JP2013184451A - Inkjet head and inkjet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ink from being entered and accumulated to a gap between a head cover and a head member.SOLUTION: A closed space 32 is formed between a recess 31 provided near a nozzle plate 21 on the side surface of a head structure 10 and a head cover 20, and the closed space is filled with a sealing material 34. A through-hole 33 for a sealing material filling path is opened in a base plate 30 on the back surface of the head structure 10.

Description

  The present invention relates to an inkjet head and an inkjet recording apparatus.

  Inkjet recording apparatuses are widely used as image recording apparatuses or image forming apparatuses such as printers, facsimiles, and copying machines.

  For the ink jet head used in this ink jet recording apparatus, a nozzle cover (ink droplet discharge port) is used to protect the head cover from external force due to contact with the wiper during nozzle cleaning or collision with the recording paper during recording paper jam. There is known a configuration in which the nozzle plate is mounted so as to cover from the nozzle plate side on which the is formed.

  However, it is difficult to close the gap between the head cover and the nozzle plate just by bringing the head cover made by drawing a thin metal plate material into contact with the peripheral edge of the nozzle plate. There is a problem that the head cover is deformed and a gap between the nozzle plate and the head cover is enlarged, and ink penetrates and accumulates between the nozzle plate and other head members and the head cover.

  In order to improve this problem, it is conceivable to join the peripheral portion of the nozzle plate and the head cover using an adhesive. However, sufficient adhesive strength cannot be obtained between the nozzle plate surface treated with a liquid repellent material containing fluorocarbon or the like for the purpose of suppressing ink adhesion and the head cover.

  In order to increase the adhesive strength of the head cover, a configuration in which the peripheral portion of the nozzle plate joined to the head cover is a non-liquid-repellent treatment surface is disclosed in Patent Document 1 (FIGS. 1, 2, and paragraphs 0030 to 0030 of Patent Document 1). 0032). However, it is necessary to remove the liquid repellent material film on the peripheral edge of the nozzle plate after the liquid repellent treatment, or to apply a mask to the peripheral edge of the nozzle plate in advance to form a liquid repellent material, which increases the number of manufacturing processes. Cost. In order to prevent the adhesive from sticking out to the nozzle surface, it is necessary to consider using a film adhesive, which also causes a problem such as high cost.

  Rather than bonding the nozzle plate and the head cover, the outer shape of the head frame of the drive unit joined to the liquid chamber unit (laminated unit of nozzle plate and diaphragm) is made larger than the liquid chamber unit and protrudes from the side of the liquid chamber unit A configuration in which the peripheral portion of the head frame and the vicinity of the nozzle plate of the head cover are joined by an adhesive is also disclosed in Patent Document 1 (see FIG. 3 of Patent Document 1 and paragraph 0038). However, with the nozzle plate facing upward, the adhesive is applied to the periphery of the head frame so that it rises up to the height of the nozzle plate, making it difficult to apply the adhesive and manage the amount of application. There are problems such as insufficient adhesive strength due to insufficient coating amount and swelling amount.

  A main object of the present invention is an ink jet that can more reliably prevent ink from penetrating and accumulating between a head member such as a nozzle plate and a head cover, and avoiding the problems as in the configuration of Patent Document 1. To provide a head.

In order to solve the above problem, the invention according to claim 1
A head structure having a function of ejecting ink droplets from nozzle holes provided in the nozzle plate in response to an electrical signal supplied from the outside; and a head cover that covers a peripheral portion of the nozzle plate and a side surface of the head structure. In an inkjet head comprising:
A closed space formed between a recessed portion including an end surface of the nozzle plate provided on a side surface of the head structure and the head cover;
A sealing material filled in the closed space;
An inkjet head having a through-hole that is open as a surface opposite to the nozzle plate of the head structure and can be used as a sealing material filling path into the closed space.

  According to the present invention, it is possible to more reliably prevent ink from penetrating and accumulating into the gap between the nozzle plate and the head cover in the ink jet head, and avoid problems as in the configuration disclosed in Patent Document 1. it can.

1 is a schematic external perspective view of an ink jet according to an embodiment of the present invention. 2 is a schematic exploded perspective view of the inkjet head. FIG. It is a general | schematic disassembled perspective view of the head structure of the said inkjet head. It is explanatory drawing of the cross-sectional structure of the said head structure. It is explanatory drawing of the cross-section of the state which filled the sealing material in the side surface closed space of the said head structure. It is explanatory drawing of the sealing material filling process to the side surface closed space of the said head structure. 2 is a schematic external perspective view showing a state in which the inkjet head is mounted on an example of a carriage. FIG. It is a schematic diagram for demonstrating an example of the inkjet recording device in which the said inkjet head is used.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic external perspective view of an inkjet head according to an embodiment of the present invention, and FIG. 2 is a schematic exploded perspective view of the inkjet head.

  As shown in FIGS. 1 and 2, an inkjet head 100 according to this embodiment includes a head structure 10 having an ink droplet ejection function, a side surface of the head structure 10, a peripheral portion of an ink droplet ejection surface 21c, and the like. The head cover 20 is generally composed of a housing 40, and a connector board 42 fixed to the housing 40.

  The ink jet head 100 is mounted on a carriage of an ink jet recording apparatus. FIG. 7 shows an example of a carriage on which the inkjet head 100 is mounted.

  The housing 40 holds the head structure 10, the head cover 20, and an ink cartridge or an ink tank (not shown), and is usually molded. The housing 40 is associated with a position reference surface 40a serving as a position reference in a direction perpendicular to the ink droplet discharge surface 21c when mounted on the carriage 93 (FIG. 7), and an opening 93d (FIG. 7) on the side surface of the carriage 93. A projection 40c to be joined and an ink supply port 73 connected to the ink flow path inside the head structure 10 are provided. A seal member 44 is attached to the ink supply port 73. As the material of the seal member 44, an elastic body having high solvent resistance to ink can be used. Specifically, for example, fluorine rubber, silicone rubber, or EPDM (ethylene propylene diene rubber) can be suitably used.

  The connector substrate 42 has a plurality of pads 42 a that are electrically connected to connectors (not shown) provided on the carriage 93, and a drive IC for driving the electromechanical transducer inside the head structure 10. (Not shown) and FPC (Flexible Printed Circuit) 41 are connected. An electrical signal supplied from the ink jet recording apparatus is transmitted to a drive IC of an electromechanical transducer in the head structure 10 via a connector (not shown) of the carriage 93, a connector substrate 42, and an FPC 41. The head structure 10 and the head cover 20 are fastened and fixed to the housing 40 with screws 43, and screw holes 40 f for that purpose are provided in the housing 40.

  The head structure 10 has a function of ejecting ink droplets from nozzle holes (ink droplet ejection openings) provided on the ink droplet ejection surface 21c in accordance with an electrical signal supplied from the outside via the FPC 41. , A plurality of individual liquid chambers corresponding to the nozzle holes, a means (actuator) for generating pressure for ejecting ink in the individual liquid chambers as droplets from the nozzles, and for supplying ink to a plurality of individual liquid chambers The ink flow path is provided. Next, a specific structure of the head structure 10 will be described.

  FIG. 3 is a schematic exploded perspective view of the head structure 10. FIG. 4 is an explanatory diagram of a cross-sectional structure of the head structure 10.

  The head structure 10 includes a nozzle plate 21, an actuator substrate 22, ink flow path substrates 23, 24, 25, damper members 26, 27, and a base plate 30 as constituent members, and these constituent members are laminated and joined in the illustrated order. There is an internal cross-sectional structure schematically shown in FIG.

  The nozzle plate 21 has a nozzle hole row 21b in which a plurality of nozzle holes (ink droplet discharge ports) 21a (FIG. 4) are arranged. In the present embodiment, four nozzle hole rows 21b are provided in parallel. The surface on the exposed side of the nozzle plate 21 (the upper surface in FIG. 3) is an ink droplet ejection surface 21c.

  The actuator substrate 22 includes a nozzle hole for supplying ink to the nozzle hole 21a of the nozzle plate 21 and an individual liquid chamber (frequently referred to as a pressurized liquid chamber or a pressure generation chamber) 22f corresponding to the nozzle hole, and a diaphragm. An electromechanical transducer 22h composed of a lower electrode, a piezoelectric body, and an upper electrode sequentially formed on 22g, a drive IC 22i for driving the electromechanical transducer 22h, and nozzle holes connected to a plurality of individual liquid chambers 22f A common liquid chamber 22j corresponding one-to-one with the row 21b is provided. The electromechanical conversion element 22h converts the electrical signal supplied from the drive IC 22i into mechanical vibration, and ink inside the individual liquid chamber 22f is passed through the vibration plate 22g forming one wall surface of the individual liquid chamber 22f by this mechanical vibration. And act as a piezoelectric actuator for ejecting ink in the individual liquid chambers as ink droplets from the nozzle holes 21a.

  The ink flow path substrates 23, 24, and 25 are connected to the common liquid chamber 22j in the actuator substrate 22, and have a one-to-one correspondence with the common liquid chamber 22j (also referred to as a common liquid chamber) 23j, 24j, and 25j. Have The damper members 26 and 27 are members for suppressing residual fluid vibration in the common liquid chamber.

  The sizes of the short sides (sides orthogonal to the nozzle hole row 21b) of the nozzle plate 21 and the actuator substrate 22 are narrower than the sizes of the short sides of the ink flow path substrates 23, 24, 25 and the damper members 26, 27. ing. As a result, as shown in FIG. 4, a recess 31 is formed on the long side surface of the head structure 10 with the end surface of the actuator substrate 22 and the end surface of the nozzle plate 21 as the bottom surface.

  The base plate 30 has a position reference surface 30a that serves as a position reference in the recording paper transport direction Y (FIG. 7) when mounted on the carriage 93, and a hole 30f through which the screw 43 passes. The base plate 30 and the damper members 25, 26 have four ink supply holes 30c, 27c, 26c for supplying ink to the common liquid chamber of the ink flow path substrate at corresponding positions. Further, the ink flow path substrates 23, 24, 25, the damper members 26, 27, and the base plate 30 are provided at corresponding positions at the pin alignment openings 23b, 24b, 25b, 26b, 27b, 30b, and the sealing material filling path. It has holes 23d, 24d, 25d, 26d, 27d, and 30d.

  In the present embodiment, the nozzle plate 21 has four nozzle hole rows 21b, and ink of four colors can be ejected by supplying different color inks for each nozzle hole row. As the material of the nozzle plate 21, it is preferable to use a plate material such as SUS, and it is preferable to form the nozzle hole by a press working method. Further, the nozzle plate 21 is surface-treated with a liquid repellent material in order to prevent ejection failure such as ink droplet ejection bending due to uneven adhesion of ink. As the liquid repellent material, an organic material containing fluorocarbon having a small surface energy can be suitably used, and a material applied to the surface of the nozzle plate 21 by a vapor deposition method or a dipping method is preferably used.

  The electromechanical transducer 22h of the actuator substrate 22 is formed by a film formation method using a sol-gel method and a semiconductor process, for example. According to this, it is easy to increase the density of the electromechanical transducer 22h. Here, the sol-gel method is an inorganic oxide that is completed by hydrolyzing and polycondensing a metal organic compound such as a metal alkoxide in a solution system to grow a metal-oxygen-metal bond and finally sintering. This is a manufacturing method. Specifically, as a piezoelectric material film formed by the sol-gel method, lead acetate, isopropoxide zirconium, and isopropoxide titanium are used as starting materials, and these starting materials are dissolved in methoxyethanol as a common solvent. A lead zirconate titanate (PZT) -based material can be preferably used.

  The ink flow path substrates 23, 24, 25, the damper members 26, 27, and the base plate 30 can be easily formed if they are formed in a flat plate shape using the same type of metal plate material, and heat treatment is performed at the time of joining them. Even if it goes, it does not warp due to thermal expansion difference. As the metal plate material, SUS or Fe—Ni alloy can be preferably used. Examples of the processing method include a press processing method, an etching method, and a laser processing method, and the press processing method can be suitably used from the viewpoint of cost.

  Next, the assembly process of the inkjet head 100 will be described.

  First, the first structure 61 composed of the nozzle plate 21 and the actuator substrate 22, and the second structure 62 composed of the ink flow path substrates 23, 24, 25, the damper members 26, 27, and the base plate 30 are assembled separately. Next, the first structure and the second structure are joined to form one head structure 10.

  For the first structure 61, the alignment pattern on the actuator substrate 22 is optically observed through a pin alignment opening hole having a diameter of about several tens to several hundreds of μm formed in the longitudinal direction of the nozzle plate 21. Thus, the nozzle plate 21 and the actuator substrate 22 are aligned. Then, the nozzle plate 21 and the actuator substrate 22 are bonded to each other by pressurizing and heating the actuator substrate 22 and the nozzle plate 61 in which an adhesive is previously applied to the bonding surface. As an adhesive for this bonding, an adhesive having high solvent resistance to the ink used can be used, and specifically, a thermosetting adhesive containing an epoxy resin or a silicone resin is preferably used. be able to. One end of the FPC 41 is connected to the actuator substrate 61.

  For the second structure 62, the ink flow path substrates 23, 24, 25, the damper members 26, 27, and the base plate 30 that are preliminarily coated with a thermosetting adhesive on the bonding surfaces are sequentially stacked on a bonding jig (not shown). Then, bonding is performed by applying pressure and heating. Alignment is performed by pin bonding openings 23b, 24b, 25b, 26b, 27b, and 30b provided at corresponding positions of the ink flow path substrates 23, 24, and 25, the damper members 26 and 27, and the base plate 30. By inserting.

  Next, the pin alignment opening hole provided in the surface of the nozzle plate 21 of the first structure 61 and the position reference surface 30a of the base plate 30 of the second structure 62 are optically aligned, and the bonding surface is previously formed. The 1st structure 61 and the 2nd structure 62 which apply | coated the said thermosetting adhesive are joined by pressurizing and heating. Thus, the head structure 10 in which the base plate 30 having the position reference surface that engages with a specific portion of the carriage and the nozzle plate 21 are positioned with high accuracy is completed.

  Further, in the present embodiment, it is not necessary to arrange the pin alignment opening hole in the actuator substrate 22, and the outer shape of the actuator substrate 22 is formed in millimeter order smaller than the outer shape of the ink flow path substrates 23, 24, 25. The number of actuator substrates taken from the wafer can be increased accordingly. Therefore, the cost can be reduced as compared with the conventional inkjet head in which the piezoelectric element is formed using the MEMS technology.

  The head structure 10 and the head cover 20 completed as described above are fastened and fixed to the housing 40 with screws 43 as shown in FIG. As a result, the ink supply hole 30 c of the base plate 30 and the seal member 44 are coupled, and the ink supply port 73 and the ink flow path (common liquid chamber) of the head structure 10 are connected via the seal member 44. The FPC 41 having one end connected to the actuator substrate 22 of the head structure 10 is bent toward the housing 40, and the other end is connected to the connector substrate 42. Thus, the drive IC in the actuator substrate 22 and the connector substrate 42 are electrically connected.

  The head cover 20 includes a substantially box-shaped part 20a and a flange part 20b. In a state where the head cover 20 is fastened and fixed, the ink droplet discharge surface 21c of the head structure 10, that is, the peripheral portion of the front side surface of the nozzle plate 21, the nozzle plate 21 forming the side surface of the head structure 10, the actuator substrate 22, and the ink flow path. Substrate 23, 24, 25, the end surface of damper member 26, 27, and the connection part with the actuator board | substrate 22 of FPC41 are covered with the substantially box-shaped part 20a. In addition, the flange 20b of the head cover 20 covers a surface portion of the base plate 30 that extends outward from the damper member 27. A hole 20f through which the screw 43 is passed is formed in the flange portion 20b. The same SUS as that of the nozzle plate 21 can be used as the material of the head cover 20, but is not limited to this.

  As described above, the recess 31 is formed on the nozzle plate side of the long side surface of the head structure 10 (see FIG. 4). Therefore, as shown in FIG. 5, a closed space 32 is formed by the recessed portion 31 on the side surface of the head structure 10 and the head cover 20 covering the recessed portion 31. The base plate of the head structure 10 is formed by holes 23d, 24d, 25d, 26d, 27d, and 30d provided at corresponding positions of the ink flow path substrates 23, 24, and 25, the damper members 26 and 27, and the base plate 30 of the head structure 10. A through hole 33 penetrating from 30 to the ink flow path substrate 23 and communicating with the closed space 32 is formed. By using the through hole 33 as a sealing material filling path and filling the closed space 32 with the sealing material 34 as shown by hatching, the inkjet head 100 of this embodiment is completed. In addition, the cross-sectional shape of the closed space 32 or the hollow part 31 is not necessarily limited to what was shown in FIG.4 and FIG.5. The member structure of the head structure 10 is not limited to that shown in FIG. 3, and an electrostatic actuator or the like can be used as a means for generating pressure for ejecting ink droplets.

  FIG. 6 is an explanatory diagram of the sealing material filling step into the closed space 32. The housing 40 has an ink flow path member 70. The ink flow path member 70 has a plurality of protrusions 72 into which ink cartridges or ink tanks 95 (FIG. 8) corresponding to the common liquid chambers (ink flow paths) of the head structure 10 are fitted. The ink flow path member 70 is provided with an opening hole 71 corresponding to the sealing material filling path through hole 33 (23d, 24d, 25d, 26d, 27d) of the head structure 10. The syringe 300 of the dispenser is inserted into the sealing material filling path through hole 33 through the opening hole 71 and the sealing material 34 is filled into the closed space 32. As this sealing material, it is preferable to use an adhesive having high solvent resistance to the ink used, and specifically, an adhesive containing an epoxy resin or a silicone resin can be preferably used.

  With the sealing structure as described above, the gap between the head cover 20 and the constituent members such as the nozzle plate 21 and the actuator substrate 22 of the head structure 10 is well sealed. In addition, since the actuator substrate 22 and the ink flow path substrate 23 of the head structure 10 and the head cover 20 are firmly bonded to each other with a sufficient adhesion area by the sealing material, external force due to the collision of the recording paper or the contact of the wiper is generated. Even if added, deformation of the head cover 20 and expansion of the gap between the head cover 20 and the head structure 10 can be prevented. Therefore, it is possible to more reliably prevent ink permeation and accumulation between the head cover 20 and the nozzle plate 21 of the head structure 10. In the filling operation of the sealing material into the closed space 32, there is no problem of management of the application amount / swelling amount of the adhesive and insufficient adhesion area as in the configuration of FIG.

  The head cover 20 is preferably drawn on the bottom surface portion (the portion in contact with the nozzle plate 21) in order to suppress the flow of the sealing material, but when a gap is formed by bending. However, the gap is sealed in advance with a sealing material, filled with a sealing material on a jig on which a soft member having sealing properties is disposed, or the viscosity of the sealing material is adjusted appropriately. Therefore, it is possible to suppress the flow of the sealing material from the gap.

  In the ink jet recording apparatus, image recording is performed while the ink jet head 100 is moved in the main scanning, and this main scanning moving direction is usually a direction orthogonal to the nozzle hole row 21b. Therefore, external force due to the collision of the recording paper or the contact of the nozzle cleaning wiper is mainly applied to the side wall portion of the head cover 20 on the long side of the nozzle plate 21. Further, since the ink deposited in the gap between the long side portion of the nozzle plate 21 and the head cover 20 is directly linked to the contamination of the recorded image, it is necessary to suppress the enlargement of the gap between the long side portion of the nozzle plate 21 and the head cover 20 as much as possible. From the above, the configuration in which the closed space 31 is formed on the side surface of the head structure 10 on the long side of the nozzle plate and the sealing material is filled is effective. However, it is also possible to form a similar closed space on the side surface of the head structure 10 on the short side of the nozzle plate and fill with the sealing material.

  The diameter, arrangement, and number of the through hole 33 for sealing material filling path and the opening hole 71 may be appropriately changed. It is also possible to use a through hole provided for another purpose as a sealing material filling path without providing a dedicated through hole for the sealing material filling path. For example, the pin alignment openings 23b, 24b, 25b, 26b, 27b, and 30b can be used as the sealing material filling path.

  The ink jet head 100 is used by being mounted on a carriage 93 as shown in FIG. For example, the inkjet head 100 is mounted in the following procedure. The ink jet head 100 is pushed into the carriage 93 from the lower side in the drawing, and the ink droplet ejection surface 21 c is projected from the window 93 c of the carriage 93. While the position reference surface 40 a of the ink jet head 100 is brought into contact with the inner wall surface of the carriage 93, the ink jet head 100 is slid in the direction of arrow A, and the position reference surface 30 a is engaged with the positioning protrusion 93 a of the carriage 93. At this time, the protrusion 40 c of the inkjet head 100 is engaged with the opening 93 d of the carriage 93, and the inkjet head 100 is fixed to the carriage 93. The inkjet head 100 is positioned with respect to the carriage 93 in the recording paper transport direction Y by the engagement of the position reference surface 30 a and the positioning protrusion 93 a, and the ink droplets by the engagement of the position reference surface 40 a and the inner wall surface of the carriage 93. The ejection surface is positioned in the vertical direction.

  The carriage 93 shown here is used, for example, in an ink jet recording apparatus 51 as shown in FIG. 8, and includes a guide rod fitting portion 91a into which a main guide rod 91 (FIG. 8) is slidably fitted. And a stepped portion 93e that engages with the secondary guide rod 92 (FIG. 8).

  The ink jet recording apparatus 51 shown in FIG. 8 will be described. In this ink jet recording apparatus 51, the carriage 93 has a main guide rod 91 slidably fitted to a guide roller fitting portion 91a on the rear side (downstream in the recording paper conveyance direction), and on the front side (upstream in the recording paper conveyance direction). The step portion 93e is slidably supported by the secondary guide rod 92. A timing belt 106 is stretched between a driving pulley 98 and a driven pulley 99 that are rotationally driven by the main scanning motor 97. The carriage 93 is fixed to the timing belt 106, and the carriage 93 is reciprocated in the main scanning direction X by forward and reverse rotation of the main scanning motor 97.

  As described above, the inkjet head is mounted on the carriage 93 with the ink droplet ejection surface facing downward. Further, an ink cartridge or an ink tank 95 for supplying yellow (Y), cyan (C), magenta (M), and black (Bk) ink to the ink jet head is replaceably mounted on the carriage 93. The ink cartridge or the ink tank 95 has an air port that communicates with the atmosphere above, a supply port that supplies ink to the inkjet head below, and a porous body filled with ink inside. The ink supplied to the inkjet head is maintained at a slight negative pressure by the capillary force of the body.

  Although not shown in FIG. 8, there is a recording paper transport mechanism, which is driven by the sub-scanning motor 107. During recording, the inkjet head is driven in accordance with the image signal while moving the carriage 93 in the main scanning direction, thereby recording by discharging ink droplets onto the stopped recording paper. When this recording operation is completed, the recording paper is conveyed by a predetermined amount and the next recording operation is performed.

  A recovery device 117 for recovering defective ejection of the inkjet head is provided at a position outside the recording area in the moving direction of the carriage 93 (right end position in the figure). The recovery device 117 may have a known configuration including a cap unit, a suction unit, and a wiper member as a cleaning unit. During printing standby, the carriage 93 is moved to the recovery device 117, and the ink droplet discharge surface (nozzle hole) of the ink jet head is capped by the capping unit to keep the ink droplet discharge port (nozzle hole) in a wet state. Prevent defects. Apart from this, by performing ink droplet ejection not related to recording during recording or the like, it is also possible to maintain a stable ejection performance by making the ink viscosity of all ink droplet ejection ports constant.

  In case of ink droplet ejection failure, etc., the ink droplet ejection surface of the inkjet head is sealed with the capping means, and bubbles and the like are sucked out from the ink droplet ejection port with the suction means through the tube and adhered to the ink ejection port surface. Ink and dust are wiped off by a wiper member as a cleaning means to recover the ejection failure. The ink sucked here is discharged to a waste ink reservoir (not shown) and is absorbed and held by an ink absorber inside the waste ink reservoir.

  In the ink jet head according to the embodiment described above, the head cover 20 covers the side surface of the head structure 10 and the peripheral portion of the ink droplet ejection surface, so the scanning direction X of the carriage 93 and the recording paper transport direction Y In either case, contact between the recording paper and the head structure 10 can be prevented, and damage to the head structure 10 due to contact with the recording paper can be prevented. Further, the head cover 20 covers the surface of the surface portion that extends outward from the damper member of the base plate 30, thereby preventing contact between the cleaning member that wipes ink on the ink droplet ejection surface and the base plate 30. The head cover 20 covers the side surface of the head structure 10, the base plate 30, and the like, thereby preventing adhesion of ink mist generated when ink is ejected from the nozzle holes onto the recording paper. In this way, the ink is difficult to adhere to the head structure 10, which is effective in preventing the recording paper from being contaminated by the accumulated ink.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited only to the said embodiment, It can take various modified embodiment.

DESCRIPTION OF SYMBOLS 10 Head structure 20 Head cover 21 Nozzle plate 21a Nozzle hole (ink droplet discharge opening)
21b Nozzle hole array 21c Ink droplet ejection surface 22 Actuator substrate 22f Individual liquid chamber 22g Vibration plate 22h Electromechanical transducer 22i Drive IC
22j Common liquid chambers 23, 24, 25 Ink flow path substrates 26, 27 Damper substrate 30 Base plate 31 Recessed portion 32 Closed space 33 Sealing material filling path through hole 34 Sealing material 40 Housing 91 Main guide rod 92 Subordinate guide rod 93 Carriage 97 Main scanning motor 106 Timing belt 107 Sub scanning motor 117 Recovery device 300 Syringe

Japanese Patent Laid-Open No. 10-16240

Claims (4)

A head structure having a function of ejecting ink droplets from nozzle holes provided in the nozzle plate in response to an electrical signal supplied from the outside; and a head cover that covers a peripheral portion of the nozzle plate and a side surface of the head structure. In an inkjet head comprising:
A closed space formed between a recessed portion including an end surface of the nozzle plate provided on a side surface of the head structure and the head cover;
A sealing material filled in the closed space;
An ink-jet head comprising: a through-hole opened on a surface opposite to the nozzle plate of the head structure, which can be used as a sealing material filling path into the closed space.   The member constituting the surface of the head structure opposite to the nozzle plate has a surface portion extending outward from the side surface of the head structure, and the head cover has a flange portion covering the surface portion. The inkjet head according to claim 1.   The head structure generates individual liquid chambers corresponding to the respective nozzle holes of the nozzle plate, and pressure for ejecting ink in the individual liquid chambers as ink droplets from the corresponding nozzle holes in accordance with the electrical signals. The inkjet head according to claim 1, further comprising: an actuator substrate bonded to the nozzle plate, wherein the recess includes an end surface of the nozzle plate and an end surface of the actuator substrate.   An inkjet recording apparatus that records an image by ejecting ink droplets onto a recording sheet from an inkjet head, wherein the inkjet head is the inkjet head according to any one of claims 1 to 3. apparatus.