JP2005343039A - Inkjet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet head having an inexpensive and simple structure which can prevent a medium to be recorded and a wiping member from colliding with a side surface of a cavity unit. <P>SOLUTION: In the cavity unit 1, a plurality of plates, which include a nozzle plate with a drilled nozzle and a spacer plate arranged on the backside of the nozzle plate, are laminated together. In the plurality of plates toward a front surface, which include at least the nozzle plate and the spacer plate among the plates constituting the cavity unit 1, a bent piece, which is formed by being extended outward with respect to side edges of the other plates and bent to the backside, is provided at a side end serving as an entry side with respect to at least an edge of the medium to be recorded, among side ends in the direction of relative movement with respect to the medium to be recorded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inkjet head that ejects ink while moving relative to a recording medium.

  As a prior art inkjet head, there are a plurality of nozzles provided on the front surface, a pressure unit corresponding to each nozzle, and a cavity unit formed by laminating and joining a plurality of plates, and a back surface of the cavity unit. There is known a structure including a piezoelectric actuator that is laminated and selectively drives each pressure chamber to discharge ink, and a flexible flat cable that supplies an electrical signal to the piezoelectric actuator. The nozzles are arranged in a row along the sub-scanning direction (X direction) in which the recording medium moves (conveys), and the inkjet head is arranged in the main scanning direction (Y direction) perpendicular to the sub-scanning direction. By ejecting ink while moving, recording is performed on the recording medium.

  In such an ink jet head, since the gap between the recording medium and the nozzle surface is set to be extremely narrow, the tip of the recording medium collides with the side surface of the cavity unit during relative movement with the recording medium. Easy to do. When a collision occurs, the movement is not performed properly, which adversely affects the recording quality. Further, a wiping member is provided so as to slidably contact the nozzle surface in order to wipe away ink or paper dust adhering to the nozzle surface. When the wiping member rubs against the side surface of the cavity unit at the time of sliding contact, a force for peeling the plate is bonded to the cavity unit, and the wiping member itself is damaged at the edge (edge, etc.) of the cavity unit.

  Therefore, as a structure that covers the side surface of the ink jet head (cavity unit), the present applicant has shown a structure in which a protective cover plate having an opening window that exposes a nozzle is attached to the front surface of the ink jet head in Patent Document 1 or the like. ing. The opening window has a size that exposes the row of nozzles, and is formed in the bottom of the protective cover plate. A protective cover plate is attached so that the bottom portion overlaps the front side of the inkjet head, and the side surface of the head perpendicular to the main scanning direction is covered with a wall protruding from another component.

In addition, in the patent document 2, the applicant of the present application shows a structure in which a side end portion of a nozzle plate of an ink jet head is bent toward a holder (back surface) side of the ink jet head. In Patent Document 2, a flow path unit (corresponding to a cavity unit) having a nozzle plate on the forefront is fixed to a holder disposed on the back side via an actuator unit, a flexible flat cable, an ink reservoir, and the like. Yes. Then, by bending the side edge of the nozzle plate toward the holder, not only the collision between the recording medium and the side surface of the inkjet head is prevented, but also the flexible flat cable is stably held along the outside of the holder. That is also the purpose.
JP 2002-67345 A (see FIG. 4) Japanese Patent Laying-Open No. 2003-311953 (see FIGS. 3 and 12)

  However, in the structure of Patent Document 1, a protective cover plate is added, and the protective cover plate and the inkjet head are bonded and fixed so that the nozzle row is exposed. There is a problem that the number of processes increases.

  On the other hand, the structure of Patent Document 2 utilizes the side end portion of an existing nozzle plate to reduce component costs. However, since the bent portion of the nozzle plate is provided along the outside of the holder, the bending can be formed only after a plurality of parts such as a flow path unit and a flexible flat cable are correctly assembled at their predetermined positions. First, the bending process was large. For this reason, there has been a demand for further facilitating the production.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems and to provide an ink jet head capable of preventing a recording medium and a wiping member from colliding with a side surface of a cavity unit with a low cost and an easy structure.

  In order to achieve the above object, an ink jet head according to the first aspect of the present invention has a cavity unit having a nozzle on the front surface for ejecting ink onto a recording medium, and is relative to the recording medium. In the inkjet head that moves, the cavity unit is configured by laminating a plurality of plates including a nozzle plate in which the nozzles are formed and a spacer plate disposed on the back surface of the nozzle plate. Among the plates constituting the unit, a plurality of plates closer to the front surface including at least the nozzle plate and the spacer plate are on the entry side with respect to at least the edge of the recording medium among the side edges in the relative movement direction. Extends outward from the side edges of other plates and bends to the back side It has a bent piece formed Te is characterized in.

  According to a second aspect of the present invention, in the inkjet head according to the first aspect, the bent piece protects a side surface of the cavity unit in the relative movement direction from a wiping member with respect to the nozzle surface of the cavity unit. It is characterized by being provided as follows.

  According to a third aspect of the present invention, in the inkjet head according to the first or second aspect, of the plurality of plates having the bent pieces, the nozzle plate is made of resin, and the other plates are made of metal. The bent piece in the metal plate is bent by plastic deformation, and the bent piece of the resin nozzle plate is attached along the bent piece of the metal plate. .

  The invention according to claim 4 is the ink jet head according to claim 3, wherein the back side of the base end portion of the bent piece of the metal plate is along the direction orthogonal to the relative movement direction. A groove portion that facilitates bending toward the back side is formed.

  According to a fifth aspect of the present invention, in the ink jet head according to the third aspect, the metal plate having the bent piece has a communication hole corresponding to the position of the nozzle of the nozzle plate. The plate-making plate and the nozzle plate are pre-integrated and laminated with the other plate, and the nozzle is processed in the nozzle plate through the communication hole.

  According to the first aspect of the present invention, the plurality of plates closer to the front surface including the nozzle plate and the spacer plate extend outward from the side edges of the other plates and bend toward the rear surface to be bent pieces. Therefore, the bent piece is inclined to the back side continuously from the nozzle surface and covers the side surface of the cavity unit. Thereby, the bent piece prevents the edge of the recording medium from colliding with the side surface of the cavity unit, and promptly guides the recording medium to a predetermined position facing the nozzle plate. As a result, since the relative movement between the recording medium and the ink jet head is appropriately performed, it is possible to prevent the recording quality from being impaired.

  And since the said bending piece is formed in the plate which comprises a cavity unit, the bending process can be performed in the early stage in the manufacturing process of a cavity unit, in other words, the manufacturing process of an inkjet head, and manufacture is easy. Can be achieved.

  According to the second aspect of the present invention, the bending piece prevents the sliding contact between the side surface of the cavity unit and the wiping member, so that the wiping member acts to peel off the plates stacked as the cavity unit. In addition, it is possible to prevent the wiping member itself from being damaged by the side surface of the cavity unit.

  According to the invention described in claim 3, since the nozzle plate is made of resin and has higher flexibility than the metal plate, the bent piece is composed of a plurality of plates and is bent even if its rigidity is increased. The effect of facilitating bending when forming the piece is achieved.

  According to the invention described in claim 4, since the groove portion that promotes bending toward the back side is formed along the direction orthogonal to the relative movement direction, the bending piece is constituted by a plurality of plates. Even if the rigidity is increased, there is an effect of facilitating bending when forming the bent piece.

  According to the invention described in claim 5, since the resin plate and the metal plate on which the bent piece is formed are integrated in advance for nozzle processing, the bent plate is bent. There is no need to bother integration for processing, and the manufacturing process can be simplified.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view of the periphery of a recording unit in the ink jet printer of the embodiment, FIG. 2 is a perspective view from the lower surface (nozzle surface) side of the recording unit, FIG. 3 is an exploded perspective view of the cavity unit, and FIG. FIG. 5A is a partial cross-sectional view of the inkjet head, FIG. 6A is a vertical cross-sectional view in the vicinity of the side end of the cavity unit, FIG. 6B is a vertical cross-sectional view before bending of the bent piece, and FIG. (C) is a longitudinal sectional view of the bent piece after bending, FIG. 7 is a partial longitudinal sectional view of a state where the carriage is fixed to the head holder, and FIG. 8 is a longitudinal sectional view showing a cleaning operation by the wiping member.

  An ink jet printer equipped with the ink jet head 10 of the present invention includes a recording unit 100 (see FIG. 1) that records ink by discharging ink onto a paper P as a recording medium, inside a main body frame (not shown). ing. The ink jet printer is applied as a printer function of a multi-function device (MFD) having a copy function, a scanner function, a facsimile function, and the like.

  As shown in FIG. 1, the recording unit 100 includes horizontally long plate-shaped guide rails 51 and 52 that extend in parallel to the Y direction (a direction orthogonal to the paper transport direction X, the main scanning direction), and the inkjet head 10. A carriage 53 that reciprocally moves across the guide rails 51 and 52, a timing belt 56 that reciprocates the carriage 53, a drive pulley 57 and a driven pulley 58 around which the timing belt 56 is stretched, and a timing belt. In order to drive 56, a drive motor (not shown) connected to a drive pulley 57 is provided.

  As shown in FIG. 2, the carriage 53 includes a substantially box-shaped main body 54a and a connecting support piece 54b protruding from the main body 54a toward the downstream side in the paper transport direction (the direction of arrow A in FIGS. 1 and 2). A head holder 54 provided, the inkjet head 10 fixed to face the paper P on the lower surface side of the bottom plate 54c of the head holder 54, and the upper surface side of the bottom plate 54c communicating with the inkjet head 10 so as to supply ink A buffer tank (not shown) and the like fixed to the are mounted.

  In this embodiment, the reciprocating movement of the carriage 53 in the Y direction causes the ink jet head 10 to move so as to pass through both edges extending in the X direction of the paper P, and the both edges of the paper P are relatively alternating. The ink jet head 10 is configured to enter the lower surface side.

  Further, outside the width of the conveyed paper P (short side of the paper P), an ink receiving portion 59 is provided on one end side (left side in FIG. 1 in the embodiment) and the other end side (right side in FIG. 1). A maintenance unit 50 as a maintenance means is arranged respectively. As a result, the inkjet head 10 periodically discharges ink to prevent nozzle clogging during a recording operation at the flushing position provided in the ink receiving portion 59, and the ink receiving portion 59 receives the ink. . At a standby position of the carriage 53 provided corresponding to the maintenance unit 50, a cap portion (not shown) in the maintenance unit 50 covers the nozzle surface of the inkjet head 10 from below and selectively sucks ink for each color. Or a recovery process for removing bubbles in the buffer tank (not shown). When the carriage 53 moves laterally closer to the maintenance unit 50 portion, a wiper blade (see FIG. 8) as the wiping member 60 wipes the nozzle surface and performs cleaning.

  This ink jet printer has individual ink tanks (not shown) of yellow ink (Y), magenta ink (M), cyan ink (C), and black ink (Bk) as ink supply sources for full color recording. The ink is supplied to the inkjet head 10 from each of these ink tanks via an ink supply pipe (not shown) and a buffer tank (not shown).

  As shown in FIGS. 3 and 5, the inkjet head 10 includes a cavity unit 1 having a large number of nozzles 4 for ejecting ink onto the paper P on the surface (front surface) exposed to the outside, and the cavity unit 1. The plate-type piezoelectric actuator 2 is stacked and fixed on the back surface of the piezoelectric actuator 2, and the flexible flat cable 3 is stacked and fixed on the back surface of the piezoelectric actuator 2 for connection to an external device.

  As shown in FIG. 3, the cavity unit 1 includes a total of eight plates including a nozzle plate 11, a spacer plate 12, a damper plate 13, two manifold plates 14 a and 14 b, a supply plate 15, a base plate 16, and a cavity plate 17. It has a structure in which thin plates are joined together with adhesive.

  In the embodiment, each of the plates 11 to 17 has a thickness of about 50 to 150 μm, the nozzle plate 11 is made of synthetic resin such as polyimide, and the other plates 12 to 17 are made of 42% nickel alloy steel plate. The nozzle plate 11 is provided with a large number of ink ejection nozzles 4 having a minute diameter (in the embodiment, about 25 μm) at minute intervals. The nozzles 4 are arranged in five rows in a staggered manner along the long side direction (X direction) of the nozzle plate 11.

  In the cavity plate 17, as shown in FIG. 4, a plurality of pressure chambers 36 are arranged in five rows in a staggered arrangement along the long side (the X direction) of the cavity plate 17. In the embodiment, each of the pressure chambers 36 is formed in an elongated shape in plan view, and the longitudinal direction thereof is bored along the short side direction (Y direction) of the cavity plate 17, and one end portion 36 a in the longitudinal direction is formed. The other end 36b communicates with a common ink chamber 7 described later.

  The distal end portion 36a in each pressure chamber 36 has a small diameter that is similarly drilled in a staggered arrangement in the base plate 16, the supply plate 15, the two manifold plates 14a and 14b, the damper plate 13, and the spacer plate 12. The nozzles 11 communicate with the nozzles 4 through the communication holes 37.

  In the base plate 16 adjacent to the lower surface of the cavity plate 17, a through hole 38 is formed at a position corresponding to each other end 36 b in order to connect to the other end 36 b of each pressure chamber 36.

  The supply plate 15 adjacent to the lower surface of the base plate 16 is provided with a connection flow path 40 for supplying ink from the common ink chamber 7 described later to each pressure chamber 36. Each connection channel 40 is connected between an inlet hole into which ink enters from the common ink chamber 7, an outlet hole opened on the pressure chamber 36 side (the through hole 38), and the inlet hole and the outlet hole. A throttle part formed with a reduced cross-sectional area so as to have the largest flow path resistance in the path 40 is provided.

  In the two manifold plates 14 a and 14 b, five common ink chambers 7 extending along the long side direction (X direction) are formed so as to penetrate the plate thickness so as to extend along each row of the nozzles 4. Has been. That is, as shown in FIGS. 3 and 5, two manifold plates 14 a and 14 b are stacked, and the upper surface thereof is covered with the supply plate 15, and the lower surface is covered with the damper plate 13. An ink chamber (manifold chamber) 7 is formed in a sealed state. Each of the common ink chambers 7 extends in the row direction of the pressure chambers 36 (the row direction of the nozzles 4) so as to overlap with a part of the pressure chamber 36 when viewed in plan from the stacking direction of the plates.

  As shown in FIGS. 4 and 5, a damper chamber 45 isolated from the common ink chamber 7 is formed as a recess on the lower surface side of the damper plate 13 adjacent to the lower surface of the manifold plate 14a. The positions and shapes of the damper chambers 45 are matched with the common ink chambers 7 as shown in FIG. Since the damper plate 13 is a metal material that can be elastically deformed as appropriate, the thin plate-like ceiling portion of the damper chamber 45 can freely vibrate both on the common ink chamber 7 side and on the damper chamber 45 side. . Even when the pressure fluctuation generated in the pressure chamber 36 propagates to the common ink chamber 7 during ink ejection, the ceiling portion elastically deforms and vibrates, thereby producing a damper effect that absorbs and attenuates the pressure fluctuation. It is possible to prevent the crosstalk that the fluctuation propagates to the other pressure chambers 36.

  Further, as shown in FIG. 3, four ink supply ports 47 are formed in the end portions on one short side of the cavity plate 17, the base plate 16, and the supply plate 15 so as to correspond to the upper and lower positions. Has been. An outlet opening of a buffer tank (not shown) communicates with one end of the common ink chamber 7 through these ink supply ports 47. The four ink supply ports 47 are individually labeled 47a, 47b, 47c, and 47d in order from the right side of FIG.

  In the ink flow path from the ink supply port 47 to the nozzle 4, the ink supplied from the ink supply source side is supplied from the ink supply port 47 to the common ink chamber 7 as an ink supply channel, and then, FIG. 4 and FIG. 5. As shown in FIG. 5, the pressure is distributed and supplied to each pressure chamber 36 via the connection flow path 40 of the supply plate 15 and the through hole 38 of the base plate 16. As will be described later, when the piezoelectric actuator 2 is driven, the ink passes from the pressure chambers 36 through the communication holes 37 to the nozzles 4 corresponding to the pressure chambers 36.

  In this embodiment, as shown in FIG. 3, four ink supply ports 47 are provided, whereas five common ink chambers 7 are provided, and only two ink supply ports 47a are common. The ink chambers 7 and 7 are connected. The ink supply port 47a is set so that black ink is supplied, and it is considered that black ink is used more frequently than other color inks. The other ink supply ports 47b, 47c, and 47d are supplied with yellow, magenta, and cyan inks, respectively. A filter body 20 having a filtration portion 20a corresponding to each opening is attached to the ink supply ports 47a, 47b, 47c, and 47d with an adhesive or the like.

  The nozzle plate 11 and the spacer plate 12 are, as shown in FIG. 3 and FIG. 6A, side edges that are on the entry side with respect to at least the edge of the paper P among both side edges extending in the X direction. The plate has a bent piece 21 that extends outward from the side edges of the other plates and is bent to the back side. In other words, among the plurality of plates constituting the cavity unit 1, the nozzle plate 11 and the spacer plate 12 are made longer in the Y direction in advance than the other plates, and the side of the other plate when stacked A portion extending outward from the edge is bent toward the back side to form a bent piece 21. The bending angle of the bending piece 21 is smaller than 90 ° with respect to the nozzle surface, and the length dimension of the bending piece 21 is a length that reliably covers the stacked side surfaces of the remaining plates 13 to 17 of the cavity unit 1. Is set to

  In this embodiment, since both the side end portions extending in the X direction of the nozzle plate 11 and the spacer plate 12 can be on the entry side with respect to the paper P, the bent pieces 21 are provided at both side end portions. For the sake of explanation, these bent pieces 21 are individually labeled with bent pieces 21a and 21b of the nozzle plate 11 and bent pieces 21c and 21d of the bent pieces of the spacer plate 21, respectively. Bending pieces closer to the maintenance unit 50 to be described later are bent pieces 21b and 21d.

  In the manufacturing process, the cavity unit 1 includes a first subunit 1a including two nozzle plates 11 and a spacer plate 12, a damper plate 13, manifold plates 14 a and 14 b, a supply plate 15, a base plate 16, and a cavity plate 17. Are manufactured separately, and then the first subunit 1a and the second subunit 1b are laminated and bonded (see FIG. 5).

  As described above, since the spacer plate 12 is made of metal and the nozzle plate 11 is made of resin, the nozzle plate 11 is attached to the spacer plate 12 in the manufacturing process of the first subunit 1a. Therefore, the bent pieces 21c and 21d of the spacer plate 12 are formed by being bent by plastic deformation, but the bent pieces 21a and 21b of the nozzle plate 11 are bent by being attached along the bent pieces 21c and 21d. .

  Then, on the back side of the base end portions of the bent pieces 21c and 21d of the spacer plate 12, a groove portion 22 that facilitates bending toward the back side is formed along the X direction (FIGS. 6B and 6). (See (c)). Here, although the groove part 22 is continuously formed so that the both ends edge (short side) of the spacer plate 12 extended in the Y direction may be tied, it may be formed intermittently. The groove portion 22 is grooved in the step of forming the nozzle 4 in the first subunit 1a described later, but may be simultaneously processed in the step of forming the communication hole 37 of the spacer plate 12.

  The ink supply port 47, the common ink chamber 7, the communication hole 37, the through hole 38, the connection channel 40, the recess chamber 45, and the like in the metal plates 12 to 17 are formed by etching, It is formed by electric discharge machining, plasma machining, laser machining, or the like. In one filter body 20 made of a synthetic resin such as polyimide and having a substantially rectangular thin sheet shape in plan view, a filtering portion 20a having a very small hole formed by laser processing or the like is formed. When the filter body 20 is made of metal, it may be formed by electroforming.

  On the other hand, the piezoelectric actuator 2 has a structure in which a plurality of piezoelectric sheets (not shown) are laminated, each having a thickness of about 30 μm, as is well known in JP-A-4-341853. In the upper surface (wide surface) of the even-numbered piezoelectric sheet from the bottom, narrow individual electrodes are provided along the long side direction (X direction) for each location corresponding to each pressure chamber 36 in the cavity unit 1. It is formed in a row. A common electrode common to the plurality of pressure chambers 36 is formed on the upper surface (wide surface) of the odd-numbered piezoelectric sheet from the bottom, and a surface electrode 48 is formed on the upper surface of the uppermost sheet. A surface electrode electrically connected to each of the individual electrodes and a surface electrode electrically connected to the common electrode are provided.

  An adhesive sheet (not shown) made of an ink non-permeable synthetic resin material as an adhesive is formed on the entire lower surface (the wide surface facing the pressure chamber 36) of the plate-type piezoelectric actuator 2 having such a configuration. Next, the piezoelectric actuator 2 is bonded and fixed to the cavity unit 1 with the individual electrodes corresponding to the pressure chambers 36 in the cavity unit 1. Also, the flexible flat cable 3 (see FIG. 4) is pressed against the upper surface of the piezoelectric actuator 2 so that various wiring patterns (not shown) in the flexible flat cable 3 are It is electrically joined to the surface electrode 48.

  In the embodiment configured as described above, in the manufacture, first, the material plate (nozzle unprocessed state) of the nozzle plate 11 is formed on the spacer plate 12 in which the communication holes 37 are previously formed at positions corresponding to the nozzles 4. It is pasted. Similarly to the known method disclosed in Japanese Patent Application Laid-Open No. 11-147316, a laser beam is irradiated from the spacer plate 12 side to the material plate of the nozzle plate 11 from the spacer plate 12 side, and a number of nozzles 4 are formed. The Thereby, the first subunit 1a is formed (see FIG. 5).

  On the other hand, the damper plate 13, the manifold plates 14a and 14b, the supply plate 15, the base plate 16 and the cavity plate 17, each of which has been subjected to necessary drilling and the like, are laminated and integrated by bonding to form the second subunit 1b ( 5) is formed. The second subunit 1b is stacked on the first subunit 1a and integrated by bonding to form the cavity unit 1 (see FIG. 5).

  When the first subunit 1a and the second subunit 1b are bonded together, a pressing jig (bonding device) is used, and both end portions of the first subunit 1a are bent by the jig. By adding the structure 23 (see the two-dot chain line in FIG. 6A), the bent piece 21 is simultaneously formed by using the pressure during bonding. Thereby, the number of man-hours can be reduced. However, the step of forming the bent piece 21 is not limited to this. For example, the bent piece 21 is formed in the state of the first subunit 1a, and then the second piece is formed. You may adhere | attach with the subunit 1b, or you may form the bending piece 21 in another process, after adhere | attaching the 1st subunit 1a and the 2nd subunit 1b.

  Next, the cavity unit 1 is joined to the piezoelectric actuator 2 and the flexible flat cable 3 is joined to form the ink jet head 10.

  7 and 8, the inkjet head 10 is bonded and fixed to the lower surface side of the bottom plate 54 c of the head holder 54 through the frame 61. Here, the inkjet head 10 is fitted into a region surrounded by a rib 54d that protrudes on the lower surface side of the bottom plate 54c. The gap between the inkjet head 10 and the rib 54d is sealed with a seal member 62 to prevent ink, paper dust, or the like from entering the gap.

  In the recording unit 100, during recording on the paper P, the reciprocating movement of the carriage 53 in the Y direction (main scanning direction) and the transport of the paper P in the X direction (sub-scanning direction) are combined. Accordingly, during recording, the paper P enters the position facing the nozzle surface relatively many times, but the edge on the entry side of the paper P is guided by the bent piece 21. Without entering the side surface of the cavity unit 1, it quickly enters the predetermined position. As a result, the conveyance of the paper P and the movement of the carriage 53 are performed appropriately, and the recording quality is not impaired.

  Then, during or after the recording operation, the carriage 53 moves to the position of the maintenance unit 50 (in the direction of arrow C in FIG. 8), and cleaning of the nozzle surface and removal of bubbles in the buffer tank (not shown) are performed. However, during the movement, the wiping member 60 provided in the maintenance unit 50 relatively slidably contacts the nozzle surface. Since the wiping member 60 immediately contacts the bent piece 21 (21b, 21d) and slides along the inclination, the wiping member 60 does not touch the side surface of the cavity unit 1. Therefore, it is possible to prevent the wiping member 60 from exerting a force to peel off the plate, and it is possible to prevent the wiping member 60 itself from being damaged at the side edge of the cavity unit 1. In particular, if the edge of the metal plate of the cavity unit 1 is etched, the wiping member 60 is easily damaged, and the bent piece 21 provides a great protection effect on the wiping member 60.

  Further, as shown in the above-described embodiment, the bent piece 21 is bent at an early stage in the manufacturing of the inkjet head, which is the manufacturing process of the cavity unit 1, in other words, the bent piece 21 is bent at a relatively simple part forming stage. Since it is processed, the apparatus and work required for bending can be facilitated.

  Further, when the bent piece 21 is formed by bending only the nosle plate 11, if the wiping member 60 or the paper P repeatedly contacts the bent piece 21, the bent portion is damaged, and the bent piece 21. However, in this embodiment, the bent piece 21 is formed by bending the nozzle plate 11 and the spacer plate 12 in an overlapped state, and the rigidity is increased. Its durability is greatly improved.

  Moreover, in this embodiment, since the groove part 22 is provided in the back side of the base end part of the bending piece 21, and the nozzle plate 11 is made of a highly flexible resin like polyimide, the rigidity of the bending piece 21 is increased. While improving, the bending workability of the bending piece 21 can be improved and production efficiency can be raised.

  In the present embodiment, the bent pieces 21 are provided at both side end portions of the cavity unit 1, but the portions where the bent pieces 21 are provided (both side end portions of the cavity unit 1 or one of the side end portions) are provided. The position of the paper P and the maintenance unit 50 and the cavity unit 1 is determined as appropriate.

  Further, the plate having the bent piece 21 is not limited to the two plates of the nozzle plate 11 and the spacer plate 12 of the present embodiment, and may be configured of three or more plates as long as the plate is closer to the front surface.

FIG. 2 is a plan view of the periphery of a recording unit in the inkjet printer according to the embodiment. It is a perspective view from the lower surface (nozzle surface) side of a recording part. It is a disassembled perspective view of a cavity unit. It is an expansion disassembled perspective view of a cavity unit. It is a fragmentary sectional view of an inkjet head. (A) is a longitudinal sectional view in the vicinity of the side end of the cavity unit, (b) is a longitudinal sectional view before the bent piece is bent, and (c) is a longitudinal sectional view after the bent piece is bent. It is a partial longitudinal cross-sectional view of a state in which the carriage is fixed to the head holder. It is a longitudinal cross-sectional view which shows the cleaning operation | movement by a wiping member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cavity unit 1a 1st subunit 1b 2nd subunit 2 Piezoelectric actuator 3 Flexible flat cable 4 Nozzle 10 Inkjet head 11 Nozzle plate 12 Spacer plate 21 Bending piece 22 Groove part 36 Pressure chamber 37 Communication hole 50 Maintenance unit 53 Carriage 54 Head holder 59 Ink receiving portion 60 Wiping member 61 Frame 62 Seal member 100 Recording portion

Claims (5)

In an inkjet head that has a cavity unit provided on the front surface with a nozzle for discharging ink to a recording medium and moves relative to the recording medium,
The cavity unit is configured by laminating a plurality of plates including a nozzle plate in which the nozzle is drilled and a spacer plate disposed on the back surface of the nozzle plate.
Among the plates constituting the cavity unit, a plurality of plates near the front surface including at least the nozzle plate and the spacer plate are at least with respect to the edge of the recording medium among the side end portions in the relative movement direction. An ink-jet head comprising: a bent piece extending outward from the side edge of the other plate and bent toward the back side at a side end portion which becomes an entrance side.   The inkjet head according to claim 1, wherein the bent piece is provided so as to protect a side surface of the cavity unit in the relative movement direction from a wiping member with respect to a nozzle surface of the cavity unit.   Of the plurality of plates having the bent pieces, the nozzle plate is made of resin, the other plates are made of metal, and the bent pieces in the metal plate are formed by bending by plastic deformation. The inkjet head according to claim 1, wherein the bent piece is attached along the bent piece of the metal plate.   The groove part which promotes the bending to a back side is formed in the back side in the base end part of the bending piece of the said metal plate along the direction orthogonal to the said relative movement direction. The inkjet head described in 1.   The metal plate having the bent piece has a communication hole corresponding to the position of the nozzle of the nozzle plate, and the metal plate and the nozzle plate are integrated in advance before lamination with the other plates. The inkjet head according to claim 3, wherein a nozzle is processed in the nozzle plate through the communication hole.

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