JP2005271540A - Inkjet head unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a small and compact head unit of inkjet printer capable of surely preventing poor printing, e.g. missing of dots, due to pressure variation incident to movement of a head unit. <P>SOLUTION: The head unit 4 of an inkjet printer 1 comprises a head chip 12 formed flatly and having an ink nozzle surface 12a provided with ink ejection nozzles as the front face, a unit substrate 13 supporting the head chip 12 on the front face and provided with recesses 35(1)-35(4) in the rear surface, flexible damper film 14 for blocking the recesses 35(1)-35(4) and provided with bends 14a(1)-14a(4) formed along the inner circumference of the recesses 35(1)-35(4), damper chambers 21(1)-21(4) defined by blocking the recesses 35(1)-35(4) with the damper film 14 and relaxing pressure variation acting on ink being supplied to the head chip 12, and ink supply openings 23(1)-23(4) formed in the unit substrate 13 and supplying ink from the damper chambers 21(1)-21(4) to the head chip 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inkjet head unit used in an inkjet printer.

  In a serial type ink jet printer configured such that a flexible ink tube connects between an ink tank and a head unit mounted on a carriage, when the head unit is moved by the carriage, pressure is applied to the ink supplied to the head unit. Works. This pressure greatly depends on the acceleration of the head unit, the length of the ink flow path from the ink tank to the head unit, and the specific gravity of the ink. When this pressure acts on the ink nozzles of the head unit, ink droplets cannot be ejected properly, which causes printing defects such as ink droplet scattering and dot missing.

  Therefore, the head unit is provided with a damper mechanism for absorbing pressure acting on the ink flow path as the head unit moves. For example, the following Patent Documents 1 and 2 disclose a head unit including such a damper mechanism.

  As disclosed in these Patent Documents 1 and 2, the conventional head unit has a long shape in a direction perpendicular to the ink nozzle surface. That is, the shape is long in the direction orthogonal to the moving direction of the head unit. This is because it is considered that the damper effect can be obtained more efficiently by arranging the damper chamber in a direction orthogonal to the moving direction of the head unit.

JP-A-3-224744 Japanese Patent Laid-Open No. 4-269553

  However, the pressure that can be absorbed by the damper mechanism mounted on the head unit is the pressure acting on the ink flow path between the damper mechanism and the ink tank, and the pressure on the ink flow path from the damper mechanism to the ink nozzles. It cannot absorb the acting pressure. Therefore, when the head unit is long in the direction perpendicular to the ink nozzle surface as in the prior art, the ink flow path from the damper mechanism to the ink nozzle becomes long, so that a large pressure is applied as the head unit moves. It occurred in the ink flow path and was transmitted directly to the ink nozzles, and it was easy for problems such as missing dots to occur.

  Further, the head unit having a shape that is long in the direction orthogonal to the moving direction requires a large space for the movement, which has been an obstacle to miniaturization and downsizing of the ink jet printer.

  In addition, to reduce the size of an inkjet printer, it is necessary to reduce the size of the head unit. However, as the size of the head unit is reduced, the size of the damper mechanism is inevitably reduced. Ink may be ejected from the ink nozzles due to pressure fluctuations in the ink flow path.

  In view of the above, an object of the present invention is to propose a head unit of an ink jet printer in which an ink flow path from a damper chamber forming a damper mechanism to an ink nozzle is extremely short.

  Another object of the present invention is to propose an ink jet printer head unit having a very small dimension in a direction perpendicular to the moving direction.

  Another object of the present invention is to provide an ink jet printer head having a damper mechanism that prevents ink from being ejected from ink nozzles due to pressure fluctuations in the ink flow path caused by movement of the head unit even when the head unit is downsized. To propose a unit.

  In order to solve the above-described problems, a head unit of the present invention includes a unit base that supports the head chip on the front surface and has a recess formed on the rear surface, and a flexible damper film that seals the recess. Pressure fluctuations that act on the ink supplied to the head chip, each of which has a bent portion formed along the inner periphery of the concave portion and that is partitioned by sealing the concave portion with the damper film. And a damper chamber that is formed in the unit base and for supplying the ink from the damper chamber to the head chip.

  With the above configuration, since the head chip and the damper chamber are stacked, the length of the ink flow path between the head chip and the damper chamber (the length of the ink supply port) can be shortened. That is, the length of the ink supply port is only the thickness of the unit base, and if the thickness of the portion between the head chip and the damper chamber in the unit base is reduced, the ink flow path can be made extremely short. . Therefore, the pressure acting on the ink flow path with the movement of the head unit can be made extremely small, so that it is possible to avoid a drop in print quality such as missing dots. Further, if the head chip and the damper chamber are flat and layered, the dimension in the direction perpendicular to the moving direction (the direction of the ink nozzle surface) in the head unit can be shortened. As a result, the space required for moving the head unit can be reduced, which is advantageous for downsizing and compacting the ink jet printer. Furthermore, by forming a bent portion in the damper film, it is possible to increase the flexibility of the damper film and improve the damper function, so that the ink from the ink nozzles is affected by the pressure fluctuation of the ink flow path caused by the movement of the head unit. It is possible to prevent problems such as being discharged. In this case, it is preferable that a plurality of the bent portions are formed in a ripple shape on the damper film. In this way, the flexibility of the damper film can be further improved, so that the required damper function is ensured even in a small damper chamber, which is advantageous for downsizing of the head unit.

  In the case of a head unit mounted on a color ink jet printer, a damper chamber is provided for each color ink flow path. In this case, if each damper chamber is arranged in a direction parallel to the ink nozzle surface of the head chip, the ink flow path from each damper chamber to the ink nozzle can be shortened, and the direction orthogonal to the moving direction in the head unit. This is preferable because the size of can be reduced.

  Further, each of the damper films corresponding to the plurality of recesses is formed of a common sheet, and a plurality of the bent portions are formed corresponding to the plurality of recesses, so that the number of parts is reduced. Therefore, it is desirable that the parts cost, the assembly cost, etc. can be reduced and the cost can be reduced. In addition, it is possible to easily and stably seal each damper chamber.

  Next, the head unit of the present invention has an ink supply pipe for supplying ink to the damper chamber, the damper film is a rubber film, and has an insertion hole into which the ink supply pipe can be inserted. The insertion hole has a smaller diameter than the tip portion of the ink supply pipe, and the tip portion of the ink supply pipe penetrates the insertion hole in a state in which the insertion hole is expanded. The ink supply pipe includes a tip portion that is inserted into the insertion hole and communicates with the damper chamber. In this way, the damper chamber and the ink supply pipe can be connected by a simple operation of inserting the ink supply pipe into the damper film, and the seal state between them is formed by the elastic force of the damper film. As a result, it is not necessary to attach a separate member to form the seal. Therefore, the assembling work is extremely simplified, and it is advantageous for reducing the number of parts of the head unit and reducing the cost.

  In this case, the damper film is bonded to the unit base, and has a damper press attached to the back surface of the damper film, and the ink supply pipe is integrally formed with the damper press, and the difference It is desirable that a tip portion of the ink supply pipe inserted into the insertion hole protrudes by a predetermined length into the damper chamber. In this way, the ink supply path to the damper chamber can be easily formed, the assembly of the head unit is simplified, and the head unit is advantageously reduced in size. Further, since the tip portion of the ink supply pipe is protruded by a predetermined amount inside the damper chamber, it is possible to reliably avoid the adverse effect that the ink supply pipe is clogged due to the clogging of the portion.

  As described above, the head unit of the ink jet printer according to the present invention has a configuration in which the head chip is attached to the front surface of the unit base and the damper chamber is partitioned on the rear surface thereof. The ink flow path can be shortened, and the pressure fluctuation acting on the ink flow path when the head unit is moved can be reduced.

  In the present invention, the damper chamber has a shape that is long in the direction parallel to the ink nozzle surface of the head chip, that is, long in the moving direction of the head unit. Therefore, the dimension of the head unit in the direction orthogonal to the moving direction can be reduced.

  In the present invention, since the flexibility of the damper film is enhanced by providing the damper film with a bent portion, the damper chamber can be made small while ensuring the required damper function.

  As a result, it is possible to reliably prevent printing defects such as missing dots due to pressure fluctuations accompanying the movement of the head unit, and to realize a small and compact inkjet printer.

  Hereinafter, an example of a head unit of an inkjet printer to which the present invention is applied will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing the main part of the ink jet printer of this example. The ink jet printer 1 of this example is of a serial type, and a head unit 4 is mounted on a carriage 3 that can reciprocate along a guide shaft 2. Ink is supplied to the head unit 4 from an ink tank 5 disposed at a fixed position via a flexible ink tube 6. In this example, the head unit 4 passes through four ink tubes 6-1 to 6-4 from ink tanks 5-1 to 5-4 in which inks of four colors of cyan, magenta, yellow, and black are respectively stored. To be supplied.

  FIG. 2 is a cross-sectional view showing the head unit 4 of this example, FIG. 3 is an exploded perspective view showing the head unit 4 disassembled and viewed from the front, and FIG. 4 is an exploded rear view of the head unit 4. It is a disassembled perspective view which shows the state seen from. 5 (a) and 5 (b) are exploded perspective views of the unit base 13 of the head unit 4 as viewed from the front and rear, respectively. FIGS. 6 (a) and 6 (b) are views of the damper rubber film 14 of the head unit 4 at the front and rear, respectively. It is the disassembled perspective view seen from back. Referring to these drawings, the head unit 4 of the present example includes a rectangular parallelepiped unit cover 11 having an open rear side, and a head unit component member is accommodated in the unit cover 11. Yes.

  In the unit cover 11, a head chip 12, a unit base 13, a damper rubber film 14, a damper presser 15 and a relay substrate 16 are laminated in this order from the front side. The unit base 13 and the damper rubber film 14 define four damper chambers 21 (1) to 21 (4). The unit cover 11, the unit base 13, and the damper presser 15 are made of, for example, a resin molded product.

  The damper chambers 21 (1) to 21 (4) communicate with the tip portions 22 a (1) to 22 a (4) of the ink supply pipes 22 (1) to 22 (4) integrally formed with the damper presser 15. The ink tubes 6 (1) to 6 (4) are connected to the rear end portions 22b (1) to 22b (4) of the ink supply tubes 22 (1) to 22 (4). Each of the damper chambers 21 (1) to 21 (4) has four ink intake ports 24 (1) to 24 (24) formed in the head chip 12 via the ink supply ports 23 (1) to 23 (4). It communicates with (4).

  Therefore, the ink from the ink tanks 5 (1) to 5 (4) passes through the ink tubes 6 (1) to 6 (4) and the ink supply pipes 22 (1) to 22 (4), and the damper chambers 21. (1) to 21 (4) are supplied to the ink supply ports 23 (1) to 23 (4) and the ink intake ports 24 (1) to 24 (4) from the damper chambers 21 (1) to 21 (4). And supplied to the ink nozzle group of each color.

  The head chip 12 has a flat rectangular parallelepiped shape, and the front surface thereof is an ink nozzle surface 12a, in which an ink nozzle row (not shown) for discharging ink of each color is formed. The ink nozzle surface 12 a is exposed from the front opening 11 a of the unit cover 11. Further, the flexible wiring boards 25 (1) and 25 (2) for power feeding are pulled out from each side surface of the head chip 12, and are pulled out rearward along the inner side of each side surface of the unit cover 11. It is connected to the rear surface. Head chip driving ICs 26 (1) and 26 (2) are attached to portions of the flexible wiring boards 25 (1) and 25 (2) facing the side surfaces of the unit cover 11.

  The unit base 13 disposed on the rear side of the head chip 12 includes a front plate portion 31 to which the head chip 12 is bonded and fixed, and an outer peripheral side plate portion 32 extending perpendicularly from the four peripheral edges of the front plate portion 31 to the rear. And a vertical partition plate portion 33 and a horizontal partition plate portion 34 that partition the portion surrounded by the rear surface of the front plate portion 31 and the outer peripheral side plate portion 32 into a cross shape.

  A mounting recess 31a in which the head chip 12 is fitted is formed on the front surface of the front plate portion 31, and an adhesive groove 31b for filling an adhesive is formed on the bottom surface of the mounting recess 31a. The upper end portion of the adhesive groove 31 b is drawn to the upper surface of the outer peripheral side plate portion 32. The head chip 12 is fitted into the mounting recess 31a and is adhesively fixed to the front plate portion 31 with an adhesive filled in the adhesive groove 31b.

  Four damper chamber recesses 35 (1) to 35 (4) are formed by the vertical partition plate portion 33 and the horizontal partition plate portion 34 in the rear portion of the unit base 13. Each recess has substantially the same shape, and the ink supply ports 23 (1) to 23 (4) formed in the front plate portion 31 are formed on the bottom surface 35a of each of the damper chamber recesses 35 (1) to 35 (4). Is open. The filter 36 is thermally welded so as to cover the bottom surface 35a.

  Next, the damper rubber film 14 is bonded and fixed to the rear surface of the unit base 13, that is, the outer peripheral side plate portion 32 and the rear surfaces of the vertical and horizontal partition plate portions 33 and 34. The damper rubber film 14 is pressed against the unit base 13 by a damper presser 15 attached to the rear surface side. Due to the bent portions 14 a (1) to 14 a (4) of the damper rubber film 14, deformation of the damper rubber film 14 when the unit base 13 and the damper presser 15 are assembled, and an adhesive that bonds the damper rubber film 14 to the unit base 13 are provided. Since the deformation of the damper rubber film during drying is absorbed, the bent portion inner sides 14b (1) to 14b (4) can be kept flat. If the bent portion inner sides 14b (1) to 14b (4) are in a flat state, the flex amount of the bent portion inner sides 14b (1) to 14b (4) is maximized, and the ink is caused by the movement of the head unit 4. It is advantageous to absorb pressure fluctuations acting on the ink in the tube 6.

  In the damper rubber film 14, the portions 14 (1) to 14 (4) facing the respective recesses for the damper chambers 35 (1) to 35 (4) are made thin, and the thin portions 14 (1) to 14 (4) ) Are formed with bent portions 14a (1) to 14a (4), so that they are easily bent in the out-of-plane direction. The damper chamber recesses 35 (1) to 35 (4) are sealed by the thin portions 14 (1) to 14 (4) which are the flexible portions of the damper rubber film 14, and the damper chambers 21 (1) to 21 (21) to 21 (21) to 21. (4) is partitioned.

  The damper retainer 15 has a rear plate portion 41, an outer peripheral side plate portion 42 extending at right angles from the four peripheral edges to the front, and a front portion surrounded by the front surface of the rear plate portion 41 and the outer peripheral side plate portion 42. A vertical partition plate portion 43 and a horizontal partition plate portion 44 are provided, and four recesses 45 (1) to 45 (4) facing the damper chambers 21 (1) to 21 (4) are formed. ing. These concave portions 45 (1) to 45 (4) communicate with the atmosphere through the respective vent holes 46 formed in the rear plate portion 41, and the respective damper rubber films are formed by the concave portions 45 (1) to 45 (4). 14 thin-walled portions 14 (1) to 14 (4) can flex freely in the out-of-plane direction.

  Here, in the damper presser 15 of this example, four ink supply pipes 22 (1) to 22 (4) are integrally formed at a portion 47 where the vertical and horizontal partition plate portions intersect each other. It consists of a molded product. The rear end portions 22b (1) to 22b (4) of the respective ink supply pipes 22 (1) to 22 (4) pass through the through holes 51 (1) to 51 (4) opened in the relay substrate 16 and are located on the rear side. And are connected to the ink tubes 6 (1) to 6 (4). On the other hand, the tip portions 22a (1) to 22a (4) of the ink supply pipes 22 (1) to 22 (4) are inserted into the insertion holes 52 (1) to 52 (4) formed in the damper rubber film 14, respectively. And protrudes into each of the damper chambers 21 (1) to 21 (4). The insertion holes 52 (1) to 52 (4) are of a predetermined length protruding into the damper chambers 21 (1) to 21 (4), and the inner diameter dimensions thereof are the ink supply pipes 22. (1) It is shape | molded in the dimension slightly smaller than the outer-diameter dimension of the front-end | tip part 22a (1) -22a (4) of 22 (4).

  Therefore, the portion of the damper rubber film 14 forming each insertion hole 52 (1) to 52 (4) is in close contact with the outer peripheral surface of the tip end portion 22a (1) to 22a (4) by its own elastic restoring force. The space between them is completely sealed.

  The head unit 4 of this example configured as described above ejects ink droplets while moving in the direction indicated by the arrow A in FIGS. Pressure fluctuations acting on the ink in the ink tube 6 due to the movement are absorbed or alleviated by the four damper chambers 21 (1) to 21 (4) provided in the head unit 4 and the damper rubber film 14. . In particular, even when the area of the damper film is not sufficient due to the downsizing of the head unit, the bending effect of the damper rubber film 14 is enhanced by the bending portion 14a being bent, and pressure can be absorbed. Ink droplet ejection from the nozzle is stabilized. Thus, providing the bent portion 14 a in the damper rubber film 14 is advantageous for reducing the size of the head unit 4. Further, the portions where the damper effect by the damper chambers 21 (1) to 21 (4) cannot be expected are the ink supply ports 23 (1) to 23 (from the damper chambers 21 (1) to 21 (4) to the head chip 12. The length up to 4) is very short. Therefore, since the pressure acting on the ink in this portion is very small, it does not adversely affect the ejection of ink droplets from the ink nozzles. Therefore, it is possible to reliably prevent printing defects such as missing dots due to ink pressure fluctuations caused by the movement of the head unit 4.

  In this example, by reducing the thickness of the front plate portion 31 of the unit base 13, the ink supply ports 23 (1) to 23 (4) formed there can be shortened. Basically, the ink supply port can be shortened to a thickness necessary for forming the adhesive groove 31b.

  In this example, four damper chambers 21 (1) to 21 (4) are arranged along the direction parallel to the ink nozzle surface 12a of the head chip 12, that is, the moving direction of the head unit 4. The damper chambers 21 (1) to 21 (4) are longer in the direction parallel to the direction perpendicular to the ink nozzle surface 12a. Therefore, according to this example, each component can be incorporated in the rectangular parallelepiped unit cover 11 which is longer in a direction parallel to the direction orthogonal to the moving direction of the head unit 4. As a result, a head unit having a small dimension in the direction orthogonal to the moving direction can be configured, so that the space required for the movement can be reduced, and thus the ink jet printer can be reduced in size and size. Further, the damper rubber film 14 is formed of one rubber film for the four damper chambers 21 (1) to 21 (4). Therefore, the four damper chambers 21 (1) to 21 (4) can be easily sealed by the damper rubber film 14 at the outer peripheral side plate portion 32, the vertical partition portion 33, and the horizontal partition portion 34.

  Next, in this example, ink supply pipes 22 (1) to 22 (4) are formed integrally with the damper presser 15, and the insertion holes 52 (1) to 52 (52) in which these ink supply pipes are opened in the damper rubber film 14. The ink supply path to each of the damper chambers 21 (1) to 21 (4) can be formed by a simple operation of inserting into (4). Therefore, the head unit 4 can be easily assembled. In addition, since the structure of the ink supply path can be simplified, it is advantageous for reducing the size and size of the head unit.

  In this example, the elastic force of the damper rubber film 14 is used to make the insertion holes 52 (1) to 52 (4) formed therein and the ink supply pipes 22 (1) to 22 inserted therein. The seal state between (4) is formed. Therefore, it is not necessary to attach another member to form the sealed state, and the sealed state is automatically formed only by inserting the ink supply pipe. Therefore, the assembly operation of the head unit is simplified, the number of parts can be reduced, and a reduction in size, size and cost can be realized.

  Further, in this example, the tip portions 22a (1) to 22a (4) of the ink supply pipes 22 (1) to 22 (4) are placed in the damper chambers 21 (1) to 21 (4) to a predetermined length. Only protruding. In this way, bubbles that have entered the damper chambers 21 (1) to 21 (4) through the ink supply pipes 22 (1) to 22 (4) become the ink supply pipes 22 (1) to 22 (4). ) Can be avoided because the ink supply pipes 22 (1) to 22 (4) are clogged. That is, since the tip of the ink supply pipes 22 (1) to 22 (4) protrudes from the other damper chamber peripheral surface portion, the air bubbles remaining in this portion are in an unstable state. It is because it is easy to move to the damper chamber peripheral surface portion.

  (Other Embodiments) Although the above example relates to a head unit mounted on an ink jet printer that performs four-color printing, the present invention relates to a head unit for an ink jet printer that performs single-color printing, or The present invention can be similarly applied to a head unit for an ink jet printer that performs printing with a plurality of colors other than four colors.

  The present invention is not limited to the above-described embodiment, and various changes can be made. For example, the damper rubber films 14 of the four damper chambers 21 (1) to 21 (4) are formed of one rubber film, but two rubber chambers corresponding to two damper chambers are used. A sheet may be used. However, the smaller the number, the more the cost can be reduced. Moreover, the damper effect of the damper rubber film 14 can be further enhanced by providing a plurality of bent portions 14a (1) to 14a (4) formed in the damper rubber film 14 in a ripple pattern.

  Further, although four examples of the damper chambers 21 (1) to 21 (4) are shown, a flat damper chamber is stacked on the rear portion of the head chip formed in a flat shape even if there is one. According to the configuration, the pressure acting on the ink flow path, which is the effect of the present invention, can be made extremely small, so that it is possible to avoid a drop in print quality such as missing dots, and the moving direction (ink nozzles) in the head unit. The dimension in the direction orthogonal to the direction of the surface can be shortened.

1 is a schematic configuration diagram showing a main part of a serial type ink jet printer to which the present invention is applied. It is sectional drawing which shows the head unit of the inkjet printer of FIG. FIG. 3 is an exploded perspective view illustrating a state in which the head unit of FIG. 2 is disassembled and viewed from the front. FIG. 3 is an exploded perspective view illustrating a state in which the head unit of FIG. 2 is disassembled and viewed from the rear. FIG. 5 is an exploded perspective view of a unit base body of the head unit of FIGS. 3 and 4 as viewed from the front and rear. FIG. 5 is an exploded perspective view of the damper film of the head unit of FIGS. 3 and 4 as viewed from the front and rear.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Guide shaft 3 Carriage 4 Head unit 5 Ink tank 6 Ink tube 11 Unit cover 11a Front opening part 12 Head chip 12a Ink nozzle surface 13 Unit base 14 Damper rubber film 14 (1) -14 (4) Damper rubber film thin part 14a bent portion 14b bent portion inner flat portion 15 damper holding member 16 relay substrate 21 (1) to 21 (4) damper chamber 22 (1) to 22 (4) ink supply tube 22a (1) to 22a (4) ink supply tube Tip end portions 22b (1) to 22b (4) of the ink supply pipes. Rear end portions 23 (1) to 23 (4) of the ink supply ports 24 (1) to 24 (4) Ink intake ports 35 (1) to 35 ( 4) Damper chamber recess 36 Filter 45 (1) -45 (4) Recess 52 (1) -52 (4) Insert hole A Head unit Moving direction

Claims (6)

A head chip formed in a flat shape with an ink nozzle surface on which nozzles for discharging ink are formed as a front surface;
A unit base supporting the head chip on the front surface and having a recess formed on the rear surface;
A flexible damper film that seals the recess, and includes a bent portion formed along the inner periphery of the recess;
A damper chamber that is partitioned by sealing the recess with the damper film, and that relaxes pressure fluctuations acting on the ink supplied to the head chip;
An ink jet head unit, comprising: an ink supply port formed on the unit base for supplying the ink from the damper chamber to the head chip. In claim 1,
The inkjet head unit, wherein the damper film has a plurality of bent portions formed in a ripple pattern. In claim 1,
By forming the plurality of recesses in the unit base, the inkjet head unit has a plurality of damper chambers,
Each of the damper chambers is arranged in a direction parallel to the ink nozzle surface of the head chip. In claim 3,
Each of the damper films corresponding to the plurality of recesses is formed of a common sheet, and a plurality of the bent portions are formed corresponding to the plurality of recesses. Head unit. In claim 1,
An ink supply pipe for supplying the ink to the damper chamber;
The damper film is a rubber film, and includes an insertion hole into which the ink supply pipe can be inserted.
The insertion hole has a smaller diameter than the distal end portion of the ink supply pipe, and the distal end portion of the ink supply pipe passes through the insertion hole in a state where the insertion hole is pushed and widened.
The ink-jet head unit, wherein the ink supply pipe is inserted into the insertion hole and communicates with the damper chamber. In claim 5,
The damper film is bonded to the unit base,
Having a damper retainer attached to the back surface of the damper film;
The ink supply pipe is integrally formed with the damper presser,
The ink jet head unit according to claim 1, wherein a tip portion of the ink supply pipe inserted into the insertion hole protrudes a predetermined length into the damper chamber.

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