Patent Description:
The liquid discharge head includes a deformable nozzle plate having a nozzle to discharge a liquid and a deformable piezoelectric element on the nozzle plate. The liquid discharge head deforms the nozzle plate to pressurize the liquid in a liquid chamber to discharge the liquid from the nozzle.

For example, the liquid discharge head includes a substrate, a diaphragm, and the nozzle plate. The substrate has a first surface, a second surface opposite to the first surface, and a cylindrical hole communicating with the first surface and the second surface. The diaphragm laminated on the first surface of the substrate to close one end of the hole to forms a pressure chamber and has a nozzle communicating with the pressure chamber.

The nozzle plate includes a drive element that deforms the diaphragm when a voltage is applied to change a volume of the pressure chamber. The liquid discharge head includes an insulating film on a surface of a driving element and a protective film on a surface of the insulating film (<CIT> and <CIT>).

When a protective film is formed on the insulating film of an electromechanical conversion element, there is a problem that the adhesion between the insulating film and the protective film is reduced. <CIT> discloses background art to the invention.

According to an embodiment of the present invention, a liquid discharge head having an actuator is provided as specified in the claims.

The invention is defined by the scope of the appended claims.

It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to another element or intervening elements may be present.

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, embodiments of the present disclosure are described below.

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, embodiments of the present disclosure are described below.

Next, a liquid discharge head <NUM> according to a first embodiment of the present disclosure is described with reference to <FIG>.

<FIG> is exploded perspective view a liquid discharge head <NUM> according to the first embodiment of the present disclosure.

<FIG> is a cross-sectional side view of the liquid discharge apparatus along a line A-A of <FIG>.

The liquid discharge head <NUM> includes multiple actuators <NUM> and a chamber forming member <NUM>. Hereinafter "the liquid discharge head" is simply referred to as the "head".

The actuator <NUM> includes a thin-film member <NUM> and a piezoelectric element <NUM> (see <FIG>). The thin-film member <NUM> serves as a deformable nozzle plate and a diaphragm having an opening 102a. The opening 102a forms a nozzle <NUM> from which a liquid is discharged. The piezoelectric element <NUM> is formed by an annular electromechanical conversion element disposed on one surface (upper surface in <FIG>) of the thin-film member <NUM> around the opening 102a (nozzle <NUM>).

Thus, the electromechanical conversion element such as the piezoelectric element <NUM> has an annular shape surrounding the opening 102a (nozzle <NUM>).

Thus, the piezoelectric element <NUM> is an example of the electromechanical conversion element.

The piezoelectric element <NUM> is formed by sequentially laminating a lower electrode <NUM>, a piezoelectric film <NUM> as an electromechanical conversion film, and an upper electrode <NUM> on one surface (upper surface in <FIG>) of the thin-film member <NUM>. The actuator <NUM> includes an insulating film <NUM> covering the piezoelectric element <NUM>.

In the piezoelectric element <NUM>, the insulating film <NUM> is opened, and an electrode wiring <NUM> is connected to the lower electrode <NUM> as a lower electrode lead wiring. An electrode wire <NUM> serving as an upper electrode lead wire is connected (coupled) to the upper electrode <NUM>.

Further, an adhesion improving film <NUM> is formed on each of surfaces including a surface of the insulating film <NUM> of the piezoelectric element <NUM> and surfaces of electrode wirings <NUM> and <NUM>. A protective film <NUM> is formed on this adhesion improving film <NUM>. In other words, the actuator <NUM> includes the protective film <NUM> over a surface of the insulating film <NUM> to cover the electrode wirings <NUM> and <NUM> connected (coupled) to the piezoelectric element <NUM>. Further, the adhesion improving film <NUM> is interposed at least between the electrode wirings <NUM> and <NUM> and the protective film <NUM>.

The adhesion improving film <NUM> continuously extends over the electrode wirings <NUM> and <NUM>, the insulating film <NUM>, and the piezoelectric element <NUM>. Multiple openings 102a are partially opened in the adhesion improving film <NUM> as the nozzles <NUM> (see <FIG>). The adhesion improving film <NUM> is also referred to as an "adhesion layer".

The adhesion improving film <NUM> is a layer having a function of increasing the adhesion between the protective film <NUM> and the electrode wirings <NUM> and <NUM> as compared with a case in which the protective film <NUM> is directly formed on the surfaces of the electrode wirings <NUM> and <NUM>.

Here, the insulating film <NUM> is an SiO<NUM> film, the protective film <NUM> is a resin film formed from benzocyclobutene (BCB), and the adhesion improving film <NUM> is an SiO<NUM> film.

A chamber forming member <NUM> is bonded to another surface (lower surface in <FIG>) of the thin-film member <NUM> of the actuator <NUM>. The chamber forming member <NUM> has a liquid chamber <NUM> with which the nozzle <NUM> (opening 102a) communicates.

A portion in the thin-film member <NUM> that faces a liquid chamber <NUM> becomes a displaceable portion <NUM>.

The above-described configuration can improve the adhesion between the protective film <NUM> made of benzocyclobutene (BCB) and the electrode wirings <NUM> and <NUM>.

The actuator <NUM> according to the first embodiment includes the protective film <NUM> serving as an uppermost layer film. The protective film <NUM> is film-formed using a material of benzocyclobutene (BCB) having high chemical resistance, low moisture absorption, high heat resistance, high planarization, and high liquid repellency. However, if the protective film <NUM> made of BCB is directly formed on a foundation layer, it is difficult to ensure that the protective film <NUM> is sufficiently adhere to the wiring material of the electrode wirings <NUM> and <NUM>.

Particularly, the aluminum wiring forming the electrode wirings <NUM> and <NUM> and the protective film <NUM> are displaced when the actuator <NUM> is driven. The electrode wirings <NUM> and <NUM> are disposed in the displaceable portion <NUM> Therefore, stress is generated in the electrode wirings <NUM> and <NUM> and the protective film <NUM>. If the adhesion between the protective film <NUM> and the electrode wirings <NUM> and <NUM> is not sufficient, the protective film <NUM> may be peeled off at an interface between the protective film <NUM> and the electrode wirings <NUM> and <NUM>. Thus, actuator <NUM> may not function to perform a liquid discharge operation or may not ensure reliability.

However, the adhesion of the protective film <NUM> made of BCB at an interface is greatly affected by the foundation material. A covalent bond is formed between the protective film <NUM> and the foundation material to ensure sufficient adhesion.

The SiO<NUM> film is used as the insulating film <NUM> that covers the piezoelectric element <NUM>. If a surface of the foundation is clean, the SiO<NUM> film can form a strong siloxane bond (-O-Si-O -) with the protective film <NUM>. However, the adhesion of the SiO<NUM> film with the metal material (here, aluminum wiring) forming the electrode wirings <NUM> and <NUM> is inferior to the adhesion with the insulating film <NUM>.

Therefore, the SiO<NUM> film is formed as the adhesion improving film <NUM> on the surfaces of the electrode wirings <NUM> and <NUM> so that a strong covalent bond (siloxane bond) can be formed between the SiO<NUM> film and the protective film <NUM> as similarly with the insulating film <NUM>. Thus, the actuator <NUM> in the first embodiment includes a film contacting the protective film <NUM> as the SiO<NUM> film. The SiO<NUM> film serves as the adhesion improving film <NUM> that covers the entire surface of the electrode wirings <NUM> and <NUM> that faces (opposed to) the protective film <NUM>.

A thickness of the adhesion improving film <NUM> is preferably <NUM> or less since the thickness of the adhesion improving film <NUM> affects the rigidity of the thin-film member <NUM>. Thus, the thickness of the adhesion improving film <NUM> is equal to or smaller than <NUM>.

The adhesion improving film <NUM> may be film-formed by a method of sputtering, vapor deposition, atomic layer deposition (ALD), or the like. Functionally, the film formation by the ALD method is preferable from the viewpoints of thin-film formation, step coverage, film quality stability, and film thickness uniformity.

The BCB film used as the protective film <NUM> is excellent in low moisture absorption as a resin. However, a function of the moisture absorption of the BCB film is inferior to the moisture absorption of inorganic substances. Therefore, a barrier layer such as an Al<NUM>O<NUM> film or a SiN film having lower moisture permeability than the protective film <NUM> is provided on the surface of the foundation layer including the insulating film <NUM> and electrode wirings <NUM> and <NUM>. The adhesion improving film <NUM> is provided (formed) on this barrier layer to further improve the reliability.

Note that the insulating film <NUM> is not limited to the SiO<NUM> film, and a SiN film or the like may be used as the insulating film <NUM>. In the case in which the SiN film is used as the insulating film <NUM> instead of the SiO<NUM> film, the adhesion improving film <NUM> including the surface of the insulating film <NUM> is formed to improve the adhesion between the protective film <NUM> and the foundation layer as in the present embodiment.

Next, an example of a manufacturing process of the head <NUM> according to the first embodiment is described below with reference to <FIG> and <FIG>.

<FIG> and <FIG> are cross-sectional views of the head <NUM> illustrating the manufacturing process of the head <NUM>.

As illustrated in <FIG>, a silicon oxide film <NUM> (SiO<NUM> film <NUM>) having a thickness of <NUM> is formed, by plasma chemical vapor deposition (plasma CVD), on a silicon substrate <NUM> having a crystal plane orientation (<NUM>) and a plate thickness of <NUM>. The SiO<NUM> film <NUM> is formed to be the thin-film member <NUM> (see <FIG>). The silicon substrate <NUM> is formed to be the chamber forming member <NUM>
Then, a TiO<NUM> film and Pt are film-formed by sputtering to a film thickness of <NUM> and <NUM>, respectively, on the SiO<NUM> film <NUM>. The TiO<NUM> film and Pt serve as a lower electrode layer <NUM> that becomes the lower electrode <NUM> (see <FIG>). The TiO<NUM> film serves as an adhesion layer with the SiO<NUM> film <NUM>. The Pt serves as an electrode. The TiO<NUM> film may be formed by forming a film of Ti by sputtering and then oxidizing the film of Ti by a rapid thermal anneal (RTA) method in an oxygen atmosphere.

Further, a piezoelectric (PZT) film <NUM> is formed on the lower electrode layer <NUM> in multiple steps by, for example, a spin coating method, and finally film-formed to a thickness of <NUM>. The PZT film <NUM> serves as the piezoelectric film <NUM> On this PZT film <NUM>, Pt is film-formed with a film thickness of, for example, <NUM> by sputtering.

A film (layer) of Pt serves as an upper electrode layer <NUM> that becomes the upper electrode <NUM>. Here, the film-forming method of the PZT film <NUM> is not limited to the spin coating method, and may be formed by, for example, a sputtering method, an ion plating method, an aerosol method, a sol-gel method, an inkjet method, or the like.

Then, as illustrated in <FIG>, the upper electrode layer <NUM>, the PZT film <NUM>, and the lower electrode layer <NUM> are patterned by a lithography-etching method to dispose the piezoelectric element <NUM> at a position corresponding to the liquid chamber <NUM> to be formed later. As a result, the upper electrode <NUM>, the piezoelectric film <NUM>, and the lower electrode <NUM> are formed as illustrated in <FIG>. Then, an SiO<NUM> film <NUM> is formed to a thickness of, for example, <NUM> by the plasma CVD method as the insulating film <NUM>.

Next, as illustrated in <FIG>, a contact portion <NUM> that connects the lower electrode <NUM> and the electrode wiring <NUM> and a contact portion <NUM> that connects the upper electrode <NUM> and the electrode wiring <NUM> are formed on the SiO<NUM> film <NUM> by the lithography-etching method.

Then, TiN/AL films <NUM> and <NUM> are formed with a film thickness of <NUM> and <NUM>, respectively, by sputtering. The TiN/AL films <NUM> and <NUM> respectively serve as the electrode wirings <NUM> and <NUM>, for example. Here, Pt as a material of the upper electrode <NUM> or the lower electrode <NUM> directly contacts with Al as a material of a lead wiring at a bottom of the contact portion <NUM> so that TiN is alloyed by a thermal history in a later process. Thus, the TiN is applied as a barrier layer to prevent film from peeling due to stress caused by volume change.

Then, the TiN/Al films <NUM> and <NUM> are formed in desired patterns by the lithography-etching method, thereby forming electrode wirings <NUM> and <NUM>, respectively.

Then, a SiO<NUM> film <NUM> is film-formed as the adhesion improving film <NUM> to obtain sufficient adhesion with the protective film <NUM>. The SiO<NUM> film <NUM> is formed by, for example, an atomic layer deposition (ALD) method capable of forming a thin-film with good step coverage and good uniformity. The SiO<NUM> film <NUM> has a thickness that does not hinder a displacement of the displaceable portion <NUM>. Further, the protective film <NUM> and the adhesion improving film <NUM> may be formed by siloxane bonding (-O-Si-O-). Thus, it is sufficient that the SiO<NUM> film <NUM> has only one SiO<NUM> molecular layer.

Next, as illustrated in <FIG>, a benzocyclobutene (BCB) film <NUM> having a thickness of <NUM> is film-formed as a protective film <NUM> by a spin coating method. Then, the BCB film <NUM> is heat treated in a nitrogen atmosphere at <NUM> for one hour for polymerization and curing.

Then, the silicon substrate <NUM> is polished to a desired depth of the liquid chamber <NUM> as illustrated in <FIG>.

Next, a resist pattern is formed by a lithography-etching method to form the nozzle <NUM>. Further, the BCB film <NUM> serving as the protective film <NUM>, the SiO<NUM> film <NUM> serving as the adhesion improving film <NUM>, the SiO<NUM> film <NUM> serving as the insulating film <NUM>, and the SiO<NUM> film <NUM> serving as the thin-film member <NUM> are etched. The etching is performed by dry etching. The BCB film <NUM> is etched by a gas of O<NUM> or CF<NUM>/O<NUM>. For example, the BCB film <NUM> is etched by a reactive ion etching (RIE) etcher or a high-density plasma etcher.

Then, the silicon substrate <NUM> is etched to form an opening serving as the chamber forming member <NUM> as illustrated in <FIG>.

Thus, the head <NUM> is formed by the above-described processes.

In this head <NUM>, the adhesion of the protective film <NUM> is secured and high reliability can be obtained since the adhesion improving film <NUM> is interposed between the protective film <NUM> and the foundation layer (the insulating film <NUM>, and the electrode wirings <NUM> and <NUM>).

Thus, the actuator <NUM> includes the deformable thin-film member <NUM> having the opening 102a (nozzle <NUM>), the electromechanical conversion element (piezoelectric element <NUM>) disposed at a periphery of the opening 102a (nozzle <NUM>) of the deformable thin-film member <NUM>, an insulating film <NUM> covering the electromechanical conversion element (piezoelectric element <NUM>), the protective film <NUM> over the surface of the insulating film <NUM>, the protective film <NUM> covering the surface of the insulating film <NUM> and the surface of the electrode wirings <NUM> and <NUM> connected to the electromechanical conversion element (piezoelectric element <NUM>), and the adhesion improving film <NUM> disposed between the electrode wirings <NUM> and <NUM> and the protective film <NUM>.

Ahead <NUM> according to a second embodiment of the present disclosure is described with reference to <FIG>.

<FIG> is a cross-sectional side view of the head <NUM> according to the second embodiment of the present disclosure.

The head <NUM> in the second embodiment includes a barrier layer <NUM> between the adhesion improving film <NUM> and the foundation layer (insulating film <NUM>, and electrode wirings <NUM> and <NUM>). A film of Al<NUM>O<NUM>, SiN, or the like can be used as the barrier layer <NUM>, for example.

When the BCB film <NUM> is used as the protective film <NUM>, the resin is excellent in low moisture absorption, but the moisture permeability is relatively high as compared with an inorganic material. Therefore, the head <NUM> includes a barrier layer <NUM> having higher moisture permeability resistance than the protective film <NUM>, that is, having lower moisture permeability Thus, moisture permeated through the protective film <NUM> is blocked by the barrier layer <NUM>, and the head <NUM> can obtain further higher reliability.

The head <NUM> includes a two layer film of SiO<NUM>/SiN or a two layer film of Al<NUM>O<NUM>/SiO<NUM> in place of the barrier layer <NUM> to form a three layer film structure as a whole to improve the adhesion between the adhesion improving film <NUM> and the foundation layer (insulating film <NUM>, and electrode wirings <NUM> and <NUM>).

Thus, the barrier layer <NUM> has a moisture permeability lower than the protective film <NUM>. One surface of the barrier layer <NUM> contacting the surface of the insulating film <NUM> and the surface of the electrode wirings <NUM> and <NUM>, and another surface of the barrier layer <NUM> contacting the adhesion improving film <NUM>.

Next, an example of a liquid discharge apparatus <NUM> according to an embodiment of the present disclosure is described with reference to <FIG> and <FIG>.

<FIG> is a plan view of a portion of the liquid discharge apparatus <NUM>.

<FIG> is a side view of a portion of the liquid discharge apparatus <NUM> of <FIG>.

The liquid discharge apparatus <NUM> is a serial-type apparatus, and a carriage <NUM> reciprocally moves in a main scanning direction by a main scan moving unit <NUM>. The main scanning direction is indicated by arrow "MSD" in <FIG>. The main scan moving unit <NUM> includes a guide <NUM>, a main scan motor <NUM>, a timing belt <NUM>, and the like.

The guide <NUM> is bridged between a left-side plate 491A and a right-side plate 491B to moveably hold the carriage <NUM>. The main scan motor <NUM> reciprocally moves the carriage <NUM> in the main scanning direction MSD via the timing belt <NUM> bridged between a drive pulley <NUM> and a driven pulley <NUM>.

The carriage <NUM> mounts a liquid discharge device <NUM>. The head <NUM> and a head tank <NUM> forms the liquid discharge device <NUM> as a single unit. The head <NUM> has a configuration of one of the head <NUM> illustrated in <FIG>. The head <NUM> of the liquid discharge device <NUM> discharges liquid of each color, for example, yellow (Y), cyan (C), magenta (M), and black (K). The head <NUM> includes a nozzle array including multiple nozzles <NUM> arrayed in a sub-scanning direction as indicated by arrow "SSD". The sub-scanning direction is orthogonal to the main scanning direction MSD. The head <NUM> is mounted to the carriage <NUM> so that ink droplets are discharged downward.

The liquid stored in liquid cartridges <NUM> is supplied to the head tank <NUM> by a supply unit <NUM> to supply the liquid stored outside the head <NUM> (liquid cartridges <NUM>) to the head <NUM>.

The supply unit <NUM> includes a cartridge holder <NUM> serving as a filling part to mount the liquid cartridges <NUM>, a tube <NUM>, a liquid feeder <NUM> including a liquid feed pump, and the like. The liquid cartridge <NUM> is detachably attached to the cartridge holder <NUM>. The liquid is fed from the liquid cartridge <NUM> to the head tank <NUM> by the liquid feeder <NUM> via the tube <NUM>.

The liquid discharge apparatus <NUM> includes a conveyor <NUM> to convey a sheet <NUM>. The conveyor <NUM> includes a conveyance belt <NUM> as a conveyor and a sub scan motor <NUM> to drive the conveyance belt <NUM>. The sheet <NUM> is an example of a medium (object) onto which a liquid is to be discharged from the head <NUM>.

The conveyance belt <NUM> attracts the sheet <NUM> and conveys the sheet <NUM> to a position facing the head <NUM>. The conveyance belt <NUM> is an endless belt stretched between a conveyance roller <NUM> and a tension roller <NUM>. Attraction of the sheet <NUM> to the conveyance belt <NUM> may be applied by electrostatic adsorption, air suction, or the like.

The conveyance belt <NUM> rotates in the sub-scanning direction SSD as the conveyance roller <NUM> is rotationally driven by the sub scan motor <NUM> via a timing belt <NUM> and a timing pulley <NUM>.

At one side in the main scanning direction MSD of the carriage <NUM>, a maintenance unit <NUM> to maintain the head <NUM> in good condition is disposed on a lateral side of the conveyance belt <NUM>.

The maintenance unit <NUM> includes, for example, a cap <NUM> to cap a nozzle face (i.e., a face on which nozzles are formed) of the head <NUM> and a wiper <NUM> to wipe the nozzle face.

The main scan moving unit <NUM>, the supply unit <NUM>, the maintenance unit <NUM>, and the conveyor <NUM> are mounted to a housing that includes a left-side plate 491A, a right-side plate 491B, and a rear-side plate 491C.

In the liquid discharge apparatus <NUM> thus configured, the sheet <NUM> is conveyed on and attracted to the conveyance belt <NUM> and is conveyed in the sub-scanning direction SSD by the cyclic rotation of the conveyance belt <NUM>.

The head <NUM> is driven in response to image signals while the carriage <NUM> moves in the main scanning direction MSD, to discharge a liquid to the sheet <NUM> stopped, thus forming an image on the sheet <NUM>.

As described above, the liquid discharge apparatus <NUM> includes the head <NUM> according to the above-described embodiments of the present disclosure, thus allowing stable formation of high quality images.

Next, the liquid discharge device <NUM> according to another embodiment of the present disclosure is described with reference to <FIG> is a plan view of a portion of the liquid discharge device <NUM> according to another embodiment of the present disclosure.

The liquid discharge device <NUM> includes a housing, the main scan moving unit <NUM>, the carriage <NUM>, and the head <NUM> among components of the liquid discharge apparatus <NUM>. The left-side plate 491A, the right-side plate 491B, and the rear-side plate 491C configure the housing.

The liquid discharge device <NUM> may be configured to further attach at least one of the above-described maintenance unit <NUM> and the supply unit <NUM> to, for example, the right-side plate 491B of the liquid discharge device <NUM>.

Next, still another example of the liquid discharge device <NUM> according to the present embodiment is described with reference to <FIG>.

<FIG> is a front view of still another example of the liquid discharge device <NUM>.

The liquid discharge device <NUM> includes the head <NUM> to which a channel part <NUM> is mounted and a tube <NUM> connected to the channel part <NUM>.

Further, the channel part <NUM> is disposed inside a cover <NUM>. Instead of the channel part <NUM>, the liquid discharge device <NUM> may include the head tank <NUM>. A connector <NUM> electrically connected with the head <NUM> is provided on an upper part of the channel part <NUM>.

Still another example of the liquid discharge apparatus <NUM> according to the present embodiment is described with reference to <FIG>.

<FIG> is a perspective view of the liquid discharge apparatus <NUM>.

In this liquid discharge apparatus <NUM>, a Y-axis driver <NUM> is disposed on a frame <NUM>. A stage <NUM> to mount an object <NUM> is set on the Y-axis driver <NUM>. The Y-axis driver <NUM> reciprocally moves the stage <NUM> in a Y-axis direction as indicated by arrow in <FIG>. The object <NUM> is an example of a medium onto which a liquid is discharged from the head <NUM>.

An X-axis driver <NUM> is attached to an X-axis support <NUM>. A head base <NUM> mounted on a Z-axis driver <NUM> is attached to this X-axis driver <NUM>. The head base <NUM> is moved in an X-axis direction and a Z-axis direction as indicated by arrows in <FIG>.

The Y-axis driver <NUM> serves as a conveyor to convey the object <NUM> to a position facing the head <NUM>.

One or more heads <NUM> according to the above-described embodiments according to the present disclosure to discharge a liquid are mounted on the head base <NUM>. The liquid is supplied from the liquid reservoir to the head <NUM> via a supply unit <NUM> such as a tube and a pump.

The liquid discharge apparatus including the liquid discharge head according to the above-described embodiments can highly efficiently discharge a liquid.

In the present embodiments, a "liquid" discharged from the head is not particularly limited as long as the liquid has a viscosity and surface tension of degrees dischargeable from the head. Preferably, the viscosity of the liquid is not greater than <NUM> mPa s under ordinary temperature and ordinary pressure or by heating or cooling.

Examples of the liquid include a solution, a suspension, or an emulsion that contains, for example, a solvent, such as water or an organic solvent, a colorant, such as dye or pigment, a functional material, such as a polymerizable compound, a resin, or a surfactant, a biocompatible material, such as DNA, amino acid, protein, or calcium, or an edible material, such as a natural colorant.

Such a solution, a suspension, or an emulsion can be used for, e.g., inkjet ink, surface treatment solution, a liquid for forming components of electronic element or light-emitting element or a resist pattern of electronic circuit, or a material solution for three-dimensional fabrication.

Examples of an energy source to generate energy to discharge liquid include a piezoelectric actuator (a laminated piezoelectric element or a thin-film piezoelectric element), a thermal actuator that employs a thermoelectric conversion element, such as a heating resistor, and an electrostatic actuator including a diaphragm and opposed electrodes.

For example, the "liquid discharge device" includes a combination of the head with at least one of a head tank, a carriage, a supply unit, a maintenance unit, and a main scan moving unit to form a single unit.

Here, examples of the "single unit" include a combination in which the head and a functional part(s) or unit(s) are secured to each other through, e.g., fastening, bonding, or engaging, and a combination in which one of the head and a functional part(s) or unit(s) is movably held by another. Further, the head, the functional parts, and the mechanism may be configured to be detachable from each other.

For example, the head and the head tank may form the liquid discharge device as a single unit. Alternatively, the head and the head tank coupled (connected) with a tube or the like may form the liquid discharge device as a single unit. A unit including a filter may be added at a position between the head tank and the head of the liquid discharge device.

In another example, the head and the carriage may form the liquid discharge device as a single unit.

In still another example, the liquid discharge device includes the head movably held by a guide that forms part of a main scan moving unit, so that the head and the main scan moving unit form a single unit. The liquid discharge device may include the head, the carriage, and the main scan moving unit that form a single unit.

In still another example, a cap that forms a part of the maintenance unit may be secured to the carriage mounting the head so that the head, the carriage, and the maintenance unit form a single unit to form the liquid discharge device.

Further, in still another example, the liquid discharge device includes tubes connected to the head tank or the head mounting a channel member so that the head and the supply unit form a single unit. A liquid in a liquid reservoir source such as an ink cartridge is supplied to the head through this tube.

The main scan moving unit may be a guide only. The supply unit may be a tube(s) only or a loading unit only.

The term "liquid discharge apparatus" used herein also represents an apparatus including the head or the liquid discharge device to drive the head to discharge a liquid. The liquid discharge apparatus may be, for example, an apparatus capable of discharging a liquid to a material to which liquid can adhere or an apparatus to discharge liquid toward gas or into liquid.

The "liquid discharge apparatus" may include units to feed, convey, and eject the material on which liquid can adhere. The liquid discharge apparatus may further include a pretreatment apparatus to coat a treatment liquid onto the material, and a post-treatment apparatus to coat a treatment liquid onto the material, onto which the liquid has been discharged.

The "liquid discharge apparatus" may be, for example, an image forming apparatus to form an image on a sheet by discharging ink, or a three-dimensional fabrication apparatus to discharge a fabrication liquid to a powder layer in which powder material is formed in layers to form a three-dimensional fabrication object.

The "liquid discharge apparatus" is not limited to an apparatus to discharge liquid to visualize meaningful images, such as letters or figures. For example, the liquid discharge apparatus may be an apparatus to form arbitrary images, such as arbitrary patterns, or fabricate three-dimensional images.

The above-described term "material on which liquid can adhere" represents a material on which liquid is at least temporarily adhered, a material on which liquid is adhered and fixed, or a material into which liquid is adhered to permeate.

Examples of the "material on which liquid can adhere" include recording media, such as paper sheet, recording paper, recording sheet of paper, film, and cloth, electronic component, such as electronic substrate and piezoelectric element, and media, such as powder layer, organ model, and testing cell.

The "material on which liquid can adhere" includes any material on which liquid can adhere, unless particularly limited.

Examples of the "material on which liquid can adhere" include any materials on which liquid can adhere even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, and ceramic.

The "liquid discharge apparatus" may be an apparatus to relatively move the head and a material on which liquid can adhere. However, the liquid discharge apparatus is not limited to such an apparatus. For example, the liquid discharge apparatus may be a serial head apparatus that moves the head or a line head apparatus that does not move the head.

Examples of the "liquid discharge apparatus" further include a treatment liquid coating apparatus to discharge a treatment liquid to a sheet to coat the treatment liquid on a sheet surface to reform the sheet surface, and an injection granulation apparatus in which a composition liquid including raw materials dispersed in a solution is injected through nozzles to granulate fine particles of the raw materials.

Claim 1:
A liquid discharge head (<NUM>) comprising:
an actuator (<NUM>) wherein the actuator (<NUM>) comprises of:
a deformable thin-film member (<NUM>) having an opening (102a);
an electromechanical conversion element (<NUM>) which has an annular shape surrounding the opening (102a) of the deformable thin-film member (<NUM>);
an insulating film (<NUM>) covering the electromechanical conversion element (<NUM>);
a protective film (<NUM>) over a surface of the insulating film (<NUM>), the protective film (<NUM>) covering the surface of the insulating film (<NUM>) and a surface of an electrode wiring (<NUM>, <NUM>) connected to the electromechanical conversion element (<NUM>), wherein the protective film (<NUM>) is a resin film formed from benzocyclobutene; and
an adhesion improving film (<NUM>) disposed between the electrode wiring (<NUM>, <NUM>) and the protective film (<NUM>), wherein the adhesion improving film (<NUM>) is an SiO<NUM> film; and
the liquid discharge head (<NUM>) further comprises a liquid chamber (<NUM>) communicating with the opening (102a) of the deformable thin-film member (<NUM>).