JP2007050550A - Liquid jetting head and liquid jetting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jetting head which can prevent separation of each substrate that constitutes a head body, while maintaining an ejection characteristic of liquid droplets good, and to provide a liquid jetting apparatus. <P>SOLUTION: The liquid jetting head is equipped with both the head body and a head case 200 joined to the head body. The head body has at least both a nozzle plate 20 where a plurality of nozzle openings are bored, and a passage formation substrate 10 where a plurality of pressure generation chambers 12 communicating with the nozzle openings that eject the liquid droplets by driving of pressure generating means 300 are arranged side by side. The head case 200 is joined to the head body by an adhesion part which includes at least an adhesive layer composed of an adhesive. Moreover, the adhesion part 210 includes both a deformation regulating part 211 which substantially regulates deformation of the head body, and a deformation permitting part 212 which is lower in rigidity than the deformation regulating part 211 to permit the deformation of the head body by elastic deformation. At the same time, the deformation regulating part 211 is prepared only at the outside of a region corresponding to arrays of the pressure generation chambers 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink droplets by driving a pressure generating unit.

  Inkjet recording heads that eject ink droplets from nozzle openings use a longitudinal vibration mode piezoelectric actuator that expands and contracts in the axial direction of the piezoelectric element as a driving source for the pressure generating means, and a flexural vibration mode piezoelectric actuator. Two types using actuators have been put into practical use.

  For example, in an ink jet recording head using a piezoelectric actuator in a flexural vibration mode, a nozzle plate having a nozzle opening is bonded to one surface of a flow path forming substrate in which a pressure generating chamber is formed. In addition, there is one in which a reservoir forming substrate or the like provided with a reservoir portion that constitutes a reservoir in which ink to be supplied to each pressure generating chamber is provided is joined to the other surface side of the flow path forming substrate (for example, a patent Reference 1).

However, such an ink jet recording head has a problem that delamination occurs due to a change in environmental temperature because the linear expansion coefficient of each member is different. For example, in the structure of Patent Document 1, the flow path forming substrate and the reservoir forming substrate are made of a silicon substrate, and the linear expansion coefficient thereof is approximately 2.0 [× 10 ⁻⁶ / ° C.], and the nozzle plate is made of stainless steel (SUS). The linear expansion coefficient is 16 [× 10 ⁻⁶ / ° C.], and the linear expansion coefficients of the two are greatly different. For this reason, for example, when the head is placed at a lower temperature due to the temperature at which the flow path forming substrate and the nozzle plate are bonded, the nozzle plate contracts relatively, causing the head to warp and shear between each member. There is a problem that peeling due to stress occurs.

  Further, for example, as described in Patent Document 1, there is a recording head body composed of a flow path forming substrate, a reservoir forming substrate, and the like, in which a head case for fixing the recording head body is fixed. This head case is also formed of a material different from the reservoir forming substrate or the like constituting the recording head body, for example, a resin material. For this reason, stress is also generated from the head case side, and due to this stress, there is a possibility that separation occurs between the members of the recording head main body. Further, when the nozzle plate constituting the recording head main body is warped, there is a problem that the ink droplet ejection direction is changed, and the landing position is changed to deteriorate the image quality.

  These problems can be prevented by fixing the recording head main body to a head case made of a highly rigid material such as stainless steel (SUS). However, when the recording head body is fixed to the head case having such a high rigidity and the warping of the recording head body is corrected, the stress generated in the recording head body increases, and the increase in the stress constitutes the recording head body. There is a possibility that problems such as peeling between members and the like, and cracks may occur.

  Such a problem exists not only in an ink jet recording head that ejects ink, but also in other liquid ejecting heads that eject droplets other than ink.

JP 2003-80703 A (FIG. 2 etc.)

  In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head and a liquid ejecting apparatus capable of preventing the separation of each substrate constituting the head body while maintaining good droplet discharge characteristics. And

According to a first aspect of the present invention for solving the above problems, a nozzle plate having a plurality of nozzle openings and a plurality of pressure generating chambers communicating with the nozzle openings for discharging droplets by driving pressure generating means are provided. A head body having at least a flow path forming substrate arranged side by side; and a head case joined to the head body, wherein the head case is formed by an adhesive portion including at least an adhesive layer made of an adhesive. A deformation restricting portion which is bonded to the main body and the bonding portion substantially restricts deformation of the head main body, and a deformation permitting portion which is lower in rigidity than the deformation restricting portion and allows deformation of the head main body by elastic deformation. And the deformation restricting portion is provided only outside the region corresponding to the row of pressure generating chambers.
In the first aspect, the head main body and the head case are firmly fixed by the deformation restricting portion, but the warpage of the head main body is allowed by the deformation allowing portion, and therefore, between each member accompanying an increase in stress of the head main body. Peeling and cracking are prevented.

A second aspect of the present invention is the liquid ejecting head according to the first aspect, wherein the deformation restricting portion is provided only in a central portion on a long side of the head body.
In the second aspect, by providing the deformation restricting portion only in the predetermined region, the warpage of the head main body is reliably allowed by the deformation allowing portion while the head main body and the head case are well bonded.

According to a third aspect of the present invention, in the liquid jet head according to the first aspect, the deformation restricting portion is provided only in a central portion on a short side of the head body.
In the third aspect, by providing the deformation restricting portion only in the predetermined region, the warpage of the head main body is reliably permitted by the deformation permitting portion while favorably joining the head main body and the head case.

According to a fourth aspect of the present invention, in the liquid jet head according to the first aspect, the deformation restricting portion is provided only in a short side and a long side of the head body. is there.
In the fourth aspect, by providing the deformation restricting portion only in the predetermined region, the warpage of the head main body is reliably allowed by the deformation allowing portion while the head main body and the head case are well bonded.

According to a fifth aspect of the invention, in the liquid jet head according to the first aspect, the deformation restricting portion is provided only in a region corresponding to each corner of the head body.
In the fifth aspect, by providing the deformation restricting portion only in the predetermined region, the head main body and the head case are satisfactorily bonded, and the warpage of the head main body is reliably allowed by the deformation allowing portion.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a liquid flow including the pressure generation chamber of the head body outside the region where the head case corresponds to the row of the pressure generation chambers. The liquid ejecting head includes a communication hole communicating with a path, and the periphery of the communication hole of the head case is joined to the head body by the deformation restricting portion.
In the sixth aspect, it is possible to reliably prevent the leakage of liquid droplets from the joint portion between the head case and the head body.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the thickness of the adhesive layer of the deformation allowing portion is thicker than the thickness of the adhesive layer of the deformation restricting portion. In the liquid jet head.
In the seventh aspect, the rigidity of the deformation allowing portion is surely lower than the rigidity of the deformation restricting portion, and the warpage of the head body is more reliably allowed by the deformation allowing portion.

According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the deformation restricting portion includes a first protrusion provided on a joint surface of the head case with the head body. The liquid ejecting head is characterized.
In the eighth aspect, since the adhesive layer constituting the deformation restricting portion is well formed and the rigidity of the deformation restricting portion is increased, the head case and the head main body are more firmly fixed by the deformation restricting portion.

According to a ninth aspect of the present invention, in the eighth aspect, the deformation allowing portion includes a second protruding portion having a height lower than that of the first protruding portion provided on the joint surface of the head case. The liquid ejecting head is characterized by the above.
In the ninth aspect, the adhesive layer constituting the deformation allowing portion is satisfactorily formed. Further, the rigidity of the deformation-permitting portion is surely lower than the rigidity of the deformation restricting portion.

A tenth aspect of the present invention is a liquid ejecting apparatus including the liquid ejecting head according to any one of the first to ninth aspects.
In the tenth aspect, a liquid ejecting apparatus having excellent reliability and durability can be realized.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of FIG. As shown in the drawing, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in this embodiment, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation. An elastic film 50 of 5 to 2 μm is formed. The flow path forming substrate 10 is provided with two rows in which a plurality of pressure generating chambers 12 are arranged in the width direction. In addition, a communication portion 13 is formed for each row of the pressure generation chambers 12 in a region outside the longitudinal direction of the pressure generation chamber 12 of the flow path forming substrate 10. It is communicated through. The communication part 13 constitutes a part of a reservoir that communicates with a reservoir part of a protective substrate, which will be described later, and serves as a common ink chamber for the pressure generating chambers 12. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

Further, on the opening surface side of the flow path forming substrate 10, a mask film 51 used as a mask when forming the pressure generating chamber 12 is interposed, and the pressure generating chamber 12 is opposite to the ink supply path 14. A nozzle plate 20 having a nozzle opening 21 communicating in the vicinity of the end is fixed through an adhesive, a heat-welded film, or the like. The nozzle plate 20 has a thickness of, for example, 0.01 to 1 mm, a linear expansion coefficient of 300 ° C. or less, and a glass ceramic or silicon single crystal of, for example, 2.5 to 20 [× 10 ⁻⁶ / ° C.]. It consists of a substrate or stainless steel.

  On the other hand, as described above, the elastic film 50 having a thickness of, for example, about 1.0 μm is formed on the side opposite to the opening surface of the flow path forming substrate 10. For example, an insulator film 55 having a thickness of about 0.4 μm is formed. Further, on the insulator film 55, a lower electrode film 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and a thickness of, for example, about 0 The upper electrode film 80 having a thickness of 0.05 μm is laminated to form a piezoelectric element 300 that serves as a driving source for the pressure generating means. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In the present embodiment, the lower electrode film 60 is used as a common electrode of the piezoelectric element 300 and the upper electrode film 80 is used as an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for convenience of a drive circuit and wiring.

  A lead electrode 90 is connected to the vicinity of one end of the upper electrode film 80 of each piezoelectric element 300. The lead electrode 90 extends to the vicinity of the central portion of the flow path forming substrate 10 and is electrically connected to a driving IC mounted on a protective substrate 30 described later.

Furthermore, in the present embodiment, each layer constituting the piezoelectric element 300 and the lead electrode 90 are covered with an insulating film 100 made of, for example, an inorganic insulating material, except for the connection portion with the driving IC. The material of the insulating film 100 is not particularly limited as long as it is an inorganic insulating material, and examples thereof include aluminum oxide (Al ₂ O ₃ ) and tantalum pentoxide (Ta ₂ O ₅ ). Aluminum (Al ₂ O ₃ ) is preferably used. Since the insulating film 100 made of such an inorganic insulating material has a very low moisture permeability even in a thin film, the surface of the lower electrode film 60, the piezoelectric layer 70, the upper electrode film 80, and the lead electrode 90 is formed by the insulating film 100. By covering the surface, it is possible to prevent the piezoelectric layer 70 from being damaged due to moisture (humidity).

  Further, on the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, a protective substrate having a piezoelectric element holding portion 31 capable of ensuring a space that does not hinder the movement in a region facing the piezoelectric element 300. 30 is bonded via an adhesive 35. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment. The piezoelectric element holding portion 31 may be sealed, but may not be sealed. Further, in the present embodiment, the piezoelectric element holding portion 31 is provided for each row of the piezoelectric elements 300 arranged in parallel.

  In addition, a reservoir portion 32 constituting at least a part of the reservoir 110 is provided outside the piezoelectric element holding portions 31 of the protective substrate 30. These reservoir portions 32 are provided across the width direction of the pressure generating chamber 12 through the protective substrate 30 in the thickness direction, and are communicated with the communicating portion 13 of the flow path forming substrate 10 to each pressure generating chamber. Each of the reservoirs 110 is a common ink chamber for each of the 12 columns. In the present embodiment, in the region between the piezoelectric element holding portions 31 of the protective substrate 30, through holes 33 that penetrate the protective substrate 30 in the thickness direction are provided corresponding to the rows of the piezoelectric elements 300. ing. The lead electrode 90 drawn from each piezoelectric element 300 is exposed in the through hole 33 in the vicinity of its end. In addition, as such a protective substrate 30, it is preferable to use a material substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10, for example, glass, a ceramic material, etc. In this embodiment, the flow path forming substrate 10 and It was formed using a silicon single crystal substrate of the same material.

  A driving IC (semiconductor integrated circuit) 120 for driving the piezoelectric element 300 is provided on the surface of the protective substrate 30, that is, the surface opposite to the bonding surface with the flow path forming substrate 10. Implemented for each column. The drive ICs 120 and the lead electrodes 90 drawn from the piezoelectric elements 300 are electrically connected by connection wirings 130 that are extended in the through holes 33 of the protective substrate 30 by wire bonding.

  Further, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded on the protective substrate 30 so as to surround a peripheral portion including a region corresponding to the reservoir portion 32. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm). The sealing film 41 seals one surface of the reservoir portion 32. It has been stopped. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 110 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 110 is sealed only by the flexible sealing film 41. Has been.

  As described above, the head main body 150 according to this embodiment includes the flow path forming substrate 10, the nozzle plate 20, the protective substrate 30, and the compliance substrate 40. On the opposite side of the head main body 150 from the side where the nozzle plate 20 is formed, a head case 200 having an IC holding portion 201 that is a space surrounding the driving IC 120 is provided in a band-shaped adhesive portion 210. It is joined via.

  The IC holding portion 201 is filled with a potting agent 250 made of a low-stress resin material such as silicone resin or urethane resin, and the driving IC 120 and the connection wiring 130 provided on the protective substrate 30 are, for example, The potting agent 250 filled in the IC holding part 201 is completely covered. The head case 200 is formed with an ink communication hole 202 having one end connected to an ink cartridge (not shown) and the other end connected to the reservoir 110. Is to be supplied.

  Note that the head case 200 according to the present embodiment is preferably formed of a material having relatively high rigidity. Specifically, metal materials, such as nickel, aluminum, stainless steel, are mentioned. For example, in this embodiment, stainless steel (SUS) is used as the material of the head case 200.

  Here, the bonding portion 210 that joins the head main body 150 and the head case 200 has a deformation restriction portion 211 that substantially restricts deformation of the head main body 150, and is less rigid than the deformation restriction portion 211, and deformation of the head main body 150. And a deformation allowing portion 212 that allows the elastic deformation. In the present invention, the deformation restricting portion 211 is provided only outside the region corresponding to the row of the pressure generating chambers 12, and at least in the region corresponding to the row of the pressure generating chambers 12, the head main body 150 and the head case 200. Are joined only through the deformation allowing portion 212. For example, in the present embodiment, as shown in FIG. 3, an adhesive portion 210 provided on the short side of the head main body 150 (both ends in the juxtaposition direction of the pressure generating chamber 12), and both ends on the long side of the head main body 150. The bonding portion 210 provided around the ink communication hole 202 is the deformation restricting portion 211, and the other bonding portions 210 are the deformation allowing portions 212.

  In such a configuration, while maintaining the positional accuracy of the nozzle opening 21, it is possible to prevent warpage due to a temperature change or the like in the outer peripheral portion of the head main body 150 and to prevent the substrate constituting the head main body 150 from peeling or cracking. Can do.

  Here, in this embodiment, the deformation restricting portion 211 includes a first protrusion 203 protruding at a predetermined height on the joint surface of the head case 200 with the head main body 150, and the first protrusion 203. It is comprised with the 1st contact bonding layer 230 formed in the area | region to include. On the other hand, the deformation allowing portion 212 includes a second protrusion 204 having a height lower than that of the first protrusion 203 and a second adhesive layer 231 formed in a region including the second protrusion 204. Thus, the rigidity is lower than that of the deformation restricting portion 211. That is, since the thickness of the second adhesive layer 231 provided on the second protrusion 204 is relatively thicker than that of the first adhesive layer 230 provided on the first protrusion 203, deformation is allowed. The portion 212 is relatively lower in rigidity than the deformation restricting portion 211. Since the head case 200 and the head body 150 are firmly fixed by the deformation restricting portion 211, the deformation allowing portion 212 functions as a sealing agent for preventing the ink or the potting agent 250 from flowing out. What is necessary is just to have rigidity.

  Although the adhesive agent used as the 1st contact bonding layer 230 and the 2nd contact bonding layer 231 is not specifically limited, For example, in this embodiment, the silicone adhesive agent is used. Further, the thickness d1 of the first adhesive layer 230 constituting the deformation restricting portion 211 is not particularly limited, but is preferably about 1 to 20 μm. The thickness d2 of the second adhesive layer 231 constituting the deformation allowing portion 212 is preferably about 30 to 200 μm. The difference between the thickness d1 of the first adhesive layer 230 and the thickness d2 of the second adhesive layer 231 is preferably about 100 μm. For this reason, in this embodiment, the height of the first protrusion 203 is about 150 μm, and the height of the second protrusion 204 is about 50 μm. As a result, the rigidity of the deformation allowing portion 212 is sufficiently lower than that of the deformation restricting portion 211, and the deformation of the head main body 150 is reliably allowed by the elastic deformation of the second adhesive layer 231.

  In the present invention, the deformation restricting portion 211 is provided only outside the region corresponding to the row of pressure generating chambers 12, that is, only in the outer peripheral portion of the head body 150, and at least in the region corresponding to the row of pressure generating chambers 12, The head main body 150 and the head case 200 are joined via the deformation allowing portion 212. Thereby, the head main body 150 and the head case 200 are firmly fixed in a state where the head main body 150 and the head case 200 are positioned with high accuracy by the deformation restricting portion 211, but warpage of the head main body 150 due to a change in environmental temperature or the like is caused by the deformation permissible portion 212. Permissible. That is, the head body 150 can be deformed to some extent in the thickness direction even when it is joined to the head case 200. Accordingly, when the environmental temperature changes or the like, the head main body 150 is warped, but the increase in stress can be suppressed. Therefore, it is possible to prevent the separation of each substrate and the occurrence of cracks due to the increase in stress. .

  In this embodiment, the deformation restricting portion 211 is provided at both ends of the short side of the head main body 150 and around the ink communication hole 202. However, the present invention is not limited to this, and for example, as shown in FIG. In addition, the head main body 150 may be provided only at both ends on the short side. Further, for example, as shown in FIG. 5, it may be provided only around the ink communication hole 202. Furthermore, for example, as shown in FIG. 6, independent deformation restriction portions 211 may be provided only at the corners of the head main body 150, that is, only at the four corners of the head main body 150. In any case, the deformation restricting portion 211 may be provided only outside the row region of the pressure generating chambers 12, that is, only on the outer peripheral portion of the head main body 150. If the deformation restricting portion 211 is provided only outside the row region of the pressure generating chambers 12 as described above, the warp of the head main body 150 is reliably allowed by the deformation allowing portion 212. Thereby, peeling of each substrate constituting the head body 150 can be prevented, and a highly reliable liquid ejecting head can be realized.

  In such an ink jet recording head, ink is taken in from an external ink supply unit such as an ink cartridge through an ink communication hole 202 provided in the head case 200. Then, after filling the interior from the reservoir 110 to the nozzle opening 21 with ink, it is driven between the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12 in accordance with a drive signal from the drive IC 120. A voltage is applied, and the pressure in each pressure generating chamber 12 is increased by the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70, and ink droplets are ejected from the nozzle openings 21.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment mentioned above. For example, in the above-described embodiment, the first protrusion and the first adhesive layer provided on the head case are used as the deformation restricting portion, and the second protrusion and the second adhesive layer are used as the deformation allowing portion. However, the present invention is not limited to this. For example, the deformation allowing portion may be only the second adhesive layer applied with a dispenser or the like. When only the second adhesive layer is used as the deformation allowing portion in this way, it is desirable to appropriately adjust the rigidity of the deformation restricting portion and the deformation allowing portion by changing the height of the first protrusion.

  Further, the ink jet recording head of the above-described embodiment constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on the ink jet recording apparatus. FIG. 7 is a schematic view showing an example of the ink jet recording apparatus. As shown in FIG. 7, the recording head units 1A and 1B having the head main body are detachably provided with cartridges 2A and 2B constituting the ink supply means, and the carriage 3 on which the recording head units 1A and 1B are mounted is A carriage shaft 5 attached to the apparatus body 4 is provided so as to be movable in the axial direction. The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively. The driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the recording head units 1A and 1B are mounted is moved along the carriage shaft 5. The On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S, which is a recording medium such as paper fed by a paper feed roller (not shown), is conveyed on the platen 8. It is like that.

  In the above-described embodiment, the piezoelectric element made of a thin film is exemplified as the pressure generating means for ejecting ink droplets. However, the pressure generating means is not particularly limited, and may be, for example, a heating element. .

  In the above-described embodiment, the ink jet recording head unit including the ink jet recording head has been described as an example of the liquid ejecting head unit of the present invention. However, the basic configuration of the liquid ejecting head is limited to the above. It is not something. Of course, the present invention can also be applied to a liquid ejecting liquid other than ink. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FED (surface emitting). Examples thereof include an electrode material ejection head used for electrode formation such as a display, and a bioorganic matter ejection head used for biochip production.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment. FIG. 3 is a plan view of the recording head according to the first embodiment. FIG. 6 is a plan view illustrating a modification of the recording head according to the first embodiment. FIG. 6 is a plan view illustrating a modification of the recording head according to the first embodiment. FIG. 6 is a plan view illustrating a modification of the recording head according to the first embodiment. 1 is a schematic diagram of a recording apparatus according to an embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 13 Communication part, 14 Ink supply path, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 31 Piezoelectric element holding part, 32 Reservoir part, 40 Compliance board, 50 Elastic film, 55 Insulator film, 60 Lower electrode film, 70 Piezoelectric layer, 80 Upper electrode film, 90 Lead electrode, 110 Reservoir, 120 Driving IC, 150 Head body, 200 Head case, 203 First protrusion, 204 Second Projection part, 210 Adhering part, 211 Deformation restricting part, 212 Deformation allowing part, 230 First adhesive layer, 231 Second adhesive layer, 300 Piezoelectric element

Claims (10)

A head having at least a nozzle plate having a plurality of nozzle openings and a flow path forming substrate in which a plurality of pressure generating chambers communicating with the nozzle openings for discharging droplets by driving pressure generating means are arranged in parallel. A main body, and a head case joined to the head main body,
The head case is bonded to the head main body by an adhesive portion including at least an adhesive layer made of an adhesive, and the adhesive portion substantially restricts deformation of the head main body, and the deformation restricting portion. And a deformation allowing portion that allows deformation of the head main body by elastic deformation, and the deformation restricting portion is provided only outside the region corresponding to the row of pressure generating chambers. A liquid ejecting head. The liquid ejecting head according to claim 1, wherein the deformation restricting portion is provided only in a central portion on a long side of the head main body. The liquid ejecting head according to claim 1, wherein the deformation restricting portion is provided only in a central portion on a short side of the head main body. The liquid ejecting head according to claim 1, wherein the deformation restricting portion is provided only in a short side and a central portion on the long side of the head main body. The liquid ejecting head according to claim 1, wherein the deformation restricting portion is provided only in a region corresponding to each corner of the head main body. In any one of claims 1 to 5, the head case has a communication hole communicating with a liquid flow path including the pressure generation chamber of the head main body outside a region corresponding to the row of the pressure generation chambers. The liquid ejecting head according to claim 1, wherein the periphery of the communication hole of the head case is joined to the head body by the deformation restricting portion. The liquid ejecting head according to claim 1, wherein a thickness of the adhesive layer of the deformation allowing portion is thicker than a thickness of the adhesive layer of the deformation restricting portion. The liquid ejecting head according to claim 1, wherein the deformation restricting portion includes a first protrusion provided on a joint surface of the head case with the head main body. 9. The liquid ejecting head according to claim 8, wherein the deformation allowing portion includes a second protruding portion having a height lower than that of the first protruding portion provided on the joint surface of the head case. A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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