JP2007030379A - Liquid jet head unit and liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet head unit and liquid jet apparatus having enhanced reliability by preventing the break or crack of a passage-forming substrate and diaphragm which compose a liquid jet head. <P>SOLUTION: A liquid jet head unit is equipped with the liquid jet head 220 for jetting a droplet and a head case 230 which is fixed at a liquid supply port side of the liquid jet head 220. The liquid jet head 220 and the head case 230 are fixed through a stress relaxation member 250 which permits the warpage of the liquid jet head 220 by its deformation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head unit and a liquid ejecting apparatus that include a liquid ejecting head that ejects liquid, and in particular, a part of a pressure generation chamber that communicates with a nozzle opening that ejects ink droplets is configured by a vibration plate. The present invention relates to an ink jet recording head unit and an ink jet recording apparatus including an ink jet recording head in which a piezoelectric element is provided via a plate and ink droplets are ejected by displacement of the piezoelectric element.

  An ink jet recording apparatus, such as an ink jet printer or a plotter, includes an ink jet recording head unit (hereinafter referred to as an ink jet recording head unit) that can eject ink stored in an ink storage section such as an ink cartridge or an ink tank as ink droplets. The head unit).

  Such a head unit includes an ink jet recording head and a head case fixed to the liquid supply port side of the ink jet recording head. The ink jet recording head is provided with a flow path forming substrate composed of a silicon single crystal substrate in which a pressure generation chamber communicating with a nozzle opening is formed, and a region opposite to the pressure generation chamber of the flow path formation substrate via a vibration plate. A piezoelectric substrate, a protective substrate bonded to the piezoelectric element side of the flow path forming substrate, and a compliance substrate provided on the protective substrate, and the head case is fixed to the compliance substrate (for example, Patent Documents) 1).

  However, in such a head unit, since the flow path forming substrate constituting the ink jet recording head is made of a silicon single crystal substrate and the nozzle plate is made of stainless steel or the like, warping occurs due to a difference in linear expansion coefficient due to temperature change. End up. At this time, when the ink jet recording head is fixed to the head case, the warping stress is not relieved, and there is a problem that cracks or cracks occur in the flow path forming substrate or the vibration plate.

  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.

Japanese Patent Laying-Open No. 2005-096419 (pages 7 to 14, FIGS. 1 to 5)

  In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head unit and a liquid ejecting apparatus that have improved reliability by preventing cracks and cracks in a flow path forming substrate and a diaphragm constituting the liquid ejecting head. And

A first aspect of the present invention that solves the above-described problem includes a liquid ejecting head that ejects liquid droplets, and a head case that is fixed to a liquid supply port side of the liquid ejecting head. A head case is fixed to the liquid jet head unit through a stress relaxation member that allows warpage of the liquid jet head by deformation.
In the first aspect, the liquid ejecting head and the head case are fixed via the stress relaxation member, and the warp due to heat of the liquid ejecting head is allowed by the deformation of the stress relaxing member. It is possible to prevent cracks, cracks and the like from occurring in each member.

According to a second aspect of the present invention, in the first aspect, the stress relaxation member is bonded to each of the liquid ejecting head and the head case, and the fixed portion is bonded between the fixed portions. The liquid ejecting head unit includes a flat plate-like support portion provided so that a direction orthogonal to the surface is a surface direction.
In the second aspect, the warp of the liquid ejecting head can be allowed as the shape of the stress relaxation member being easily deformable.

According to a third aspect of the present invention, in the liquid jet head unit according to the second aspect, the cross-sectional shape of the stress relaxation portion is a U-shape.
In the third aspect, the stress relaxation member can be easily deformed by forming a U-shaped cross section.

According to a fourth aspect of the present invention, in the third aspect, the stress relaxation member is disposed such that the U-shaped opening faces the outer peripheral side of the liquid ejecting head. In the unit.
In the fourth aspect, the stress relaxation member can be easily deformed in the direction in which the outer peripheral side of the liquid jet head expands.

According to a fifth aspect of the present invention, in the liquid jet head unit according to the second aspect, the cross-sectional shape of the stress relaxation member is an H shape.
In the fifth aspect, the stress relaxation member can be easily deformed by forming an H-shaped cross section.

According to a sixth aspect of the present invention, in the liquid jet head unit according to the second aspect, a cross-sectional shape of the stress relaxation member is a square shape.
In the sixth aspect, the stress relaxation member can be easily deformed by forming the cross section of the stress relaxation member in a square shape.

A seventh aspect of the present invention is the flow path forming substrate according to any one of the first to sixth aspects, wherein the liquid ejecting head is provided with a pressure generating chamber communicating with a nozzle opening for ejecting liquid droplets. A piezoelectric element provided on the side through a vibration plate, and a reservoir portion that is bonded to the piezoelectric element side of the flow path forming substrate and forms a part of a reservoir that supplies liquid to each pressure generating chamber in the thickness direction A protective substrate provided therethrough and a compliance substrate provided with a flexible portion having flexibility to seal the opening of the reservoir portion, and the stress relaxation member includes the compliance substrate and the compliance substrate. The liquid ejecting head unit is provided between the head case and the liquid ejecting head unit.
In the seventh aspect, by providing the stress relaxation member between the compliance substrate and the head case, the warp due to heat of the liquid ejecting head can be allowed to be deformed.

According to an eighth aspect of the present invention, in the seventh aspect, the compliance substrate includes a sheet member that seals the opening of the reservoir portion, and the stress relaxation member extends around the flexible portion. The liquid ejecting head unit is provided, wherein the flexible portion defines a flexible space.
In the eighth aspect, the stress relaxation member can make the flexible portion flexible and reduce the number of components to reduce the cost.

According to a ninth aspect of the present invention, in the seventh or eighth aspect, the flow path forming substrate is made of a silicon single crystal substrate, the compliance substrate is made of stainless steel, and the head case is made of stainless steel. The liquid ejecting head unit is characterized in that.
In the ninth aspect, the warp due to heat can be reduced by the stress relaxation member due to the difference in the linear expansion coefficient between the flow path forming substrate and the head case.

According to a tenth aspect of the present invention, in any one of the seventh to ninth aspects, the flow path forming substrate includes a communication portion that constitutes a part of the reservoir and communicates with one end portion of the pressure generation chamber. The liquid ejecting head unit is provided, and the stress relaxation portion is provided in a region facing the end portion of the pressure generating chamber on the side of the communication portion.
In the tenth aspect, by providing the stress relaxation member in the region that is easily broken by the warp of the liquid ejecting head, the stress due to the warp of the liquid ejecting head can be relieved by the stress relaxing member. Breakage such as cracks can be prevented.

An eleventh aspect of the present invention is a liquid ejecting apparatus comprising the liquid ejecting head unit according to any one of the first to tenth aspects.
In the eleventh aspect, a liquid ejecting apparatus with improved reliability 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 unit according to Embodiment 1 of the present invention, FIG. 2 is an assembled perspective view of the ink jet recording head unit, and FIG. It is. As shown in FIG. 1, an ink cartridge (not shown), which is an ink supply means, is mounted on each cartridge case 210, which is a holding member that constitutes an ink jet recording head unit 200 (hereinafter referred to as the head unit 200). A cartridge mounting portion 211 is provided. For example, in this embodiment, the ink cartridge is configured as a separate body filled with black and three color inks, and the ink cartridges of the respective colors are mounted in the cartridge case 210. Further, as shown in FIG. 3, a plurality of ink communication paths 212 having one end opened to each cartridge mounting portion 211 and the other end opened to the head case side described later are provided on the bottom surface of the cartridge case 210. . Further, an ink supply needle 213 inserted into the ink supply port of the ink cartridge is provided in the ink communication path 212 of the cartridge mounting portion 211 in order to remove bubbles and foreign matters in the ink. It is fixed via a formed filter (not shown).

  In addition, an ink jet type that has a plurality of piezoelectric elements 300 on the bottom surface side of the cartridge case 210 and ejects ink droplets from the nozzle openings 21 by driving the piezoelectric elements 300 on the end surface opposite to the cartridge case 210. It has a head case 230 to which the recording head 220 is fixed. In the present embodiment, a plurality of ink jet recording heads 220 that eject ink of each color of the ink cartridge are provided corresponding to each ink color, and a plurality of head cases 230 are also provided independently corresponding to each ink jet recording head 220. Is provided.

  Here, the ink jet recording head 220 and the head case 230 of this embodiment mounted on the cartridge case 210 will be described. FIG. 4 is an exploded perspective view of the ink jet recording head and the head case, and FIG. 5 is a cross-sectional view of the ink jet recording head and the head case. As shown in FIGS. 4 and 5, the flow path forming substrate 10 constituting the ink jet recording head 220 is composed of a silicon single crystal substrate in the present embodiment, and silicon dioxide previously formed on one surface thereof by thermal oxidation. An elastic film 50 made of is formed. This flow path forming substrate 10 is formed with two rows in which pressure generation chambers 12 partitioned by a plurality of partition walls are arranged in parallel in the width direction by anisotropic etching from the other side. Further, on the outer side in the longitudinal direction of the pressure generating chambers 12 in each row, a communicating portion constituting a reservoir 100 that communicates with a reservoir portion 31 provided on a protective substrate 30 to be described later and serves as a common ink chamber for each pressure generating chamber 12. 13 is formed. The communication portion 13 is in communication with one end portion in the longitudinal direction of each pressure generating chamber 12 via the ink supply path 14.

Further, a nozzle plate 20 having a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 on the opening surface side of the flow path forming substrate 10 is an adhesive, a heat-welded film, or the like. It is fixed through. That is, in this embodiment, two nozzle rows 21A in which the nozzle openings 21 are arranged in parallel are provided in one ink jet recording head. 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 4.5 [10 ⁻⁶ / ° C.]. It consists of a substrate or stainless steel.

  A water repellent film (not shown) is provided on the ink droplet ejection surface side of the nozzle plate 20. Examples of the water repellent film include a metal film containing a fluorine-based polymer and a plasma polymerized film obtained by plasma polymerizing siloxane. In this embodiment, the water-repellent film is formed by eutectoid plating of fluororesin on the nozzle plate 20 made of stainless steel.

  On the other hand, on the side opposite to the opening surface of the flow path forming substrate 10, on the elastic film 50, a lower electrode film made of metal, a piezoelectric layer made of lead zirconate titanate (PZT) or the like, and made of metal. A piezoelectric element 300 formed by sequentially laminating the upper electrode film is formed. On the flow path forming substrate 10 on which such a piezoelectric element 300 is formed, a protective substrate 30 having a reservoir portion 31 constituting at least a part of the reservoir 100 is bonded. In the present embodiment, the reservoir portion 31 is formed through the protective substrate 30 in the thickness direction and across the width direction of the pressure generation chamber 12. As described above, the communication portion 13 of the flow path forming substrate 10. The reservoir 100 is configured as a common ink chamber for the pressure generation chambers 12.

  A piezoelectric element holding portion 32 having a space that does not hinder the movement of the piezoelectric element 300 is provided in a region of the protective substrate 30 that faces the piezoelectric element 300. The piezoelectric element holding part 32 may seal the piezoelectric element 300 or may not seal it. Examples of such a protective substrate 30 include glass, ceramic, metal, plastic, and the like, but it is preferable to use a material that is substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. It was formed using a silicon single crystal substrate made of the same material as the path forming substrate 10.

  Furthermore, a drive IC 110 for driving each piezoelectric element 300 is provided on the protective substrate 30. Each terminal of the drive IC 110 is connected to a lead wiring drawn from the individual electrode of each piezoelectric element 300 via a bonding wire or the like (not shown). Each terminal of the driving IC 110 is connected to the outside via an external wiring 111 such as a flexible printed cable (FPC) as shown in FIG. 1, and various signals such as a print signal from the outside via the external wiring 111. To receive.

  A compliance substrate 40 is bonded onto the protective substrate 30. The compliance substrate 40 is made of a film member such as a resin film made of polyimide (PI), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyethersulfone (PES), fluorine-containing resin or chlorine-containing resin. Further, an ink introduction port 44 for supplying ink to the reservoir 100 is formed in a region facing the reservoir 100 of the compliance substrate 40 by penetrating in the thickness direction. Further, the region other than the ink introduction port 44 in the region facing the reservoir 100 of the compliance substrate 40 is a flexible portion 43 that seals the opening of the reservoir 100, and the flexible portion 43 is flexible. , Compliance is provided in the reservoir 100.

  As described above, the ink jet recording head 220 according to the present embodiment includes the four substrates of the nozzle plate 20, the flow path forming substrate 10, the protective substrate 30, and the compliance substrate 40. A head case 230 is fixed on the compliance substrate 40 of the ink jet recording head 220 through a stress relaxation member 250.

  The head case 230 is provided with an ink supply communication passage 231 that communicates with the ink introduction port 44 and communicates with the ink communication passage 212 of the cartridge case 210 and supplies ink from the cartridge case 210 to the ink introduction port 44. Yes. The head case 230 is provided with a drive IC holding part 233 penetrating in the thickness direction in a region facing the drive IC 110 provided on the protective substrate 30, and the external wiring 111 is connected to the drive IC holding part 233. Is connected to the drive IC 110.

  The stress relaxation member 250 is provided between the ink jet recording head 220 and the head case 230, and can fix and deform both.

  Such a stress relaxation member 250 is provided between the ink jet recording head 220 and the head case 230 via an adhesive, and allows the ink jet recording head 220 to deform by warping due to heat. The stress concentration due to the warp of the recording head 220 is alleviated to prevent breakage of the flow path forming substrate 10 and the vibration plate of the ink jet recording head 220 and breakage such as cracks.

  In other words, the inkjet recording head 220 is warped by heat because the nozzle plate 20 made of stainless steel (SUS) and the flow path forming substrate 10 made of a silicon single crystal substrate have different linear expansion coefficients. For this reason, when the ink jet recording head 220 is directly fixed to the head case 230 or fixed via a member that does not deform, warpage due to heat of the ink jet recording head 220 is hindered by the head case 230, and the ink jet recording head. The warping stress 220 is concentrated, and breakage such as cracks or cracks occurs in the flow path forming substrate 10 or the vibration plate constituting the ink jet recording head 220. Therefore, by fixing the ink jet recording head 220 and the head case 230 via the deformable stress relieving member 250, the warp due to heat of the ink jet recording head 220 is allowed to be deformed, and the ink jet recording head. It is possible to prevent breakage such as cracks and cracks of the flow path forming substrate 10 and the vibration plate 220.

  Here, the stress relaxation member 250 of the present embodiment will be described in detail. The stress relaxation member 250 of this embodiment has a U-shaped cross section. Thus, the stress relaxation member 250 of the present embodiment can be deformed by making the cross section U-shaped.

  Specifically, as shown in FIG. 6, the stress relaxation member 250 includes a plate-like fixing portion 251 that is bonded to the ink jet recording head 220 and the head case 230 via an adhesive, and one end portion of the pair of fixing portions 251. And a plate-like support portion 252 provided continuously. The support portion 252 is bent so that the surface direction of the support portion 252 is perpendicular to the bonding surface of the fixing portion 251. As shown in FIG. 6A, the stress relaxation member 250 can be deformed by bending the corners of the fixed portion 251 and the support portion 252.

  The stress relaxation member 250 is preferably arranged so that the U-shaped opening opens to the outer peripheral side of the ink jet recording head 220. This is because the ink jet recording head 220 warps so that the central portion of the surface on the nozzle opening 21 side becomes concave at low temperatures, so that the stress relieving member 250 is disposed on both ends of the nozzle row 21A. The outer peripheral side of 220 is deformed so that the space between the ink jet recording head 220 and the head case 230 is widened. As shown in FIG. 6B, the stress relieving member 250 is located at the center of the nozzle row 21A. This is because the ink jet recording head 220 is prevented from being broken by facilitating deformation so that the space between the head case 230 and the head case 230 is narrowed.

  Furthermore, the stress relaxation member 250 only needs to be provided at least in the direction in which the nozzle openings 21 are arranged in parallel, and even if provided continuously in the direction in which the nozzle openings 21 are arranged, it is provided intermittently. Also good. In addition, the stress relaxation member 250 is preferably provided in a region facing the end portion communicating with the communicating portion 13 of the pressure generating chamber 12. This is because when the ink jet recording head 220 is warped by heat, stress is easily concentrated in a region opposite to the end portion communicating with the communicating portion of the pressure generating chamber 12, and the flow path forming substrate 10 and the diaphragm are broken. This is because cracks are likely to occur. That is, by providing the stress relaxation member 250 in a region communicating with the communicating portion 13 of the pressure generating chamber 12, it is possible to prevent the breakage of the region where the flow path forming substrate 10 and the diaphragm are particularly weak.

  In the present embodiment, by providing the stress relaxation member 250 around the flexible portion 43, a space that allows the flexible portion 43 to be flexibly deformed is defined between the compliance substrate 40 and the head case 230. I made it. Further, by providing the stress relaxation member 250 around the flexible portion 43, it is possible to prevent the flexible portion 43 of the compliance substrate 40 from being peeled off from the protective substrate 30, and to prevent ink leakage. Can do. The stress relaxation member 250 is provided with an ink introduction port 44 that communicates with the ink introduction port 44 of the compliance substrate 40.

  In addition, although it does not specifically limit as a material of the stress relaxation member 250, For example, stainless steel etc. can be mentioned. Moreover, the thickness of the stress relaxation member 250 is about 100 μm in this embodiment. Furthermore, the joining of the stress relaxation member 250, the ink jet recording head 220, and the head case 230 is not particularly limited, and examples thereof include adhesion with a thermosetting epoxy adhesive or an ultraviolet curable adhesive. .

  In this embodiment, a member having a U-shaped cross section is used as the stress relaxation member 250, but the shape of the stress relaxation member 250 is not particularly limited thereto. For example, as shown in FIG. 7, a member having an H-shaped cross section may be used as the stress relaxation member 250, and as shown in FIG. 8, the cross-sectional shape is a rectangular shape as the stress relaxation member 250. These members may be used. In any case, as shown in FIGS. 6 to 8, warping of the ink jet recording head 220 at low temperatures is allowed by deformation of the stress relaxation member 250, and stress due to warping of the ink jet recording head 220 is relieved. Thus, the ink jet recording head 220 can be prevented from being broken. As shown in FIG. 8, when the stress relaxation member 250 having a square cross section is used, the stress relaxation member 250 is hardly deformed at both ends of the nozzle row 21A, but the center of the nozzle row 21A. It is possible to prevent the ink jet recording head 220 from being broken by deforming the stress relieving member 250 in the direction in which the warp of the ink jet recording head 220 is allowed to be deformed.

  Such an ink jet recording head 220 of this embodiment takes in ink from the ink cartridge from the ink introduction port 44 via the ink communication path 212 and the ink supply communication path 231, and the inside from the reservoir 100 to the nozzle opening 21. After the ink is filled with ink, a voltage is applied to each piezoelectric element 300 corresponding to the pressure generating chamber 12 in accordance with a recording signal from the driving IC 110 to cause the elastic film 50 and the piezoelectric element 300 to bend and deform, thereby generating each pressure. The pressure in the chamber 12 increases and ink droplets are ejected from the nozzle openings 21.

  Each member constituting the ink jet recording head 220 and the head case 230 are provided with two pin insertion holes 234 into which pins for positioning the respective members are inserted at the time of assembly. The ink jet recording head 220 and the head case 230 are integrally formed by inserting pins into the pin insertion hole 234 and joining the members while performing relative positioning of the respective members.

  The above-described ink jet recording head 220 forms a large number of chips on one silicon wafer at the same time, and bonds and integrates the nozzle plate 20 and the compliance substrate 40. By dividing the chip-sized flow path forming substrate 10 into each other, the ink jet recording head 220 is obtained.

  Four such ink jet recording heads 220 and head cases 230 are fixed to the cartridge case 210 described above at predetermined intervals in the direction in which the nozzle rows 21A are arranged. That is, the head unit 200 of this embodiment is provided with eight nozzle rows 21A. In this way, by increasing the number of nozzle rows 21A composed of the nozzle openings 21 arranged side by side using a plurality of ink jet recording heads 220, a plurality of nozzle rows 21A are formed on one ink jet recording head 220. Compared to the above, the yield can be prevented from decreasing. Further, by using a plurality of ink jet recording heads 220 in order to increase the number of nozzle rows 21A, the number of ink jet recording heads 220 that can be formed from one silicon wafer can be increased. It is possible to reduce the manufacturing cost by reducing the useless area.

  Further, the four ink jet recording heads 220 held by the cartridge case 210 via the head case 230 are covered with a cover head 240 having a box shape as shown in FIGS.

  The cover head 240 includes an exposed opening 241 that exposes the nozzle opening 21 and a joint 242 that defines the exposed opening 241.

  In the present embodiment, the joining portion 242 extends between the frame portion 243 provided along the outer periphery of the ink droplet discharge surface across the plurality of ink jet recording heads 220 and the adjacent ink jet recording head 220. And a beam portion 244 that divides the exposed opening 241. Further, the frame portion 243 of the joint portion 242 is formed so as to close the pin insertion hole 234 that positions each member when the ink jet recording head 220 is manufactured. Further, the cover head 240 is provided with a side wall portion 245 that extends so as to bend over the outer peripheral edge portion of the ink droplet ejection surface on the side surface side of the ink droplet ejection surface of the ink jet recording head 220. .

  As such a cover head 240, metal materials, such as stainless steel, are mentioned, for example, A metal plate may be formed by press work and may be formed by shaping | molding.

  Further, the joint portion 242 is provided with a flange portion 246 provided with a fixing hole 247 for positioning and fixing the cover head 240 to another member. The flange portion 246 is bent and provided so as to protrude from the side wall portion 245 in the same direction as the surface direction of the droplet discharge surface. In the present embodiment, as shown in FIGS. 2 and 3, the cover head 240 is fixed to a cartridge case 210 that is a holding member that holds the ink jet recording head 220 and the head case 230. Specifically, as shown in FIGS. 2 and 3, the cartridge case 210 is provided with a protrusion 215 that protrudes toward the ink droplet discharge surface and is inserted into the fixing hole 247 of the cover head 240. The cover head 240 is fixed to the cartridge case 210 by inserting the portion 215 into the fixing hole 247 of the cover head 240 and heating and crimping the tip of the protrusion 215. The protrusion 215 provided on the cartridge case 210 has an outer diameter smaller than that of the fixing hole 247 of the flange 246, so that the cover head 240 is positioned in the surface direction of the ink droplet discharge surface and the cartridge case. 210 can be fixed.

  Such a head unit 200 is mounted on an ink jet recording apparatus. FIG. 9 is a schematic view showing an example of the ink jet recording apparatus. As shown in FIG. 9, a head unit 200 having an ink jet recording head is provided with cartridges 1 </ b> A and 1 </ b> B constituting an ink supply means in a detachable manner, and a carriage 3 on which the head unit 200 is mounted is attached to the apparatus main body 4. The carriage shaft 5 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.

  Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 3 on which the head unit 200 is mounted is moved along the carriage shaft 5. 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.

(Other embodiments)
As mentioned above, although each embodiment of the present invention was described, the present invention is not limited to what was mentioned above. For example, in the first embodiment described above, a film member is used as the compliance substrate 40 and the flexible space of the flexible portion 43 is defined by the stress relaxation member 250. However, the compliance substrate 40 is not particularly limited thereto. Instead, for example, as the compliance substrate, a plate-like member made of stainless steel or the like may be used to reduce the thickness of a part of the flexible portion. Even in such a case, by providing the stress relaxation member 250 between the compliance substrate and the head case 230, the ink jet recording head 220 can be warped by heat, and the ink jet recording head 220 can be destroyed. Can be prevented.

  In the first embodiment described above, the stress relaxation member 250 has a predetermined shape so that the stress relaxation member can be easily deformed and the warp due to heat of the ink jet recording head 220 is allowed. For example, a resin material or a rubber material having a quadrangular prism shape in cross section may be used as the stress relaxation member. In any case, the warp due to heat of the ink jet recording head 220 can be allowed to be deformed, and the ink jet recording head 220 can be prevented from being broken due to stress concentration.

  Furthermore, in the above-described first embodiment, the flexural vibration type ink jet recording head 220 is illustrated, but the present invention is not limited to this. For example, a longitudinal direction in which piezoelectric materials and electrode forming materials are alternately stacked and expanded and contracted in the axial direction is used. Needless to say, the present invention can be applied to a head unit having an ink jet recording head having various structures, such as an ink jet recording head that ejects ink droplets by bubbles generated by heat generation of a vibration type ink jet recording head or a heating element. .

  The head unit and the ink jet recording apparatus having an ink jet recording head that discharges ink as the liquid ejecting head have been described as an example. However, the present invention broadly includes a liquid ejecting head unit having a liquid ejecting head and a liquid ejecting apparatus in general. It is intended. Examples of the liquid ejecting head include a recording head used in an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an electrode formation such as an FED (surface emitting display). Electrode material ejecting heads used in manufacturing, bioorganic matter ejecting heads used in biochip production, and the like.

FIG. 3 is an exploded perspective view of the head unit according to the first embodiment. FIG. 3 is an assembled perspective view of the head unit according to the first embodiment. FIG. 3 is a cross-sectional view of a main part of the head unit according to the first embodiment. 3 is an exploded perspective view of a head and a head case according to Embodiment 1. FIG. 2 is a cross-sectional view of a head and a head case according to Embodiment 1. FIG. 2 is a cross-sectional view of a stress relaxation member according to Embodiment 1. FIG. 2 is a cross-sectional view of a stress relaxation member according to Embodiment 1. FIG. 2 is a cross-sectional view of a stress relaxation member according to Embodiment 1. FIG. 1 is a schematic diagram of an ink jet recording apparatus according to Embodiment 1. FIG.

Explanation of symbols

3 Carriage, 10 Flow path forming substrate, 12 Pressure generating chamber, 100 Reservoir, 200 Head unit, 210 Cartridge case, 220 Inkjet recording head, 230 Head case, 240 Cover head, 241 Exposed opening, 242 Joint, 245 Side wall Part, 246 flange part, 247 fixing hole, 250 stress relaxation member, 300 piezoelectric element

Claims (11)

  A liquid ejecting head that ejects liquid droplets, and a head case fixed to the liquid supply port side of the liquid ejecting head, wherein the liquid ejecting head and the head case deform the warp of the liquid ejecting head. A liquid ejecting head unit, which is fixed via an allowable stress relaxation member. 2. The surface direction according to claim 1, wherein the stress relieving member is fixed to each of the liquid jet head and the head case, and a direction perpendicular to the bonding surface of the fixing portion is between the fixing portions. A liquid ejecting head unit comprising: a flat plate-like support portion provided so as to be. The liquid ejecting head unit according to claim 2, wherein a cross-sectional shape of the stress relaxation portion is a U-shape. The liquid ejecting head unit according to claim 3, wherein the stress relaxation member is disposed such that a U-shaped opening faces an outer peripheral side of the liquid ejecting head. The liquid ejecting head unit according to claim 2, wherein a cross-sectional shape of the stress relaxation member is an H shape. The liquid ejecting head unit according to claim 2, wherein a cross-sectional shape of the stress relaxation member is a square shape. 7. The liquid jet head according to claim 1, wherein the liquid jet head is provided on one side of a flow path forming substrate provided with a pressure generating chamber communicating with a nozzle opening for jetting liquid droplets via a diaphragm. A protective substrate provided with a piezoelectric element and a reservoir portion that is bonded to the piezoelectric element side of the flow path forming substrate and constitutes a part of a reservoir that supplies liquid to each pressure generating chamber in a thickness direction; And a compliance substrate provided with a flexible portion for sealing the opening of the reservoir portion, and the stress relaxation member is provided between the compliance substrate and the head case. A liquid ejecting head unit. 8. The compliance substrate according to claim 7, wherein the compliance substrate is made of a sheet member that seals the opening of the reservoir portion, the stress relaxation member is provided around the flexible portion, and the flexible portion is flexible. A liquid ejecting head unit characterized by defining a possible space. 9. The liquid ejecting head unit according to claim 7, wherein the flow path forming substrate is made of a silicon single crystal substrate, the compliance substrate is made of stainless steel, and the head case is made of stainless steel. The flow path forming substrate according to claim 7, wherein the flow path forming substrate is provided with a communication portion that constitutes a part of the reservoir and communicates with one end portion of the pressure generation chamber, and the stress relaxation portion. Is provided in a region opposite to the end portion of the pressure generating chamber on the side of the communication portion. A liquid ejecting apparatus comprising the liquid ejecting head unit according to claim 1.

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