage, a voltage for generating an electric field in the vicinity of the negative coercive electric field at which the capacitance is substantially maximum, a change in polarization can be increased, and thus sensitivity of humidity measurement can be improved.

(<NUM>) In liquid ejecting head according to the aspect, the interlayer may be formed of the same material as a material of the vibration plate.

With the liquid ejecting head according to the aspect, by detecting the capacitance of the vibration plate, information on humidity of the vibration plate can be detected with high accuracy.

(<NUM>) In the liquid ejecting head according to the aspect, in plan view of the liquid ejecting head in the lamination direction, the plurality of pressure chambers may be arranged in a first pressure chamber row along a first arrangement direction and in a second pressure chamber row along a second arrangement direction parallel to the first arrangement direction. The interlayer, the first detection electrode, and the second detection electrode may be disposed at least one position of positions adjacent to the first pressure chamber row along the first arrangement direction and positions adjacent to the second pressure chamber row along the second arrangement direction.

With the liquid ejecting head according to the aspect, the humidity detection sections can be individually provided for each of the first pressure chamber row and the second pressure chamber row, and thus information on humidity for each pressure chamber row can be acquired with high accuracy.

(<NUM>) In the liquid ejecting head according to the aspect, in plan view of the liquid ejecting head in the lamination direction, the plurality of pressure chambers may be arranged in a first pressure chamber row along a first arrangement direction and in a second pressure chamber row along a second arrangement direction parallel to the first arrangement direction. A wiring substrate that is electrically coupled to the liquid ejecting head may be disposed between the first pressure chamber row and the second pressure chamber row. The interlayer, the first detection electrode, and the second detection electrode may be disposed at positions adjacent to the wiring substrate along the first arrangement direction.

With the liquid ejecting head according to the aspect, by disposing the humidity detection section at a position separated from the piezoelectric element, an influence of noise of the drive signal of the piezoelectric element on the humidity detection section can be reduced.

The present disclosure can also be realized in various aspects other than the liquid ejecting apparatus and the liquid ejecting head. For example, the present disclosure can be realized in aspects of a method for manufacturing a liquid ejecting head, a method for manufacturing a liquid ejecting apparatus, or the like.

The present disclosure is not limited to an ink jet method, and can be applied to any liquid ejecting apparatuses that ejects a liquid other than ink and a liquid ejecting head that is used in the liquid ejecting apparatuses. For example, the present disclosure can be applied to the following various liquid ejecting apparatuses and liquid ejecting heads thereof.

Claim 1:
A liquid ejecting head (<NUM>) comprising:
a piezoelectric element (<NUM>) that includes a first drive electrode (<NUM>), a second drive electrode (<NUM>), and a piezoelectric body (<NUM>), the piezoelectric body being provided between the first drive electrode and the second drive electrode in a lamination direction in which the first drive electrode, the second drive electrode, and the piezoelectric body are laminated;
a vibration plate (<NUM>) that is provided on one side of the lamination direction with respect to the piezoelectric element and is deformed by driving of the piezoelectric element; and
a pressure chamber substrate (<NUM>) that is provided on the one side of the lamination direction with respect to the vibration plate and is provided with a plurality of pressure chambers, characterized by further comprising
an interlayer (<NUM>) that is laminated on at least one of the piezoelectric body, the vibration plate, or the pressure chamber substrate and of which capacitance changes according to humidity;
a first detection electrode (<NUM>) that is in contact with the interlayer; and
a second detection electrode (<NUM>) that is in contact with the interlayer and is disposed to be separated from the first detection electrode.