JP4876724B2 - Droplet discharge head and droplet discharge apparatus - Google Patents

Description

  The present invention relates to a droplet discharge head that discharges droplets and a droplet discharge apparatus that includes the droplet discharge head.

  As a droplet discharge head for discharging droplets, a damper chamber in which an ink channel plate in which an ink channel communicating with a pressure chamber is formed, a damper plate, and an air damper chamber disposed opposite to the ink channel is formed Ink jet recording heads formed by laminating a forming plate are known (for example, Patent Documents 1 to 4).

  According to this configuration, even if the pressure wave acting on the pressure chamber propagates to the ink flow path communicating with the pressure chamber, the pressure wave can be released from the air damper chamber, so that the pressure wave propagates to the ink flow path. This suppresses the adverse effect on ink ejection that occurs.

The air damper chamber communicates with an opening formed on the surface on the side opposite to the nozzle or on the side surface through a ventilation path formed in the damper chamber forming plate.
JP 2002-36549 A JP-A-9-141856 JP 2003-11356 A JP-A-9-314863

  The ventilation path is formed by forming a groove portion in the damper chamber forming plate and laminating each plate including the damper chamber forming plate. When the plates are joined, the portion where the groove portion is formed is sufficient. Since pressurization is not performed, poor bonding of the plates occurs. As a result, bubbles are generated in an ink flow path or an ink pool on the ink flow path, or ink leakage occurs.

  In consideration of the above-described facts, the present invention provides a droplet discharge head capable of preventing poor bonding of plates in a droplet discharge head formed by stacking plates, and a droplet discharge apparatus including the droplet discharge head The purpose is to do.

A droplet discharge head according to a first aspect of the present invention is a droplet discharge head formed by laminating a plurality of plates, and temporarily supplies liquid supplied to a plurality of nozzles formed in a plurality of rows. A liquid storage portion that is stored in a row for each row along the row, a damper plate having one surface joined to the storage portion formation plate, and the other surface of the damper plate A damper chamber forming plate formed with a plurality of air damper chambers, each of which is disposed opposite to each of the liquid storage portions, and a vent passage formed in the damper chamber forming plate for extracting air from the air damper chamber, wherein formed on the damper chamber forming plate, positioned between the air passage and the damper plate, and a support portion for supporting the damper plate, the reservoir forming plate, the Danpapure Formed on the damper and the damper chamber forming plate, arranged on one end side in the formation direction of each liquid storage portion formed along the row, and the one end portion communicates with each other to supply liquid to each liquid storage portion A liquid pool main stream, and an air communication path that extends to the opposite side of the nozzle surface on which the nozzles are formed and that communicates the air passage with the atmosphere through a plurality of openings. Between the main pool and each air damper chamber, the air damper chamber communicates with each other .

  According to this configuration, the liquid discharged from the nozzle is temporarily stored in the liquid storage unit. The air damper chamber disposed opposite to the liquid storage part releases the pressure wave propagating to the liquid storage part through the air passage.

  Here, in the structure of Claim 1, since the support part located between a ventilation path and a damper plate supports a damper plate, a storage part formation plate, a damper plate, and a damper chamber formation plate are joined. At this time, even in the portion where the air passage is formed, the plate is sufficiently pressurized, so that bonding failure of each plate does not occur.

  According to a second aspect of the present invention, there is provided the liquid droplet ejection head according to the first aspect, wherein the damper chamber forming plate includes a first damper chamber forming plate joined to the other surface of the damper plate, and the first damper chamber forming plate. A second damper chamber forming plate joined to the damper chamber forming plate, the vent path is formed in the second damper chamber forming plate, and the support portion is formed in the first damper chamber forming plate. It is characterized by.

  Thus, the damper chamber forming plate of the present invention may be formed of a plurality of plates.

  According to a third aspect of the present invention, the liquid droplet ejection head according to the first aspect is characterized in that the air damper chamber and the air passage are formed by half etching.

  According to this configuration, since the air damper chamber and the air passage are formed by half etching, the productivity of the droplet discharge head is improved.

A droplet discharge head according to a fourth aspect of the present invention is characterized in that, in the configuration of any one of the first to third aspects, the air passage has a narrower width than the air damper chamber.

  According to this configuration, since the air passage has a narrower width than the air damper chamber, the rigidity of the damper chamber forming plate is higher than that of the portion where the air damper chamber is formed. For this reason, since it does not bend even if it applies a higher applied pressure, it pressurizes more reliably and can prevent the defective joint of each plate.

A droplet discharge device according to a fifth aspect of the present invention includes the droplet discharge head according to any one of the first to fourth aspects.

  Since the present invention is configured as described above, in a droplet discharge head formed by laminating plates, it is possible to prevent poor bonding of the plates.

  Hereinafter, an example of an embodiment according to a droplet discharge head of the present invention and a droplet discharge apparatus including the droplet discharge head will be described with reference to the drawings. In this embodiment, as a droplet discharge head that discharges droplets and a droplet discharge device that includes the droplet discharge head, an inkjet recording head that discharges ink droplets and records an image on a recording medium, and the inkjet recording head thereof are used. The ink jet recording apparatus provided will be described.

  First, the outline of the ink jet recording apparatus 10 will be described with reference to FIG. The recording medium will be described as recording paper P. In FIG. 1, the conveyance direction of the recording paper P in the inkjet recording apparatus 10 is represented by an arrow S as a sub-scanning direction, and the direction orthogonal to the conveyance direction is represented by an arrow M as a main scanning direction.

  As shown in FIG. 1, an ink jet recording apparatus 10 according to this embodiment includes a carriage 12 on which black, yellow, magenta, and cyan ink jet recording heads 30 are mounted. The carriage 12 has a pair of brackets 14 projecting upstream in the conveyance direction of the recording paper P (only one bracket 14 is shown in the figure), and circular holes 14A formed in the pair of brackets 14 respectively. The shaft 20 is inserted in the main scanning direction.

  A driving pulley (not shown) and a driven pulley (not shown) constituting the main scanning mechanism are disposed on both ends in the main scanning direction with respect to the carriage 12. A part of a timing belt 22 that is wound around these drive pulleys and driven pulleys and travels in the main scanning direction is fixed to the carriage 12. As a result, when the timing belt 22 travels in the main scanning direction by the rotational driving of the driving pulley, the carriage 12 reciprocates in the main scanning direction with the pair of brackets 14 being guided by the shaft 20.

  A paper feed tray 26 for storing recording paper P before image recording in a bundle is provided at the lower front side of the inkjet recording apparatus 10. Disposed above the paper feed tray 26 is a paper discharge tray 28 from which the recording paper P on which images are recorded by the ink jet recording heads 30 of the respective colors is discharged. Also, below the carriage 12 and the shaft 20, there is a sub-scanning mechanism 18 including a transport roller and a discharge roller that transport the recording paper P fed one by one from the paper feed tray 26 in the sub-scanning direction at a predetermined pitch. Is provided.

  In addition, the inkjet recording apparatus 10 is provided with a control panel 24 for performing various settings during image recording, a maintenance station (not shown), and the like. The maintenance station includes a cap member, a suction pump, a dummy jet receiver, a cleaning mechanism, and the like, and performs maintenance operations such as a suction recovery operation, a dummy jet operation, and a cleaning operation.

  A plurality of nozzles 56 (see FIG. 2) for ejecting ink droplets are formed on the lower surface (ink ejection surface) of each color inkjet recording head 30 so as to face the recording paper P.

  The ink jet recording apparatus 10 according to this embodiment is a so-called Partial Width Array (PWA) type ink jet recording apparatus configured as described above, and operates as follows.

  That is, in the ink jet recording apparatus 10 according to the present embodiment, ink droplets are selectively ejected from the nozzle 56 of the ink jet recording head 30 onto the recording paper P while the ink jet recording head 30 is moved in the main scanning direction by the main scanning mechanism. As a result, a part of the image based on the image data is recorded in a predetermined band area.

  When one movement in the main scanning direction is completed, the recording paper P is conveyed by a predetermined pitch in the sub scanning direction by the sub scanning mechanism 18, and the ink jet recording head 30 is again moved in the main scanning direction (the direction opposite to the above). A part of the image based on the image data is recorded in the next band area while moving to the next band area. By repeating such an operation a plurality of times, the entire image based on the image data is recorded on the recording paper P. The image is recorded in full color.

  Next, the ink jet recording head (droplet discharge head) 30 mounted on the ink jet recording apparatus 10 according to the present embodiment will be described.

  As shown in FIG. 2, the inkjet recording head 30 according to the present embodiment is formed by stacking a plurality of plates, and includes a nozzle plate 32, a damper chamber forming plate 34, a damper plate 36, a pool forming plate (reservoir section). Forming plate) 38, supply path plate 40, and pressure chamber plate 42.

  The nozzle plate 32, the damper chamber forming plate 34, the damper plate 36, the pool forming plate 38, the supply path plate 40, and the pressure chamber plate 42 are stacked in this order, and the plates are joined to each other as shown in FIG. .

  The damper chamber forming plate 34, the damper plate 36, and the pool forming plate 38 are formed with a substantially rectangular ink pool main flow (liquid storage portion) 44 that temporarily stores ink (liquid) discharged from the nozzles 56. Yes.

  One end of the ink pool main flow 44 in the longitudinal direction has a narrow passage width, and an ink supply hole 46 communicating with one end of the ink pool main flow 44 in the longitudinal direction is formed in the supply path plate 40 and the pressure chamber plate 42. Yes.

  The ink supply hole 46 is connected to an ink tank (not shown), and ink sent from the ink tank is supplied to the ink pool main stream 44 through the ink supply hole 46.

  A plurality of (three in this embodiment) ink pool tributaries (liquid storage portions) 48 communicating with the ink pool main flow 44 are formed on the pool forming plate 38. The ink pool tributary 48 branches off from the main ink pool 44 and extends in a direction perpendicular to the longitudinal direction of the main ink pool 44, temporarily stores ink, and forms a plurality of pressures on the pressure chamber plate 42. The ink is distributed to each of the chambers 50.

  In the supply path plate 40, an ink supply path 52 including a circular through hole is formed at a position above the ink pool branch 48. The ink supply path 52 has a passage width narrower than that of the ink pool branch 48, and connects the ink pool branch 48 and each pressure chamber 50. As a result, ink is supplied from the ink pool branch 48 to each pressure chamber 50.

  The pressure chambers 50 are arranged in a matrix (3 columns × 3 rows in this embodiment) at predetermined intervals on the pressure chamber plate 42. The upper opening of the pressure chamber 50 is closed by a diaphragm (not shown), and a piezoelectric body (not shown) disposed opposite to the pressure chamber 50 is provided on the diaphragm. The piezoelectric body is deformed so as to reduce the volume in the pressure chamber 50 when an electric signal (driving signal) is applied, and applies pressure to the pressure chamber 50.

  As described above, the ink flow path through which ink (liquid) flows from the ink tank to each pressure chamber 50 is formed by the ink supply hole 46, the ink pool main flow 44, the ink pool tributary 48, and the ink supply path 52.

  The nozzle plate 32 is formed with a plurality of nozzles 56 each having a circular through-hole, and these nozzles 56 correspond to the pressure chambers 50 in a matrix shape (in this embodiment, 3 rows × (3 rows).

  The damper chamber forming plate 34, the damper plate 36, the pool forming plate 38, and the supply path plate 40 are connected to upper positions corresponding to the respective nozzles 56 of the nozzle plate 32, and are formed of circular through holes having a diameter slightly larger than the nozzle diameter. Each passage 54 is formed. The pressure chamber 50 communicates with the nozzle 56 through the communication passage 54, and when a pressure is applied to the pressure chamber 50, ink droplets are ejected from the nozzle 56 through the communication passage 54.

  Here, the configuration of the air damper chamber 58 formed in the damper chamber forming plate 34 will be described.

  The air damper chamber 58 formed in the damper chamber forming plate 34 is disposed to face the ink pool tributary 48.

  The air damper chamber 58 is formed in the upper layer of the damper chamber forming plate 34 by forming a rectangular groove on the upper surface of the damper chamber forming plate 34, as shown in FIG. A lower wall is formed on the lower surface side (lower layer of the damper chamber forming plate 34).

  In the damper chamber forming plate 34, as shown in FIGS. 4A and 4B and FIG. 5, an individual air passage 60 communicating with one end portion of each air damper chamber 58 is formed. The lateral width W <b> 1 of the individual air passage 60 is narrower than the lateral width W <b> 2 of the air damper chamber 58. The damper chamber forming plate 34 is formed with a common air passage 62 communicating with each individual air passage 60.

  Each individual vent path 60 and the common vent path 62 are formed in the lower layer of the damper chamber forming plate 34 by forming a groove on the lower surface of the damper chamber forming plate 34. A support upper wall (support portion) 63 that supports the damper plate 36 is formed on the upper surface side (upper layer of the damper chamber forming plate 34).

  Thus, the support upper wall 63 is positioned between each individual ventilation path 60 and the common ventilation path 62 and the damper plate 36, and when the damper plate 36 and the damper chamber forming plate 34 are joined, the damper plate 36 is removed. Support from below.

  Moreover, the groove part for forming the air damper chamber 58, each individual ventilation path 60, and the common ventilation path 62 is formed by the half etching, for example.

  An atmosphere communication path 64 that connects the common ventilation path 62 and the atmosphere is formed in the damper chamber forming plate 34, the damper plate 36, the pool forming plate 38, the supply path plate 40, and the pressure chamber plate 42. The atmosphere communication path 64 extends upward and opens on the side opposite to the nozzle plate 32.

  Next, the operation of the above embodiment will be described.

  According to the configuration of this embodiment, ink is supplied from the ink tank (not shown) to the main ink pool 44 through the ink supply hole 46. The ink supplied to the ink pool main stream 44 is sent to the ink pool branch 48, temporarily stored in the ink pool branch 48, and supplied to each pressure chamber 50 through the ink supply path 52.

  A drive signal is applied to the piezoelectric body, pressure is applied to the ink in the pressure chamber 50, and the pressure-applied ink is ejected as ink droplets from the nozzle 56 through the communication path 54.

  Even if the pressure wave acting on the pressure chamber 50 propagates to the ink pool tributary 48 communicating with the pressure chamber 50, the pressure wave can escape from the air damper chamber 58, so that the pressure wave propagates to the ink flow path. The adverse effect on ink ejection caused by this is suppressed.

  Here, in the configuration of the present embodiment, the support upper wall 63 positioned between each individual ventilation path 60 and the common ventilation path 62 and the damper plate 36 supports the damper plate 36, so the pool forming plate 38, When the damper plate 36 and the damper chamber forming plate 34 are joined, sufficient pressure can be applied even in the portions where the individual ventilation paths 60 and the common ventilation path 62 are formed, resulting in poor bonding of the plates. Absent. As a result, it is possible to prevent the occurrence of bubbles and ink leakage in the main ink pool stream 44 and the ink pool tributary 48.

  Further, according to the configuration of the present embodiment, the air damper chamber 58, the individual ventilation paths 60, and the common ventilation path 62 are formed by half etching, so that the productivity of the inkjet recording head 30 is improved.

  Further, according to the configuration of the present embodiment, the atmosphere communication path 64 extending to the side opposite to the nozzle surface where the nozzle 56 is formed communicates the common ventilation path 62 and the atmosphere. For this reason, the droplets discharged from the nozzle 56 do not enter the atmosphere communication path 64, the air damper chamber 58 is maintained in a communication state communicating with the atmosphere, and the damper effect is stably exhibited.

  Further, according to the configuration of the present embodiment, the individual ventilation paths 60 and the common ventilation path 62 communicate with the air damper chambers 58, so that the ventilation paths can be shared.

  Further, according to the configuration of the present embodiment, each individual air passage 60 has a narrower width than the air damper chamber 58, so that the rigidity of the damper chamber forming plate 34 is higher than the portion where the air damper chamber 58 is formed. For this reason, since it does not bend even if it applies a higher applied pressure, it pressurizes more reliably and can prevent the defective joint of each plate.

  Further, according to the configuration of the present embodiment, the damper chamber forming plate 34 is formed by a single plate, so that the number of parts can be reduced and the manufacturability of the ink jet recording head 30 is improved. Further, since the rigidity of the plate itself is improved, the handling property at the time of manufacture is also improved. Further, since the rigidity of the entire inkjet recording head 30 can be increased, it becomes stronger against a load applied to head maintenance (for example, suction or wiping of the nozzle surface).

  In the above embodiment, the damper chamber forming plate 34 is formed by a single plate, but as shown in FIGS. 7A and 7B, FIGS. 8A and 8B, A plurality of plates, for example, two first damper chamber forming plates 34A and second damper chamber forming plates 34B may be formed.

  In the case of this configuration, as shown in FIGS. 7A and 7B, an air damper chamber 58 is formed in the upper first damper chamber forming plate 34A, and individual ventilation is provided in the lower second damper chamber forming plate 34B. A path 60 is formed. Further, as shown in FIGS. 8A and 8B, a common ventilation path 62 is formed in the lower second damper chamber forming plate 34B.

  In the above embodiment, the atmosphere communication path 64 extends upward and opens on the side opposite to the nozzle plate 32. However, as shown in FIGS. 9A and 9B, a plurality of plates are provided. A common ventilation path 62 may be extended in the direction (lateral direction) perpendicular to the stacking direction of the above to communicate with the atmosphere.

  According to this configuration, the common air passage 62 extends in a direction in which there is no ink pool main stream 44 and no ink pool tributary, and therefore does not intersect the ink pool main stream 44 and the ink pool tributary. Even if the liquid leaks from the ink pool tributary, the liquid does not enter the common air passage 62. For this reason, the air damper chamber 58 maintains a communication state communicating with the atmosphere, and the damper effect is stably exhibited.

  Further, in the above embodiment, one opening is formed in the atmosphere communication path 64, but a configuration in which a plurality of openings are formed may be employed. By forming a plurality of openings, a plurality of paths for communicating the air damper chamber to the atmosphere are secured, and even if a foreign object (for example, a droplet or an adhesive) enters the opening and one of the openings is blocked, the other Therefore, the air damper chamber is maintained in a communication state communicating with the atmosphere, and the damper effect is stably exhibited.

  Further, the ink jet recording apparatus according to the present embodiment is a so-called “Partial Width Array (PWA)” type. However, as the liquid droplet ejection apparatus according to the present invention, an effective recording area has a width of the recording paper (conveying direction). 4 ink jet recording heads corresponding to four colors of yellow (Y), magenta (M), cyan (S), and black (K) respectively. A so-called full width array (FWA) type that records a full-color image may be used.

  In this embodiment, an ink jet recording apparatus that discharges ink droplets and records an image is described as a liquid droplet discharging apparatus that discharges liquid droplets, and ink is discharged as a liquid droplet discharging head that discharges liquid droplets. The ink jet recording head for recording an image has been described. However, the droplet discharge device and the droplet discharge head according to the present invention are not limited to those that record an image on a recording sheet, and the liquid to be discharged is not limited to ink.

  For example, it is used industrially, such as a device that creates a color filter for display by discharging ink onto a polymer film or glass, or a device that forms bumps for component mounting by discharging solder in a welded state onto a substrate. The present invention can be applied to a droplet discharge device and a droplet discharge head in general used in the droplet discharge device.

  The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made without departing from the gist of the present invention.

FIG. 1 is a diagram showing an overall configuration of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing each plate of the ink jet recording head according to the present embodiment. FIG. 3 is a perspective view showing a state where the plates of the ink jet recording head according to the present embodiment are joined. 4 is a view showing a case where the damper chamber forming plate of the ink jet recording head according to the present embodiment is broken along the line AA in FIG. (A) is sectional drawing, (B) is a perspective view. FIG. 5 is a plan view of a damper chamber forming plate of the ink jet recording head according to the present embodiment. FIG. 6 is a diagram illustrating a case where the damper chamber forming plate of the ink jet recording head according to the present embodiment is broken along the line BB in FIG. (A) is sectional drawing, (B) is a perspective view. FIG. 7 is a view showing a modified example in which the damper chamber forming plate of the ink jet recording head according to the present embodiment is formed of two plates, taken along line AA in FIG. (A) is sectional drawing, (B) is a perspective view. FIG. 8 is a diagram showing a modified example in which the damper chamber forming plate of the ink jet recording head according to the present embodiment is formed of two plates, broken along line BB in FIG. (A) is sectional drawing, (B) is a perspective view. FIG. 9 is a diagram showing a modified example in which the air passage formed in the damper chamber forming plate of the ink jet recording head according to the present embodiment extends in the lateral direction, broken along line BB in FIG. is there. (A) is sectional drawing, (B) is a perspective view.

Explanation of symbols

10 Inkjet recording device (droplet ejection device)
30 Inkjet recording head (droplet ejection head)
34 Damper chamber forming plate 34A First damper chamber forming plate 34B Second damper chamber forming plate 36 Damper plate 38 Pool forming plate (reservoir forming plate)
48 Ink pool tributary (liquid reservoir)
56 Nozzle 60 Individual air passage (air passage)
62 Common air passage (air passage)
63 Support upper wall (support part)
64 Air communication passage

Claims (5)

A droplet discharge head formed by laminating a plurality of plates,
A storage portion forming plate in which a liquid storage portion that temporarily stores liquid supplied to a plurality of nozzles formed in a plurality of rows is formed along the row for each row, and
A damper plate having one surface joined to the reservoir forming plate;
A damper chamber forming plate formed with a plurality of air damper chambers joined to the other surface of the damper plate, each of which is disposed to face each of the liquid storage portions;
An air passage formed in the damper chamber forming plate and for extracting air from the air damper chamber;
A support portion that is formed on the damper chamber forming plate, is located between the ventilation path and the damper plate, and supports the damper plate;
Formed in the storage portion forming plate, the damper plate and the damper chamber forming plate, arranged on one end side in the forming direction of the plurality of liquid storage portions formed along the row, and the one end portions communicate with each other; A liquid pool mainstream for supplying liquid to each of the liquid reservoirs;
An atmosphere communication path that extends to the opposite side of the nozzle surface on which the nozzle is formed and communicates the ventilation path with the atmosphere through a plurality of openings;
With
The liquid discharge head according to claim 1, wherein the air passage communicates with each air damper chamber between the liquid pool main stream and each air damper chamber . The damper chamber forming plate is composed of a first damper chamber forming plate bonded to the other surface of the damper plate and a second damper chamber forming plate bonded to the first damper chamber forming plate.
The air passage is formed in the second damper chamber forming plate,
The liquid droplet ejection head according to claim 1, wherein the support portion is formed on the first damper chamber forming plate.   The droplet discharge head according to claim 1, wherein the air damper chamber and the air passage are formed by half etching.   The droplet discharge head according to claim 1, wherein the air passage has a narrower width than the air damper chamber.   A liquid droplet ejection apparatus comprising the liquid droplet ejection head according to claim 1.

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