JP2014136359A - Liquid jet head and liquid jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet head and a liquid jet device capable of suppressing failure of discharge of droplets and decrease in vibration performance, and preventing destruction of a diaphragm.SOLUTION: The liquid jet head includes: a flow path forming substrate provided with a pressure generation chamber 12 communicating with nozzle openings 21 for jetting liquid; and pressure generation means provided, via a diaphragm, on one surface side of the flow path forming substrate. The pressure generation chamber 12 includes: a narrow width part 121 provided on one end side communicating with the nozzle opening 21, in a second direction Y orthogonal to a first direction X being a lining direction of the nozzle openings 21; and a wide width part 122 provided on the other end side and having a width in the first direction X, wider than the narrow width part 121. A boundary 124d of the diaphragm with the pressure generation chamber 12 and the flow path forming substrate, defined by an end surface of the pressure generation chamber 12, on a side of communicating with the nozzle opening 21 in the second direction, is disposed at a position avoiding corner parts 123a, 123b formed of an inner wall surface of the narrow width part 121 and an inner wall surface of the wide width part 122.

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject liquid from nozzle openings, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink as liquid.

  A typical example of a liquid ejecting head that ejects droplets is an ink jet recording head that ejects ink droplets. As the ink jet recording head, for example, a flow path forming substrate having a pressure generating chamber, a nozzle plate provided with a nozzle opening on one surface side of the flow path forming substrate, and a vibration on the other surface side of the flow path forming substrate. Pressure generating means such as a piezoelectric actuator provided via a plate, and by deforming the diaphragm by driving the pressure generating means to cause a pressure change in the pressure generating chamber, an ink droplet from the nozzle opening Have been proposed (see, for example, Patent Documents 1 and 2).

JP 2009-172878 A JP 2012-143948 A

  However, when the nozzle plate is bonded to the flow path forming substrate with an adhesive, the adhesive flows into the pressure generating chamber, the nozzle opening is blocked, and ink droplet ejection failure occurs. In addition, there is a problem that the adhesive flowing into the pressure generating chamber adheres to the diaphragm and the displacement characteristics of the diaphragm are degraded. In particular, when the nozzle opening and the width of the nozzle communication passage communicating with the nozzle opening are narrower than the width of the pressure generation chamber, the inflowing adhesive is applied to the bottom surface of the pressure generation chamber (the surface of the bonded substrate such as the nozzle plate). The adhering adhesive is dropped by the ink passing through the pressure generating chamber and becomes a foreign substance, and the nozzle opening is clogged.

  In addition, the diaphragm is likely to concentrate stress on the boundary between the fixed region on the flow path forming substrate and the deforming region such as the pressure generating chamber, and when the corner of the wall of the pressure generating chamber coincides with this boundary, Cracks are likely to occur in the diaphragm starting from the corners. If cracks occur in the diaphragm, the vibration characteristics vary and ink leakage occurs.

  In view of such circumstances, it is an object of the present invention to provide a liquid ejecting head and a liquid ejecting apparatus that can suppress the ejection failure of a droplet and a decrease in vibration characteristics, and can suppress the destruction of a vibration plate. .

An aspect of the present invention that solves the above problem is provided with a flow path forming substrate provided with a pressure generating chamber communicating with a nozzle opening for ejecting liquid, and provided on one surface side of the flow path forming substrate via a diaphragm. And the pressure generating chamber is provided on one end side communicating with the nozzle opening in a second direction orthogonal to the first direction, which is a parallel arrangement direction of the nozzle openings. The nozzle in the second direction of the pressure generating chamber, and a wide portion provided on the other end side and having a width in the first direction wider than the narrow portion. The boundary between the pressure generating chamber of the diaphragm and the flow path forming substrate defined by the end face on the side communicating with the opening is an angle formed by the inner wall surface of the narrow portion and the inner wall surface of the wide portion. The liquid ejecting head is disposed at a position avoiding the portion.
In such an aspect, by providing the narrow portion, the adhesive flows into the pressure generating chamber when a member such as a nozzle plate or a communication plate provided with a nozzle opening is bonded to the flow path forming substrate via the adhesive. It is difficult to prevent clogging of the nozzle opening and the deformation of the diaphragm due to excessive adhesive. In addition, since the boundary between the pressure generating chamber of the diaphragm and the flow path forming substrate is disposed at a position avoiding the corner, cracks and the like start from the corner at the boundary where the stress of the diaphragm is concentrated. Can be prevented from occurring.

  Here, between the flow path forming substrate and the nozzle plate, there is provided a communication plate provided with a nozzle communication path for communicating the narrow portion of the pressure generating chamber and the nozzle opening, In the first direction, the width of the nozzle communication path is preferably wider than the width of the narrow portion. According to this, it is difficult for the adhesive to flow into the pressure generating chamber via the nozzle communication passage of the communication plate, and the adhesive is hardly peeled off.

  Further, the end surface of the pressure generation chamber on the side communicating with the nozzle opening in the second direction is inclined so as to expand the pressure generation chamber from the diaphragm side toward the nozzle plate side. It is preferable that it is a surface. According to this, the flow of the liquid can be smoothed by the inclined surface, and the flow velocity of the droplet can be increased.

  The inclined surface includes a first inclined surface provided on the diaphragm side, a second inclined surface provided on the nozzle plate side, and the first inclined surface and the second inclined surface. It is preferable to provide a step surface that is provided and has a surface direction that intersects the surface direction of the first inclined surface and the surface direction of the second inclined surface. According to this, even if the adhesive flows into the pressure generating chamber by providing the step surface, it is possible to further suppress the adhesive from adhering to the diaphragm by keeping the adhesive on the step surface. .

  The flow path forming substrate communicates with an end of the pressure generation chamber opposite to the narrow portion in the second direction, and the width in the first direction is the width of the pressure generation chamber. A supply path that is narrower than the supply path, and a communication path that is provided on the opposite side of the supply path from the pressure generation chamber and that is wider in the first direction than the supply path. The boundary between the diaphragm and the flow path forming substrate, which is defined by the end surface on the side opposite to the supply path, avoids the corner formed by the inner wall surface of the supply path and the inner wall surface of the communication path. It is preferable to arrange in the position. According to this, by arranging the boundary between the communication path of the diaphragm and the flow path forming substrate at a position avoiding the corner, the diaphragm starts from the corner at the boundary where the stress of the diaphragm is concentrated. Generation | occurrence | production of cracks etc. can be suppressed.

According to another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to the above aspect.
In this aspect, it is possible to realize a liquid ejecting apparatus that suppresses the failure of the diaphragm and suppresses the diaphragm from being broken by suppressing the liquid discharge failure and the discharge characteristics from being deteriorated.

FIG. 2 is an exploded perspective view of a recording head according to Embodiment 1 of the invention. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment of the invention. FIG. 2 is an enlarged cross-sectional view of a main part of the recording head according to Embodiment 1 of the invention. FIG. 2 is an enlarged cross-sectional view of a main part of the recording head according to Embodiment 1 of the invention. It is a top view of the channel concerning Embodiment 1 of the present invention. It is a schematic perspective view of the flow path which concerns on Embodiment 1 of this invention. It is sectional drawing to which the principal part of the head concerning other embodiment of this invention was expanded. It is a schematic perspective view of the flow path which concerns on other embodiment of this invention. 1 is a schematic perspective view of a recording apparatus according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view of an ink jet recording head that is an example of a liquid jet head according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view of the ink jet recording head, and FIG. FIG. 4 is an enlarged cross-sectional view of a main part, and FIG. 4 is a cross-sectional view taken along line AA ′ of FIG.

  As shown in the drawing, an ink jet recording head I which is an example of a liquid jet head according to the present embodiment includes a plurality of members such as a head main body 11 and a case member 40, and the plurality of members are joined by an adhesive or the like. Yes. In the present embodiment, the head body 11 includes a flow path forming substrate 10, a communication plate 15, a nozzle plate 20, a protective substrate 30, and a compliance substrate 45.

  In the present embodiment, the flow path forming substrate 10 constituting the head body 11 is made of a silicon single crystal substrate having a crystal plane orientation of (110). The flow path forming substrate 10 is provided with a plurality of nozzle openings 21 in which pressure generation chambers 12 partitioned by a plurality of partition walls discharge ink of the same color by performing anisotropic etching from one side. It is arranged along the direction. Hereinafter, this direction is referred to as a direction in which the pressure generating chambers 12 are arranged side by side or a first direction X. Further, the flow path forming substrate 10 is provided with a plurality of rows in which the pressure generation chambers 12 are arranged in parallel in the first direction X, and in this embodiment, two rows. An arrangement direction in which a plurality of rows of the pressure generation chambers 12 in which the pressure generation chambers 12 are formed along the first direction X is provided is hereinafter referred to as a second direction Y.

  Further, the flow path forming substrate 10 has a supply path 13 communicating with one end side in the second direction of the pressure generating chamber 12 (the side opposite to the side communicating with the nozzle opening 21), and pressure is generated in the supply path 13. And a communication passage 14 communicating on the opposite side to the chamber 12 is provided.

  The supply path 13 is provided narrower than the pressure generation chamber 12 by narrowing the pressure generation chamber 12 from both sides in the first direction X, and flows into the pressure generation chamber 12 from the communication path 14. The ink flow path resistance is kept constant.

  In addition, the communication path 14 is provided wider than the supply path 13 in the first direction X.

  That is, in the flow path forming substrate 10 of the present embodiment, the pressure generation chamber 12, the supply path 13, and the communication path 14 are partitioned by the partition walls in the first direction X as individual flow paths communicating with the nozzle openings 21. It is installed side by side. Details of the pressure generating chamber 12 will be described later.

  Further, a vibration plate 50 is provided on one side of the flow path forming substrate 10, and the flow paths such as the pressure generation chamber 12 are sealed by the vibration plate 50.

  The communication plate 15 is joined to the other surface side of the flow path forming substrate 10 (the side opposite to the vibration plate 50). A nozzle plate 20 having a plurality of nozzle openings 21 communicating with the pressure generating chambers 12 is bonded to the communication plate 15 via an adhesive 200.

  The communication plate 15 is provided with a nozzle communication path 16 that connects the pressure generation chamber 12 and the nozzle opening 21. The communication plate 15 has a larger area than the flow path forming substrate 10, and the nozzle plate 20 has a smaller area than the flow path forming substrate 10. Thus, cost reduction can be achieved by making the area of the nozzle plate 20 relatively small. In the present embodiment, a surface on which the nozzle openings 21 of the nozzle plate 20 are opened and ink droplets are ejected is referred to as a liquid ejecting surface.

  The communication plate 15 is provided with a first manifold portion 17 and a second manifold portion 18 that constitute a part of the manifold 100.

  The first manifold portion 17 is provided through the communication plate 15 in the thickness direction (the stacking direction of the communication plate 15 and the flow path forming substrate 10).

  Further, the second manifold portion 18 is provided to open to the nozzle plate 20 side of the communication plate 15 without penetrating the communication plate 15 in the thickness direction.

  Further, the communication plate 15 is provided with a supply communication passage 19 that communicates with one end portion of the pressure generation chamber 12 in the second direction Y independently for each pressure generation chamber 12. The supply communication path 19 communicates the second manifold portion 18 and the communication path 14.

  Such a communication plate 15 is preferably made of a material having a linear expansion coefficient equivalent to that of the flow path forming substrate 10. That is, when a material having a linear expansion coefficient that is significantly different from that of the flow path forming substrate 10 is used as the communication plate 15, warping due to a difference in linear expansion coefficient between the flow path forming substrate 10 and the communication plate 15 due to heating or cooling. Will occur. In the present embodiment, by using the same material as the flow path forming substrate 10 as the communication plate 15, that is, a silicon single crystal substrate, warpage due to heat can be suppressed.

  The nozzle plate 20 is formed with nozzle openings 21 communicating with the pressure generation chambers 12 via the nozzle communication passages 16. That is, in the nozzle openings 21, a plurality of rows arranged in the first direction X are formed in the second direction Y, and in this embodiment, two rows are formed.

  As such a nozzle plate 20, for example, a metal such as stainless steel (SUS) or a silicon single crystal substrate can be used. In addition, by using a silicon single crystal substrate as the nozzle plate 20, the linear expansion coefficients of the nozzle plate 20 and the communication plate 15 can be made equal, and the occurrence of warpage due to heating or cooling can be suppressed.

  Here, the pressure generation chamber 12 provided in the flow path forming substrate 10 will be described in detail with reference to FIGS. 5 and 6. 5 is a plan view from the nozzle opening side of the pressure generation chamber and the like, and FIG. 6 is a perspective view from the nozzle opening side of the pressure generation chamber and the like.

  As shown in FIGS. 5 and 6, the pressure generating chamber 12 is arranged in the first direction X at the end in the second direction Y on the side communicating with the nozzle opening 21, that is, on the end opposite to the supply path 13. The narrow portion 121 is narrow. In other words, the pressure generation chamber 12 includes a narrow portion 121 provided on the nozzle opening 21 side in the second direction Y and a first direction X on the supply path 13 side in the second direction Y than the narrow portion 121. Includes a wide portion 122 provided with a wide width, and a first connection portion 123 provided between the narrow portion 121 and the wide portion 122.

  As shown in FIG. 4A, the narrow portion 121 is formed so that the width in the first direction X is narrower than that of the nozzle communication path 16.

  The wide portion 122 is formed so that the width in the first direction X is wider than the nozzle communication path 16.

  In the present embodiment, the first connection portion 123 is formed by an inclined surface whose side surface is inclined from the wide portion 122 toward the narrow portion 121.

  As described above, by providing the narrow portion 121 in which the width (first direction X) of the region communicating with the nozzle communication path 16 of the pressure generation chamber 12 is narrowed, the nozzle plate 20 is bonded to the communication plate 15. Even if the adhesive 200 crawls up to the pressure generating chamber 12 via the corners of the nozzle communication passage 16, it is possible to prevent the scooped adhesive 200 from entering the pressure generating chamber 12. .

  On the other hand, as shown in FIG. 4B, if the width of the region communicating with the nozzle communication path 16 of the pressure generation chamber 12 is formed to be the same width as the wide portion 122, the width of the pressure generation chamber 12 is reduced to the nozzle connection. Since the width is wider than the passage 16, the adhesive 200 that adheres the nozzle plate 20 and the communication plate 15 crawls up through the corners of the nozzle communication passage 16, and the scooped adhesive 200 becomes the pressure generating chamber 12. Invades inside. As described above, when the adhesive 200 enters the pressure generation chamber 12, the solidified adhesive 200 is peeled off by the ink flowing in the pressure generation chamber 12 and becomes dust, which causes clogging of the nozzle openings 21 and ink droplets. There arises a problem that the recording medium to be landed is soiled. In the present embodiment, as shown in FIG. 4A, a narrow portion 121 is provided in the pressure generation chamber 12, and the width of the narrow portion 121 (first direction X) is narrower than the width of the nozzle communication path 16. As a result, the adhesive 200 is prevented from entering the pressure generating chamber 12, and the adhesive 200 that has entered the nozzle communication path 16 is held in a region where the ink flow is weak (a region where the ink flows). Therefore, it is difficult for the adhesive 200 to be peeled off by the flow of ink, and the occurrence of clogging of the nozzle openings 21 and contamination of the recording medium can be suppressed.

  Further, the end surface of the pressure generating chamber 12 on the side communicating with the nozzle opening 21 in the second direction Y, that is, the short side on the one end side in the longitudinal direction of the pressure generating chamber 12 is an inclined surface 124.

  Specifically, in the present embodiment, the end surface of the pressure generating chamber 12 on the side communicating with the nozzle opening 21 includes a first inclined surface 124a provided on the diaphragm 50 side and a first inclined surface 124a provided on the nozzle plate 20 side. 2 inclined surfaces 124b, and a step surface 124c provided between the first inclined surface 124a and the second inclined surface 124b.

  The first inclined surface 124a is formed to be inclined so as to expand the pressure generating chamber 12 from the diaphragm 50 side toward the nozzle plate 20 side. That is, the first inclined surface 124a is formed to be inclined with respect to a direction perpendicular to the surface on which the diaphragm 50 is formed.

  Similarly to the first inclined surface 124a, the second inclined surface 124b is formed to be inclined so as to expand the pressure generating chamber 12 from the diaphragm 50 side toward the nozzle plate 20 side.

  A step surface 124c between the first inclined surface 124a and the second inclined surface 124b is formed in a direction intersecting with the surface directions of the first inclined surface 124a and the second inclined surface 124b. In the present embodiment, the step surface 124c is formed in the same plane direction as the surface on which the diaphragm 50 is formed.

  In this way, by forming the inclined surface 124 and providing the stepped surface 124 c on the inclined surface 124, the adhesive 200 when the nozzle plate 20 is bonded to the communication plate 15, the communication plate 15 and the flow path forming substrate 10. Even when the adhesive or the like at the time of bonding flows into the pressure generating chamber 12, the adhesive 200 or the like that has flowed through the second inclined surface 124b can be retained at the stepped surface 124c. 200 or the like can be prevented from reaching the diaphragm 50. For this reason, the adhesive 200 or the like that has flowed into the pressure generating chamber 12 does not adhere to the vibration plate 50, and the displacement characteristics of the vibration plate 50 are prevented from being lowered by the adhesive 200 or the like. It can suppress that it falls.

  In addition, in the pressure generation chamber 12, a space shallower than the pressure generation chamber 12 is defined by the second inclined surface 124 b and the step surface 124 c in the vicinity of the nozzle communication path 16, so that the ink in the pressure generation chamber 12 is removed. When ejecting from the nozzle opening 21, the impact of ink flow can be buffered by this space. Thereby, stable ink ejection characteristics can be obtained.

  In addition, an inclined surface 125 is formed at the end of the communication path 14 opposite to the pressure generation chamber 12 in the second direction Y, that is, at the short side of the communication path 14 in the longitudinal direction of the pressure generation chamber 12. Yes.

  The inclined surface 125 is provided so as to be inclined in the direction of expanding the communication path 14 from the diaphragm 50 side toward the communication plate 15 side. That is, the inclined surface 125 is provided to be inclined with respect to a direction orthogonal to the surface of the flow path forming substrate 10 on which the diaphragm 50 is formed.

  Here, in the present embodiment, the flow path such as the pressure generation chamber 12 is formed by anisotropically etching the flow path forming substrate 10 from one surface side. Anisotropic etching is performed using the difference in etching rate of the silicon single crystal substrate. In the present embodiment, since the flow path forming substrate 10 is composed of a silicon single crystal substrate having a plane orientation (110), the etching rate of the (111) plane is approximately compared to the etching rate of the (110) plane of the silicon single crystal substrate. This is performed using the property of 1/180. That is, when a silicon single crystal substrate is immersed in an alkaline solution such as KOH, the first (111) plane perpendicular to the (110) plane is gradually eroded and the first (111) plane is 70.53 degrees. And a second (111) plane perpendicular to the (110) plane appears. By this anisotropic etching, precision processing is performed based on a parallelogram formed by two first parallel surfaces (111) and two second parallel surfaces (111). The pressure generating chambers 12 can be arranged with high density. That is, the partition wall defining the pressure generation chamber 12 and the like of the present embodiment is formed so that the surface thereof becomes the first (111) plane.

  Further, when the silicon single crystal substrate is anisotropically etched, an inclined surface having a (111) plane of crystal plane orientation forming an angle of 35.26 degrees with respect to the (110) plane of the surface is formed.

  The inclined surfaces 124 and 125 of this embodiment are formed by the inclined surface of the (111) plane. That is, the inclined surfaces 124 and 125 of this embodiment can be formed together with the pressure generation chamber 12 and the like by anisotropically etching the flow path forming substrate 10.

  Specifically, the first inclined surface 124 a and the second inclined surface 124 b of the inclined surface 124 and the inclined surface 125 are at an angle of 35.26 degrees with respect to the (110) surface which is the surface of the flow path forming substrate 10. (111) plane having Further, the step surface 124c is formed by a plane parallel to the (110) plane of the surface of the flow path forming substrate 10, that is, the (110) plane.

  A boundary 124d between the pressure generating chamber 12 of the diaphragm 50 and the flow path forming substrate 10 (peripheral wall) defined by the inclined surface 124 (first inclined surface 124a) is a narrow portion as shown in FIG. The corner portion 123 a serving as a boundary between the first connecting portion 123 and the corner portion 123 b serving as the boundary between the wide portion 122 and the first connecting portion 123 is disposed at a position away from the corner portion 123 a.

  That is, the side surfaces (the surfaces on both sides in the first direction X) of the narrow portion 121 are formed by parallel first (111) surfaces, and the side surface of the first connection portion 123 is wide from the wide portion 122. It is an inclined surface whose width gradually decreases toward the narrow portion 121. For this reason, since the side surface of the narrow part 121 and the side surface of the first connection part 123 are formed at different angles, an angle is formed at the boundary between the side surface of the narrow part 121 and the side surface of the first connection part 123. A portion 123a is formed. Similarly, a corner portion 123 b is formed at the boundary between the side surface of the first connection portion 123 and the side surface of the wide portion 122.

  And the boundary 124d which is the edge part by the side of the diaphragm 50 of the inclined surface 124 is arrange | positioned in the position which avoided these corner | angular parts 123a and 123b. That is, the boundary 124d that is the end portion of the inclined surface 124 (first inclined surface 124a) on the diaphragm 50 side has one end in the first direction X disposed in the narrow portion 121 and the other end in the wide portion 122. Is arranged. That is, the boundary 124 d that is the end portion of the first inclined surface 124 a on the diaphragm 50 side is formed from the narrow portion 121 through the first connecting portion 123 to the wide portion 122.

  Similarly, the inclined surface 125 on the communication passage 14 side has a boundary 125a between the communication passage 14 (including the supply passage 13 and the like) of the diaphragm 50 defined by the inclined surface 125 and the flow path forming substrate 10 (peripheral wall). The generating chamber 12, the supply path 13, and the communication path 14 are disposed so as to avoid the corners formed on the side surfaces.

  Specifically, the pressure generation chamber 12 and the supply path 13 are connected via the second connection portion 131. The second connection portion 131 is formed by a surface whose side surface is inclined so that the width of the pressure generation chamber 12 in the first direction X is gradually reduced toward the supply path 13. Therefore, a corner portion 131 a is formed at the boundary between the side surface of the pressure generation chamber 12 and the side surface of the second connection portion 131, and the corner between the side surface of the second connection portion 131 and the side surface of the supply path 13 is an angle. A portion 131b is formed.

  The supply path 13 and the communication path 14 are connected via a third connection portion 141. The third connection portion 141 is formed with an inclined side surface so that the width of the supply passage 13 in the first direction X gradually increases toward the communication passage 14. Therefore, a corner 141 a is formed at the boundary between the side surface of the supply path 13 and the side surface of the third connection portion 141, and a corner portion 141 b is formed at the boundary between the side surface of the third connection portion 141 and the side surface of the communication path 14. Is formed.

  In the inclined surface 125, a boundary 125 a between the communication path 14 of the diaphragm 50 and the flow path forming substrate 10 defined by the inclined surface 125 is formed by a side surface of the pressure generating chamber 12 and the second connection portion 131. Corner 131a, corner 131b formed by the side surface of the second connection portion 131 and the supply path 13, corner portion 141a formed by the side surface of the supply path 13 and the third connection portion 141, and the third connection portion. 141 and the communication path 14 are disposed at positions avoiding the corners 141b defined by the side surfaces.

  In the present embodiment, the boundary 125 a that is the end portion of the inclined surface 125 on the diaphragm 50 side has one end in the first direction X disposed in the third connection portion 141 and the other end disposed in the communication path 14. ing. That is, the boundary 125 a formed by the inclined surface 125 is formed across the communication path 14 from the third connection portion 141.

  As described above, the boundaries 124d and 125a between the flow path space (the pressure generation chamber 12 and the communication path 14) of the diaphragm 50 defined by the inclined surfaces 124 and 125 and the flow path forming substrate 10 are formed at the corners 123a, 123b, and 131a. , 131b, 141a, 141b (hereinafter, also simply referred to as corners) can be prevented from cracking the diaphragm 50 starting from the corners.

  That is, when the diaphragm 50 is deformed by driving the piezoelectric actuator 300, a region deformed in the space such as the pressure generating chamber 12 of the diaphragm 50 and a region fixed on the flow path forming substrate 10 of the diaphragm 50 are obtained. A large stress is applied to the boundaries, that is, the boundaries 124 d and 125 a defined by the inclined surfaces 124 and 125. For this reason, if the boundaries 124d and 125a are arranged at the same positions as the corners, the deformation stress of the diaphragm 50 is concentrated on the corners, and the diaphragm 50 is damaged such as cracks starting from the corners. There is a risk of it.

  In the present embodiment, by arranging the boundaries 124d and 125a defined by the inclined surfaces 124 and 125 at positions avoiding the corners, it is possible to suppress stress concentration at the corners, and to start from the corners. Generation of cracks in the diaphragm 50 can be suppressed.

  The inclined surfaces 124 and 125 can be formed by anisotropically etching the flow path forming substrate 10 as described above, but the positions of the inclined surfaces 124 and 125, that is, the positions of the boundaries 124d and 125a. Can be arranged at a desired position, for example, by adjusting the opening shape of the mask when performing anisotropic etching.

  Incidentally, the inclined surfaces 124 and 125 do not need to be formed by controlling the angle by the time (etching time) for etching the flow path forming substrate 10 and can always be formed at the same angle. can do. That is, if the angles of the inclined surfaces 124 and 125 are adjusted by adjusting the etching time, the etching rate changes due to variations in etching characteristics (temperature and composition of the etching solution), and thus the inclined surfaces 124 having the same shape are always obtained. , 125 is difficult to form, but by forming the inclined surfaces 124, 125 on the (111) plane that appears when the silicon single crystal substrate is etched, the inclined surfaces having the same shape are always formed regardless of the etching time. 124, 125 can be formed.

  By providing the inclined surfaces 124 and 125 in this way, the flow of ink can be made smooth and the flow velocity of ink droplets can be increased.

  On the other hand, as shown in FIG. 2, a diaphragm 50 is formed on the surface of the flow path forming substrate 10 opposite to the communication plate 15. The diaphragm 50 according to the present embodiment includes an elastic film 51 formed on the flow path forming substrate 10 and an insulator film 52 formed on the elastic film 51. The pressure generation chamber 12 is formed by anisotropic etching of the flow path forming substrate 10 from one surface, and the other surface of the pressure generation chamber 12 is configured by a diaphragm (elastic film 51).

  On the diaphragm 50, a piezoelectric actuator 300 including a first electrode 60, a piezoelectric layer 70, and a second electrode 80 is provided as pressure generating means of the present embodiment. Here, the piezoelectric actuator 300 refers to a portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. In general, one electrode of the piezoelectric actuator 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 addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In the present embodiment, the first electrode 60 is used as a common electrode for the piezoelectric actuator 300 and the second electrode 80 is used as an individual electrode for the piezoelectric actuator 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In the above-described example, the diaphragm 50 includes the elastic film 51 and the insulator film 52. However, the present invention is not limited to this. For example, the vibration film 50 includes the elastic film 51 and the insulating film. Any one of the body films 52 may be provided, and the elastic film 51 and the insulator film 52 are not provided as the vibration plate 50, and only the first electrode 60 acts as the vibration plate. Also good. Further, the piezoelectric actuator 300 itself may substantially serve as a diaphragm. However, when the first electrode 60 is provided directly on the flow path forming substrate 10, it is necessary to protect the first electrode 60 with an insulating film so that the first electrode 60 and the ink do not conduct.

The piezoelectric layer 70 is made of a piezoelectric material of the oxide having a polarization structure formed on the first electrode 60, for example, may consist of a perovskite oxide represented by the general formula ABO _3, A is Pb B can contain at least one of zirconium and titanium. The B may further contain niobium, for example. Specifically, as the piezoelectric layer 70, for example, lead zirconate titanate (Pb (Zr, Ti) O ₃ : PZT), lead zirconate titanate niobate containing silicon (Pb (Zr, Ti, Nb) ) O ₃ : PZTNS) or the like can be used.

  Further, the piezoelectric layer 70 is a lead-free piezoelectric material that does not contain lead, for example, a composite oxide having a perovskite structure containing bismuth ferrate or bismuth ferrate manganate, barium titanate or potassium bismuth titanate, or the like. It is good.

  One end of each lead electrode 90 is connected to the second electrode 80. The other end of the lead electrode 90 is connected to a wiring board 211 provided with a drive circuit 210, such as COF.

  A protective substrate 30 having substantially the same size as the flow path forming substrate 10 is fixed to the surface of the flow path forming substrate 10 on the piezoelectric actuator 300 side. The protective substrate 30 has a holding portion 31 that is a space for protecting the piezoelectric actuator 300. The protective substrate 30 is provided with a through hole 32. The other end side of the lead electrode 90 is extended so as to be exposed in the through hole 32, and the lead electrode 90 and the wiring substrate 211 are electrically connected in the through hole 32.

  In addition, a case member 40 is fixed to the head main body 11 having such a configuration. The case member 40 defines a manifold 100 communicating with the plurality of pressure generating chambers 12 together with the head main body 11. The case member 40 has substantially the same shape as the communication plate 15 described above in a plan view, and is fixed to the protective substrate 30 with an adhesive, and is also fixed to the communication plate 15 with an adhesive. Specifically, the case member 40 has a recess 41 having a depth in which the flow path forming substrate 10 and the protective substrate 30 are accommodated on the protective substrate 30 side. The concave portion 41 has an opening area larger than the surface of the protective substrate 30 bonded to the flow path forming substrate 10. The opening surface on the nozzle plate 20 side of the recess 41 is sealed by the communication plate 15 in a state where the flow path forming substrate 10 and the like are accommodated in the recess 41. As a result, a third manifold portion 42 is defined by the case member 40 and the head body 11 on the outer peripheral portion of the flow path forming substrate 10. The first manifold portion 17 and the second manifold portion 18 provided on the communication plate 15 and the third manifold portion 42 defined by the case member 40 and the flow path forming substrate 10 are used in the manifold 100 of the present embodiment. Is configured.

  In addition, as a material of case member 40, resin, a metal, etc. can be used, for example. Moreover, the material of the protective substrate 30 is preferably a material having the same linear expansion coefficient as that of the flow path forming substrate 10 to which the protective substrate 30 is fixed. In this embodiment, a silicon single crystal substrate is used.

  A compliance substrate 45 is provided on the surface of the communication plate 15 where the first manifold portion 17 and the second manifold portion 18 open. The compliance substrate 45 seals the openings of the first manifold portion 17 and the second manifold portion 18.

  In this embodiment, the compliance substrate 45 includes a sealing film 46 and a fixed substrate 47. The sealing film 46 is made of a flexible thin film (for example, a thin film having a thickness of 20 μm or less formed of polyphenylene sulfide (PPS) or stainless steel (SUS)), and the fixed substrate 47 is made of stainless steel ( It is formed of a hard material such as a metal such as SUS. Since the region of the fixed substrate 47 facing the manifold 100 is an opening 48 that is completely removed in the thickness direction, one surface of the manifold 100 is sealed only with a flexible sealing film 46. It is a compliance part that is a flexible part.

  The case member 40 is provided with an introduction path 44 that communicates with the manifold 100 and supplies ink to each manifold 100. The case member 40 is provided with a connection port 43 that communicates with the through hole 32 of the protective substrate 30 and through which the wiring substrate 211 is inserted.

  In the ink jet recording head I having such a configuration, when ink is ejected, the ink is taken in from the ink storing means such as a cartridge through the introduction path 44, and the inside of the flow path is extended from the manifold 100 to the nozzle opening 21. Fill with. Thereafter, a voltage is applied to each piezoelectric actuator 300 corresponding to the pressure generation chamber 12 in accordance with a signal from the drive circuit 210, so that the elastic film 51 and the insulator film 52 are deformed together with the piezoelectric actuator 300. As a result, the pressure in the pressure generating chamber 12 is increased and ink droplets are ejected from the predetermined nozzle openings 21.

(Other embodiments)
Although the basic configuration of the present invention has been described above, the basic configuration of the present invention is not limited to the above-described configuration.

  For example, in the first embodiment described above, the inclined surface 124 includes the first inclined surface 124a, the second inclined surface 124b, and the step surface 124c. However, the present invention is not particularly limited thereto. The first inclined surface 124a and the second inclined surface 124b may be continuous without providing the 124c. Such an example is shown in FIGS. 7 is an enlarged cross-sectional view of a main part of a recording head according to another embodiment of the present invention, and FIG. 8 is a plan view from the nozzle opening side of a pressure generating chamber or the like.

  As shown in the drawing, the end surface in the second direction Y of the pressure generating chamber 12 is an inclined surface 124A. The inclined surface 124A is formed as a single flat surface, and the step surface 124c of the first embodiment described above is not formed in the middle. Even in such a configuration, as in the first embodiment described above, the boundary 124d between the flow path forming substrate 10 and the pressure generating chamber 12 of the diaphragm 50 defined by the inclined surface 124A is avoided from the corners 123a and 123b. What is necessary is just to arrange | position so that it may become.

  In Embodiment 1 described above, the end surface of the communication passage 14 opposite to the pressure generation chamber 12 is the inclined surface 125, but at least the side of the pressure generation chamber 12 that communicates with the nozzle opening 21 in the second direction Y. The end surface of the communication path 14 may be an inclined surface 124, and the end surface of the communication path 14 opposite to the pressure generation chamber 12 may be a vertical surface perpendicular to the surface.

  Further, for example, in the first embodiment described above, the flow path forming substrate 10 and the nozzle plate 20 are joined via the communication plate 15, but the present invention is not particularly limited thereto. The nozzle plate 20 may be directly joined. Further, a substrate other than the communication plate 15 may be interposed between the nozzle plate 20 and the flow path forming substrate 10.

  Further, in the first embodiment described above, the thin film piezoelectric actuator 300 is used as the pressure generating means for ejecting ink droplets from the nozzle openings 21. However, the present invention is not particularly limited thereto. It is possible to use a thick film type piezoelectric actuator formed by a method such as affixing, a longitudinal vibration type piezoelectric actuator in which piezoelectric materials and electrode forming materials are alternately stacked and expanded and contracted in the axial direction.

  Further, the ink jet recording head of each of these embodiments constitutes a part of an ink jet recording head unit having an ink flow path communicating with a cartridge or the like, and is mounted on the ink jet recording apparatus. FIG. 9 is a schematic view showing an example of the ink jet recording apparatus.

  In the ink jet recording apparatus II shown in FIG. 9, ink jet recording head units 1A and 1B (hereinafter also referred to as head units 1A and 1B) each having a plurality of ink jet recording heads I include a cartridge 2A and an ink supply unit. 2B is detachably provided, and the carriage 3 on which the head units 1A and 1B are mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. The head units 1A and 1B, for example, discharge 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 units 1A and 1B are 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 that is a recording medium such as paper fed by a paper feed roller (not shown) is wound around the platen 8. It is designed to be transported.

  In the ink jet recording apparatus II described above, the ink jet recording head I (head units 1A, 1B) is mounted on the carriage 3 and moved in the main scanning direction. The present invention can also be applied to a so-called line recording apparatus in which the ink jet recording head I is fixed and printing is performed simply by moving the recording sheet S such as paper in the sub-scanning direction.

  In the above-described example, the ink jet recording apparatus II has a configuration in which the cartridges 2A and 2B, which are liquid storage units, are mounted on the carriage 3. However, the invention is not particularly limited thereto, and for example, a liquid storage such as an ink tank or the like. The means may be fixed to the apparatus body 4 and the storage means and the ink jet recording head I may be connected via a supply pipe such as a tube. Further, the liquid storage means may not be mounted on the ink jet recording apparatus II.

  In the above embodiment, an ink jet recording head has been described as an example of a liquid ejecting head, and an ink jet recording apparatus has been described as an example of a liquid ejecting apparatus. The present invention is intended for the entire apparatus, and can of course be applied to a liquid ejecting head and a liquid ejecting apparatus that eject 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 FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bio-organic matter ejection head used for biochip production, and the like, and can also be applied to a liquid ejection apparatus provided with such a liquid ejection head.

  I Inkjet recording head (liquid ejecting head), II Inkjet recording apparatus (liquid ejecting apparatus), 1A, 1B head unit, 2A, 2B cartridge, 3 carriage, 4 apparatus main body, 5 carriage shaft, 6 drive motor, 7 timing Belt, 8 platen, 10 flow path forming substrate, 12 pressure generating chamber, 13 supply path, 14 communication path, 15 communication plate, 16 nozzle communication path, 20 nozzle plate, 21 nozzle opening, 30 protective substrate, 40 case member, 45 Compliance board, 100 manifold, 121 narrow part, 122 wide part, 123 first connection part, 124, 125 inclined surface, 131 second connection part, 141 third connection part, 210 drive circuit, 211 wiring board, 300 piezoelectric actuator Yueta (pressure generating means)

Claims (6)

A flow path forming substrate provided with a pressure generating chamber communicating with a nozzle opening for ejecting liquid;
Pressure generating means provided on one side of the flow path forming substrate via a vibration plate,
The pressure generation chamber includes a narrow portion provided on one end side communicating with the nozzle opening and a second end side in a second direction orthogonal to the first direction, which is a parallel arrangement direction of the nozzle openings. A wide portion having a width in the first direction wider than the narrow portion,
The boundary between the pressure generating chamber of the diaphragm and the flow path forming substrate defined by the end surface of the pressure generating chamber on the side communicating with the nozzle opening in the second direction is the inner wall surface of the narrow portion. And a liquid ejecting head, wherein the liquid ejecting head is disposed at a position avoiding a corner formed by the inner wall surface of the wide portion. Between the flow path forming substrate and the nozzle plate, a communication plate provided with a nozzle communication path that connects the narrow portion of the pressure generating chamber and the nozzle opening is provided,
2. The liquid jet head according to claim 1, wherein in the first direction, the width of the nozzle communication path is wider than the width of the narrow portion.   The end surface of the pressure generating chamber on the side communicating with the nozzle opening in the second direction is an inclined surface that is inclined so as to expand the pressure generating chamber from the diaphragm side toward the nozzle plate side. The liquid ejecting head according to claim 1, wherein the liquid ejecting head is formed.   The inclined surface is provided between a first inclined surface provided on the diaphragm side, a second inclined surface provided on the nozzle plate side, and the first inclined surface and the second inclined surface. The liquid ejecting head according to claim 3, further comprising: a step surface having a surface direction intersecting with a surface direction of the first inclined surface and a surface direction of the second inclined surface. The flow path forming substrate communicates with an end of the pressure generation chamber opposite to the narrow portion in the second direction, and the width in the first direction is larger than the wide portion of the pressure generation chamber. A narrow supply path,
A communication path provided on the opposite side of the supply path from the pressure generation chamber and having a width in the first direction wider than the supply path,
The boundary between the diaphragm and the flow path forming substrate defined by the end surface of the communication path opposite to the supply path is an angle formed by the inner wall surface of the supply path and the inner wall surface of the communication path. The liquid ejecting head according to claim 1, wherein the liquid ejecting head is disposed at a position avoiding the portion.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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