JP6686805B2 - Inkjet head and inkjet recording device - Google Patents

Description

  The present invention relates to an inkjet head and an inkjet recording apparatus, and more particularly, to an inkjet head and an inkjet recording apparatus that can efficiently remove residual bubbles in a common ink chamber of the inkjet head.

  As an inkjet head used in a printer (inkjet recording apparatus), there is an inkjet head provided with a common ink chamber for supplying ink to each pressure chamber. The common ink chamber is supplied with ink from the ink tank and communicates with each pressure chamber whose internal pressure is changed by driving the piezoelectric element, and supplies ink to each pressure chamber. If residual bubbles are present in the common ink chamber, the bubbles may enter the pressure chamber. When air bubbles enter the pressure chamber, there is a risk that the ink ejection performance from the nozzle communicating with the pressure chamber may be affected.

  As an inkjet head capable of removing such residual bubbles, there has been proposed one in which the bubbles are removed from the inner wall of the ink flow path by utilizing a resonance phenomenon and the residual bubbles are removed by the ink flow in the common ink chamber (Patent Document 1). Reference 1). In addition, there has been proposed a structure in which the ceiling surface of the common ink chamber is inclined so that the ink discharge side is directed upward, and residual bubbles are removed by utilizing the buoyancy of bubbles (Patent Document 2).

JP 2008-0887288A JP, 2009-126044, A

  By the way, in the inkjet head, the number of nozzles tends to increase due to the demand for higher resolution and wider print width. Therefore, the ink consumption per unit time also increases, the capacity of the common ink chamber increases, and the ink supply pressure to the common ink chamber also tends to increase.

  In the inkjet head described in Patent Document 1, when the volume of the common ink chamber is increased, there is a possibility that an ink flow velocity that sufficiently removes bubbles cannot be obtained in the common ink chamber. Further, when the ink supply pressure to the common ink chamber is set to a high pressure such as 70 kPa, the ink flow in the common ink chamber is on the opposite side of the ink supply port, that is, when the ink supply port is the common ink chamber. When it is on the ceiling side, it concentrates on the bottom side, the air bubbles on the ceiling side are not sufficiently removed, and a large amount of ink is discharged from the nozzles.

  Further, in the inkjet head described in Patent Document 2, if the capacity is increased while maintaining the inclination angle of the ceiling surface of the common ink chamber, the height dimension of the common ink chamber becomes large. If the height of the common ink chamber is maintained and the volume is increased, the inclination angle of the ceiling surface becomes small, and it becomes impossible to sufficiently remove small residual bubbles.

  Therefore, it is an object of the present invention to provide an inkjet head and an inkjet recording apparatus that can efficiently remove residual bubbles in a common ink chamber of the inkjet head.

  Other problems of the present invention will be clarified by the following description.

  The above problems can be solved by the following inventions.

1.
A common ink chamber,
An ink supply port that is formed in the common ink chamber and communicates with a flow path that supplies ink to the common ink chamber;
An ink recovery port formed in the common ink chamber and communicating with a flow path for recovering ink from the common ink chamber;
At least one pressure chamber that communicates with the common ink chamber through an injection hole and that causes a volume change by applying a voltage;
A nozzle communicating with the pressure chamber and serving as a flow path for ink ejected from the pressure chamber to the outside;
A straightening plate for changing the flow of ink from the ink supply port to the ink recovery port on the upper side of the common ink chamber,
The inkjet head is characterized in that at least a part of the straightening plate is arranged in the vicinity of the ink supply port in the common ink chamber.
2.
2. The ink jet head according to the above 1, further comprising a discharge path communicating with the pressure chamber and discharging ink in the pressure chamber.
3.
3. The inkjet head according to 1 or 2 above, wherein the straightening plate has a shape that guides the ink flowing near the ink supply port to an upper side of a central portion of the common ink chamber.
4.
2. The inkjet head according to 1, 2, or 3, wherein two or more rectifying plates are arranged in the common ink chamber.
5.
5. The ceiling of the common ink chamber is inclined with respect to a horizontal plane, and the ink recovery port is located higher than the ink supply port. Inkjet head.
6.
The inkjet head according to any one of 1 to 5 above, wherein the straightening plate is integrally connected to the common ink chamber via a vertical wall portion.
7.
7. The inkjet head according to any one of 1 to 6 above, wherein the straightening plate has a curved surface portion along the flow of the ink in the common ink chamber.
8.
8. The inkjet head according to any one of 1 to 7 above, wherein a filter is provided inside the common ink chamber.
9.
9. The inkjet head according to any one of 1 to 8 above, wherein the flow straightening plate is provided in a pressure attenuating unit arranged in the common ink chamber.
10.
In the common ink chamber, at least the first member provided with the ink supply port and the ink recovery port and the second member provided with at least the mounting portion of the pressure chamber and the rectifying plate are butt-coupled to each other. 10. The inkjet head according to any one of 1 to 9 above, which is configured by:
11.
The inkjet head according to any one of 1 to 10 above,
An ink tank for storing ink transferred to the common ink chamber of the inkjet head;
An ink jet recording apparatus, comprising: an ink transfer unit that transfers the ink in the ink tank to the common ink chamber.
12.
The inkjet head according to any one of 2 to 10,
An ink tank for storing ink to be transferred to the inkjet head;
An ink transfer unit for transferring the ink in the ink tank to the inkjet head, and collecting the ink transferred to the inkjet head,
The ink jet recording apparatus is characterized in that the ink discharged from the pressure chamber through the discharge passage is combined with the ink collected from the ink jet head.

  INDUSTRIAL APPLICABILITY The present invention can provide an inkjet head and an inkjet recording device that can efficiently remove residual bubbles in the common ink chamber of the inkjet head.

FIG. 1 is a schematic view of a main part of an example of the inkjet recording apparatus of the present invention. Flow path diagram showing ink flow paths in an inkjet head Exploded perspective view schematically showing the head chip portion of the inkjet head A perspective view showing an embodiment of a flow rate adjusting member of an inkjet head. FIG. 3 is a vertical cross-sectional view of a main part showing another embodiment of the current plate of the inkjet head FIG. 3 is a vertical cross-sectional view of a main part showing another embodiment of the current plate of the inkjet head A schematic configuration diagram of a main part showing another example of the inkjet recording apparatus of the present invention FIG. 3 is a vertical cross-sectional view of a main part showing another embodiment of the current plate of the inkjet head. FIG. 6 is a vertical cross-sectional view showing another embodiment of the current plate of the inkjet head. FIG. 6 is a vertical cross-sectional view showing another embodiment of the current plate of the inkjet head. FIG. 3 is a vertical cross-sectional view showing an embodiment in which a filter is provided inside the common ink chamber. Perspective view showing an embodiment provided with an external filter Exploded perspective view of common ink chamber of inkjet head

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Inkjet recording device]
FIG. 1 is a schematic configuration diagram of a main part showing an example of an inkjet recording apparatus according to the present invention, in which an inkjet head is partially shown in section.

  The inkjet recording apparatus 100 records an image by ejecting ink from the inkjet head 1 onto a recording medium that is conveyed in a certain direction (sub-scanning direction) by a conveying unit (not shown). In a so-called one-pass inkjet recording apparatus, the inkjet head 1 is fixedly arranged, and ink is ejected from the nozzles toward the recording medium in the process of conveying the recording medium. Further, in a so-called scan type inkjet recording apparatus, the inkjet head 1 is mounted on a carriage (not shown), and in the process in which the carriage moves along the main scanning direction orthogonal to the sub-scanning direction, the nozzles face the recording medium. Ink is ejected.

  Although only one inkjet head 1 is shown in FIG. 1, the inkjet recording apparatus 100 is generally used for each color ink such as yellow (Y), magenta (M), cyan (C), and K (black). A plurality of inkjet heads 1 are mounted. In the inkjet recording apparatus 100 according to the present embodiment, the ink tank 101 that stores ink and the common ink chamber 41 of the inkjet head 1 are connected by the ink transfer pipe 102 and the ink return pipe 103.

  A transfer pump 105, which is driven and controlled by the control unit 104 of the inkjet recording apparatus 100, is provided in the middle of the ink transfer tube 102. By driving the transfer pump 105, the ink in the ink tank 101 is transferred to the inkjet head 1 via the ink transfer pipe 102. Further, when the transfer pump 105 is driven, the ink (ink including bubbles) in the inkjet head 1 is returned to the ink tank 101 via the ink return pipe 103.

  In the inkjet recording apparatus 100, the ink transfer pipe 102, the control unit 104, and the transfer pump 105 constitute an ink transfer unit that transfers the ink in the ink tank 101 to the inkjet head 1.

  Although not particularly limited, the ink tank 101 is preferably partitioned into an ink transfer chamber 101b and an ink return chamber 101c by a partition plate 101a that does not reach the bottom surface of the tank. In this case, one end of the ink transfer pipe 102 is arranged in the ink transfer chamber 101b, and one end of the ink return pipe 103 is arranged in the ink return chamber 101c. The partition plate 101a is provided to sufficiently deaerate the ink so that the bubbles in the ink returned to the ink return chamber 101c do not flow into the ink transfer tube 102 again. Since the bubbles themselves have a high buoyancy, the bubbles are restricted from passing under the partition plate 101a and flowing into the ink transfer chamber 101b. Such an aspect is a preferable aspect when the ink is recycled.

[Inkjet head]
Next, a specific configuration of the inkjet head 1 according to the present invention shown in FIG. 1 will be described.

  The present invention can be applied to various inkjet heads such as a shear mode (edge (end) shooter and side shooter) type, a bend mode type, and a so-called MEMS type. That is, the inkjet head according to the present invention can be configured as these various inkjet heads.

  The inkjet head 1 shown in the present embodiment is configured as a shear mode head. The inkjet head 1 is installed and used so that the ink ejection surface 1S faces downward in the vertical direction. In addition, in this specification, "upper" and "lower" mean "vertical direction upper side" and "vertical direction lower side", and correspond to the upper side and the lower side in FIG. 1 (side view showing a usage state). To do. However, the use state of the inkjet head of the present invention is not limited to the state in which the ink ejection surface 1S is directed downward in the vertical direction, and the ink jet head may be used while being inclined.

  As shown in FIG. 1, the inkjet head 1 includes an ink manifold 4 that forms a common ink chamber 41, a wiring substrate 3 that is adhered to a pressure chamber attachment portion 4 a of the ink manifold 4, and an ink sandwiching the wiring substrate 3. The head chip 2 is attached to the opposite surface (lower surface) of the manifold 4. The wiring board 3 is, for example, a glass substrate. A wiring pattern (not shown) is formed on the wiring board 3 so as to be connected to a power circuit (not shown) via the FPC board. The ink manifold 4 is formed of a synthetic resin material or the like in a horizontally long box shape having a pressure chamber attachment portion 4a, which is an opening, on the lower surface. The wiring board 3 is adhered to the ink manifold 4 so as to close the pressure chamber attachment portion 4a. The internal space of the ink manifold 4 serves as a common ink chamber 41 in which the ink supplied from the ink tank 101 is stored.

  FIG. 2 is a flow path diagram showing ink flow paths in this inkjet head.

  As shown in FIGS. 1 and 2, the common ink chamber 41 is provided with an ink supply port 5a. The ink supply port 5a is connected to an ink supply pipe 51a which forms a flow path for supplying ink into the common ink chamber 41. The ink supply port 5a communicates the common ink chamber 41 to the outside on the upper side of the common ink chamber 41. A connection portion 7a is provided on the upper end side of the ink supply pipe 51a connected to the ink supply port 5a. The connecting portion 7a is detachably connected to the connecting portion 106a on the ink jet recording apparatus 100 side. The connection portion 106 a on the ink jet recording apparatus 100 side communicates with the ink transfer tube 102. As a result, the inkjet head 1 can transfer ink from the inkjet recording device 100.

  Further, the common ink chamber 41 is provided with an ink recovery port 5b. The ink recovery port 5b is connected to an ink recovery pipe 51b which forms a flow path for recovering ink from the common ink chamber 41. The ink recovery port 5b connects the common ink chamber 41 to the outside on the upper side of the common ink chamber 41. A connection portion 7b is provided on the upper end side of the ink recovery pipe 51b connected to the ink recovery port 5b. The connecting portion 7b is detachably connected to the connecting portion 106b on the ink jet recording apparatus 100 side. The connection portion 106 b on the ink jet recording apparatus 100 side communicates with the ink return pipe 103. As a result, the inkjet head 1 can return ink to the inkjet recording device 100.

  In the inkjet head 1, a flow path from the ink supply port 5a to a buffer space portion 6 described later in the middle of the ink recovery pipe 51b is a main flow path F1.

  The ink supply port 5a and the ink recovery port 5b are preferably arranged apart from each other at both ends in the longitudinal direction of the common ink chamber 41. The ink supply port 5a in the present embodiment is arranged at the left end in FIG. 1 on the upper surface of the ink manifold 4, and the ink recovery port 5b is the right end in FIG. 1 on the upper surface of the ink manifold 4. It is located in. This allows the ink supplied from the ink supply port 5a to the common ink chamber 41 to flow toward the ink recovery port 5b throughout the common ink chamber 41. Therefore, it is difficult to form a portion where the ink stays in the common ink chamber 41, and the bubbles in the ink can be removed more efficiently.

  Inside the ink manifold 4, as shown in FIG. 1, a rectifying plate 41a is provided. The current plate 41a is formed integrally with the ink manifold 4. This straightening plate 41a changes the flow of ink (main flow path F1) from the ink supply port 5a to the ink recovery port 5b on the upper side in the common ink chamber 41, and is configured as a horizontal plate in this embodiment. Has been done. At least a part of the straightening plate 41a is arranged in the common ink chamber 41 in the vicinity of the ink supply port 5a. In this embodiment, the current plate 41a is provided at a position extending from the side end of the common ink chamber 41 to directly below the ink supply port 5a. The rectifying plate 41a does not extend from one end side to the other end side in the common ink chamber 41, and is arranged in only a partial region in the longitudinal direction in the common ink chamber 41.

  Since at least a part of the rectifying plate 41a is located in the vicinity of the ink supply port 5a, when the ink flows in from the ink supply port 5a, the flow velocity of the ink is high, so that the flow direction of the ink is easily changed. The straightening plate 41a allows the ink to flow more to the upper side in the common ink chamber 41, thereby increasing the flow velocity of the ink in the upper side of the common ink chamber 41. By increasing the flow velocity of the ink in this way, residual bubbles in the common ink chamber 41 are rapidly moved, and even when the ink pressure difference between the ink supply port 5a side and the ink recovery port 5b side is low, Residual bubbles can be removed efficiently. The straightening plate 41a exerts a more remarkable effect especially when the ink supply pressure to the common ink chamber 41 is high. That is, the flow of ink that tends to concentrate on the bottom surface side can be changed to the flow on the upper side in the common ink chamber 41. Since the ink flow can be changed to the upward flow, a large amount of ink is not discharged from the nozzle.

  An ink discharge chamber 412 is provided in the ink manifold 4 adjacent to the common ink chamber 41. The ink discharge chamber 412 is separated from the common ink chamber 41 by a partition wall 45. The partition wall 45 is formed integrally with the ink manifold 4.

  FIG. 3 is an exploded perspective view schematically showing the head chip portion of the inkjet head.

  As shown in FIG. 3, the head chip 2 has a plurality of pressure chambers 23 formed therein. These pressure chambers 23 are through-holes having a rectangular cross section that penetrates from the upper surface portion to the lower surface portion of the head chip 2 and is open at the upper end side and the lower end side. The head chip 2 has a piezoelectric element corresponding to each pressure chamber 23.

  Each pressure chamber 23 communicates with the common ink chamber 41 via an injection hole 31a formed in the wiring board 3. The ink in the common ink chamber 41 is injected into each pressure chamber 23 via the injection hole 31a. The volume of each pressure chamber 23 is changed by applying a voltage to the piezoelectric element. A nozzle plate 21 having a plurality of nozzles 22 corresponding to each pressure chamber 23 is adhered to the lower surface of the head chip 2. The nozzle 22 communicates with the pressure chamber 23 via an opening at the lower end of the pressure chamber 23, and communicates the pressure chamber 23 with the outside (downward). The lower surface of the nozzle plate 21 becomes the ink ejection surface 1S. The ink in each pressure chamber 23 is given a discharge pressure by the action of the piezoelectric element, and is discharged toward the outside (downward) recording medium through the nozzle 22.

  Any known means can be adopted regardless of the specific means for applying the discharge pressure to the ink in the pressure chamber 23. In this embodiment, the pressure chambers 23, 23 adjacent to each other are separated by a drive wall 24 formed of a piezoelectric element. The drive wall 24 applies a drive voltage of a predetermined voltage to a drive electrode (not shown) formed on a surface facing the pressure chamber 23 from a power circuit (not shown) through a wiring pattern (not shown) formed on the FPC board and the wiring board 3. As a result, shear deformation occurs. The drive walls 24, 24 on both sides of the pressure chamber 23 undergo shear deformation, whereby the internal volume of the pressure chamber 23 expands or contracts. As a result, pressure is applied to the ink in the pressure chamber 23, and the ink is ejected through the nozzle 22.

  The number of pressure chambers 23 formed in the head chip 2 is not particularly limited. In the head chip 2 shown in this embodiment, a plurality of pressure chambers 23 are arranged in a plurality of rows along the X direction in FIG. 3, which is the longitudinal direction of the head chip 2.

  In this embodiment, no dummy channel is provided between the pressure chambers 23, 23, and the adjacent pressure chambers 23, 23 share one drive wall 24. Therefore, since each pressure chamber 23 cannot be independently driven (expanded or contracted), so-called three-cycle driving is performed. When two drive walls 24, 24 are provided for one pressure chamber 23 so as to form both wall portions of each pressure chamber 23, the pressure chamber 23 adjacent to the drive wall 24 forming one pressure chamber 23 is formed. A gap between the drive wall 24 and the drive wall 24 is a dummy channel. In this case, each pressure chamber 23 can be independently driven (expanded or contracted).

  An individual communication passage 422 is formed at the side of each pressure chamber 23. The individual communication passage 422 communicates with the side of the pressure chamber 23 (between the injection hole 31a and the nozzle 22). In the present embodiment, the individual communication passages 422 are grooves formed on the upper surface of the nozzle plate 21 so as to correspond to the nozzles 22, and the head chip 2 is superposed on the nozzle plate 21 to form a flow path. There is.

  These individual communication passages 422 communicate with the common flow passage 421 and join each other. The common flow channel 421 is a tunnel provided in the side portion of the head chip 2 in the arrangement direction (X direction) of the pressure chambers 23. The end portion of the common flow channel 421 communicates with the discharge channel 424 formed in the head chip 2. The discharge channel 424 is formed on one end side in the longitudinal direction of the head chip 2 and is located below the ink discharge chamber 412. In this way, each pressure chamber 23 is in communication with the discharge channel 424.

  A part of the ink injected from the injection hole 31 a toward each pressure chamber 23 reaches the common flow channel 421 through each individual communication passage 422. Then, the ink that has reached the common flow channel 421 passes through the discharge channel 424, passes through the discharge holes 31b formed in the wiring substrate 3, and reaches the ink discharge chamber 412.

  The individual communication path 422 and the common flow channel 421 are not limited to the above-mentioned aspect. It suffices if a flow path from each pressure chamber 23 to the discharge chamber 412 via the individual communication passage 422, the common flow path 421 and the discharge channel 424 can be formed. Therefore, the individual communication path 422 may be provided in the head chip 2 or a spacer member (not shown) provided between the head chip 2 and the nozzle plate 21, for example. Further, the common flow channel 421 may be provided in, for example, the nozzle plate 21 or a spacer member (not shown) provided separately between the head chip 2 and the nozzle plate 21.

  Note that, in this inkjet head 1, in consideration of the fact that a flow path is formed from each pressure chamber 23 to each individual communication path 422 and the common flow path 421 to the ink discharge chamber 412, the nozzles are set under this condition. The conditions such as the pressure applied by the transfer pump 105 are determined so that the meniscus break from 22 does not occur.

  As shown in FIGS. 1 and 2, the ink discharge chamber 412 is connected to an ink discharge pipe 51c that forms a flow path for discharging ink from the ink discharge chamber 412. The upper end side of the ink discharge pipe 51c merges with the ink recovery pipe 51b. The ink collection pipe 51b and the ink discharge pipe 51c are joined by being connected to the joining box 61.

  The junction box 61 is integrally formed of a synthetic resin material or a metal material, and has the buffer space portion 6 formed therein. First to third openings 48a, 48b, 48c reaching the buffer space 6 are formed on the outer surface of the junction box 61. A flow path from the first opening portion 48a to the third opening portion 48c via the buffer space portion 6 is interposed in the middle part of the ink recovery pipe 51b. In the mounted state, the ink recovery pipe 51b is divided into the upstream side and the downstream side in the middle part, the upstream side is connected to the first opening 48a, and the downstream side is connected to the third opening 48c. Then, the ink discharge pipe 51c is connected to the second opening 48b.

  In the inkjet head 1, the flow path from each individual communication path 422 to the buffer space 6 via the common flow path 421, the discharge channel 424, the discharge hole 31b, the ink discharge chamber 412, and the ink discharge pipe 51c is a discharge path. It becomes 423. The discharge path 423 is a flow path that communicates with each pressure chamber 23, discharges the ink in each pressure chamber 23, and joins the ink recovery pipe 51b in the buffer space portion 6. The sub-flow passage F2 extends from each injection hole 31a to the discharge passage 423 (the inlet from each individual communication passage 422 to the buffer space 6) (see FIG. 2).

  By the way, since the discharge passage 423 is formed as a flow passage that passes through all the individual communication passages 422 corresponding to the respective pressure chambers 23, the flow passage resistance of the entire discharge passage 423 increases as the pressure chambers 23 become higher in density. It is getting bigger. Therefore, even if the ink discharge pipe 51c is merged with the ink recovery pipe 51b, the flow rate of the main flow path F1 from the ink supply port 5a through the ink recovery pipe 51b is large, and the sub flow path F2 from each injection hole 31a to the discharge path 423. It is conceivable that these do not merge smoothly due to the small flow rate. In the inkjet head 1, the main flow passage F1 and the sub flow passage F2 are merged (the ink discharge pipe 51c and the ink recovery pipe 51b are merged) in the buffer space portion 6, and the flow rate adjusting member 9 and By using the suction pump, even if the flow rates of the main flow path F1 and the sub flow path F2 are different, they can be smoothly combined.

  According to the ink jet head 1 and the ink jet recording apparatus 100 including the ink jet head 1 as described above, residual ink bubbles in the common ink chamber 41 pass through the main flow path F1 and the ink recovery pipe only by supplying ink from the ink supply port 5a. It is discharged from 51b. At this time, since the flow velocity of the ink on the upper side of the common ink chamber 41 is increased by the action of the straightening plate 41a, the residual bubbles in the common ink chamber 41 can be satisfactorily discharged. Further, in the inkjet head 1, residual bubbles in the vicinity of each pressure chamber 23 can also be discharged from the ink discharge pipe 51c via the sub-flow passage F2. Therefore, the residual bubbles in the entire ink manifold 4 (in the common ink chamber 41 and in the vicinity of each pressure chamber 23) can be efficiently removed.

  Further, according to the inkjet head 1 and the inkjet recording device 100 including the inkjet head 1, when the ink is circulated between the ink tank 101 and the ink tank 101 during the image recording, the ink in the vicinity of each pressure chamber 23 is also separated. It can be efficiently circulated through the flow path F2. Therefore, the bubbles drawn from the nozzle 22 during image recording can also be quickly discharged. When an ink containing particles or pigments that easily settle is used, the settling of particles or pigments in each individual communication path 422 and the common flow channel 421 during image recording is effectively suppressed. It is possible to suppress the ink density deviation.

[Pressure loss adjusting means]
The inkjet head 1 may be provided with pressure loss adjusting means for adjusting the relative relationship between the flow path resistance of the main flow path F1 and the flow path resistance of the sub flow path F2.

  The pressure loss adjusting means applies a pressure loss ΔP corresponding to the difference in flow resistance between the main flow passage F1 and the sub flow passage F2 to the main flow passage F1. Alternatively, the pressure loss adjusting means reduces the flow passage resistance of the sub flow passage F2 so as to correspond to the flow passage resistance of the main flow passage F1.

   The flow passage resistance of the sub flow passage F2 is determined by the flow passage diameter, the flow passage length, the number of bent portions, the flow velocity, etc. in the entire discharge passage 423 including all the injection holes 31a, all the individual communication passages 422 and the common flow passage 421. Flow resistance. Since the individual communication passages 422 and the common flow passage 421 have a very small flow passage diameter and a long flow passage length, a large flow passage resistance is generated.

  In the ink jet head 1, the pressure loss adjusting means balances the flow path resistance of the main flow path F1 and the flow path resistance of the sub flow path F2, so that the ink pressure P0 in the ink supply pipe 51a facilitates the operation. Ink can be evenly flowed in both the main flow channel F1 and the sub flow channel F2.

  An example of the pressure loss adjusting means is shown in FIG. FIG. 4 is a perspective view showing a state in which the ink recovery pipe 51b provided with an example of the pressure loss adjusting means is partially broken.

  As the pressure loss adjusting means, for example, as shown in FIG. 4, a flow rate adjusting member 9 that partially narrows the flow passage cross-sectional area of the ink recovery pipe 51b can be used. The flow rate adjusting member 9 is a member that is held in the ink recovery tube 51b and partially narrows the inner diameter of the ink recovery tube 51b. The flow rate adjusting member 9 of the present embodiment is integrally configured by including a cylindrical portion 95 along the inner wall of the ink recovery pipe 51b and a disc portion 96 that closes one end of the cylindrical portion 95. A flow path hole 94 is formed in the center of the disk portion 96. The flow path hole 94 is the only flow path of the ink recovery pipe 51b in the area where the flow rate adjusting member 9 is arranged. Therefore, the flow rate adjusting member 9 partially narrows the flow path cross-sectional area of the ink recovery pipe 51b by the flow path hole 94, and the pressure of the ink flowing in the ink recovery pipe 51b is lost.

  The material of the flow rate adjusting member 9 is not particularly limited, and examples thereof include metals such as stainless steel, ceramics, and synthetic resins, which are excellent in ink impermeability, easy to insert into the ink recovery tube 51b, and excellent in corrosion resistance to ink.

  By shortening the length of the flow path hole 94 of the flow rate adjusting member 9, it is possible to suppress the fluctuation of the flow path resistance when bubbles enter the flow path hole 94 and the variation of the flow velocity. The flow path hole 94 of the flow rate adjusting member 9 shown in FIG. 4 has a length of, for example, about 0.5 mm. By setting the length of the flow path hole 94 to about 0.5 mm, it is possible to suppress fluctuations in the flow path resistance due to bubbles.

  The pressure loss ΔP imparted by the flow rate adjusting member 9 is a pressure loss ΔP corresponding to the difference in flow passage resistance between the main flow passage F1 and the sub flow passage F2, and is adjusted by the inner diameter of the flow passage hole 94. This pressure loss ΔP balances the flow path resistance of the main flow path F1 and the flow path resistance of the sub flow path F2. That is, the ink pressure P0 in the ink supply pipe 51a is reduced to the pressure P1 immediately before the buffer space portion 6 of the main flow path F1 and becomes substantially equal to the pressure P2 immediately before the buffer space portion 6 of the sub flow path F2. . The ink pressure P0 in the ink supply pipe 51a is almost equal to the pressure given by the transfer pump 105. The pressure P2 of the sub flow path F2 is set to be smaller than the pressure Px at which the meniscus break occurs so that the meniscus break from the discharge nozzle 22 does not occur. That is, [P1 = (P0−ΔP) = P2 <Px]. As a result, the ink pressure P0 in the ink supply pipe 51a allows the ink to flow evenly in both the main flow passage F1 and the sub flow passage F2.

  The ink pressure P0 can be measured with a manometer at the tip of the T-shaped branch provided in the ink supply pipe 51a. The pressure P1 can be measured by a manometer at the branched end of the ink recovery pipe 51b (downstream of the flow rate adjusting member 9 and upstream of the buffer space 6). The pressure P2 can be measured by a manometer at the tip of the T-shaped branch provided in the ink discharge pipe 51c (upstream from the buffer space 6).

  Regarding the specific inner diameter of the flow path hole 94 of the flow rate adjusting member 9, the pressure loss of the ink recovery pipe 51b is a desired pressure loss in consideration of the pressure loss due to the pressure loss element such as the individual communication passage 422 and the common flow path 421. It is adjusted appropriately so that For example, the flow rate of the flow rate adjusting member 9 is adjusted so that the ink flow rate recovered from the ink recovery tube 51b and the ink flow rate discharged from the ink discharge tube 51c through the individual communication passages 422 and the common flow channel 421 become uniform. By adjusting the inner diameter of the passage hole 94, the ink can be made to flow evenly in both the main flow passage F1 and the sub flow passage F2. As a result, ink can be quickly stored in the ink storage chamber 41 (main flow path F1), in each pressure chamber 23, in the individual communication path 422 and in the common flow path 421 (sub flow path F2). In particular, it is a preferable mode at the initial introduction of the ink.

  By adjusting the inner diameter of the flow path hole 94 of the flow rate adjusting member 9, the ink flow rate (main flow path F1) recovered from the ink recovery tube 51b, and the ink discharge via each individual communication path 422 and the common flow path 421. The flow rate of ink discharged from the tube 51c (sub-flow path F2) can be different. For example, by increasing the flow path resistance of the flow rate adjusting member 9 and from the ink discharge pipe 51c via the individual communication passages 422 and the common flow passage 421 rather than the ink flow rate (main flow passage F1) recovered from the ink recovery pipe 51b. By increasing the flow rate of the discharged ink (sub flow passage F2) (increasing the flow velocity of the sub flow passage F2), it is possible to more easily remove the difficult-to-remove bubbles attached around the pressure chamber 23. On the contrary, the flow resistance of the flow rate adjusting member 9 may be lowered to increase the flow rate of the main flow channel F1 rather than the sub flow channel F2 (increase the flow velocity of the main flow channel F1). In this case, it is possible to easily remove the bubbles adhering to the ceiling surface and the corners in the main channel F1. Further, in this case, even when a damper member (MF (Manifold) damper member) located above the pressure chamber 22 is provided in the ink manifold 4, bubbles easily remaining around the damper member can be easily removed. can do.

  The flow rate adjusting member 9 may be provided in the junction box 61. If the flow rate adjusting member 9 is held in advance in the junction box 61, a desired pressure loss can be applied to the ink recovery tube 51b by simply connecting the junction box 61 to the ink recovery tube 51b. Further, when it is desired to change or replace the flow rate adjusting member 9, the merging box 61 can be replaced, and quick and easy replacement can be performed. Further, even when foreign matters adhere to the vicinity of the flow rate adjusting member 9 and become contaminated, the confluence box 61 can be replaced to quickly and easily bring it into a clean state.

  Further, the ink discharge pipe 51c may be provided with a check valve 8 as shown in FIGS. The check valve 8 functions to allow the outflow of ink from the ink discharge chamber 412 toward the buffer space portion 6 and to prevent the ink flow in the opposite direction. For example, when the individual communication passages 422 and the common flow passage 421 are clogged by the contaminants contained in the ink and the pressure P2 of the sub flow passage F2 decreases, the pressure P1 of the main flow passage F1 in the common ink chamber 41 There is a pressure difference between them. In this case, the ink recovered from the ink recovery tube 51b may flow back to the ink discharge tube 51c via the buffer space 6. By providing the check valve 8 in the ink discharge pipe 51c, it is possible to prevent bubbles and impurities from returning to the common flow channel 421 and the individual communication passages 422 due to the reverse flow of ink.

  Since the check valve 8 is also a pressure loss element, the cracking pressure (valve opening pressure) of the check valve is preferably low, and is lower than the pressure Px (for example, about 5 kPa) at which the meniscus break from the nozzle 22 occurs. Also needs to be low. Further, in order to reliably prevent the meniscus break from the nozzle 22, the pressure is not applied by the transfer pump 105 to the ink return pipe 103 (more than the buffer space portion 6 between the ink recovery pipe 51b and the discharge flow channel 423). A suction pump may be provided on the downstream side and the ink may be circulated only by the negative pressure generated by the suction pump.

  In the inkjet recording apparatus 100 of the embodiment described above, ink is circulated between the inkjet head 1 and the ink tank 101, but the present invention is not limited to this. Although not shown, the ink flowing out from the ink recovery pipe 51b and the ink discharge pipe 51c may be discharged to the waste ink tank without returning to the ink tank 101. The same applies when the inkjet head 1 according to another embodiment described later is used.

[Other Embodiments of Rectifier Plate]
FIG. 5 is a vertical cross-sectional view of a main part showing another embodiment of the current plate of the inkjet head.

  As shown in FIG. 5A, in the inkjet head 1, the flow straightening plate 41a is preferably provided with the tip end side inclined upward. The base end side may be separated from the supply port 5a as long as a part of the front end side is arranged near the supply port 5a. In this case, the ink that has flowed in from the ink supply port 5a is blocked by the flow straightening plate 41a in the straight flow path, changes its course toward the tip side of the flow straightening plate 41a, and the straightening flow plate 41a is inclined, so that the common ink Flows upward in the chamber 41. Therefore, the ink flow rate on the upper side in the common ink chamber 41 is increased and the flow velocity is increased, so that the residual bubbles are efficiently discharged. Further, it is more preferable that the straightening plate 41a has a shape that guides the ink that has flowed in from the ink supply port 5a to the upper side of the central portion in the common ink chamber 41. For example, it is preferable that the straightening plate 41a is provided so as to be inclined such that the leading end side faces the upper side of the central portion in the common ink chamber 41. In this case, the ink flowing in from the ink supply port 5a flows toward the upper side of the central portion in the common ink chamber 41. Therefore, since the flow path is wider than the vicinity of the ink supply port 5a and the vicinity of the ink recovery port 5b, the flow velocity becomes slower, and the ink flow velocity near the central portion where bubbles are likely to remain can be increased, and residual bubbles can be efficiently removed. Can be discharged to.

  Further, the current plate 41a may have a curved surface portion that follows the flow of ink in the common ink chamber 41, as shown in FIG. 5B. The straightening plate 41a has a curved surface portion corresponding to the desired path in order to change the path of the ink flowing from the ink supply port 5a to the desired path. By providing the curved portion on the rectifying plate 41a, it is possible to change the ink path to a desired path without narrowing the flow path. By using this straightening vane 41a, the ink flowing in from the ink supply port 5a is blocked by the straightening vane 41a in the straight flow path, and the course is changed toward the tip side of the straightening vane 41a along the curved surface portion, and the common path is maintained. It flows toward the upper side of the central portion in the ink chamber 41. Therefore, the ink flow rate on the upper side in the common ink chamber 41 is increased and the flow velocity is increased, so that the residual bubbles are efficiently discharged.

  FIG. 6 is a longitudinal cross-sectional view of a main part showing another embodiment of the current plate of the inkjet head.

  As shown in FIG. 6, the current plate 41a may be provided on a damper member (MF (Manifold) damper) 81 which is a pressure damping means. The damper member 81 is arranged on the bottom surface of the common ink chamber 41 and is located above each pressure chamber 22. The damper member 81 buffers the pressure wave generated by the deformation of the pressure chamber 22 and returning to the common ink chamber 41, and prevents the pressure wave from affecting the other pressure chambers 22 (crosstalk). . The current plate 41 a is integrally provided on the upper plate of the damper member 81 so as to project. As described above, the rectifying plate 41a may be inclined toward the upper side of the central portion of the common ink chamber 41 (FIG. 6A) or horizontal (FIG. 6B). Good. In the inkjet head 1, bubbles that tend to remain around the damper member 81 can be efficiently removed.

[Other Embodiments of Inkjet Head]
As shown in FIG. 7, a plurality of discharge paths 423 may be provided in the ink manifold 4. FIG. 7 is a schematic configuration diagram of a main part showing another example of the ink jet recording apparatus according to the present invention, and shows an ink jet head in a partial cross section. Since the parts having the same reference numerals as those in FIG. 1 are the parts having the same configurations, the above description is incorporated by reference and the description thereof is omitted here.

  In this embodiment, partition walls 45 and 45 are provided on one side and the other side in the longitudinal direction of the head chip 2 in the ink manifold 4, and two ink discharge chambers 412 and 412 are provided on both sides of the ink storage chamber 41. . Then, one and the other two discharge paths 423 and 423 passing through the ink discharge chambers 412 and 412 are provided. The one discharge path 423 is the same as the discharge path 423 in the above-described embodiment. The other discharge path 423 can also be configured similarly to the discharge path 423 in the above-described embodiment.

  That is, as described above, the one ink discharge chamber 412 is provided with the one ink discharge pipe 51c forming a flow path for discharging the ink from the ink discharge chamber 412. Similarly, the other ink discharge chamber 412 is also provided with the other ink discharge pipe 51c forming a flow path for discharging ink from the ink discharge chamber 412.

  Then, the upper ends of the ink discharge pipes 51c and 51c are joined to the ink recovery pipe 51b. The ink discharge pipes 51c, 51c and the ink recovery pipe 51b can be joined by connecting to the joining box 61 as in the above-described embodiment.

First to fourth openings 48a, 48b, 48c, 48d reaching the buffer space 6 are formed on the outer surface of the junction box 61. From the first opening 48a through the buffer space 6 to the third
The flow path reaching the opening 48c of the ink recovery pipe 51b is interposed in the middle of the ink recovery pipe 51b. In the mounted state, the ink recovery pipe 51b is divided into the upstream side and the downstream side in the middle part, the upstream side is connected to the first opening 48a, and the downstream side is connected to the third opening 48c. Then, one ink discharge pipe 51c is connected to the second opening 48b. The other ink discharge pipe 51c is connected to the fourth opening 48d.

  In the present embodiment, the discharge passages 423, 423 are divided into one side and the other side in the longitudinal direction of the head chip 2 from the respective injection holes 31a through the respective pressure chambers 23, and the discharge holes 31b, 31b on both sides and the both sides are formed. It serves as a path for ink to reach the buffer space portion 6 through the discharge channels 424 and 424. That is, the ink that has reached the common channel 421 from inside the pressure chamber 23 is divided into one side and the other side in the longitudinal direction of the head chip 2, and reaches the discharge holes 31b and 31b via the discharge channels 424 and 424, respectively. The ink that has reached the respective discharge holes 31b and 31b passes through these discharge holes 31b and 31b, passes through the one and the other ink discharge chambers 412 and 412, and then reaches the one and the other ink discharge pipes 51c and 51c.

  When a plurality of discharge passages 423 are provided in this way, each pressure chamber 23 having a short distance to the discharge hole 31b can be increased, so that the flow passage resistance of the entire discharge passage 423 can be suppressed to a low level. The flow path resistance of the flow path F2 can be suppressed low.

  FIG. 8 is a vertical cross-sectional view of a main part showing another embodiment of the current plate of the inkjet head.

  As shown in FIG. 8, the current plate 41a in this embodiment is integrally connected to the common ink chamber 41 via a partition wall (vertical wall portion) 45. That is, the partition wall 45 that separates the common ink chamber 41 and the ink discharge chamber 412 and the rectifying plate 41a are integrally connected, and these are integrally connected to the common ink chamber 41. Since the partition wall 45 and the rectifying plate 41a are integrally connected to the common ink chamber 41, the manufacturing is easy and the rigidity and durability of the rectifying plate 41a can be improved.

  FIG. 9 is a vertical cross-sectional view showing another embodiment of the current plate of the inkjet head.

  Two or more rectifying plates 41a may be arranged in the common ink chamber 41, and FIG. 9 shows an example in which two rectifying plates 41a and 41b are arranged. As shown in FIG. 9, in the common ink chamber 41, the rectifying plate 41a described above is provided as the first rectifying plate 41a, and further, the second rectifying plate 41b is provided. The second rectifying plate 41b is located substantially at the center of the common ink chamber 41 in the longitudinal direction, the upstream side of the ink flow in the common ink chamber 41 is located at the lower side, and the downstream side is lifted upward. It is formed into a shape. The second straightening plate 41b can be integrally provided in the common ink chamber 41.

  The second flow straightening plate 41b can return the flow of the ink that hits the ceiling surface of the common ink chamber 41 and is rebound to the upper side again. Therefore, the ink flow rate on the upper side of the common ink chamber 41 can be increased and the flow velocity can be increased. Therefore, the residual bubbles on the upper side of the common ink chamber 41 are efficiently discharged. When the common ink chamber 41 is elongated, it is preferable to further increase the number of second rectifying plates 41b according to the length of the common ink chamber 41. By increasing the number of the second rectifying plates 41b, the flow velocity of the ink above the common ink chamber 41 can be maintained, and the residual bubbles above the common ink chamber 41 can be efficiently discharged.

  FIG. 10 is a vertical sectional view showing another embodiment of the current plate of the inkjet head.

  As shown in FIG. 10, the partition wall 45 on the ink recovery port 5b side gradually collects ink from the bottom surface of the common ink chamber 41 in accordance with the direction of ink flow from the inside of the common ink chamber 41 toward the ink recovery port 5b. It may be inclined so as to approach the mouth 5b.

  In each of the above-described embodiments, the ceiling surface of the common ink chamber 41 may be inclined with respect to the horizontal plane. That is, the ceiling surface is inclined so that the ink recovery port 5b is located higher than the ink supply port 5a. Due to this inclination, the residual bubbles in the common ink chamber 41 move to the higher side along the ceiling surface, that is, to the ink recovery port 5b side. Therefore, the residual bubbles are more efficiently generated by the synergistic effect with the rectifying effect of the rectifying plate 41a. Can be discharged.

  FIG. 11 is a vertical cross-sectional view showing an embodiment in which a filter is provided inside the common ink chamber.

  As shown in FIG. 11, a filter 71 may be provided inside the common ink chamber 41. The filter 71 is horizontally provided in the common ink chamber 41 at substantially the same height as the tip of the rectifying plate 41a, and divides the common ink chamber 41 into an upper side and a lower side. Unlike the rectifying plate 41a, the filter 71 extends from one end side to the other end side in the common ink chamber 41. The filter 71 removes bubbles and sedimented particles and pigments contained in the ink when the ink flowing from the upper side to the lower side in the common ink chamber 41 is transmitted. In the inkjet head 1, since the flow velocity of the ink on the upper side of the filter 71 is increased due to the provision of the rectifying plate 41a, the residual bubbles on the upper side of the filter 71 are efficiently discharged, and the ink is ejected from the nozzle 22. It is also possible to remove fine bubbles generated by the filter 71 when the bubbles are caught.

  FIG. 12 is a perspective view showing an embodiment in which an external filter is provided.

  As shown in FIG. 12, an external filter 72 can be used as the filter. The external filter 72 is installed outside the ink manifold 4 and in the middle of the ink recovery pipe 51b so that the ink recovered from the ink recovery port 5b can pass through. The ink that has passed through the external filter 72 is returned to the ink tank 101 after removing the air bubbles, sedimented particles, pigments, and the like contained in the ink.

[Embodiment of common ink chamber]
FIG. 13 is an exploded perspective view of the common ink chamber of the inkjet head.

  In the inkjet head 1, the common ink chamber 41 can be configured by abutting and joining a first member 91 and a second member 92 as shown in FIG. The first and second members 91 and 92 are integrally formed of a synthetic resin material.

  The first member 91 is provided with at least the ink supply port 5a and the ink recovery port 5b. The first member 91 has a flat canopy plate 93 that serves as a canopy portion of the common ink chamber 41, and ink supply ports 5a and ink recovery ports 5b are provided at both ends of the canopy plate 93. .

  The second member 92 is provided with at least the mounting portion 4a of the pressure chamber and the current plate 41a. In addition, the second member 92 has a space portion which becomes the common ink chamber 41, and the flow straightening plate 41a is provided in this space portion. The open lower end of the space that becomes the common ink chamber 41 serves as the pressure chamber mounting portion 4a. Further, the second member 92 is provided with an ink discharge chamber 412 and an ink discharge pipe 51c.

  The first and second members 91 and 92 are butted against each other and connected to each other to form the ink manifold 4, and the common ink chamber 41 is formed in the ink manifold 4.

  In this embodiment, the ink discharge chamber 412 and the ink discharge pipe 51c are provided on both sides of the ink manifold 4, respectively. That is, the discharge passages 423, 423 are divided into one side and the other side in the longitudinal direction of the head chip 2 from each injection hole 31a through each pressure chamber 23, and the discharge holes 31b, 31b on both sides and the discharge channels 424 on both sides are formed. It is a path for ink to reach the buffer space portion 6 via 424. Therefore, the ink that has reached the common flow channel 421 from each pressure chamber 23 is divided into one side and the other side in the longitudinal direction of the head chip 2, and reaches the discharge holes 31b and 31b via the discharge channels 424 and 424, respectively. The ink that has reached the respective discharge holes 31b and 31b passes through these discharge holes 31b and 31b, passes through the one and the other ink discharge chambers 412 and 412, and then reaches the one and the other ink discharge pipes 51c and 51c.

  When a plurality of discharge passages 423 are provided in this way, the distance from each pressure chamber 23 to the discharge hole 31b can be shortened, so that the flow passage resistance of the entire discharge passage 423 can be suppressed to a low level, and the sidestream flow can be suppressed. The flow path resistance of the path F2 can be suppressed low.

  The above-described embodiment is an example in which the inkjet head according to the present invention is configured as a shear mode head, but the present invention is not limited to this, as long as the inkjet head includes a common ink chamber in which bubbles can remain, It can be applied to various inkjet heads.

1: Inkjet head 2: Head chip 21: Nozzle plate 22: Nozzle 23: Pressure chamber 24: Drive wall 24a: Piezoelectric element 3: Wiring board 31a: Injection hole 31b: Discharge hole 31c: Individual discharge hole 4: Ink manifold 41: Common ink chamber 412: Ink discharge chamber 421: Common flow path 422: Individual communication path 423: Discharge path 424: Discharge channel 45: Partition wall 46: Communication path 47: Partition plate 5a: Ink supply port 5b: Ink recovery port 51a: Ink Supply pipe 51b: Ink recovery pipe 51c: Ink discharge pipe 6: Buffer space 61: Merge box 71: Filter 72: External filter 8: Check valve 81: Damper member 9: Flow rate adjusting member F1: Main flow path F2: Sub flow Path 100: Inkjet recording apparatus 101: Ink tank 102: Ink transfer tube 103: In Return pipe 104: Control unit 105: Transfer pump

Claims (15)

A common ink chamber,
An ink supply port that is formed in the common ink chamber and communicates with a flow path that supplies ink to the common ink chamber;
An ink recovery port formed in the common ink chamber and communicating with a flow path for recovering ink from the common ink chamber;
At least one pressure chamber that communicates with the common ink chamber through an injection hole and that causes a volume change by applying a voltage;
A nozzle communicating with the pressure chamber and serving as a flow path for ink ejected from the pressure chamber to the outside;
A straightening plate for changing the flow of ink from the ink supply port to the ink recovery port on the upper side of the common ink chamber,
The straightening plate is integrally connected to the common ink chamber via a vertical wall portion, and at least a part of the straightening plate is arranged in the vicinity of the ink supply port in the common ink chamber. Inkjet head. A common ink chamber,
An ink supply port that is formed in the common ink chamber and communicates with a flow path that supplies ink to the common ink chamber;
An ink recovery port formed in the common ink chamber and communicating with a flow path for recovering ink from the common ink chamber;
At least one pressure chamber that communicates with the common ink chamber through an injection hole and that causes a volume change by applying a voltage;
A nozzle communicating with the pressure chamber and serving as a flow path for ink ejected from the pressure chamber to the outside;
A straightening plate for changing the flow of ink from the ink supply port to the ink recovery port on the upper side of the common ink chamber,
The ink jet head is characterized in that the rectifying plate is provided in a pressure attenuating means arranged in the common ink chamber, and at least a part thereof is arranged in the vicinity of the ink supply port in the common ink chamber. A common ink chamber,
An ink supply port that is formed in the common ink chamber and communicates with a flow path that supplies ink to the common ink chamber;
An ink recovery port formed in the common ink chamber and communicating with a flow path for recovering ink from the common ink chamber;
At least one pressure chamber that communicates with the common ink chamber through an injection hole and that causes a volume change by applying a voltage;
A nozzle communicating with the pressure chamber and serving as a flow path for ink ejected from the pressure chamber to the outside;
A straightening plate for changing the flow of ink from the ink supply port to the ink recovery port on the upper side of the common ink chamber,
In the common ink chamber, at least the first member provided with the ink supply port and the ink recovery port and the second member provided with at least the mounting portion of the pressure chamber and the rectifying plate are butt-coupled to each other. Composed by
The inkjet head is characterized in that at least a part of the straightening plate is arranged in the vicinity of the ink supply port in the common ink chamber. A common ink chamber,
An ink supply port that is formed in the common ink chamber and communicates with a flow path that supplies ink to the common ink chamber;
An ink recovery port formed in the common ink chamber and communicating with a flow path for recovering ink from the common ink chamber;
At least one pressure chamber that communicates with the common ink chamber through an injection hole and that causes a volume change by applying a voltage;
A nozzle communicating with the pressure chamber and serving as a flow path for ink ejected from the pressure chamber to the outside;
A straightening plate for changing the flow of ink from the ink supply port to the ink recovery port on the upper side of the common ink chamber,
At least a part of the rectifying plate is arranged near the ink supply port in the common ink chamber ,
A filter is provided inside the common ink chamber,
The ink jet head is characterized in that the filter divides the inside of the common ink chamber into upper and lower parts, and the ink supply port and the ink recovery port are provided on the upper side . The inkjet head according to claim 2 , wherein the straightening plate is integrally connected to the common ink chamber via a vertical wall portion. The ink jet head according to claim 3 , wherein the flow straightening plate is provided in a pressure damping unit arranged in the common ink chamber. In the common ink chamber, at least the first member provided with the ink supply port and the ink recovery port and the second member provided with at least the mounting portion of the pressure chamber and the rectifying plate are butt-coupled to each other. The inkjet head according to claim 4 , wherein the inkjet head is configured by: The inkjet head according to claim 1 , wherein a filter is provided inside the common ink chamber. The rectifying plate, the ink flowing through the vicinity of the ink supply port, the ink-jet head according to any one of claims 1-8, characterized in that has a shape leading to the common ink central upper side of the chamber . The inkjet head according to any one of claims 1 to 9 , wherein two or more of the rectifying plates are arranged in the common ink chamber. The common ink chamber, the ceiling surface is inclined relative to the horizontal plane, to any one of claims 1-10, characterized in that has a higher position more of the ink recovery port than said ink supply port The described inkjet head. The rectifying plate, the ink-jet head according to any one of claims 1 to 11, characterized in that it has a curved surface portion along the flow of the ink in the common ink chamber. The inkjet head according to any one of claims 1 to 12 , further comprising a discharge path communicating with the pressure chamber and discharging ink in the pressure chamber. An ink jet head according to any one of claims 1 to 13,
An ink tank for storing ink transferred to the common ink chamber of the inkjet head;
An ink jet recording apparatus, comprising: an ink transfer unit that transfers the ink in the ink tank to the common ink chamber. An inkjet head according to claim 13 ,
An ink tank for storing ink to be transferred to the inkjet head;
An ink transfer unit for transferring the ink in the ink tank to the inkjet head, and collecting the ink transferred to the inkjet head,
The ink jet recording apparatus is characterized in that the ink discharged from the pressure chamber through the discharge passage is combined with the ink collected from the ink jet head.

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