JP5003282B2 - Droplet discharge head and image forming apparatus - Google Patents

Description

  The present invention relates to a droplet discharge head and an image forming apparatus.

  As an image forming apparatus, an ink jet printer disclosed in Patent Document 1 is known. An ink jet printer disclosed in Patent Document 1 includes an ink tank that stores ink to be supplied to each head unit, a circulation forward path that is a flow path for the ink supplied to each head unit, and a discharge from each head unit. A circulation return path serving as a flow path through which ink is circulated, and the circulation forward path and the circulation return path are arranged in a plane.

In this configuration, the ink stored in the ink tank is fed to the circulation forward path by the ink circulation mechanism and reaches each head unit through the plurality of supply paths. Then, ink is distributed and supplied from the common manifold of each head unit to the plurality of nozzles via the pressure chamber, and a part of the ink is ejected from the plurality of nozzles. The remaining ink flows into the circulation return path through the plurality of discharge paths, and is finally collected in the ink tank by the ink circulation mechanism. As described above, in Patent Document 1, ink is circulated by returning ink fed in the circulation outward path to the ink tank in the circulation return path.
JP 2005-349843 A

  An object of this invention is to suppress the increase in the viscosity of a liquid, without enlarging an apparatus structure.

A droplet discharge head according to claim 1 of the present invention includes a nozzle that discharges a droplet, a pressure chamber that communicates with the nozzle and stores a liquid, and a pressure applying unit that applies pressure to the liquid in the pressure chamber. Are disposed so as to overlap the liquid supply path when viewed from the nozzle surface on which the nozzle is formed, and the liquid is discharged from the pressure chamber. And a filter for filtering the liquid in the ejector is formed in a partition wall between the liquid supply path and the liquid discharge path.

A droplet discharge head according to a second aspect of the present invention is characterized in that, in the configuration of the first aspect , the partition is formed of a resin member.

A droplet discharge head according to a third aspect of the present invention is characterized in that, in the configuration of the first aspect, the partition is formed of an elastic member that is flexibly deformed.

According to a fourth aspect of the present invention, there is provided the liquid droplet ejection head according to any one of the first to third aspects, wherein a plurality of the ejectors are two-dimensionally arranged, and the liquid supply path and the liquid discharge path are the It is arranged between ejectors.

According to a fifth aspect of the present invention, there is provided an image forming apparatus according to any one of the first to fourth aspects, and a liquid for circulating the liquid discharged from the liquid discharge path to the liquid supply path. A circulation unit; a recording medium conveyance unit that conveys the recording medium; and a control unit that generates a drive waveform based on image data and ejects droplets from the droplet ejection head to the recording medium. And

  According to the structure of Claim 1 of this invention, compared with the case where it does not have this structure, the increase in the viscosity of a liquid can be suppressed, without enlarging an apparatus structure.

According to the configuration of the fourth aspect of the present invention, an increase in the viscosity of the liquid can be suppressed without increasing the size of the apparatus configuration even when a plurality of ejectors are arranged two-dimensionally.

According to the configuration of the second aspect of the present invention, the acoustic capacity of the liquid supply path and the liquid discharge path can be increased, and the pressure wave propagating from the pressure chamber to the liquid supply path and the liquid discharge path can be reduced.

According to the configuration of the first aspect of the present invention, clogging of the nozzle due to foreign matters mixed in the liquid can be suppressed.

According to the configuration of the third aspect of the present invention, the acoustic capacity of the liquid supply path and the liquid discharge path can be increased, and the pressure wave propagating from the pressure chamber to the liquid supply path and the liquid discharge path can be reduced.

According to the structure of Claim 5 of this invention, compared with the case where it does not have this structure, the increase in the viscosity of a liquid can be suppressed, without enlarging an apparatus structure.

Below, an example of an embodiment concerning the present invention is described based on a drawing.
In this embodiment, an ink jet recording head that discharges ink droplets and records an image on a recording medium will be described as an example of a droplet discharging head that discharges droplets.

  As an example of an image forming apparatus that forms an image, an ink jet recording apparatus that includes the ink jet recording head according to the present embodiment and that records an image on a recording medium by ejecting ink droplets from the ink jet recording head will be described.

  Note that the droplet discharge head is not limited to the one that records an image, and the liquid to be discharged is not limited to ink. As the droplet discharge head, for example, a droplet discharge head for manufacturing a color filter by discharging ink or the like onto a film or glass, or a liquid for forming a bump for mounting a component by discharging molten solder onto a substrate It may be a droplet discharge head, a droplet discharge head that discharges a liquid containing metal to form a wiring pattern, or a droplet discharge head for various film formation that discharges a droplet to form a film. Anything that discharges may be used.

(Overall configuration of inkjet recording apparatus according to this embodiment)
First, the overall configuration of the ink jet recording apparatus according to the present embodiment will be described. FIG. 1 is a schematic diagram showing the overall configuration of the ink jet recording apparatus according to the present embodiment.

  As shown in FIG. 1, the inkjet recording apparatus 10 ejects ink droplets, a sheet supply unit 12 that sends out a recording sheet P as an example of a recording medium, a registration adjustment unit 14 that controls the attitude of the recording sheet P, and an ink droplet. A recording head unit 16 that forms an image on the recording paper P, a controller 35 as an example of a control unit that supplies a drive waveform based on image data to the ink jet recording head 32 of the ink jet recording unit 30 of the recording head unit 16, and the recording head unit 16 includes a recording unit 20 including a maintenance unit 18 that performs 16 maintenance, and a discharge unit 22 that discharges the recording paper P on which an image is formed by the recording unit 20.

  The paper supply unit 12 includes a paper storage unit 24 in which recording papers P are stacked and stored, and a conveyance device 26 that takes out the paper from the paper storage unit 24 one by one and conveys it to the registration adjustment unit 14. The registration adjusting unit 14 includes a loop forming unit 28 and a guide member 29 that guides the recording paper P and controls the posture of the recording paper P, and the recording paper P passes through this portion, thereby By utilizing this stiffness, the inclination of the recording paper P with respect to the paper conveyance direction is corrected, and the conveyance timing is controlled and supplied to the recording unit 20. The discharge unit 22 stores the recording sheet P on which the image is formed by the recording unit 20 in the sheet storage unit 25 via the discharge belt 23.

  Between the recording head unit 16 and the maintenance unit 18, a paper transport path 27 through which the recording paper P is transported is formed (the paper transport direction is indicated by an arrow PF). The paper transport path 27 includes a star wheel 17 and a transport roll 19 as an example of a recording medium transport unit, and continuously transports the recording paper P while sandwiching the recording paper P between the star wheel 17 and the transport roll 19. Then, ink droplets are ejected from the recording head unit 16 to the recording paper P, and an image is formed on the recording paper P.

  The maintenance unit 18 includes a maintenance device 21 that is disposed to face the ink jet recording unit 30, and performs capping on the ink jet recording head 32, wiping of the nozzle surface, preliminary ink droplet ejection, and ink suction. And so on.

  As shown in FIG. 2, each inkjet recording unit 30 includes a support member 34 disposed in a direction intersecting with the sheet conveyance direction indicated by an arrow PF, and a plurality of inkjet recording heads 32 are attached to the support member 34. It has been. A plurality of nozzles 56 are two-dimensionally formed in the inkjet recording head 32, and the nozzles 56 are arranged in parallel in the width direction of the recording paper P at a constant pitch as the entire inkjet recording unit 30.

  An image is recorded on the recording paper P by ejecting ink droplets from the nozzles 56 onto the recording paper P that is continuously transported through the paper transporting path 27. For example, four inkjet recording units 30 are arranged corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (K) in order to record a so-called full-color image. Yes.

  As shown in FIG. 3, the print area width by the nozzle 56 of each inkjet recording unit 30 is longer than the maximum sheet width PW of the recording sheet P on which image recording by the inkjet recording apparatus 10 is assumed, Image recording over the entire width of the recording paper P is possible without moving the inkjet recording unit 30 in the paper width direction.

  Here, the print area width is basically the largest of the recording areas obtained by subtracting the margins not to be printed from both ends of the recording paper P, but is generally larger than the maximum paper width PW to be printed. ing. This is because the recording paper P may be conveyed at a predetermined angle with respect to the conveyance direction and there is a high demand for borderless printing.

  As shown in FIG. 4, the ink jet recording apparatus 10 includes an ink tank 80 for storing ink. One end of a supply tube 82 as a supply tube for supplying ink from the ink tank 80 to the ink jet recording head 32 is connected to the ink tank 80. The other end of the supply tube 82 is connected to one end of the ink jet recording head 32, and the ink tank 80 communicates with the ink jet recording head 32 via the supply tube 82.

  The ink tank 80 is connected to one end of a circulation tube 84 serving as a circulation pipe for returning the ink discharged from the ink jet recording head 32 to the ink tank 80. The other end of the circulation tube 84 is connected to the other end of the inkjet recording head 32, and the ink tank 80 communicates with the inkjet recording head 32 via the circulation tube 84. Thus, by connecting the circulation tube 84, a flow path for circulating the ink supplied to the inkjet recording head 32 is formed.

  The supply tube 82 is provided with a filtration filter 83 that filters ink. As the ink passes through the filtration filter 83, foreign matter in the ink is removed. Further, the supply tube 82 is provided with a pump 81 as an example of a liquid circulation means on the downstream side of the filtration filter 83. By driving the pump 81, ink is sent from the ink tank 80 to the inkjet recording head 32. Further, ink discharged from the ink jet recording head 32 without being ejected as ink droplets by the ink jet recording head 32 is returned to the ink tank 80 by the circulation tube 84.

  Thus, by returning ink from the inkjet recording head 32 to the ink tank 80 by the circulation tube 84, in this embodiment, the ink supplied to the inkjet recording head 32 is circulated.

  The supply tube 82 is connected to a common supply path main stream 39A of a common supply path 39 described later, and supplies ink to the common supply path main stream 39A. The circulation tube 84 is connected to a common discharge path main flow 42A of the common discharge path 42 described later, and returns ink discharged from the common discharge path main flow 42A to the ink tank 80.

  In this embodiment, the discharged ink is returned to the ink tank 80 and reused. However, the circulation tube 84 is connected to the waste liquid tank, and the ink is recovered as waste liquid without being reused. There may be.

(Configuration of Inkjet Recording Head 32 According to the Present Embodiment)
Next, the configuration of the ink jet recording head 32 according to the present embodiment will be described. FIG. 5 is a plan view partially showing the ink jet recording head 32 according to the present embodiment. FIGS. 6A and 6B are views showing a main part by partially taking out the ink jet recording head 32 according to the present embodiment, in which FIG. 6A is a plan view and FIG. 6B is a schematic longitudinal sectional view. FIG. 7 is a perspective view of a portion where ink flows in the ink jet recording head 32.

  As shown in FIG. 5, the ink jet recording head 32 distributes a plurality of ejectors 37 arranged two-dimensionally, a common supply path 39 that supplies ink to each ejector 37, and the ink discharged from each ejector 37. A common discharge path 42 is provided.

  A column is formed by a group of ejectors 37 arranged along the Y direction in FIG. 5 and a row is formed by a group of ejectors 37 arranged along the X direction. In FIG. A column is shown. The ejector 37 is an example of one nozzle 56 that ejects ink droplets, one pressure chamber 50 that communicates with the nozzle 56 and stores ink, and pressure application means that applies pressure to the ink in the pressure chamber 50. It comprises a single piezoelectric body 46 (see FIGS. 6A and 6B).

  The common supply path 39 is formed along the common supply path main stream 39A formed along the row (X direction) of the ejectors 37, and is formed along each column (Y direction) of the ejectors 37 from the common supply path main stream 39A. And a common supply path branch 39B that supplies ink to each of the 37 columns.

  The common supply path tributary 39B is arranged between the rows of the ejectors 37, and a part thereof is arranged to overlap the ejectors 37 when viewed from the nozzle surface. Further, the common supply path tributary 39B communicates with each ejector 37, and ink is supplied to each ejector 37 from the common supply path main stream 39A through the common supply path tributary 39B.

  The common discharge path 42 is formed along the common discharge path main stream 42A formed along the rows (X direction) of the ejectors 37, and along each column (Y direction) of the ejectors 37 from the common discharge path main stream 42A. And a common discharge path tributary 42B for sending ink discharged from each of the 37 rows to the common discharge path main stream 42A.

  The common discharge path tributary 42B is arranged between the rows of the ejectors 37, and a part thereof is arranged so as to overlap the ejectors 37 when viewed from the nozzle surface. The common discharge path tributary 42B communicates with each ejector 37, and the ink discharged from each ejector 37 is sent to the common discharge path main stream 42A through the common discharge path tributary 42B.

  Further, as shown in FIG. 6B, the ink jet recording head 32 according to the present embodiment includes a recess forming plate 31, a nozzle plate 33, a discharge path forming plate 36, a discharge hole forming plate 43, and a common discharge path tributary forming plate. 44, a resin plate 47 as an example of a resin member, a common supply path branch flow forming plate 49, a first supply hole forming plate 53, a supply path forming plate 55, a second supply hole forming plate 57, a pressure chamber forming plate 63, and a vibration plate 38. A piezoelectric body 46 as an example of the pressure applying means is provided. Recess formation plate 31, nozzle plate 33, discharge path formation plate 36, discharge hole formation plate 43, common discharge path branch flow formation plate 44, resin plate 47, common supply path branch flow formation plate 49, first supply hole formation plate 53, supply The path forming plate 55, the second supply hole forming plate 57, the pressure chamber forming plate 63, the vibration plate 38, and the piezoelectric body 46 are laminated in this order.

  As shown in FIGS. 6A, 6B, and 7, the nozzle plate 33 is formed with nozzles 56 that eject ink droplets. A recess 72 is formed in the periphery of the nozzle 56 in the recess forming plate 31. The concave portion 72 is a step formed at the periphery of the nozzle 56, and the portion where the nozzle 56 is formed is retracted from the surrounding plate surface. This prevents mechanical friction due to wiping of the nozzle surface.

  A pressure chamber 50 communicating with the nozzle 56 and storing ink is formed in the pressure chamber forming plate 63. The pressure chamber 50 includes a discharge path forming plate 36, a discharge hole forming plate 43, a common discharge path branch flow forming plate 44, a resin plate 47, a common supply path branch flow forming plate 49, a first supply hole forming plate 53, and a supply path forming plate. 55 and the passage 56 formed in the second supply hole forming plate 57 communicate with the nozzle 56 so that ink can flow from the pressure chamber 50 to the nozzle 56.

A common supply channel branch 39B is formed in the common supply channel tributary plate 49, and a supply channel 64 for supplying ink from the common supply channel tributary 39B to each pressure chamber 50 is formed in the supply channel forming plate 55. ing. The supply path 64 is configured by a groove formed along the first supply hole forming plate 53.

  Further, the supply path 64 communicates with the common supply path tributary 39 </ b> B through the first supply hole 65 formed in the first supply hole forming plate 53. Further, the supply path 64 communicates with the pressure chamber 50 through a second supply hole 67 formed in the second supply hole forming plate 57.

  Thus, in this embodiment, the ink supply path for supplying ink to the pressure chamber 50 includes the common supply path 39 having the common supply path main flow 39A and the common supply path tributary 39B, the first supply hole 65, and the supply path. 64 and a second supply hole 67.

  On the other hand, a discharge path 68 communicating with the passage 48 is formed in the discharge path forming plate 36 stacked immediately above the nozzle plate 33. The discharge path 68 communicates with the common discharge path tributary 42 </ b> B through a discharge hole 69 formed in the discharge hole forming plate 43.

  Further, the discharge path 68 is configured by a groove formed along the nozzle plate 33, but may be configured by a through-hole formed in the discharge path forming plate 36 along the plate stacking direction. Further, the discharge path 68 only needs to communicate with any part of the passage 48 between the pressure chamber 50 and the nozzle 56, and does not need to be directly above the nozzle 56.

  Thus, in this embodiment, the ink discharge path for discharging ink from the pressure chamber 50 to the outside (circulation tube 84) is the path 48, the discharge path 68, the discharge hole 69, the common discharge path main flow 42A, and the common. And a common discharge path 42 having a discharge path tributary 42B.

  The common discharge path tributary 42B and the common supply path tributary 39B are arranged so as to overlap each other when viewed from the nozzle surface where the nozzle 56 is formed, and have a two-story structure.

  The common discharge channel tributary 42B and the common supply channel tributary 39B need only partially overlap, and do not need to overlap all.

  Further, the common discharge path tributary 42B and the common supply path tributary 39B, the pressure chamber 50, the supply path 64, and the discharge path 68 are also arranged so as to partially overlap each other when viewed from the nozzle surface. .

  The resin plate 47 is disposed between the common discharge path tributary 42B and the common supply path tributary 39B, and constitutes a partition wall that partitions the common discharge path tributary 42B and the common supply path tributary 39B. The resin plate 47 is made of a material having substantially the same volume elastic modulus as that of the ink in the ejector 37 (specifically, an ink solvent), such as polyimide. The substantially same range of the bulk modulus of the ink and the resin plate 47 is a range in which the common discharge channel tributary 42B and the common supply channel tributary 39B function as one common channel from the viewpoint of acoustic capacity. That's fine.

  Instead of the resin plate 47, an elastic plate 51 as an example of an elastic member that bends and deforms may be used. As the elastic plate 51, in addition to the resin material, a metal plate such as SUS may be used as shown in FIG. When the elastic plate is flexibly deformed, the common discharge passage tributary 42B and the common supply passage tributary 39B function as one common flow passage from the viewpoint of acoustic capacity.

  The elastic plate needs to be formed to be thin enough to bend and deform, but the resin plate 47 has a thickness that does not cause bending deformation if the volume modulus of elasticity of the ink is in approximately the same range. May be.

  Further, the partition wall that divides the common discharge passage tributary 42B and the common supply passage tributary 39B is not limited to the resin plate or the elastic plate, and other materials may be used.

  Further, the resin plate 47 is formed with a filter 70 for filtering the ink flowing through the passage 48. As shown in FIG. 8, the filter 70 has a function as a filter by forming a plurality of small-diameter holes 70A with an excimer laser. A method other than excimer laser processing may be applied to the processing of the hole 70A of the filter 70.

  Further, the filter 70 may be formed at an arbitrary position in the ejector 37, and may be formed on the supply path forming plate 55 as shown in FIG. In this configuration, the supply path forming plate 55 is formed of, for example, a resin film such as polyimide, and the supply path 64 is configured by a through hole formed in the supply path forming plate 55 along the stacking direction of the plates. .

  In the present embodiment, the inside of the ejector 37 is a flow path formed by the supply path 64, the second supply hole 67, the pressure chamber 50, the passage 48, and the nozzle 56.

  The diameter of the hole 70A formed in the filter is set to be equal to or smaller than the nozzle diameter, and foreign matters such as dust that cause nozzle clogging can be captured by the filter 70.

  In the present embodiment, the number of holes 70A is set to 19. When the number of the holes 70A is small, the flow path resistance of the filter 70 is increased, and the discharge characteristics of the ejector 37 are adversely affected. Therefore, it is desirable that the number of holes 70A is large so that the flow path resistance of the filter 70 is sufficiently smaller than the flow path resistance of the nozzle 56, the supply path 64, and the discharge path 68. Specifically, the number of holes is preferably 5 or more and more preferably 10 or more so that the flow resistance of the filter 70 is 1/5 or less of the flow resistance of the nozzle 56.

  Further, as shown in FIGS. 10 and 11, at least one of an ink supply path for supplying ink to the pressure chamber 50 and an ink discharge path for discharging ink from the pressure chamber 50 to the outside (circulation tube 84) is provided. A damper mechanism for increasing the acoustic capacity of the flow path is provided. In the example shown in FIG.10 and FIG.11, the air damper 41 is provided in the common discharge path branch 42B as a damper mechanism. The air damper 41 includes an air damper chamber 41A disposed to face the common discharge passage tributary 42B, and a passage (not shown) through which the air damper chamber 41A passes through the atmosphere. For this reason, the air damper chamber 41A releases the pressure wave transmitted from the pressure chamber 50 to the common discharge passage tributary 42B through the passage, and the pressure wave is absorbed and relaxed.

  In the present embodiment, when viewed from the viewpoint of acoustic capacity, the common discharge path tributary 42B and the common supply path tributary 39B function as one common flow path, and thus the common discharge path tributary 42B and the common supply path tributary 39B. By providing a damper mechanism on one side, a damper effect is exhibited in both the common discharge path branch 42B and the common supply path branch 39B.

  The diaphragm 38 formed on the pressure chamber forming plate 63 constitutes a part of the pressure chamber 50 by closing the upper opening of the pressure chamber 50 and forming the upper wall of the pressure chamber 50.

  An electrode 73 is formed on the upper surface of the piezoelectric body 46 laminated on the vibration plate 38, and the piezoelectric body 46 is driven by acquiring an electrical signal as a drive signal via the electrode 73. Yes.

  The piezoelectric body 46 acquires an electrical signal, displaces the diaphragm 38 so as to reduce the volume in the pressure chamber 50, and applies pressure to the ink in the pressure chamber 50. Thus, ink is sent from the pressure chamber 50 to the nozzle 56 via the passage 48, and ink droplets are ejected from the nozzle 56.

  As a method for ejecting ink, a summar method in which ink is boiled by heat generation and ink is ejected by the pressure of bubbles generated at that time may be used. In this case, pressure is applied to the ink in the pressure chamber 50. As the pressure applying means, a heating element is used.

(Operation of this embodiment)
Next, the operation of the above embodiment will be described.

  The ink supplied from the ink tank 80 to the common supply path main stream 39A via the supply tube 82 is filled into the pressure chamber 50 through the common supply path branch 39B and the supply path 64 (see FIG. 7).

  The ink filled in the pressure chamber 50 is filtered by the filter 70 and a part thereof is ejected as ink droplets from the nozzle 56, and the other ink is sent to the common discharge path tributary 42 </ b> B through the discharge path 68. The ink sent to the common discharge path tributary 42B is returned to the ink tank through the common discharge path main flow 42A and the circulation tube 84.

  In the above-described embodiment, the common supply path main stream 39A is disposed on the opposite side of the common discharge path main stream 42A with the two-dimensionally arranged ejectors 37 interposed therebetween. The ink passes through the common supply path main stream 39A formed on one side in the section, is supplied to the common supply path branch 39B, and is discharged from the ejector 37 to the common discharge path branch 42B on both sides of the inkjet recording head 32. It flows through a common supply path main stream 39A formed on the other side.

  On the other hand, as shown in FIG. 12, the common supply path main stream 39A and the common discharge path main stream 42A may be arranged on one side of the ejector 37 arranged two-dimensionally. In this configuration, the common supply path main stream 39A and the common discharge path main stream 42A are formed on one of the side portions of the ink jet recording head 32 and arranged so as to overlap each other when viewed from the nozzle surface.

  The common supply passage tributary 39B formed along the rows (Y direction) of the ejector 37 from the common supply passage main flow 39A is the common formed along the rows (Y direction) of the ejector 37 from the common discharge passage main flow 42A. A portion of the ink that is in communication with the discharge path tributary 42B, flows through the common supply path tributary 39B, and has not been supplied to the ejector 37, flows back to the common discharge path tributary 42B. The ink discharged from the ejector 37 merges with the folded ink and is sent to the common discharge path main stream 42A. The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

FIG. 1 is a schematic front view showing an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is an explanatory view showing the arrangement of the ink jet recording head according to the present embodiment. FIG. 3 is an explanatory diagram showing the relationship between the width of the recording medium and the width of the print area according to the present embodiment. FIG. 4 is a diagram illustrating a circulation path of ink supplied to the ink jet recording head according to the present embodiment. FIG. 5 is a plan view partially showing the ink jet recording head according to the present embodiment. FIGS. 6A and 6B are diagrams illustrating a main portion of the ink jet recording head according to the present embodiment, in which FIG. 6A is a plan view and FIG. 6B is a schematic longitudinal sectional view. FIG. 7 is a perspective view of a portion where ink flows in the ink jet recording head. FIG. 8 is a diagram illustrating a configuration of a filter according to the present embodiment. FIG. 9 is a view showing a modification using a metal plate instead of the resin plate according to the present embodiment. FIG. 10 is a diagram illustrating a modification in which the position of the filter according to the present embodiment is changed and a damper mechanism is provided. FIG. 11 is a view showing a modified example in which a damper mechanism is provided. FIG. 12 is a plan view showing a modification in which the common supply path main stream and the common discharge path main stream are arranged on one side of the two-dimensionally arranged ejectors in the ink jet recording head according to the present embodiment. FIG. 13 is a perspective view of the configuration shown in FIG.

Explanation of symbols

10 Inkjet recording device (image forming device)
17 Star wheel (recording medium transport means)
19 Conveying roll (recording medium conveying means)
32 Inkjet recording head (droplet ejection head)
35 Controller (control means)
37 Ejector 39 Common supply path (liquid supply path)
41 Air damper (damper mechanism)
42 Common discharge path (liquid discharge path)
46 Piezoelectric (pressure applying means)
47 Resin plate (resin member)
50 Pressure chamber 51 Elastic plate (elastic member)
56 Nozzle 70 Filter 81 Pump (Liquid circulation means)

Claims (5)

An ejector having a nozzle that discharges droplets, a pressure chamber that communicates with the nozzle and stores liquid, and a pressure applying unit that applies pressure to the liquid in the pressure chamber;
A liquid supply path for supplying the liquid to the pressure chamber;
A liquid discharge path disposed so as to overlap the liquid supply path when viewed from the nozzle surface on which the nozzle is formed, and discharges the liquid from the pressure chamber;
With
A liquid droplet ejection head , wherein a filter for filtering the liquid in the ejector is formed in a partition wall between the liquid supply path and the liquid discharge path .   The droplet discharge head according to claim 1, wherein the partition wall is formed of a resin member.   The droplet discharge head according to claim 1, wherein the partition wall is formed of an elastic member that bends and deforms.   A plurality of the ejectors are two-dimensionally arranged,
  The droplet discharge head according to claim 1, wherein the liquid supply path and the liquid discharge path are disposed between the ejectors.   The liquid droplet ejection head according to any one of claims 1 to 4,
  A liquid circulation means for circulating the liquid discharged from the liquid discharge path to the liquid supply path;
  A recording medium conveying means for conveying the recording medium;
  Control means for generating a drive waveform based on image data and discharging droplets from the droplet discharge head to the recording medium;
  An image forming apparatus comprising:

Images