JP2005313428A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep invariant ink ejection performance of every nozzle array by supplying ink uniformly to a plurality of common ink chambers 7 even if a filter body 20 in an ink supply passage 47 is partially choked with contaminant. <P>SOLUTION: On the back of a cavity unit, an ink supply passage 47 is opened and a filter body 20 corresponding to that opening is arranged. Ink inlets 51 in at least two adjacent common ink chambers 7 are arranged side by side while being separated by partition walls 52. The ink supply passage 47 has a projection area corresponding to a plurality of ink inlets 51 including the partition walls 52 and communicates with two or more adjacent ink inlets 51 including the partition walls 52. The filter body 20 is located on the upstream side of the ink supply passage 47 for the partition wall 52 while spaced apart therefrom. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a configuration of a piezoelectric type ink jet recording head.

  In the prior art piezoelectric ink jet recording head, for example, in Patent Document 1, a nozzle plate having two rows of nozzles formed at regular intervals and two rows of pressure chambers corresponding to the nozzle locations are formed. A cavity plate is formed by laminating a pace plate and a manifold plate interposed between the base plate and the nozzle plate and having two common ink chambers for supplying ink to the rows of the pressure chambers. It is composed. Two ink supply holes for introducing ink from the ink storage section (tank) into each common ink chamber are formed on the back side of the cavity unit, and a piezoelectric actuator is joined to the back side of the cavity unit. Then, the piezoelectric actuator is driven, and ink is ejected from the selected nozzle to record an image on the recording medium.

On the other hand, in the cavity unit described in Patent Document 2, a nozzle plate having a substantially rectangular plate shape in plan view having a plurality of nozzle opening rows, a pressure generating chamber row communicating with the nozzle opening rows, and pressure via an ink supply port A reservoir (common ink chamber) communicating with the generation chamber row and an ink flow path communicating with each reservoir are defined, and a spacer plate whose one surface is sealed by the nozzle plate and the other surface of the spacer plate are The plate member is sealed and has a single ink introduction port disposed on the symmetry line of the nozzle opening row. Therefore, the ink supplied from the single ink introduction port is branched at the start ends of the plurality of ink flow paths on the spacer plate and supplied to each reservoir (common ink chamber).
Japanese Patent Laid-Open No. 2002-67312 (see FIGS. 6 and 12) Japanese Patent No. 3267212 (refer to FIGS. 1, 5 and 6)

  In the recording head in Patent Document 1, one ink supply hole corresponds to one common ink chamber corresponding to one nozzle row, and a filter is attached to the back surface of the cavity unit so as to cover each ink supply hole. It had been.

  Therefore, for example, when a predetermined ink is supplied to one nozzle row that discharges one color of ink through the ink supply hole, a part of the filter filtering unit is clogged with dust mixed in the ink. As a result, there is a problem that the ink flow resistance is extremely increased, the ink ejection performance is greatly deteriorated, and the image quality is deteriorated.

  Also in Patent Document 2, when a filter is arranged at the position of the single ink introduction port, if a part of the filtration unit is clogged with dust, ink is not uniformly supplied to the plurality of ink flow paths, The problem that the ink ejection performance changes and the image quality deteriorates has not been solved.

  In view of the above, it is a technical object of the present invention to provide an ink jet recording head in which such problems are solved.

In order to solve this technical problem, an ink jet recording head according to a first aspect of the present invention includes a plurality of nozzle rows each having a plurality of nozzles arranged in a row on the front surface, and a plurality of pressure chambers communicating with the nozzles. A plurality of common ink chambers that distribute and supply ink to the pressure chambers corresponding to the nozzle rows, an ink flow path from the common ink chambers to the nozzles via the pressure chambers, In an ink jet recording head provided with a cavity unit having an ink supply passage for supplying ink from an ink reservoir to the plurality of common ink chambers,
On the back surface of the cavity unit, the ink supply passage is opened and a filter body having a filtration portion corresponding to the opening is disposed,
Ink inlets in at least two adjacent common ink chambers are juxtaposed across the partition wall,
The opening of the ink supply passage has a projection area through which ink flows in common to a plurality of ink inlets adjacent to each other across the partition wall, and the filter body is upstream of the ink supply passage with respect to the partition wall. It is located at an interval to the side.

  According to a second aspect of the present invention, in the ink jet recording head according to the first aspect, the ink supply passage is communicated across two or more adjacent ink inlets, and the filter section corresponding to the ink supply passage is The plan view contour shape has a projected area of a plurality of ink inlets including the partition wall.

  According to a third aspect of the present invention, in the ink jet recording head according to the first or second aspect, at least one sheet is provided between the plate having the common ink chamber and the ink inlet and the plate on which the pressure chamber is formed. A plate having a common ink chamber and an ink inlet is stacked with a spacer plate interposed therebetween, and the partition wall is formed, and an ink supply passage is opened on the back surface of the plate on which the pressure chamber is formed. The ink supply passage is formed through the plate in which the chamber is formed and the spacer plate.

  According to a fourth aspect of the present invention, in the ink jet recording head according to any one of the first to third aspects, the common ink chamber extends along a direction in which the nozzle row extends, and the ink inlet and the ink A supply passage and a filtration part are located corresponding to the end part of the nozzle row, and are formed so as to communicate with the common ink chamber.

  According to the first aspect of the present invention, in the ink supply passage, a plurality of adjacent ink inlets in the plurality of common ink chambers are arranged in parallel with the partition wall therebetween, and the opening of the ink supply passage has the partition wall separated from the ink supply passage. Since the filter body has a projected area through which ink flows in common to a plurality of adjacent ink inlets and is spaced from the partition wall to the upstream side of the ink supply passage, Even if the part is clogged with dust contained in the ink, the ink that has flowed in from other parts of the filtration part (the part that is not clogged) enters the ink supply passage in a large area, and then the ink at the part of the partition wall. There is an effect that it is possible to ensure that the flow is branched and ink is supplied almost uniformly to all the ink inlets.

  According to a second aspect of the present invention, the ink supply passage is communicated across two or more adjacent ink inlets, and the filter portion corresponding to the ink supply passage has a contour shape in plan view as the partition wall. Since the projected area of the plurality of ink inlets including the filter portion is at least substantially equal to the projected area of the plurality of ink inlets including the partition wall, the flow resistance of the supplied ink can be reduced.

  According to the invention of claim 3, since the ink supply passage having a large area and the plurality of common ink chambers having the partition wall between the adjacent ink inlets can be formed on separate plates, the present invention can be achieved by simply laminating them later. The structure can be made very easily and the production cost can be reduced.

  According to the invention of claim 4, even in relation to the nozzle row, it is not necessary to increase the width dimension in the short side direction of the cavity unit, and while maintaining the ink supply function, There is an effect that it can contribute to downsizing.

  Next, an embodiment of the present invention will be described with reference to the drawings. 1 is an exploded perspective view of a first embodiment of a piezoelectric ink jet recording head, FIG. 2 is an enlarged exploded perspective view of a cavity unit, FIG. 3 is an enlarged sectional view taken along line III-III in FIG. 1, and FIG. FIG. 5 is a partial plan view of the lower surface side as viewed from the base plate at a location where ink is separately supplied to the two common ink chambers, and FIG. 4 is an enlarged sectional view taken along line VI-VI in FIG. 4, FIG. 7 is an enlarged sectional view taken along line VII-VII in FIG. 5, FIG. 8 is an exploded perspective view of the cavity unit of the second embodiment, and FIG. FIG. 10A is a plan view showing the third embodiment, and FIG. 10B is a cross-sectional view.

  FIG. 1 is a perspective view of a cavity unit 1 and a piezoelectric actuator 2 in the piezoelectric ink jet recording head HD according to the first embodiment of the present invention. The cavity unit 1 is shown in an exploded state.

  In the ink jet recording head HD, a plate-type piezoelectric actuator 2 is joined to a cavity unit 1 made of a metal plate, and a flexible flat cable 3 (see FIG. 3) for connecting to an external device is provided on the upper surface of the plate-type piezoelectric actuator 2. ) Is lap-joined. Then, it is assumed that ink is ejected downward from the nozzle 4 opened on the lower surface side of the lowermost cavity unit 1.

  The cavity unit 1 is configured as shown in FIGS. That is, a total of eight thin plates including the nozzle plate 11, the first spacer plate 12, the damper plate 13, the two manifold plates 14a and 14b, the second spacer plate 15, the third spacer plate 16, and the base plate 17 are bonded together. It is a structure that is lap-joined with an agent.

  In the embodiment, except for the nozzle plate 11 made of synthetic resin, each of the plates 12 to 17 is made of 42% nickel alloy steel plate and has a thickness of about 50 to 150 μm. In the nozzle plate 11, a plurality of nozzles 4 for discharging ink having a minute diameter (in the embodiment, about 25 μm) are formed at minute intervals according to the resolution at the time of recording. In the embodiment, 75 nozzles 4 are formed in a length of 1 inch, and the arrangement density is 75 dpi (dot per inch). The nozzles 4 are arranged in five rows in a staggered manner along the first direction (long side direction, X direction) of the nozzle plate 11.

  Further, as shown in FIG. 1, a plurality of pressure chambers 36 are arranged on the base plate 17 along the long side (the X direction) of the base plate 17 in five rows in a staggered arrangement corresponding to the rows of the nozzles 4. ing. In the embodiment, as shown in FIG. 2, the pressure chamber 36 has a direction connecting one end portion (tip portion) 36 a of the pressure chamber 36 communicating with the nozzle 4 and the other end portion 36 b communicating with the common ink chamber 7 described later. The longitudinal direction of Each pressure chamber 36 is formed with a narrow width so that the longitudinal direction thereof is along the second direction (short side direction, Y direction) of the base plate 17.

  The front end portion 36a of each pressure chamber 36 is similarly bored in a staggered arrangement in the two spacer plates 15, 16 and the two manifold plates 14a, 14b, the damper plate 13, and the first spacer plate 12. The nozzles 11 communicate with the nozzles 4 through through-holes 37 having a very small diameter.

  The third spacer plate 16 adjacent to the lower surface of the base plate 17 is provided with a communication hole 38 at a position corresponding to each other end 36b in order to connect to the other end 36b of each pressure chamber 36. .

  The second spacer plate 15 adjacent to the lower surface of the third spacer plate 16 is provided with a connection channel 40 for supplying ink from the common ink chamber 7 to be described later to the pressure chambers 36. Each connection channel 40 includes an inlet hole 40a into which ink enters from the common ink chamber 7, an outlet hole 40b that opens to the pressure chamber 36 side (the communication hole 38), an inlet hole 40a, and an outlet hole 40b. There is a constricted portion 40c formed with a smaller cross-sectional area so as to have the largest flow path resistance in the connection flow path 40 than the outlet hole 40b.

  In this embodiment, the narrowed portion 40c is formed to have a predetermined flow path resistance by half-etching the surface side adjacent to the third spacer plate 16. The inlet hole 40a and the outlet hole 40b are formed in alignment with both ends of the throttle portion 40c. The inlet hole 40 a passes through the second spacer plate 15. The outlet hole 40b is formed in a recess in the second spacer plate 15 adjacent to the third spacer plate 16 (see FIGS. 2 and 3).

  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, by stacking two manifold plates 14a and 14b, and covering the upper surface with the second spacer plate 15 and covering the lower surface with the damper plate 13, a total of five common ink chambers (manifold chambers) 7 are respectively provided. It is formed in a sealed state. Each common ink chamber 7 overlaps a part of the pressure chamber 36 and extends long in the column direction of the pressure chambers 36 in a plan view as viewed from the stacking direction of the plates.

  As shown in FIGS. 2 and 3, 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 14 a. The positions and shapes of the damper chambers 45 are the same as those of the common ink chambers 7. 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, at least one of the base plate 17 and the third spacer plate 16 (in the embodiment, the wide surface of the third spacer plate 16 on the side of the base plate 17) is arranged between the rows of pressure chambers 36 ( An inspection flow groove 50 extending along the long side direction (X direction) and communicating with the outside is formed. In this case, sealing leaks in the region between the rows of the pressure chambers 36 are inspected by detecting the outflow of air from the outward opening of the inspection flow groove 50 or the pressure drop on the ink supply passage 47 side described later. In addition, leaks from the pressure chamber 36 to the outside can be inspected at the same time.

  An ink supply passage 47 communicating so as to supply ink from an ink storage portion (not shown) such as an ink tank to the common ink chamber 7 includes a base plate 17 in which a pressure chamber 36 is formed from the back side of the cavity unit 1; The second and third spacer plates 15 and 16 are formed so as to penetrate (see FIGS. 1 and 3). More specifically, as shown in FIG. 1, the four ink supply passages 47 are arranged along the short side direction (Y direction) of the cavity unit 1 and outside the row region of the nozzles 4 as shown in FIG. So that it is drilled. These four ink supply passages 47 are described as 47a, 47b, 47c, and 47d in order from the left side of FIG. The ink supply passages 47a, 47b, 47c, 47d are opened on the back surface of the cavity unit 1, and the filter body 20 having the filtering portions 20a, 20b, 20c, 20d corresponding to the openings is disposed and bonded. It is affixed with materials.

  In this embodiment, as shown in FIG. 1, four ink supply passages 47 are provided, whereas five common ink chambers 7 are provided (individually, reference numerals 7a, 7a, 7b). , 7c, 7d (see FIG. 1).

  The ink supply passage 47a communicates across the two ink inlets 51 that are one end in the longitudinal direction of the two common ink chambers 7a and 7a arranged adjacent to the left side in FIG. The two adjacent ink inlets 51 are arranged close to each other with the partition wall 52 interposed therebetween (see FIGS. 4 and 6). In other words, the partition wall 52 is formed in the manifold plates 14 a and 14 b having the common ink chamber 7 a and the ink inlet 51.

  As shown in FIGS. 4 and 6, the opening of the ink supply passage 47a is a projection that causes ink to circulate in common to a plurality (two in the embodiment) of ink inlets 51 that are adjacent to each other with the partition wall 52 therebetween. The filter body 20 is positioned with respect to the partition wall 52 at a distance upstream of the ink supply passage 47 a by the thickness of the base plate 17 and the second and third spacer plates 16 and 15. .

  In other words, the ink supply passage 47a communicates with the two adjacent ink inlets 51 in the two adjacent common ink chambers 7a, 7a, and the single filter portion 20a corresponding to the ink supply passage 47a The contour shape in plan view has the projected area of the two ink inlets 51 including the partition wall 52, and the filter body 20 is located at a distance from the partition wall 52. If comprised in this way, even if a part of single filtration part 20a is clogged with the garbage 53 contained in the ink, the ink which flowed in from the other part (part not clogged) of this filtration part 20a is wide. After entering the area of the ink supply passage 47a, it is ensured that the ink flow is branched into the arrows i1 and i2 in FIG. It can be done.

  In the embodiment, the ink supply passage 47a is set to be supplied with black ink. This is because the consumption of black ink per unit time is larger than that of other color inks when the recording speed during monochrome recording is higher than that in color recording.

  The other ink supply passages 47b, 47c, and 47d are supplied with yellow, magenta, and cyan inks, respectively, and the corresponding common ink chambers 7b, 7c, and 7d are supplied to the ink supply passages 47b, 47c, and 47d, respectively. Are communicated one by one (see FIGS. 1 and 5).

  Ink supply passages 47, common ink chambers 7, through holes 37, communication holes 38, connection flow paths 40, damper chambers 45, inspection flow grooves 50 and the like in the metal plates 12 to 17 are formed and through holes. Are formed by etching, electrical 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 a plan view, filtration portions 20a to 20d in which extremely small holes are formed by laser processing or the like are formed. When the filter body 20 is made of metal, it may be formed by electroforming, plasma processing, laser processing, or the like. These filter bodies 20 are joined with an adhesive so as to cover all the ink supply passages 47a to 47d.

  The cavity unit 1 is configured by aligning and joining the eight thin plates 11 to 17 formed as described above to each other. As a result, a common ink chamber 7 extending in the long side direction is formed inside the cavity unit 1 as shown in FIGS. Furthermore, individual ink flow paths are formed from the inlet hole 40a of each connection channel 40 opened to the common ink chamber 7 to the nozzle 4 via the corresponding communication hole 38, pressure chamber 36, and through hole 37 in order. The

  When the recording head HD is attached to a carriage of a recording apparatus (not shown), the ink supply passage 47 communicates with a supply pipe 48 connected to the ink storage portion via a seal member 49.

  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 shown in the known Japanese Patent Application Laid-Open No. 4-341833. Common electrodes are formed across the plurality of pressure chambers 36 in the cavity unit 1 on the lowermost step of the piezoelectric sheets and on the upper surface (wide surface) of the odd-numbered piezoelectric sheets from the bottom. On the upper surface (wide surface) of the even-numbered piezoelectric sheet from the bottom, narrow individual electrodes are formed at locations corresponding to the plurality of pressure chambers 36. Further, on the upper surface of the uppermost sheet, as shown in FIG. 1, as a surface electrode 9, a surface electrode electrically connected to each of the individual electrodes, and an electrically connected to the common electrode A surface electrode to be connected is provided.

  An adhesive sheet (not shown) made of a non-ink-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. Further, the flexible flat cable 3 is heated and pressurized on the upper surface of the piezoelectric actuator 2 so that various wiring patterns (not shown) in the flexible flat cable 3 are applied to the surface electrodes 9. Electrically joined.

  In the above configuration, when a voltage is applied between any one of the individual electrodes of the piezoelectric actuator 2 and the common electrode corresponding thereto, the stacking direction due to the piezoelectric longitudinal effect is applied to the active portion corresponding to both electrodes. Distortion occurs. This distortion reduces the internal volume of the pressure chamber 36 with respect to the arbitrary individual electrode. As a result, the ink in the pressure chamber 36 is ejected in droplet form from the nozzle 4 (predetermined printing is performed).

  Next, FIGS. 8 and 9 show a second embodiment. In this embodiment, the nozzles 4 are arranged in four rows, and a plurality of nozzles 4 are arranged in rows in the X direction. A nozzle plate 11 having a row, two manifold plates 14a and 14b, one spacer plate 15, and a base plate 17 having a pressure chamber 36 corresponding to each nozzle 4 are sequentially laminated. In the manifold plate 14a, the upper half of the plate thickness is half-etched, and in the upper manifold plate 14a, the common ink chamber 7 extends along each row of the nozzles 4 so as to penetrate the plate thickness. Is formed. That is, by stacking two manifold plates 14a and 14b and covering the upper surface with the spacer plate 15 and the lower surface with the nozzle plate 11, a total of four common ink chambers (manifold chambers) 7 are sealed. Is formed. Each common ink chamber 7 overlaps a part of the pressure chamber 36 and extends long in the column direction of the pressure chambers 36 in a plan view as viewed from the stacking direction of the plates.

  The one spacer plate 15 and the two manifold plates 14a and 14b are formed with through holes 37 for flowing ink from the pressure chambers 36 of the base plate 17 to the nozzles 4 of the nozzle plate 11. The spacer plate 15 is provided with a communication hole 38 for supplying ink from the common ink chamber 7 to the corresponding pressure chamber 36.

  In this embodiment, as shown in FIG. 8, two ink supply passages 47 are respectively provided in the base plate 17 and the spacer plate 15, and one ink supply passage 47a is disposed adjacent to the left side in FIG. The two common ink chambers 7a and 7b communicate with each other across the two ink inlets 51, which are one end in the longitudinal direction, and the other ink supply passage 47b is arranged adjacent to the right side in FIG. The common ink chambers 7c and 7d communicate with each other across two ink inlets 51 that are one end in the longitudinal direction.

  These two adjacent ink inlets 51 are arranged adjacent to each other with partition walls 52a and 52b formed so as to overlap the two manifold plates 14a and 14b in the vertical direction (see FIG. 9). In the two manifold plates 14a and 14b, one type of ink is supplied to the two common ink chambers 7a and 7b on the left side of the plate, and another type of ink is supplied to the two common ink chambers 7c and 7d on the right side. Ink is supplied.

  As shown in FIGS. 8 and 9, the ink supply passages 47 a and 47 b open the ink in common to the plurality of ink inlets 51 (two in the embodiment) adjacent to each other with the partition wall 52 therebetween. The filter body 20 having a projected area to be circulated and adhered to the back surface of the base plate 17 is spaced from the partition wall 52 by an amount corresponding to the thickness of the base plate 17 and the spacer plate 15 to the upstream side of the ink supply passage 47a. Is located. Further, the filtration parts 20a and 20b corresponding to the ink supply passages 47a and 47b respectively have a projected area of two ink inlets 51 including a partition wall 52 in a plan view outline shape. If comprised in this way, even if a part of filtration part 20a, 20b is clogged with the garbage 53 contained in the ink, the ink which flowed in from the other part (location which is not clogged) of filtration part 20a, 20b is wide. After entering the area of the ink supply passages 47a and 47b, the ink flow is branched into arrows i1 and i2 in FIG. 9 at the partition wall 52, so that the ink is almost uniformly distributed to all (two) ink inlets 51. It can be guaranteed that it will be supplied.

  FIG. 10A and FIG. 10B show a third embodiment. As an example of an embodiment in which one kind of ink is supplied to one cavity unit 1, four common ink chambers 7 are provided. The same type of ink is supplied, and the ink inlets 51 in the four common ink chambers 7 are arranged close to each other on one side of the short sides of the manifold plates 14a and 14b via the partition walls 52, respectively. Has been. The single filtration part 20a in the ink supply passage 47 and the filter body 20 formed so as to penetrate the plate thickness of the plurality of spacer plates 15 and 16 and the base plate 17 on the upper side thereof has a contour shape of 4 in plan view. The projected area includes one ink inlet 51 and three partition walls 52. Since the other configuration is the same as that of the first embodiment, the same reference numeral is given to the same configuration, and the detailed description is omitted.

  Also in this embodiment, even if a part of the filtering unit 20a is clogged with the dust 53 contained in the ink, the ink flowing from the other part (the part that is not clogged) of the filtering unit 20a is supplied with a large area of ink. After entering the passage 47, the ink flow is branched into the arrows i 1, i 2, i 3, i 4 in FIG. 10B at the three partition walls 52, and the ink is supplied almost uniformly to the four ink inlets 51. Can be guaranteed.

  The present invention is not limited to the above-described embodiment, and can be embodied in various forms. For example, the type of ink supplied from the ink supply passage is not limited to the color ink described above, and may be a fixing accelerator or the like. The type of color ink is not limited.

  Various shapes such as a substantially circular shape, a substantially oval shape, an oval shape (oval shape), a rectangular shape, a polygonal shape, and the like can be adopted as the outline shape of the ink supply passage in plan view. Along with this, the shape of the filtration unit in plan view is not limited to a substantially oval shape, and may be an oval (ellipse), a rectangle, or a polygon.

2 is an exploded perspective view of a piezoelectric inkjet recording head. FIG. It is an expansion disassembled perspective view of a cavity unit. FIG. 3 is an enlarged sectional view taken along line III-III in FIG. 1. It is the partial top view which looked at the lower surface side from the base plate in the part of two adjacent common ink chambers 7a and 7a. It is the partial top view which looked at the lower surface side from the base plate in the part of three separated common ink chambers 7a and 7a. FIG. 6 is an enlarged sectional view taken along line VI-VI in FIG. 4. FIG. 7 is an enlarged sectional view taken along the line VII-VII in FIG. 5. It is an expansion disassembled perspective view of the cavity unit of 2nd Embodiment. FIG. 9 is an enlarged cross-sectional view taken along line IX-IX in FIG. 8. (A) is the fragmentary top view seen from the back side of the cavity unit of 2nd Embodiment, (b) is the Xb-Xb arrow directional enlarged sectional view of Fig.10 (a).

Explanation of symbols

HD inkjet head 1 cavity unit 2 piezoelectric actuator 4 nozzle 7 (7a, 7b, 7c, 7d) common ink chamber 11 nozzle plate 12 first spacer plate 13 damper plate 14a, 14b manifold plate 15 second spacer plate 16 third spacer plate 17 Base plate 20 Film body 20a to 20d Filtration part 36 Pressure chamber 37 Through hole 38 Communication hole 40 Connection flow path 45 Damper chamber 47 (47a to 47d) Ink supply passage 51 Ink inlet 52 (52a) Partition wall

Claims (4)

A plurality of nozzle rows each having a plurality of nozzles arranged in a row on the front surface, a plurality of pressure chambers communicating with the nozzles, and distributing and supplying ink to the pressure chambers corresponding to the nozzle rows A plurality of common ink chambers, an ink flow path from each of the common ink chambers to the nozzles via the pressure chamber, and an ink supply path for supplying ink from the ink reservoir to the plurality of common ink chambers. In an ink jet recording head provided with a cavity unit having
On the back surface of the cavity unit, the ink supply passage is opened and a filter body having a filtration portion corresponding to the opening is disposed,
Ink inlets in at least two adjacent common ink chambers are juxtaposed across the partition wall,
The opening of the ink supply passage has a projection area through which ink flows in common to a plurality of ink inlets adjacent to each other across the partition wall, and the filter body is upstream of the ink supply passage with respect to the partition wall. An ink jet recording head, wherein the ink jet recording head is positioned at an interval to the side.   The ink supply passage is communicated across two or more adjacent ink inlets, and the filtration unit corresponding to the ink supply passage has a projected area of a plurality of ink inlets whose plan view outline shape includes the partition wall The ink jet recording head according to claim 1, comprising: Laminating at least one spacer plate between the plate having the common ink chamber and the ink inlet and the plate on which the pressure chamber is formed;
The partition wall is formed on the plate having the common ink chamber and the ink inlet,
An ink supply passage is opened at the back of the plate on which the pressure chamber is formed;
3. The ink jet recording head according to claim 1, wherein the ink supply passage is formed through the plate in which the pressure chamber is formed and the spacer plate. The common ink chamber extends along a direction in which the nozzle row extends,
4. The ink inlet, the ink supply passage, and the filtering portion are positioned so as to correspond to end portions of the nozzle rows and are formed so as to communicate with the common ink chamber. 5. 2. An ink jet recording head according to 1.

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