JP2014034138A - Liquid jetting head and liquid jetting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jetting head and a liquid jetting device the bubble discharge property of which can be improved.SOLUTION: A common liquid chamber 32 is composed of a first liquid chamber 51 in which an ink is introduced from an inlet opening part on an upper surface side of a communication substrate 23 and a second liquid chamber 52 which is formed in the communication substrate 23 from a lower surface side toward an upper surface side to a middle in a thickness direction thereof while remaining a thin-walled part 40 in an upper side. A plurality of individual communication ports 42 are formed so as to correspond to a pressure chamber at an opposite side of the first liquid chamber in a thin-walled part, and at least at both end part in a parallel direction of the individual communication port in a thin-walled part, partition walls 53 partitioning adjacent individual communication ports are formed from the first liquid chamber side toward the individual communication port.

Description

  The present invention relates to a liquid ejecting head such as an ink jet recording head and a liquid ejecting apparatus, and in particular, a nozzle forming member in which a plurality of nozzles are arranged, a liquid chamber empty portion which is a part of a common liquid chamber, and The present invention relates to a liquid ejecting head and a liquid ejecting apparatus including a common liquid chamber forming member in which an individual communication port that communicates between a liquid chamber cavity and a pressure chamber is formed.

  The liquid ejecting apparatus includes a liquid ejecting head and ejects various liquids from the ejecting head. As this liquid ejecting apparatus, for example, there is an image recording apparatus such as an ink jet printer or an ink jet plotter, but recently, various types of manufacturing have been made by taking advantage of the ability to accurately land a very small amount of liquid on a predetermined position. It is also applied to devices. For example, a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode such as an organic EL (Electro Luminescence) display or FED (surface emitting display), a chip for manufacturing a biochip (biochemical element) Applied to manufacturing equipment. The recording head for the image recording apparatus ejects liquid ink, and the color material ejecting head for the display manufacturing apparatus ejects solutions of R (Red), G (Green), and B (Blue) color materials. The electrode material ejecting head for the electrode forming apparatus ejects a liquid electrode material, and the bioorganic matter ejecting head for the chip manufacturing apparatus ejects a bioorganic solution.

  This type of liquid ejecting head includes, for example, a nozzle plate having a plurality of nozzles, individual flow paths including pressure chambers communicating with the nozzles, and a common liquid chamber (reservoir or reservoir) in which liquid common to the pressure chambers is stored. (Also called a manifold), a flow path forming substrate in which a void is formed, a plurality of piezoelectric elements (a kind of pressure generating means) provided corresponding to each pressure chamber, and common to each pressure chamber Some have a common liquid chamber forming substrate in which a common liquid chamber empty portion serving as a common liquid chamber in which various liquids are stored is formed (see, for example, Patent Document 1). In this configuration, since it is possible to form flow paths and the like with high accuracy by etching, a silicon single crystal substrate (a kind of crystalline substrate) is used as the material for the nozzle plate and flow path forming substrate. Has been.

In recent years, various configurations have been proposed in order to reduce the size of the entire head.
11A and 11B are diagrams illustrating an example of a configuration of a conventional liquid jet head, in which FIG. 11A is a cross-sectional view of a main part, FIG. 11B is a bottom perspective view (a state where a nozzle plate is not joined), and FIG. These are the enlarged views of the area | region X in (b). Note that the direction perpendicular to FIG. 11A is the nozzle row direction. In this example, reference numeral 55 is a flow path forming substrate in which a pressure chamber 56 is formed, reference numeral 57 is a nozzle plate in which a nozzle 58 is opened, and reference numeral 59 is a nozzle communication path that connects the pressure chamber 56 and the nozzle 58. 60 is a communication substrate, and these members are stacked to form a head main body. In this configuration, the common liquid chamber 61 is formed in the communication substrate 59 made of a silicon single crystal plate.

  In the above configuration, the common liquid chamber 61 includes a through portion 63 (first liquid chamber) that penetrates the thickness direction of the communication substrate 59 and a non-penetrating portion 64 (first through) that is formed adjacent to the non-penetrating portion 63. 2 liquid chambers). The non-penetrating portion 64 is formed by anisotropic etching from the lower surface (bonding surface with the nozzle plate 57) side of the communication substrate 59 to the middle of the communication substrate 59 in the thickness direction with the thin portion 65 remaining on the upper surface side. It is a hollow. And the thin part 65 functions as a joining margin with other members, such as a case member, for example. In addition, an individual communication port 66 for individually communicating the common liquid chamber 61 and each pressure chamber 56 is provided in the thin portion 65.

JP 2005-219243 A

  In the liquid ejecting head having such a configuration, liquid from a liquid supply source such as a liquid cartridge is introduced from the upper opening of the penetrating portion 63 and passes through the non-penetrating portion 64 below the thin portion 65 to enter the individual communication port 66. Via the pressure chamber 56. In general, since an introduction port for introducing ink is disposed above the central portion in the longitudinal direction of the through portion 63 (that is, the nozzle juxtaposition direction), the ink from the non-through portion 64 toward the individual communication port 66 is disposed. As for the flow velocity of the common liquid chamber 61, it becomes faster near the center in the longitudinal direction of the common liquid chamber 61, and becomes slower toward both ends in the same direction. For this reason, as shown in FIGS. 11B and 11C, the bubbles B tend to accumulate at both ends in the longitudinal direction of the common liquid chamber 61. Since the buoyancy acts on the bubble B, it is difficult to sink from the penetrating part 63 side to the non-penetrating part 64 side positioned below the penetrating part 63 in the weight direction, and the step between the penetrating part 63 and the non-penetrating part 64 Bubbles B stay in the air. The bubble B staying in this portion has a problem that it is difficult to discharge even if a so-called cleaning process is performed for the purpose of forcibly sucking and discharging ink and bubbles from the nozzle 58.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting head and a liquid ejecting apparatus having improved bubble discharge performance.

The present invention has been proposed in order to achieve the above object, and a nozzle forming member in which a plurality of nozzles are opened along the first direction;
A pressure chamber forming member in which a plurality of pressure chambers are formed along the first direction corresponding to the nozzle;
A common liquid chamber is formed as a series of cavities along the juxtaposition direction of the pressure chambers, a common liquid chamber is provided in which a common liquid is introduced into the pressure chambers, and the introduced liquid is supplied to the pressure chambers through individual communication ports. A liquid chamber forming member;
A liquid jet head comprising:
The common liquid chamber includes a first liquid chamber into which liquid is introduced from an inlet opening opened in a second surface opposite to the first surface on the nozzle side of the common liquid chamber forming member; A second liquid chamber formed in a state in which a thin portion is left on the second surface side from the first surface side toward the second surface side to the middle of the thickness direction of the common liquid chamber forming member; Comprising
The individual communication ports are formed on the side opposite to the first liquid chamber side in the thin portion so as to correspond to the pressure chambers, and a partition wall for partitioning adjacent individual communication ports is formed in the thin portion. It is characterized by being formed from the one liquid chamber side toward the individual communication port.

  According to the present invention, the common liquid chamber includes the first liquid chamber into which the liquid is introduced from the inlet opening that is open to the second surface opposite to the first surface on the nozzle side of the common liquid chamber forming member. A second liquid chamber formed in a state in which a thin portion is left on the second surface side in the thickness direction of the common liquid chamber forming member from the first surface side toward the second surface side; An individual communication port corresponding to the pressure chamber is formed on the side opposite to the first liquid chamber side in the thin portion, and a partition wall that partitions adjacent individual communication ports in the thin portion is formed. Since it is formed from the first liquid chamber side toward the individual communication port, the flow path from the first liquid chamber side to the individual communication port is partially formed by the partition wall in the common liquid chamber, and no partition wall is provided. Compared with the configuration, the flow velocity of the liquid flowing toward the individual communication port is increased. Thereby, it is possible to easily discharge the bubbles staying in the first liquid chamber on the flow of the relatively fast flow rate.

  Further, in the above configuration, at least an end portion on the first liquid chamber side of the partition wall is inclined with respect to an end portion on the individual communication port side toward both ends in the first direction of the first liquid chamber. It is desirable to adopt the configuration described above.

  According to this configuration, at least the end portion on the first liquid chamber side of the partition wall is inclined with respect to the end portion on the individual communication port side toward both end portions in the first direction of the first liquid chamber. The air bubbles staying at both ends in the first direction of the common liquid chamber are easily guided to the individual communication port side by the partition wall. Thereby, the discharge property of the bubble which stays in the both ends of the 1st direction of a common liquid chamber by a partition wall can be improved more.

  According to another aspect of the invention, a liquid ejecting apparatus includes the liquid ejecting head having any one of the above configurations.

FIG. 3 is a perspective view illustrating a configuration of a printer. FIG. 3 is an exploded perspective view of the recording head as viewed obliquely from above. It is sectional drawing of a head unit. FIG. 4 is an enlarged sectional view of a region A in FIG. 3. It is a lower surface side perspective view of a communication board. It is a lower surface side top view of a communication board. It is a lower surface side perspective view of the communicating substrate in a 2nd embodiment. It is a lower surface side perspective view of the communication board in a 3rd embodiment. It is a lower surface side perspective view of the communication board in a 4th embodiment. It is a lower surface side perspective view of the communication board in a 5th embodiment. It is a figure which shows an example of a structure of the conventional liquid ejecting head.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following description, an ink jet printer (hereinafter referred to as a printer) equipped with an ink jet recording head (hereinafter referred to as a recording head) is taken as an example of the liquid ejecting apparatus of the present invention.

  The configuration of the printer 1 will be described with reference to FIG. The printer 1 is a device that records an image or the like by ejecting liquid ink onto the surface of a recording medium 2 (a kind of landing target) such as recording paper. The printer 1 includes a recording head 3 that ejects ink, a carriage 4 to which the recording head 3 is attached, a carriage moving mechanism 5 that moves the carriage 4 in the main scanning direction, and a platen roller 6 that transfers the recording medium 2 in the sub-scanning direction. Etc. Here, the ink is a kind of liquid of the present invention, and is stored in an ink cartridge 7 as a liquid supply source. The ink cartridge 7 is detachably attached to the recording head 3. A configuration in which the ink cartridge 7 is disposed on the main body side of the printer 1 and is supplied from the ink cartridge 7 to the recording head 3 through an ink supply tube may be employed.

  The carriage moving mechanism 5 includes a timing belt 8. The timing belt 8 is driven by a pulse motor 9 such as a DC motor. Accordingly, when the pulse motor 9 is operated, the carriage 4 is guided by the guide rod 10 installed on the printer 1 and reciprocates in the main scanning direction (width direction of the recording medium 2).

FIG. 2 is an exploded perspective view showing the configuration of the recording head 3. The recording head 3 in the present embodiment is roughly configured by a case 15, a plurality of head units 16, a unit fixing plate 17, and a head cover 18.
The case 15 is a box-like member that includes a plurality of head units 16 and a supply flow path (not shown) for supplying ink to the head units 16, and a needle holder 19 is formed on the upper surface side. The needle holder 19 is a member in which the ink introduction needles 20 are erected. In the present embodiment, a total of eight ink introduction needles 20 are arranged side by side in correspondence with the inks of the ink cartridges 7 of the respective colors. It is arranged. The ink introduction needle 20 is a hollow needle-like member that is inserted into the ink cartridge 7, and the ink stored in the ink cartridge 7 is introduced into the case 15 from an introduction hole (not shown) provided at the tip. Is introduced into the head unit 16 through the supply flow path.

  Further, on the bottom surface side of the case 15, a metal unit fixing plate 17 having four openings 17 ′ corresponding to the head units 16 in a state where the four head units 16 are positioned side by side in the main scanning direction. And is fixed by a metal head cover 18 having four openings 18 'corresponding to the head units 16, respectively.

  FIG. 3 is a cross-sectional view showing an internal configuration of the head unit 16 (a kind of the liquid jet head of the present invention). FIG. 4 is an enlarged view of region A in FIG. For convenience, the stacking direction of each member will be described as the vertical direction. The head unit 16 in the present embodiment includes a pressure generating unit 14 and a flow path unit 21 and is configured to be attached to a unit case 26 (a kind of case member) in a state where these members are stacked. The flow path unit 21 includes a nozzle plate 22 (a kind of nozzle forming member) and a communication substrate 23 (a kind of common liquid chamber forming member). The pressure generating unit 14 includes a pressure chamber forming substrate (a kind of pressure chamber forming member) 29 on which a pressure chamber 31 is formed, an elastic film 30, a piezoelectric element 35 (pressure generating means), and a protective substrate 24. It is unitized.

  The unit case 26 is a box-shaped member made of synthetic resin to which the nozzle plate 22 and the communication substrate 23 to which the pressure generating unit 14 is joined are fixed to the bottom surface side. A through hole 44 having a rectangular opening elongated along the nozzle row direction is formed in a central portion of the unit case 26 in plan view so as to penetrate the height direction of the unit case 26. The penetrating void 44 communicates with the wiring void 38 of the pressure generating unit 14 and forms a void in which one end of the flexible cable 49 and a drive IC 50 (both described later) are accommodated. In addition, an accommodation space 47 that is recessed in a rectangular parallelepiped shape from the lower surface to the middle of the unit case 26 in the height direction is formed on the lower surface side of the unit case 26. The depth of the accommodation space 47 is set to be slightly larger than the thickness (height) of the pressure generation unit 14. In addition, the dimension in the first direction and the dimension in the second direction of the accommodation empty space 47 are each set to be slightly larger than the dimension in the corresponding direction of the pressure generation unit 14. When the flow path unit 21 is joined to the lower surface of the unit case 26 in a positioned state, the pressure generating unit 14 stacked on the communication substrate 23 is accommodated in the accommodating space 47. In addition, the lower end of the above-described through space 44 is open to the ceiling surface of the accommodation space 47.

  In the unit case 26, an ink introduction space 46 and an ink introduction path 45 are formed. The ink introduction path 45 is a narrow flow path whose sectional area is set to be smaller than that of the ink introduction empty portion 46, and the upper end thereof opens to the upper surface of the unit case 26, and the lower end is the longitudinal direction of the ink introduction empty portion 46. An opening is formed in the central portion (first direction). The ink from the ink cartridge 7 side flows into the ink introduction space 46 through the ink introduction path 45, and is introduced from the ink introduction space 46 into the common liquid chamber 32 of the communication substrate 23.

  The ink introduction void 46 is formed at a position outside the second void in the second direction with the partition wall 48 in between the accommodation void 47 in the unit case 26. More specifically, a total of two ink introduction vacancies 46 are formed corresponding to the common liquid chamber 32 of the communication substrate 23, one on each side of the accommodation void 47. In the state where the communication substrate 23 is bonded to the unit case 26, each ink introduction space 46 communicates with the corresponding common liquid chamber 32. A partition wall 48 that separates the storage space 47 and the ink introduction space 46 is formed at a position corresponding to the thin portion 40 of the communication substrate 23. When the unit case 26 and the communication substrate 23 are joined, the lower surface of the partition wall 48 and the upper surface of the thin portion 40 are joined together. With this configuration, the accommodation void 47 becomes a space independent from the flow path of the ink introduction void 46 and the like. Here, conventionally, the pressure generation unit is also provided with an empty portion corresponding to the common liquid chamber, whereas in the configuration of the present embodiment, the pressure generation unit 14 is provided with an empty portion corresponding to the common liquid chamber. The size of the pressure generating unit 14 is reduced without any problem. Along with this reduction in size, a partition wall 48 is provided between the ink introduction space 46 and the storage space 47 in order to make the storage space 47 independent of the flow path, and the lower surface of the partition wall 48 communicates with the communication substrate. The upper surface of the thin portion 40 of the 23 is joined to each other. Accordingly, in the head unit 16 according to the present invention, the thin portion 40 is provided on the upper surface side of the second liquid chamber 52 of the common liquid chamber 32.

  The pressure chamber forming substrate 29, which is a constituent member of the pressure generating unit 14, is made of a silicon single crystal substrate (a kind of crystalline substrate; hereinafter also simply referred to as a silicon substrate). A plurality of pressure chambers 31 corresponding to each nozzle 27 of the nozzle plate 22 are formed on the pressure chamber forming substrate 29 by anisotropic etching with respect to the silicon substrate. Thus, by forming the pressure chambers on the silicon substrate by anisotropic etching, higher dimensional and shape accuracy can be ensured. As will be described later, since the nozzle plate 22 in this embodiment has two rows of nozzles 27, the pressure chamber forming substrate 29 has two rows of pressure chambers 31 corresponding to each nozzle row. Is formed. The pressure chamber 31 is a hollow portion that is long in a direction (second direction) orthogonal to the direction in which the nozzles 27 are arranged side by side (first direction). When the pressure chamber forming substrate 29 (pressure generating unit 14) is joined in a state of being positioned with respect to the communication substrate 23 described later, one end portion of the pressure chamber 31 in the second direction is a nozzle of the communication substrate 23 described later. The nozzle 27 communicates with the communication path 36. The other end of the pressure chamber 31 in the second direction communicates with the common liquid chamber 32 via the individual communication port 42 of the communication substrate 23.

  An elastic film 30 is formed on the upper surface of the pressure chamber forming substrate 29 (the surface on the side opposite to the bonding surface with the communication substrate 23) so as to seal the upper opening of the pressure chamber 31. The elastic film 30 is made of, for example, silicon dioxide having a thickness of about 1 μm. An insulating film (not shown) is formed on the elastic film 30. This insulating film is made of, for example, zirconium oxide. And the piezoelectric element 35 is each formed in the position corresponding to each pressure chamber 31 on this elastic film 30 and an insulating film. The piezoelectric element 35 is a so-called flexure mode piezoelectric element. The piezoelectric element 35 includes a metal lower electrode film, a piezoelectric layer made of lead zirconate titanate (PZT), and a metal upper electrode film (all shown) on the elastic film 30 and the insulating film. Are sequentially layered and then patterned for each pressure chamber 31. One of the upper electrode film and the lower electrode film is a common electrode, and the other is an individual electrode. Further, the elastic film 30, the insulating film, and the lower electrode film function as a diaphragm when the piezoelectric element 35 is driven.

  From the individual electrode (upper electrode film) of each piezoelectric element 35, electrode wiring portions (not shown) are respectively extended on the insulating film, and the flexible cable 49 is connected to portions corresponding to the electrode terminals of these electrode wiring portions. A terminal on one end side is connected. The flexible cable 49 has a configuration in which, for example, a conductor pattern is formed with a copper foil or the like on the surface of a base film such as polyimide, and this conductor pattern is covered with a resist. A driving IC 50 that drives the piezoelectric element 35 is mounted on the surface of the flexible cable 49. Each piezoelectric element 35 is bent and deformed when a drive signal (drive voltage) is applied between the upper electrode film and the lower electrode film through the drive IC 50.

  A protective substrate 24 is disposed on the upper surface of the communication substrate 23 on which the piezoelectric element 35 is formed. The protective substrate 24 is a hollow box-like member having an open bottom surface, and is made of, for example, glass, a ceramic material, a silicon single crystal substrate, a metal, a synthetic resin, or the like. Inside the protective substrate 24, an escape recess 39 is formed in a region facing the piezoelectric element 35 so as not to obstruct the driving of the piezoelectric element 35. Furthermore, in the protective substrate 24, between the adjacent piezoelectric element rows, a wiring empty portion 38 penetrating in the substrate thickness direction is formed. In the wiring space 38, the electrode terminal of the piezoelectric element 35 and one end of the flexible cable 49 are disposed.

  The nozzle plate 22 is a plate material in which a plurality of nozzles 27 are opened in a row at a pitch corresponding to the dot formation density. In the present embodiment, a nozzle row (a type of nozzle group) is configured by arranging 360 nozzles 27 at a pitch corresponding to 360 dpi. In the present embodiment, two nozzle rows are formed on the nozzle plate 22. The nozzle plate 22 in the present embodiment is made from a silicon substrate. A cylindrical nozzle 27 is formed by performing dry etching on the substrate. By forming the nozzle 27 by dry etching in this way, for example, the nozzle 27 can be formed with higher accuracy compared to a configuration in which the nozzle is formed by plastic working on a metal plate such as stainless steel. Is possible. Thereby, the landing accuracy of the ink ejected from the nozzle 27 is improved.

  5 and 6 are diagrams for explaining the configuration of the communication substrate 23. FIG. 5 is a perspective view as seen from the lower surface (first surface in the present invention) side to which the nozzle plate 22 is joined. FIG. 6 is a plan view of the lower surface side of both end portions of a communication substrate 23 in a first direction (nozzle juxtaposition direction). FIG. 5 illustrates only one end of both ends of the liquid passage chamber 32 in the first direction (the same applies to FIGS. 7 to 10 described later). The communication substrate 23 is a plate material made from a silicon substrate. A common liquid chamber 32 is formed in the communication substrate 23 by anisotropic etching. The common liquid chamber 32 is a long empty portion along the juxtaposed direction of the pressure chambers 31 (that is, the first direction). The common liquid chamber 32 is common to the first liquid chamber 51 (penetrating portion) penetrating through the thickness direction of the communication substrate 23 and from the lower surface side to the upper surface (second surface in the present invention) side of the communication substrate 23. The liquid chamber forming member 23 includes a second liquid chamber 52 (non-penetrating portion) formed in a state where the thin portion 40 is left on the upper surface side to the middle of the plate thickness direction.

  The opening of the first liquid chamber 51 on the upper surface side of the communication substrate 23 functions as an inlet opening for introducing ink. That is, the ink from the ink introduction path 45 and the ink introduction space 46 formed in the unit case 26 flows into the first liquid chamber 51 through the inlet opening. The opening on the lower surface side of the first liquid chamber 51 is closed by the nozzle plate 22. There is also a configuration in which the opening on the lower surface side of the first liquid chamber 51 is closed by an elastic sheet (compliance sheet). The longitudinal direction of the first liquid chamber 51, that is, both end portions in the first direction are formed so as to become gradually narrower toward the respective end portions. More specifically, at both ends of the first liquid chamber 51, at least one of the opposing wall surfaces defining the first liquid chamber 51 is closer to the other toward the end in the first direction. Inclined to do. Thus, by tapering the opening shape at both ends of the first liquid chamber 51, it is possible to suppress a decrease in the flow rate of ink at both ends of the first liquid chamber 51. Therefore, the supply pressure of the ink supplied to each pressure chamber 31 through the individual communication port 42 can be made uniform.

  The second liquid chamber 52 is a recess formed in a state adjacent to the first liquid chamber 51. The thin portion 40 constitutes the ceiling surface of the second liquid chamber 52. One end of the second liquid chamber 52 in the second direction (the end far from the nozzle 27) communicates with the first liquid chamber 51, while the other end in the same direction is below the pressure chamber 31. It is formed in the corresponding position. At the other end of the second liquid chamber 52, that is, at the edge opposite to the first liquid chamber side 51, an individual communication port 42 that penetrates the thin portion 40 is provided in each pressure chamber of the pressure chamber forming substrate 29. A plurality are formed along the first direction corresponding to 31. The lower end of the individual communication port 42 communicates with the second liquid chamber 52, and the upper end of the individual communication port 42 communicates with the pressure chamber 31 of the pressure chamber forming substrate 29.

  Partition walls 53 for partitioning adjacent individual communication ports 42 are formed at both ends in the longitudinal direction of the second liquid chamber 52 in the present embodiment, that is, at both ends in the first direction of the thin portion 40. The partition wall 53 is a wall that continues from the boundary portion between the first liquid chamber 51 and the second liquid chamber 52 to the side wall surface on the individual communication port side, and the lower surface of the thin portion 40 (the ceiling surface of the second liquid chamber 52). Projecting toward the lower surface of the communication substrate 23. That is, the height of the partition wall 53 in the present embodiment is set to be the same as the depth of the second liquid chamber 52, and the upper end surface thereof is located on the same surface as the lower surface of the communication substrate 23. Further, the partition wall 53 in the present embodiment has one individual communication port 42 in a predetermined range at both ends in the first direction of the thin portion 40, specifically, in a range in which bubbles tend to accumulate in the common liquid chamber 32. A plurality are arranged so as to partition each one. As described above, the partition wall 53 partially forms an elongate flow path from the first liquid chamber 51 side toward the individual communication port 42 in the common liquid chamber 32, and the individual communication as compared with the configuration in which the partition wall 53 is not provided. The flow velocity of the ink flowing toward the opening 42 is increased. Thereby, the bubbles staying in the first liquid chamber 51 can be easily discharged by being put on the flow having the relatively high flow velocity. In the present embodiment, such partition walls 53 are provided at both ends in the longitudinal direction of the second liquid chamber 52, that is, at both ends in the first direction of the thin wall portion 40. It is possible to easily discharge bubbles staying at both ends in the first direction of the liquid chamber 51). In particular, when performing a so-called cleaning process performed for the purpose of forcibly sucking and discharging ink and bubbles from the nozzle 27, the opening on the first liquid chamber 51 side of the flow path defined by the partition wall 53 is formed. It serves as a suction port and sucks ink and bubbles. As a result, the bubbles staying at both ends in the first direction of the common liquid chamber 32 (first liquid chamber 51) can resist the buoyancy acting on the bubbles, and the first liquid chamber 51 and the second liquid chamber 52 It will be easy to be drawn in to the individual communication port 42 side through the step in between. Therefore, it is possible to improve the bubble discharge performance.

  In manufacturing the head unit 16 having the above-described configuration, first, after the elastic film 30 and the insulating film are sequentially formed on the upper surface of the pressure chamber forming substrate 29 (silicon substrate in which the pressure chamber 31 is not formed). The piezoelectric element 35 is formed by firing. On top of this, the protective substrate 24 is bonded in a state in which the piezoelectric element 35 is accommodated in the relief recess 39. In this state, the pressure chamber 31 is formed from the lower surface side of the pressure chamber forming substrate 29 by anisotropic etching. As described above, by stacking the piezoelectric element 35 and the protective substrate 24 on the upper surface side of the pressure chamber forming substrate 29 at a stage before the pressure chamber 31 is formed on the pressure chamber forming substrate 29, a unit is obtained. Damage to the pressure chamber forming substrate 29 during the assembly process of the pressure generating unit 14 is suppressed.

  Next, the common liquid chamber 32 (the first liquid chamber 51 and the second liquid chamber 52), the individual communication port 42, the nozzle communication path 36, and the partition wall 53 are formed on the communication substrate 23 by anisotropic etching. The The nozzle plate 22 is bonded to the lower surface of the communication substrate 23 with the nozzle communication path 36 and the nozzle 27 communicating with each other. In this way, the flow path unit 21 is unitized. Subsequently, the pressure generating unit 14 is joined to the upper surface of the communication substrate 23 in the flow path unit 21. Specifically, the one end of the pressure chamber 31 in the second direction communicates with the nozzle communication path 36 and the other end of the pressure chamber 31 in the second direction communicates with the individual communication port 42. The pressure chamber forming substrate 29 of the pressure generating unit 14 is bonded to the upper surface of the road substrate 23 with an adhesive.

  When the flow path unit 21 and the pressure generation unit 14 are assembled, the flexible cable 49 is wired to the electrode terminal of each piezoelectric element 35 through the wiring space of the protective substrate 24. That is, the terminal at one end of the flexible cable 49 is electrically connected to the portion corresponding to the electrode terminal of each piezoelectric element 35.

  Subsequently, the communication substrate 23 and the unit case 26 are bonded with an adhesive. Specifically, the upper surface of the communication substrate 23 and the lower surface of the unit case 26 are joined by an adhesive. When the flow path unit 21 and the unit case 26 are joined, the pressure generating unit 14 is housed in the housing space 47, and the ink introduction space 46 and the first liquid chamber 51 of the common liquid chamber 32 are liquidated. Communicate closely. Further, the one end portion of the flexible cable 49 and the drive IC 50 are accommodated in the through space 44 of the unit case 26. Thereby, the head unit 16 is assembled. In the head unit 16, a series of common flow paths from the ink introduction path 45 to the common liquid chamber 32, and from the individual communication port 42 to the nozzle 27 through the pressure chamber 31 and the nozzle communication path 36. Individual flow paths are formed. In the present embodiment, since the partition wall 53 that partitions the adjacent individual communication ports 42 is formed in a predetermined range at both ends in the longitudinal direction of the second liquid chamber 52, the individual communication ports are formed by the partition wall 53. The flow path formed for each 42 can also be said to be a part of the individual flow path.

  By the way, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the description of the scope of claims.

  For example, with respect to the height of the partition wall 53, the above embodiment exemplifies a configuration that is set to be the same as the depth of the second liquid chamber 52 and whose upper end surface is located on the same surface as the lower surface of the communication substrate 23. However, the depth is not necessarily the same as the depth of the second liquid chamber 52. In the second embodiment illustrated in FIG. 7, the height of the partition wall 53 is set lower than the depth of the second liquid chamber 52 (for example, about half), and the upper end surface of the partition wall 53 is connected to the communication substrate 23. Between the lower surface of the thin portion 40 and the lower surface of the thin portion 40. Thus, if the height of the partition wall 53 is at least half the depth of the second liquid chamber 52, the bubble discharge performance can be improved.

  Moreover, although the said 1st Embodiment illustrated the structure which formed the partition wall 53 so that the separate communicating port 42 might be partitioned one by one, it is not restricted to this. In the third embodiment shown in FIG. 8, a partition wall 53 is provided for each of the plurality of individual communication ports 42. In this example, a partition wall 53 is provided so as to partition adjacent groups, with three adjacent individual communication ports 42 as one group. Also in this structure, there exists an effect similar to each said embodiment.

  Furthermore, in each said embodiment, although the partition wall 53 illustrated the structure formed in linear form by planar view toward the separate communicating port 42 from the 1st liquid chamber 51 side, it is not restricted to this. In the fourth embodiment shown in FIG. 9, a portion (end portion 53 a) on the first liquid chamber 51 side from the middle of the partition wall 53 faces the end portion in the first direction of the common liquid chamber 32. It is characterized in that it is inclined with respect to the end on the individual communication port 42 side (that is, with respect to the second direction) from the middle. In the present embodiment, partition walls 53 that are inclined toward the respective end portions are provided at both end portions of the thin portion 40 in the first direction. Further, in the fifth embodiment shown in FIG. 10, a plurality of partition walls 53 are arranged at regular intervals over the entire length of the thin portion 40 in the first direction. In this configuration, the inclination angle of the end portion 53a is larger as the partition wall 53 is closer to both ends of the common liquid chamber 32 in the first direction. In these fourth or fifth embodiments, bubbles staying at both ends in the first direction of the common liquid chamber 32 are guided to the partition wall 53 and easily guided to the individual communication port 42 side. As a result, it is possible to further improve the discharge performance of bubbles staying at both ends in the first direction of the common liquid chamber 32 by the partition wall 52. In particular, the distance between the partition walls 53 located at both ends in the first direction and the inner walls on both sides in the first direction that define the common liquid chamber 32 is from the individual communication port 42 side to the first liquid chamber 51 side. By gradually approaching each other, the width of the flow path defined between the two becomes narrow, and the flow velocity of the part is increased. Thereby, it is possible to make it easier for the bubbles staying at both ends of the common liquid chamber 32 to be drawn into the individual communication port 42 side, which contributes to the improvement of the bubble discharge performance. In addition, the structure which the whole partition wall 53 inclines may be sufficient, and the structure in which the partition wall 53 inclines in multiple steps may be sufficient. In the latter case, it is desirable that the inclination angle gradually increases as it approaches the first liquid chamber 51.

  Furthermore, in each of the above-described embodiments, the so-called flexural vibration type piezoelectric element 35 is exemplified as the pressure generating means. However, the present invention is not limited to this, and for example, a so-called longitudinal vibration type piezoelectric element can be employed. Other pressure generation means include heat generating elements that generate pressure fluctuations by generating bubbles in the ink by heat generation, electrostatic actuators that generate pressure fluctuations by displacing the partition walls of the pressure chamber by electrostatic force, etc. The present invention can also be applied to a configuration that employs the pressure generating means.

  In the above description, the ink jet recording head 3 (head unit 16) which is a kind of liquid ejecting head has been described as an example. However, in the present invention, the liquid is introduced from the upper opening of the first liquid chamber, The present invention can also be applied to other liquid ejecting heads that employ a configuration in which a pressure chamber is supplied through a separate communication port through a thin portion that is a ceiling surface of a two-liquid chamber. For example, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material ejecting head used for forming an electrode such as an organic EL (Electro Luminescence) display, FED (surface emitting display), a biochip (biochemical element) The present invention can also be applied to bioorganic matter ejecting heads and the like used in the production of

  DESCRIPTION OF SYMBOLS 1 ... Printer, 3 ... Recording head, 14 ... Pressure generating unit, 16 ... Head unit, 21 ... Flow path unit, 22 ... Nozzle plate, 23 ... Communication board, 26 ... Unit case, 27 ... Nozzle, 29 ... Pressure chamber formation Substrate, 31 ... Pressure chamber, 32 ... Common liquid chamber, 35 ... Piezoelectric element, 40 ... Thin portion, 41 ... Common communication path, 42 ... Individual communication port, 51 ... First liquid chamber, 52 ... Second liquid chamber, 53 ... partition wall

Claims (3)

A nozzle forming member in which a plurality of nozzles are opened along the first direction;
A pressure chamber forming member in which a plurality of pressure chambers are formed along the first direction corresponding to the nozzle;
A common liquid chamber is formed as a series of cavities along the juxtaposition direction of the pressure chambers, a common liquid chamber is provided in which a common liquid is introduced into the pressure chambers, and the introduced liquid is supplied to the pressure chambers through individual communication ports. A liquid chamber forming member;
A liquid jet head comprising:
The common liquid chamber includes a first liquid chamber into which liquid is introduced from an inlet opening opened in a second surface opposite to the first surface on the nozzle side of the common liquid chamber forming member; A second liquid chamber formed in a state in which a thin portion is left on the second surface side from the first surface side toward the second surface side to the middle of the thickness direction of the common liquid chamber forming member; Comprising
The individual communication ports are formed on the side opposite to the first liquid chamber side in the thin portion so as to correspond to the pressure chambers, and a partition wall for partitioning adjacent individual communication ports is formed in the thin portion. A liquid ejecting head formed from one liquid chamber side toward the individual communication port.   At least an end portion on the first liquid chamber side of the partition wall is inclined with respect to an end portion on the individual communication port side toward both end portions in the first direction of the first liquid chamber. The liquid ejecting head according to claim 1.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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