JP5919757B2 - Liquid ejecting head and liquid ejecting apparatus - Google Patents

Description

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

  A typical example of a liquid ejecting head that ejects liquid is an ink jet recording head that ejects ink. As an ink jet recording head, for example, it has a manifold that stores liquid, takes ink into a pressure generating chamber that communicates with the manifold, deforms the pressure generating chamber with pressure generating means such as a piezoelectric element, and nozzles There is known one provided with a head main body for discharging liquid from the head.

  Such an ink jet recording head has a liquid flow path serving as a flow path for ink supplied to the manifold (see, for example, Patent Document 1). Examples of the liquid flow path include those formed by joining members provided with through holes with an adhesive so that the through holes communicate with each other.

JP-A-11-300987

  Bubbles generated in the liquid flow path are captured by a filter disposed in the liquid flow path, or are sucked out from the nozzle side with a negative pressure to be discharged together with the ink.

  However, when the adhesive that joins the members provided with the through holes reaches the inside of the through holes and hardens, bubbles adhere to the adhesive that protrudes into the through holes and are difficult to be discharged to the outside. That is, the discharge property of the bubbles in the liquid channel is lowered. If ink remains in the liquid flow path even when the bubble is discharged in this manner, the bubble may move to the nozzle side during printing, which may cause ink ejection failure.

  Such a problem also exists in a liquid ejecting head and a liquid ejecting apparatus that eject liquid other than ink.

  In view of such circumstances, an object of the present invention is to provide a liquid ejecting head and a liquid ejecting apparatus that improve the discharge quality of bubbles in a liquid channel and improve the ejection quality.

An aspect of the present invention that solves the above problems includes a head main body that discharges liquid from a nozzle, a liquid channel that is in communication with the nozzle and through which the liquid supplied to the head main body flows, and part of the liquid channel and a first member and a second member having a through-hole constituting are provided respectively, each through hole of the first member and the second member, the first opening close to the nozzle, and not far from the nozzle A through hole of the first member and the second member communicates, and a surface of the first member on the second opening side and a surface of the second member on the first opening side are bonded. The second opening of the first member is smaller than the first opening of the second member, and liquid is supplied to the head body from the first opening side of the first member, The adhesive is bonded to the first member at the joint surface of the first member with the second member. Than second opening there is provided a liquid ejecting head, characterized in that attached to the outside.
In this aspect, since the adhesive does not protrude into the through hole, it is possible to prevent bubbles contained in the liquid from staying in the vicinity of the adhesive protruding into the through hole. As described above, since the bubble discharge performance is improved, it is possible to prevent the bubbles from moving to the nozzle side during liquid discharge and causing a liquid discharge failure. Therefore, a liquid ejecting head with improved discharge quality is provided.

  Here, it is preferable that the through hole is formed in a taper shape whose diameter increases from the second opening toward the first opening. According to this, the internal diameters of those liquid flow paths can be suppressed to a certain level or less even upstream from the through hole of the first member to the through hole of the second member. As a result, it is possible to save space for the size in a plane perpendicular to the through hole of the liquid jet head.

  Moreover, it is preferable that the opening edge part of the said 1st opening of the said through-hole is chamfered. According to this, since the opening edge becomes the escape of the adhesive, it is possible to more reliably prevent the adhesive from protruding into the through hole.

  Moreover, it is preferable that the opening edge part of the said 2nd opening of the said through-hole is chamfered. According to this, since the circulation of the liquid can be made smooth, the bubbles in the liquid can be discharged more smoothly.

The second opening of the through hole of the first member and the second member is preferably smaller than the first opening of the through hole of the first member and the second member. The head body includes a pressure generating chamber communicating with a nozzle for discharging liquid, a plurality of pressure generating means for deforming the pressure generating chamber, and a head case to which the pressure generating means is fixed. It is preferable that an insertion hole through which each pressure generating means is inserted is provided, and the through hole is provided so as to be positioned between the insertion holes. According to this, since the inner diameter of the through hole is suppressed to a certain value or less, the two insertion holes can be made as close as possible. Therefore, in the liquid ejecting head having a plurality of pressure generating means, it is possible to save space for the size in plan view.

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, there is provided a liquid ejecting apparatus that improves the discharge quality by improving the discharge of bubbles in the liquid flow path.

1 is a perspective view illustrating a schematic configuration of a recording apparatus according to an embodiment. FIG. 2 is an exploded perspective view of a recording head according to an embodiment. FIG. 2 is a bottom view and a side view of a recording head according to an embodiment. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is principal part sectional drawing of the flow-path member which concerns on one Embodiment. It is principal part sectional drawing of the head main body which concerns on one Embodiment. It is principal part sectional drawing and a top view of a head main part concerning one embodiment. It is principal part sectional drawing of the liquid flow path which concerns on a prior art example. It is a top view of the reinforcing member concerning one embodiment. It is principal part sectional drawing of the liquid flow path which concerns on other embodiment.

<Embodiment 1>
Hereinafter, the present invention will be described in detail based on embodiments. Hereinafter, the ink jet recording head is an example of a liquid ejecting head, and is simply referred to as a recording head. The ink jet recording apparatus is an example of a liquid ejecting apparatus.

  FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to the present embodiment. The ink jet recording apparatus 1 includes a recording head 2. The recording head 2 is mounted on the carriage 4 together with the ink cartridge 3, and the carriage 4 is provided so as to be movable along the carriage shaft 9.

  A driving force of a driving motor (not shown) is transmitted to the carriage 4 via a plurality of gears and a timing belt 7, so that the carriage 4 on which the recording head 2 is mounted is moved along the carriage shaft 9.

  The position of the carriage 4 in the direction along the carriage axis 9 is detected by the linear encoder 10, and a detection signal is transmitted as position information to a control unit (not shown). Accordingly, the control unit can control the ink ejection operation and the like while recognizing the position of the carriage 4 (recording head 2) based on the position information from the linear encoder 10.

  The ink jet recording apparatus 1 includes a platen 5, and a recording sheet 6, which is a recording medium such as paper fed by a paper feeding mechanism 8, is wound around the platen 5 and conveyed. .

  2 is an exploded perspective view of the recording head, FIG. 3 is a bottom view and a side view of the recording head, FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, and FIG. FIG. 6 is a cross-sectional view taken along the line -B, and FIG.

  As shown in these drawings, the recording head 2 of the present embodiment includes a flow path member 12, a circuit board 13, a head body 14, and a head cover 15.

  The flow path member 12 is a member having a part of a liquid flow path for supplying ink from the ink cartridge 3 to the head main body 14. Specifically, the flow path member 12 is configured by joining a first flow path member 17, a second flow path member 21, and a third flow path member 19.

  The first flow path member 17 includes an ink cartridge mounting portion 22 to which a plurality of ink cartridges 3 are detachably mounted on the upper surface. A plurality of ink introduction needles 23 are formed on the upper surface of the bottom of the ink cartridge mounting portion 22 corresponding to each ink cartridge 3 to be mounted. In the present embodiment, four ink introduction needles 23 are arranged in a row corresponding to inks of four colors (for example, cyan, magenta, yellow, and black).

  A first ink supply path 24 is formed inside the ink introduction needle 23. By inserting the ink introduction needle 23 into the ink cartridge 3, the first ink supply path 24 and the inside of the ink cartridge 3 are communicated.

  Further, as shown in FIG. 5, four recesses 93 constituting a part of the horizontal flow path 95 are formed on the bottom surface (the surface on the second flow path member 21 side) of the first flow path member 17. . The first ink supply path 24 described above opens at one end of each recess 93.

  As shown in FIGS. 2 and 6, the second flow path member 21 includes a second ink supply path 29 that penetrates in the thickness direction of the second flow path member 21. A filter 20 is disposed in the opening of the second ink supply path 29 on the first flow path member 17 side. Further, the circuit board 13 side of the second ink supply path 29 protrudes to the circuit board 13 side, and is inserted into a flow path insertion hole 34 of the circuit board 13 described later.

  As shown in FIG. 6, the third flow path member 19 is sandwiched between the first flow path member 17 and the second flow path member 21. The third flow path member 19 is a member that defines a horizontal flow path 95 with the first flow path member 17. The horizontal flow path 95 communicates with the first ink supply path 24 and the second ink supply path 29.

  Specifically, each recess 93 (see FIG. 5) of the first flow path member 17 is sealed by each protrusion 94 of the third flow path member 19, thereby defining a horizontal flow path 95. The convex portion 94 constitutes a part of the horizontal flow path 95, and four convex portions 94 are provided to face the respective concave portions 93 of the first flow path member 17 (see FIG. 2). The third flow path member 19 is bonded to the first flow path member 17 with a resin adhesive 102 applied to the peripheral edge of each convex portion 94. As a result, the openings of the concave portions 93 of the first flow path member 17 are sealed by the convex portions 94 of the third flow path member 19 to form four horizontal flow paths 95. The third flow path member 19 is also bonded to the second flow path member 21 with an adhesive.

  The third flow path member 19 is provided with four communication paths 27 penetrating in the thickness direction. Each communication path 27 opens to one end of each convex portion 94 and communicates with the second ink supply path 29 of the second flow path member 21 via the filter 20. That is, the horizontal flow path 95 communicates with the first ink supply path 24 and the second ink supply path 29. The filter 20 captures feelings and foreign matters mixed in the ink in the first ink supply path 24.

  As shown in FIG. 6, a seal member 18 is sandwiched between the first flow path member 17 and the second flow path member 21. The seal member 18 is an elastic member made of resin or the like having an inner diameter larger than the outer diameter of the third flow path member 19 and formed in an annular shape.

  In the present embodiment, the seal member 18 has a concave cross section, and the joint portion 17a of the first flow path member 17 is in contact with the joint surface 91 that is the bottom surface of the concave shape. Further, the joint surface 92 opposite to the joint surface 91 of the seal member 18 is in contact with the second flow path member 21.

  Although not particularly illustrated, the second flow path member 21 is provided with a boss protruding toward the first flow path member 17, and is caulked in a state where the boss is inserted into a through hole provided in the first flow path member 17. As a result, the first flow path member 17 and the second flow path member 21 are fixed in a state where the seal member 18 is sandwiched.

  As described above, the seal member 18 is sandwiched between the first flow path member 17 and the second flow path member 21, whereby the air chamber 100 is defined by these members. Further, although not shown in particular, it communicates with the outside through a communication passage provided in the seal member 18 or the like. The second flow path member 21 and the third flow path member 19 are provided with a third atmospheric communication hole 103 and a second atmospheric communication hole 101, which are through holes, respectively. The third atmospheric communication hole 103 and the second atmospheric communication hole 101 communicate with each other and communicate with the air chamber 100 described above.

  As shown in FIGS. 2 and 4, the circuit board 13 has an electrical component such as an IC or a resistor mounted on the surface thereof. The circuit board 13 is disposed between the second flow path member 21 and the head body 14.

  The circuit board 13 is joined with a flexible cable 33 constituting the vibrator unit 45 of the head body 14. The circuit board 13 is provided with a connector 32 to which a signal cable (not shown) is connected. The signal cable is connected to the control unit of the ink jet recording apparatus 1. The circuit board 13 receives a drive signal or the like sent from the control unit through the signal cable, and drives the vibrator unit 45 through the flexible cable 33.

  The circuit board 13 is formed with a flow passage insertion hole 34 penetrating in the thickness direction in a region corresponding to the second ink supply passage 29. The lower end of the second ink supply path 29 is inserted into the flow path insertion hole 34, and the lower end of the second ink supply path 29 is below the circuit board 13 and the first flow path 71 of the head case body 47 (see FIG. 7). ).

  A head main body 14 is provided on the opposite side of the circuit board 13 from the second flow path member 21. As will be described in detail later, the head body 14 includes a head case 41, a flow path unit 39, and a vibrator unit 45 that is an example of a pressure generating unit. The head case 41 includes a head case main body 47 and a reinforcing member 48.

  The head case main body 47 is made of, for example, a resin such as epoxy resin, and extends from the case portion 47a to the side at the upper end of the case portion 47a (see FIG. 2) having a hollow box shape. Plate-shaped portion 47b (see FIG. 2). Note that a protrusion 75 that is positioned relative to the reinforcing member 48 and protrudes downward is provided on the lower surface of the case 47a (see FIG. 2). Further, the flow path unit 39 is joined to the reinforcing member 48 on the surface opposite to the head case main body 47.

  A head cover 15 is attached to the head body 14. The head cover 15 is a metal member that is connected to the head case main body 47 and protects the flow path unit 39 and the head case 41. The head cover 15 is made of a thin plate member, surrounds the side surface of the head case 41, and has a lower end bent substantially 90 degrees toward the nozzle plate 49 and is in contact with the surface of the nozzle plate 49. The surface of the head cover 15 that contacts the surface of the nozzle plate 49 is formed in a frame shape so as to expose the nozzles (not shown). Further, a flange portion 80 projecting sideways is provided at the upper end of the head cover 15, and a head cover reference hole 81 is formed in the flange portion 80. The head cover reference hole 81 is inserted with a head cover positioning portion 76 that protrudes from the lower surface side of the head case main body 47 to position the head cover 15.

  Here, the head main body 14 will be described in detail with reference to FIG. FIG. 7 is a cross-sectional view of the main part of the head body. The flow path unit 39 constituting the head body 14 includes a nozzle plate 49, a flow path forming substrate 50, and a vibration plate 51.

  In the flow path forming substrate 50, a plurality of pressure generating chambers 38 are partitioned by a partition wall and arranged in parallel in the width direction. For example, in this embodiment, two rows in which a plurality of pressure generating chambers 38 are arranged in parallel are provided on the flow path forming substrate 50.

  A manifold 52 that stores ink supplied to each pressure generating chamber 38 is provided outside the row of each pressure generating chamber 38 so as to penetrate the flow path forming substrate 50 in the thickness direction. Each pressure generating chamber 38 and the manifold 52 communicate with each other via an ink supply path 53 that is an individual flow path.

  In this embodiment, the flow path forming substrate 50 is made of a silicon single crystal substrate, and the pressure generation chamber 38 and the like provided in the flow path forming substrate 50 are formed by etching the flow path forming substrate 50. Yes.

  A nozzle plate 49 on which nozzles 36 are formed is joined to one side of the flow path forming substrate 50. The end of the pressure generating chamber 38 opposite to the manifold 52 communicates with the nozzle 36.

  A vibration plate 51 is bonded to the other surface side of the flow path forming substrate 50, that is, the opening surface side of the pressure generation chamber 38, and each pressure generation chamber 38 is sealed by the vibration plate 51.

  The vibration plate 51 is formed of a composite plate of an elastic film 55 and a support plate 54 that supports the elastic film 55, and the elastic film 55 side is bonded to the flow path forming substrate 50. The elastic film 55 is formed from an elastic member such as a resin film, for example. The support plate 54 is made of, for example, a metal material.

  In addition, in the region of the vibration plate 51 facing each pressure generating chamber 38, an island portion 60 with which the tip portion of the piezoelectric element 43 abuts is provided. That is, a thin portion 58 having a thickness smaller than that of the other regions is formed in a region facing the peripheral edge of each pressure generating chamber 38 of the diaphragm 51, and island portions 60 are respectively provided inside the thin portion 58. Yes.

  A head case body 47 is joined to the diaphragm 51. Specifically, a reinforcing member 48 fixed to the lower surface of the case portion 47 a of the head case main body 47 with an adhesive is joined on the diaphragm 51. Inside the case portion 47 a, an accommodation space 46 is formed that communicates with the insertion hole 40 of the reinforcing member 48, and a part of the vibrator unit 45, which is an example of pressure generating means, is accommodated in the accommodation space 46. Has been.

  The vibrator unit 45 includes a fixed plate 42, a piezoelectric element 43 fixed to the fixed plate 42, and a flexible cable 33 joined to the piezoelectric element 43. In the present embodiment, the piezoelectric element 43 is formed by laminating the piezoelectric material 61 and the electrode forming materials 62 and 63 alternately sandwiched vertically. The inactive region that does not contribute to the vibration of the piezoelectric element 43 is fixed to the fixing plate 42, and the tip portion that contributes to the vibration of the piezoelectric element 43 is fixed in contact with the vibration plate 51.

  In the region facing the manifold 52 of the vibration plate 51, similarly to the thin portion 58, a compliance portion 59 that is substantially composed only of the elastic film 55 is provided by removing the support plate 54 by etching. The elastic film 55 of the compliance portion 59 is formed of a resin material such as a PPS (polyphenylene sulfide) film having a thickness of about several μm, for example. The ink does not pass through the elastic film 55 of the compliance portion 59, but the water vapor evaporated from the water passes through the ink.

  A compliance space 56 that allows deformation of the compliance portion 59 is formed in a portion of the reinforcing member 48 that faces the compliance portion 59. The compliance space 56 is opened to the outside as follows.

  The head case main body 47 and the reinforcing member 48 are formed with first air communication holes 73 penetrating in the thickness direction. The first atmosphere communication hole 73 communicates with the compliance space 56 via a communication passage 48 b formed on the vibration member 51 side of the reinforcing member 48. Further, the first atmosphere communication hole 73 communicates with the second atmosphere communication hole 101 (see FIG. 4). On the other hand, as described above, the second atmospheric communication hole 101 communicates with the outside through the third atmospheric communication hole 103 and the air chamber 100.

  In other words, the compliance space 56 communicates with the air chamber 100 through the communication passage 48 b and the first atmospheric communication hole 73, and further through the second atmospheric communication hole 101 and the third atmospheric communication hole 103, and passes through the air chamber 100. It is open to the atmosphere. As a result, the compliance portion 59 is favorably deformed as the pressure of the manifold 52 changes.

  The reinforcing member 48 is formed with a first flow path 71 penetrating in the thickness direction. The head case main body 47 is formed with a second flow path 72 penetrating in the thickness direction. The first flow path 71 has one opening communicating with the manifold 52 and the other opening communicating with the second flow path 72. The second flow path 72 has one opening communicating with the first flow path 71 and the other opening communicating with the second ink supply path 29 (see FIGS. 2 and 6).

  The first flow path 71 and the second flow path 72, the first ink supply path 24, the horizontal flow path 95, and the second ink supply path 29 (see FIGS. 2 to 4) communicate with each other to form a liquid flow path. Is formed. Ink from the ink cartridge is supplied to the liquid channel, and the ink is supplied to the manifold 52 through the liquid channel.

  Here, the first flow path 71 and the second flow path 72 will be described in detail with reference to FIG. FIG. 8 is an enlarged cross-sectional view and a plan view of the main part of the main part of the head body 14.

  In the present embodiment, the first member in the claims is the reinforcing member 48, and the second member is the head case main body 47 (case portion 47 a). The through hole provided in the first member is the first flow path 71, and the through hole provided in the second member is the second flow path 72.

  An opening close to the nozzle 36 side of the first flow path 71 (opening communicating with the opening provided in the diaphragm 51) is defined as a first opening 1-1, and an opening far from the nozzle 36 (opening communicating with the second flow path 72). ) Is the second opening 2-2. Similarly, an opening close to the nozzle 36 side of the second flow path 72 (opening communicating with the first flow path 71) is defined as a first opening 2-1, and an opening far from the nozzle 36 (communication with the second ink supply path 29). Opening) is defined as a second opening 2-2.

  As for the 1st flow path 71 which is an example of the through-hole provided in the reinforcement member 48 which is an example of the 1st member, the opening shape of the 1st opening 1-1 is more open than the opening shape of the 2nd opening 1-2. Largely formed. Accordingly, the first flow path 71 is formed in a tapered shape whose width is increased from the second opening 1-2 toward the first opening 1-1.

  Similarly, the second flow path 72, which is an example of a through hole provided in the head case main body 47, which is an example of the second member, has an opening shape of the first opening 2-1 of the second opening 2-2. It is formed larger than the opening shape. Therefore, the second flow path 72 is formed in a tapered shape whose width is increased from the second opening 2-2 toward the first opening 2-1.

  Further, when the opening edge portions of the first openings 1-1 and 2-1, and the second openings 1-2 and 2-2 are defined as 1-1C, 2-1C, 1-2C, and 2-2C, respectively, The edges 1-1C, 2-1C, 1-2C, and 2-2C are chamfered (become C-plane).

  Furthermore, the opening shape of the second opening 1-2 of the reinforcing member 48 is formed smaller than the opening shape of the first opening 2-1 of the head case body 47.

  The reinforcing member 48 and the head case main body 47 are joined with an adhesive 77. Specifically, the reinforcing member 48 and the head case main body 47 are bonded with an adhesive so that the second opening 1-2 side of the reinforcing member 48 and the first opening 2-1 side of the head case main body 47 face each other. Has been.

  The first opening 1-1 of the reinforcing member 48 is joined to the diaphragm 51 with an adhesive so as to communicate with the manifold 52. The second opening 2-2 of the head case main body 47 is joined to the second flow path member 21 with an adhesive so as to communicate with the second ink supply path 29.

  The first flow path 71 and the second flow path 72 are communicated with each other by joining the reinforcing member 48 and the head case main body 47. As described above, since the second opening 1-2 has an opening shape smaller than that of the first opening 2-1, as illustrated in FIG. When viewed in a plan view, the second opening 1-2 is located inside the first opening 2-1.

  Thus, the peripheral surface of the second opening 1-2 of the reinforcing member 48 is exposed. The exposed surface of the reinforcing member 48 is defined as an exposed portion 48a. The exposed portion 48 a is an area outside the second opening 1-2 and is an area closer to the second opening 1-2 than the joint surface with the head case main body 47.

  An adhesive 77 for bonding the reinforcing member 48 and the head case main body 47 is attached to the exposed portion 48a. More specifically, the adhesive 77 is attached from between the reinforcing member 48 and the head case main body 47 to the exposed portion 48 a, and is not attached in the first flow path 71.

  Thus, the exposed portion 48a was formed by making the opening shape of the second opening 1-2 of the first flow path 71 smaller than the opening shape of the first opening 2-1 of the second flow path 72. With this exposed portion 48 a, even if the adhesive 77 provided between the reinforcing member 48 and the head case main body 47 protrudes, it can be retained at the exposed portion 48 a, so that it does not protrude into the first flow path 71. it can.

  Since the adhesive 77 is not protruded into the first flow path 71, bubbles included in the ink flowing from the second flow path 72 to the first flow path 71 are easily discharged to the downstream side (manifold 52 side). be able to.

  As shown in FIG. 9, it is assumed that the opening shapes of the first flow path 71 and the second flow path 72 are the same, and the reinforcing member 48 and the head case main body 47 are joined with an adhesive 77 so that they are communicated with each other. . If the adhesive 77 protrudes into the first flow path 71, the ink flow velocity is reduced in the region R downstream of the adhesive 77 in the first flow path 71. For this reason, in the region R, bubbles contained in the ink remain without being discharged downstream. Furthermore, if the first flow path 71 is along the vertical direction as in this embodiment, even if the bubbles try to move upstream due to buoyancy, the bubbles are restricted by the adhesive 77, and the bubbles remain more in the region R. It has become easier.

  On the other hand, if the filling amount of the adhesive 77 is reduced in order to suppress the protrusion of the adhesive 77, a region S that is closed without being filled with the adhesive 77 is generated between the reinforcing member 48 and the head case body 47. . When such a region S is generated, the ink may permeate from the region S through the interface between the adhesive 77 and the reinforcing member 48 or the head case main body 47, and may reach other components.

  In the present embodiment, since the adhesive 77 does not protrude into the first flow path 71, it is possible to prevent bubbles from staying in the vicinity of the side surface (region R) on the downstream side of the adhesive 77 as shown in FIG. Can do. As described above, since the bubble discharge property is improved, it is possible to prevent the bubbles from moving to the nozzle side at the time of printing and causing an ink discharge failure. Therefore, the recording head 2 with improved discharge quality is provided.

  Further, in the recording head 2 according to the present embodiment, the adhesive 77 can be provided between the reinforcing member 48 and the head case main body 47 until the exposed portion 48a protrudes. That is, the reinforcing member 48 and the head case main body 47 can be reliably bonded with the adhesive 77 without causing a gap. Thus, since the reinforcing member 48 and the head case main body 47 are reliably joined, it is possible to prevent ink from entering from these interfaces and shorting other electrical members.

  Further, the second opening 1-2 of the reinforcing member 48 has an opening edge 1-2C formed on the C surface. By providing such a C surface, the difference in inner diameter between the first opening 2-1 of the second flow path 72 and the second opening 1-2 of the first flow path 71 is reduced, and the flow of ink is smoothly performed. can do. Thereby, the bubbles in the ink can be discharged more smoothly from the second flow path 72 toward the first flow path 71.

  On the other hand, the opening 2-1C of the first opening 2-1 of the head case main body 47 is formed on the C surface. By providing such a C surface, since the adhesive 77 adheres to the opening edge portion 2-1C, it is possible to prevent an excessive amount of the adhesive 77 from adhering to the exposed portion 48a. That is, since the opening edge portion 2-1 </ b> C serves as a relief of the adhesive 77, it is possible to more reliably prevent the adhesive 77 from protruding into the first flow path 71.

  Here, suppose that the first opening and the second opening have the same shape and are formed in a straight shape, instead of the tapered shape in which the diameter of the first flow path 71 and the second flow path 72 is increased toward the downstream side. . In such a case, the inner diameters of the liquid flow paths become larger as they go upstream from the first flow path 71 of the reinforcing member 48 to the second flow path 72 of the head case body 47. For example, when the exposed portion 48a as described above is provided between the second ink supply path 29 of the second flow path member 21 and the second flow path 72, the inner diameter of the second ink supply path 29 is set to the second. It must be larger than the flow path 72. That is, as the number of members constituting the liquid flow path increases, the inner diameter of the liquid flow path becomes significantly larger.

  On the other hand, in this embodiment, the width of the first flow path 71 is narrowed from the first opening 1-1 on the downstream side toward the second opening 1-2 on the upstream side. The same applies to the second flow path 72. In other words, the inner diameters of the liquid channels can be suppressed to a certain level or less even upstream from the first channel 71 to the second channel.

  Thus, by forming a tapered flow path in each of a plurality of members such as the reinforcing member 48 and the head case main body 47, it is possible to prevent an increase in the inner diameter of the liquid flow path. That is, the inner diameter of the liquid flow path constituted by the first flow path 71 and the second flow path 72 is the same as that of the first opening 1-1 or the first opening 2-1 of the first flow path 71 or the second flow path 72. Below the inner diameter.

  Since the first flow path 71 and the second flow path 72 extend perpendicularly to the ink ejection direction of the recording head 2 (see FIGS. 4 and 7), the inside diameter of the first flow path 71 and the second flow path 72 can be suppressed below a certain level. Space saving is possible for the size of the recording head 2 in plan view (see FIG. 3).

  The positions of the first flow path 71 and the second flow path 72 and the vibrator unit 45 will be described with reference to FIG. FIG. 10 is a plan view of the reinforcing member 48. As illustrated, the reinforcing member 48 is formed with two insertion holes 40 along the longitudinal direction. Four first flow paths 71 are arranged between the insertion holes 40. One first air communication hole 73 is also disposed between these insertion holes 40.

  Although not particularly illustrated, the head case main body 47 is also provided with two accommodation cavities 46 facing the insertion holes 40, and the second flow path 72 and the first atmosphere communication are provided between the accommodation cavities 46. A hole 73 is provided.

  In the present embodiment, four first flow paths 71 (second flow paths 72) are provided corresponding to the four colors of ink, respectively. The flow path unit 39 is also provided with four manifolds 52, and each first flow path 71 communicates with each manifold 52. In addition, the compliance space 56 provided in each manifold 52 communicates with one first air communication hole 73 in common.

  As described above, since the inner diameters of the first flow path 71 and the second flow path 72 can be suppressed to a certain value or less, the two insertion holes 40 can be made as close as possible. Thereby, in the recording head 2 having the plurality of transducer units 45, it is possible to save the space in terms of the size in plan view.

  In the recording head 2 described above, when ejecting ink droplets, the volume of each pressure generating chamber 38 is changed by deformation of the vibrator unit 45 and the diaphragm 51 so that ink droplets are ejected from a predetermined nozzle 36. It has become.

  Specifically, the piezoelectric element 43 is contracted by applying a voltage to the piezoelectric element 43 of the vibrator unit 45. As a result, the diaphragm 51 is deformed together with the piezoelectric element 43 to expand the volume of the pressure generating chamber 38, and ink is drawn into the pressure generating chamber 38 from the manifold 52. Then, after the ink is filled up to the nozzle 36, the voltage applied to the piezoelectric element 43 is released according to the recording signal transmitted from the circuit board 13 via the flexible cable 33. As a result, the piezoelectric element 43 is expanded to return to the original state, and the diaphragm 51 is also displaced to return to the original state. As a result, the volume of the pressure generation chamber 38 contracts, the pressure in the pressure generation chamber 38 increases, and ink droplets are ejected from the nozzle 36.

<Other embodiments>
As mentioned above, although one Embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

  For example, the configurations of the first channel 71 and the second channel 72 are not limited to the shapes exemplified in the first embodiment. FIG. 11 is an enlarged cross-sectional view of the main parts of the first flow path 71 and the second flow path 72 according to another embodiment. In addition, the same code | symbol is attached | subjected to the same thing as Embodiment 1, and the overlapping description is abbreviate | omitted.

  As shown to Fig.11 (a), the 2nd flow path 72 may be diameter-expanded gradually from the 2nd opening 2-2 toward the 1st opening 2-1.

  Moreover, as shown in FIG.11 (b), the 2nd flow path 72 is continued from the 2nd opening 2-2, the straight part 72a which continues from the straight part 72a, and toward the 1st opening 2-1 side. You may be comprised from the taper part 72b which expanded the diameter.

  11A and 11B, the second opening 1-2 of the first flow path 71 is formed smaller than the first opening 2-1, and the exposed portion 48a is formed. ing. In addition, since the opening shape of the second opening 2-2 is smaller than the first opening 2-1, as described in the first embodiment, the inner diameters of the first flow path 71 and the second flow path 72 are made constant or less. Can be suppressed. Further, the shape of the second flow path 72 shown in FIGS. 11A and 11B may be applied to the shape of the first flow path 71.

  Further, in the first embodiment, the reinforcing member 48 is exemplified as the first member of the claims, and the head case main body 47 is exemplified as the second member. However, the present invention is not limited to such a member. For example, the first member is the head case main body 47, the second member is the second flow path member, the through hole of the first member is the second flow path of the head case main body 47, and the through hole of the second member is the second flow path. The second ink supply path 29 of the member may be used.

  In addition, the first flow path 71 and the second flow path 72 are extended in a direction perpendicular to the ink ejection surface (nozzle plate) of the recording head 2, but the present invention is not limited to such a mode. For example, the first channel 71 and the second channel 72 may extend in the horizontal direction. Also in this case, since the adhesive 77 does not protrude into the first flow path 71, the bubble discharge property is improved.

  Further, as the pressure generating means, for example, a thin film type piezoelectric element in which a lower electrode, a piezoelectric layer made of a piezoelectric material, and an upper electrode are formed by a film forming and lithography method may be used, or a green sheet is attached. A thick film type piezoelectric element formed by such a method can also be used. Also, as a pressure generating means, a heating element is arranged in the pressure generating chamber, and droplets are discharged from the nozzle opening by bubbles generated by the heat generated by the heating element, or static electricity is generated between the diaphragm and the electrode. In addition, it is possible to use a device in which a diaphragm is deformed by electrostatic force and droplets are ejected from a nozzle opening.

  In the ink jet recording apparatus 1 described above, the recording head 2 is mounted on the carriage 4 and moves in the main scanning direction. However, the present invention is not limited to this. For example, the recording head 2 is fixed, paper or the like The present invention can also be applied to a so-called line type recording apparatus that performs printing only by moving the recording sheet 6 in the sub-scanning direction.

  In each of the above embodiments, 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.

  DESCRIPTION OF SYMBOLS 1 Inkjet recording device (liquid ejecting apparatus), 2 Inkjet recording head (liquid ejecting head), 12 Flow path member, 14 Head main body, 36 nozzles, 40 Insertion hole, 41 Head case, 45 Vibrator unit, 49 Nozzle plate 71 First flow path, 72 Second flow path, 77 Adhesive, 1-1, 2-1 First opening, 1-2, 2-2 Second opening

Claims (7)

A head body that discharges liquid from a nozzle;
A liquid flow path through which liquid supplied to the head body communicates with the nozzle;
A first member and a second member each provided with a through-hole constituting a part of the liquid flow path;
Each through hole of the first member and the second member, the first opening close to the nozzle, and a second opening have far from said nozzle,
The through holes of the first member and the second member communicate with each other, the second opening side surface of the first member and the first opening side surface of the second member are joined with an adhesive,
The second opening of the first member is smaller than the first opening of the second member;
Liquid is supplied to the head body from the first opening side of the first member,
The liquid jet head according to claim 1, wherein the adhesive is attached to an outer side of the second opening of the first member on a joint surface of the first member with the second member. The liquid ejecting head according to claim 1,
The liquid ejecting head according to claim 1, wherein the through hole is formed in a tapered shape whose diameter increases from the second opening toward the first opening. The liquid ejecting head according to claim 1 or 2,
The liquid ejection head, wherein an opening edge portion of the first opening of the through hole is chamfered. In the liquid jet head according to any one of claims 1 to 3,
The liquid ejection head, wherein an opening edge portion of the second opening of the through hole is chamfered. In the liquid jet head according to any one of claims 1 to 4,
The second opening of the through hole of the first member and the second member is smaller than the first opening of the through hole of the first member and the second member.
A liquid jet head characterized by that. In the liquid jet head according to any one of claims 1 to 5 ,
The head body includes a pressure generation chamber communicating with a nozzle for discharging liquid, a plurality of pressure generation means for deforming the pressure generation chamber, and a head case to which the pressure generation means is fixed,
In the head case,
An insertion hole through which each pressure generating means is inserted is provided,
The liquid ejecting head, wherein the through hole is provided so as to be positioned between the insertion holes. A liquid ejecting apparatus comprising the liquid ejecting head according to any one of claims 1 to 6.

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