JP2008246891A - Liquid ejection head unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejection head unit which prevents an electric trouble attributable to leakage of liquid from a channel. <P>SOLUTION: In the liquid ejection head unit, a connection member 200 has insertion holes 202 formed therein into which pressing members 250 to be abutted on one surface of a head main body 100, close to the connection member 200, are inserted when the head main body 100 is connected to the connection member 200. Then a sealing member 350 has projections 353 formed thereon at locations corresponding to the insertion holes 202, respectively. Each projection 353 has an abutting portion 354 abutting on an opening rim of the insertion hole 202, for sealing the same. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid ejecting head unit that includes a plurality of head bodies that eject droplets, and more particularly, to an ink jet recording head unit that ejects ink as a liquid.

  Examples of the liquid ejecting head unit include an ink jet recording head unit (hereinafter simply referred to as a head unit) including a plurality of ink jet recording heads that eject ink droplets as droplets. As this head unit, for example, there is a head unit in which a plurality of recording head bodies are joined to a cartridge case body in which an ink cartridge filled with ink is held. In such a head unit, it is necessary to join each head body to the joining member in a state where the surfaces where the nozzles are opened are aligned so as to be on the same plane. For this reason, when joining each recording head main body to the cartridge case main body, for example, by pressing the surface opposite to the surface (ink ejection surface) where the nozzles of each recording head head main body are opened by a pressing member, The ink discharge surfaces of the recording head bodies are aligned (for example, see Patent Document 1).

Japanese Patent Laid-Open No. 2005-186587

  Here, the flow paths connecting the plurality of recording head bodies (head bodies) and the ink cartridges (storage means) are formed in a plurality of members including a cartridge case body (joining member) to which the plurality of head bodies are joined. There may be. In such a configuration, a sealing member made of an elastic material or the like is interposed between the plurality of members, and ink leakage from the connection portion of the flow path between the members is prevented by the sealing member.

  However, even if the sealing member is interposed in this way, it is difficult to completely prevent ink leakage from the connection portion of each flow path. Then, the leaked ink may reach the head body from the insertion hole into which the above-described pressing member provided on the joining member is inserted. Since the head main body is provided with pressure generating means for applying a pressure for ejecting ink droplets to the ink in the pressure generating chamber, if the leaked ink reaches the head main body, the ink is pressure generated. There is a risk of causing an electrical failure by adhering to the wiring connected to.

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

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting head unit that prevents an electrical failure of a head main body due to leakage of liquid from a flow path.

The present invention that solves the above-described problems includes a plurality of head bodies that apply pressure to the liquid in the pressure generation chamber by the pressure generation unit and eject droplets from the nozzle, and the storage unit in which the pressure generation chamber and the liquid are stored A connecting member that forms a part of the liquid flow path that connects the plurality of head main bodies, and a supply path that is fixed to the bonding member and forms the liquid flow path together with the connecting path. And a sealing member that is interposed between the joining member and the flow path member and seals a connecting portion between the communication path and the supply path. An insertion hole into which a pressing member that comes into contact with the surface of the head body on the side of the joining member when the main body is joined to the joining member is provided, and the seal member has an insertion hole. Abuts the periphery of the opening A liquid ejecting head unit, wherein a protruding portion for sealing the insertion hole has a contact portion is provided in correspondence with the insertion holes.
In the present invention, the insertion hole can be reliably and easily sealed by the protrusion of the seal member. Therefore, it is possible to reliably prevent the liquid from entering the insertion hole and causing an electrical failure.

  Here, it is preferable that a tip end portion of the protrusion portion is formed of a spherical surface having a diameter larger than the inner diameter of the insertion hole and serves as the contact portion. Thereby, the contact part of a projection part contact | abuts more reliably to the opening periphery of an insertion hole, and an insertion hole is sealed more favorably.

  In addition, when the opening on the flow path member side of the insertion hole has a large diameter portion having an inner diameter larger than that of the main body portion of the insertion hole, a contact portion of the projection portion is formed on the opening periphery of the main body portion. You may make it have an engaging part which contact | abuts and the said projection part engages with the said large diameter part. Even if the protruding portion has such a shape, the insertion hole can be more reliably sealed.

  Further, the protruding portion is an insertion portion that is inserted into the insertion hole at the tip side from the contact portion, and at least a part of the insertion portion is formed with a diameter substantially the same as the inner diameter of the insertion hole. You may be made to do. Even if the protruding portion has such a shape, the insertion hole can be more reliably sealed.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing a head unit according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of the head unit shown in FIG. FIG. 3 is an exploded perspective view of the head body, and FIG. 4 is a cross-sectional view of the head body.

  As shown in FIGS. 1 and 2, the head unit 1 according to the present embodiment includes a plurality of head main bodies 100, a holder 200 that is a joining member to which the plurality of recording head main bodies 100 are joined, and the holder 200. It has a cartridge case 300 that is a flow path member fixed to the surface opposite to the head main body 100.

  First, the recording head main body 100 will be described in detail. As shown in FIGS. 3 and 4, the flow path forming substrate 101 constituting the recording head main body 100 is made of, for example, a silicon single crystal substrate, and an elastic film 102 made of silicon dioxide is formed on one surface thereof. A plurality of pressure generating chambers 103 are arranged in parallel on the flow path forming substrate 101 by anisotropic etching from the other side. For example, in this embodiment, two rows of pressure generation chambers 103 arranged in parallel in the width direction are formed on the flow path forming substrate 101. Outside the row of each pressure generating chamber 103, a communicating portion 104 is formed which communicates with a reservoir portion provided on a reservoir forming substrate, which will be described later, and constitutes a reservoir serving as a common ink chamber for each pressure generating chamber 103. . The communication unit 104 is in communication with one end in the longitudinal direction of each pressure generation chamber 103 via the ink supply path 105.

  A nozzle plate 107 having a nozzle 106 communicating with the pressure generating chamber 103 is fixed to the opening surface side of the flow path forming substrate 101 via an adhesive, a heat welding film, or the like.

  On the other hand, on the elastic film 102 opposite to the opening surface of the flow path forming substrate 101, for example, a lower electrode film made of metal, a piezoelectric layer made of lead zirconate titanate (PZT), and the like, and metal The piezoelectric element 108 formed by sequentially laminating the upper electrode film is formed. A reservoir forming substrate 110 having a reservoir portion 109 is bonded onto the flow path forming substrate 101 on which such a piezoelectric element 108 is formed. In this embodiment, the reservoir portion 109 is formed across the reservoir forming substrate 110 in the thickness direction and across the width direction of the pressure generating chamber 103. As described above, the communication portion 104 of the flow path forming substrate 101 is formed. The reservoir 111 is configured to be in communication with the pressure generating chamber 103 and serve as a common ink chamber.

  A piezoelectric element holding portion 112 having a space that does not hinder the movement of the piezoelectric element 108 is provided in a region facing the piezoelectric element 108 of the reservoir forming substrate 110. Further, a drive IC 113 for driving each piezoelectric element 108 is provided on the reservoir forming substrate 110. Each terminal of the drive IC 113 is connected to a lead wire 114 drawn from an individual electrode of each piezoelectric element 108 via a bonding wire or the like (not shown). Each terminal of the driving IC 113 is connected to an external wiring 115 such as a flexible printed circuit board (FPC), and various signals such as a print signal are sent to the driving IC 113 via the external wiring 115.

  On such a reservoir forming substrate 110, a compliance substrate 116 is bonded. An ink inlet 117 for supplying ink to the reservoir 111 is formed in a region facing the reservoir 111 of the compliance substrate 116. Further, the area of the compliance substrate 116 other than the ink introduction port 117 in the area facing the reservoir 111 is a flexible portion 118 formed thin in the thickness direction. The reservoir 111 is sealed by the flexible portion 118. It has been stopped.

  Further, a head case 119 is bonded onto the compliance substrate 116. The head case 119 is provided with an ink supply communication path 120 that communicates with an ink introduction port 117 and communicates with an ink communication path (described later) of the holder 200. Since the ink inlets 117 are provided corresponding to the respective reservoirs 111, two ink supply communication paths 120 are also formed in each head case 119. The head case 119 has a recess 121 in a region facing the flexible portion 118 of the compliance substrate 116. Further, the head case 119 is provided with a driving IC holding part 122 penetrating in the thickness direction in a region facing the driving IC 113 provided on the reservoir forming substrate 110, and the external wiring 115 is connected to the driving IC holding part 122. And is connected to the drive IC 113.

  Further, the head case 119 is provided with a beam portion 123 across the central portion of the IC holding portion 122. As will be described in detail later, the recording head main body 100 is favorably bonded to the holder 200 by pressing the recording head main body 100 by bringing a pressing member into contact with the beam portion 123.

  In the present embodiment, the four recording head main bodies 100 are respectively joined to the holder 200 on the head case 119 side. Each of the four recording head bodies 100 is joined to a single fixed plate 130 with the surface on which the nozzle 106 is opened positioned with high accuracy, and is integrated with the fixed plate 130. The head case 119 side of 100 is joined to the holder 200. The fixing plate 130 is formed with openings 131 corresponding to the respective recording head main bodies 100, and each recording head main body 100 is joined to the peripheral edge of the opening 131 by an adhesive or the like.

  As shown in FIG. 2, the holder 200 to which the plurality of recording head main bodies 100 are joined is provided with an ink communication path 201 that communicates with the ink supply communication path 120 formed in the head case 119. . The holder 200 is provided with an insertion hole 202 at a portion corresponding to the central portion of each recording head main body 100. The insertion hole 202 is provided for inserting a pressing member that presses each recording head main body 100 in the manufacturing process.

  Here, when the recording head main body 100 is joined to the holder 200, for example, as shown in FIG. 5A, a predetermined jig is used with a plurality of recording head main bodies 100 being joined to the fixed plate 130. A needle-like pressing member 250 is inserted into each insertion hole 202 of the holder 200 that is disposed above and disposed opposite to the recording head main body 100, and the tip of the pressing member 250 is inserted into each recording head main body 100. Press and abut. That is, the front end portion of the pressing member 250 is brought into contact with the beam portion 123 of each head case 119 to press each recording head main body 100 toward the fixed plate 130 side.

  Then, as shown in FIG. 5B, the holder 200 is pressed toward the recording head main body 100 while pressing each recording head main body 100 with a predetermined force by the pressing member 250. That is, in a state in which the beam portion 123 of each recording head main body 100 is individually pressed by the tip portion of each pressing member 250, the holder 200 is pressed toward the recording head main body 100 to join them.

  Thereby, the head case 119 and the holder 200 of each recording head main body 100 can be favorably joined. That is, since the holder 200 is joined in a state where each recording head main body 100 is fixed by the pressing member 250, it is possible to prevent each recording head main body 100 from being inclined. The pressing member 250 is removed after the recording head main body 100 and the holder 200 are joined.

  As shown in FIGS. 1 and 2, the cartridge case 300 is fixed to a surface of the holder 200 opposite to the recording head main body 100, and an ink cartridge (not shown) which is an ink storage unit in which ink is stored. Each has a mounting portion 301 to be mounted. Of course, the ink cartridge is not directly mounted on the mounting portion 301, but the ink cartridge is placed in another area in the printer, and the ink is drawn from the ink cartridge with a tube (not shown) having flexibility. A tube may be connected to 301. For example, in the present embodiment, the ink cartridge is configured as a separate body filled with black and a plurality of color inks, and each color ink cartridge is mounted in the cartridge case 300. The cartridge case 300 is provided with a plurality of ink supply paths 302 having one end opened to each mounting portion 301 and the other end opened to the holder 200 side. Further, an ink supply needle 310 inserted into the ink cartridge is fixed to an opening portion of the ink supply path 302 of the mounting portion 301 via a filter (not shown) for removing bubbles and foreign matters in the ink. Yes. When the ink is drawn around with the tube, it is not necessary to provide the ink supply needle 310 in the mounting portion 301. Here, in any of the above forms, a member that supplies ink from the ink storage means to the recording head main body 100 is referred to as a “cartridge case”.

  Such a cartridge case 300, the recording head main body 100, and the holder 200 are integrated by a cover head. A holder 200 to which the recording head main body 100 is joined is disposed on the lower surface side of the cartridge case 300, and a cover head 400 having a window 401 that exposes the nozzle 106 of the recording head main body 100 is fitted on the outside of each member. The members are integrated by being fixed to the cartridge case 300 with screws 402 or the like.

  As shown in FIG. 6, a seal member 350 made of an elastic material such as a rubber material is interposed between the cartridge case 300 and the holder 200. Each ink supply path 302 and the ink communication path 201 are connected through a through hole 351 formed in the seal member 350. By interposing the seal member 350 in this way, the connection portion between each ink supply path 302 of the cartridge case 300 and each ink communication path 201 of the holder 200 is sealed by the seal member 350, Prevents ink leakage. For example, in the present embodiment, the protrusion 205 is formed at the opening of the ink communication path 201 of the holder 200. Further, a convex portion 352 is provided on the surface of the seal member 350 on the cartridge case 300 side corresponding to the ink supply path 302, and a through hole 351 is formed in the convex portion 352.

  Here, since the seal member 350 is interposed between the cartridge case 300 and the holder 200 in this way, the connection portion between each ink supply path 302 and the ink communication path 201 is sealed, so that the ink leaks to some extent. Can be prevented. However, it is difficult to completely prevent the leakage of ink from the connection portion by the seal member 350 after long-time use. Then, there is a possibility that ink leaking from the connection portion enters the insertion hole 202 provided in the holder 200 and adheres to the recording head main body 100 to cause an electrical failure.

  For this reason, in the present invention, as shown in FIG. 7, for example, as shown in FIG. 7, a protrusion 353 that protrudes toward the insertion hole 202 is provided at a portion corresponding to each insertion hole 202 of the seal member 350. The hole 202 was sealed. That is, the seal member 350 is provided with a projection 353 having an abutment portion 354 that abuts the periphery of the opening of the insertion hole 202, and each insertion hole 202 is sealed by the projection 353. The projecting portion 353 according to the present embodiment includes a base portion 355 having a conical shape whose diameter gradually decreases from the surface of the seal member 350 toward the distal end side, and a substantially spherical spherical portion 356 provided at the distal end portion. It is configured. The spherical portion 356 is formed with a diameter larger than the inner diameter of the insertion hole 202, and the spherical portion 356 serves as a contact portion 354 that contacts the peripheral edge portion of the insertion hole 202. The inside of the insertion hole 202 can be sealed.

  By sealing each insertion hole 202 with the protrusion 353 in this manner, even if ink leaks from the connection portion between the ink supply path 302 and the ink communication path 201, the ink enters the insertion hole 202. Therefore, the occurrence of electrical failure can be reliably prevented.

  Note that the shape of the protrusion 353 is not particularly limited as long as it has a contact portion 354 that contacts the opening periphery of the insertion hole 202.

  For example, as shown in FIG. 8A, when the insertion hole 202 has a large diameter portion 204 having an inner diameter larger than the main body portion 203 of the insertion hole 202 at the opening on the cartridge case 300 side, the protrusion 353 is provided. Preferably includes an abutting portion 354 that abuts on the peripheral edge of the opening of the main body portion 203 and an engaging portion 357 that engages with the large diameter portion 204. Thereby, the insertion hole 202 can be more reliably sealed. In addition, when providing such an engaging part 357, as shown in FIG.8 (b), you may make it make the corner | angular part 357a of the engaging part 357 into R shape. Accordingly, the engaging portion 357 is easily engaged with the large diameter portion 204 of the insertion hole 202, and the insertion hole 202 can be further reliably sealed.

  For example, as shown in FIG. 9, the protrusion 353 is provided with an engaging portion 357 that engages with the large-diameter portion 204, and substantially the same as the main body portion 203 of the insertion hole 202 on the distal end side of the engaging portion 357. A spherical portion 358 having the same diameter may be provided, and the spherical portion 358 may be inserted into the main body portion 203 of the insertion hole 202. That is, an insertion portion that is inserted into the main body portion 203 of the insertion hole 202 may be provided at the distal end portion of the projection portion 353. Of course, the insertion hole 202 can be reliably sealed even with such a projection 353.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to what was mentioned above. For example, in Embodiment 1 described above, a head unit having a flexural vibration type piezoelectric element is illustrated, but the present invention is not limited to this. For example, the present invention provides a shaft in which piezoelectric materials and electrode forming materials are alternately stacked. Applied to head units with various structures such as a head unit having a longitudinal vibration type piezoelectric element that expands and contracts in the direction and a head unit that includes a heating element and ejects ink droplets by bubbles generated by the heat generated by the heating element. It goes without saying that it can be done.

  Further, the head unit having an ink jet recording head (recording head main body) that discharges ink has been described as an example. However, the present invention is intended for a liquid ejecting head unit having a liquid ejecting head widely. Examples of the liquid ejecting head include a recording head used for an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an electrode formation such as an FED (field emission display). Electrode material ejecting heads used in manufacturing, bioorganic matter ejecting heads used in biochip production, and the like.

FIG. 3 is an exploded perspective view of the head unit according to the first embodiment. FIG. 3 is a cross-sectional view of the head unit according to the first embodiment. FIG. 3 is an exploded perspective view of the recording head body according to the first embodiment. FIG. 3 is a cross-sectional view of the recording head body according to the first embodiment. 5 is a cross-sectional view illustrating an example of a method for manufacturing the head unit according to Embodiment 1. FIG. FIG. 3 is an enlarged cross-sectional view illustrating a main part of the head unit according to the first embodiment. FIG. 3 is an enlarged cross-sectional view illustrating a main part of the head unit according to the first embodiment. FIG. 6 is an enlarged cross-sectional view illustrating a modified example of the head unit according to the first embodiment. FIG. 6 is an enlarged cross-sectional view illustrating a modified example of the head unit according to the first embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Head unit, 100 Recording head main body, 101 Flow path formation board, 102 Elastic film, 103 Pressure generating chamber, 104 Communication part, 105 Ink supply path, 106 Nozzle, 107 Nozzle plate, 108 Piezoelectric element, 109 Reservoir part, 110 Reservoir Forming substrate, 111 reservoir, 112 piezoelectric element holding portion, 113 driving IC, 114 lead-out wiring, 115 external wiring, 116 compliance substrate, 117 ink introduction port, 118 flexible portion, 119 head case, 120 ink supply communication path, 121 recess 122 IC holding part, 123 beam part, 130 fixing plate, 131 opening part, 200 holder, 201 ink communication path, 202 insertion hole, 203 main body part, 204 large diameter part, 205 protruding part, 2 0 Pressing member, 300 Cartridge case, 301 Cartridge mounting portion, 302 Ink supply path, 310 Ink supply needle, 350 Seal member, 351 Through hole, 352 Convex portion, 353 Protruding portion, 354 Abutting portion, 355 Base portion, 356 Spherical part, 357 engaging part, 358 spherical part, 400 cover head, 401 window part, 402 screw

Claims (4)

Part of a liquid flow path that connects a plurality of head bodies that apply pressure to the liquid in the pressure generation chamber by the pressure generation means and eject droplets from the nozzles, and the storage means in which the liquid is stored A joining member to which the plurality of head main bodies are joined, a flow path member having a supply passage fixed to the joining member and constituting the liquid passage with the communicating path, and the joining member And a seal member that is interposed between the flow path member and seals a connection portion between the communication path and the supply path,
The joint member is provided with an insertion hole into which a pressing member that comes into contact with the surface of the head body on the joint member side when the head body is joined to the joint member, and the seal The liquid ejecting head unit according to claim 1, wherein the member has a contact portion that contacts the periphery of the opening of the insertion hole, and a protrusion that seals the insertion hole is provided corresponding to each insertion hole.   2. The liquid ejecting head unit according to claim 1, wherein a tip portion of the projecting portion is formed of a spherical surface having a diameter larger than an inner diameter of the insertion hole and serves as the contact portion.   The opening on the flow channel member side of the insertion hole has a large-diameter portion having a larger inner diameter than the main body portion of the insertion hole, and the abutting portion of the projection portion contacts the opening periphery of the main body portion, The liquid ejecting head unit according to claim 1, wherein the protrusion has an engaging portion that engages with the large diameter portion.   The protruding portion is an insertion portion that is inserted into the insertion hole at the tip side from the contact portion, and at least a part of the insertion portion is formed with a diameter substantially the same as the inner diameter of the insertion hole. The liquid ejecting head unit according to claim 1, wherein:

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