JP2008030354A - Liquid droplet discharge device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the generation of crosstalk and simultaneously to reduce in size. <P>SOLUTION: In a flow path unit 40, two manifolds 25a, 25b extending along the arranging direction of pressure chambers 21 are arranged in positions where they overlap the plurality of pressure chambers 21 arranged in one line in a plan view. The manifold 25a is in communication with odd number pressure chambers 21 through throttle flow paths 27 on the other hand the manifold 25b is in communication with the odd number pressure chambers 21 through the throttle flow paths 27. Further, an ink flowing in port 32 formed in the odd number pressure chambers 21 and through which an ink fed from the manifold 25a flows in and an ink flowing in port 32 formed in even number pressure chambers 21 and through which an ink flows in from the manifold 25b are positioned on the same line along the arranging direction of the pressure chambers 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a droplet discharge device that discharges droplets from a nozzle.

  As a droplet discharge device that discharges droplets onto a discharge target body, Patent Document 1 discloses an inkjet head that discharges ink from a nozzle onto a recording sheet. Such an ink jet head communicates with each of a plurality of nozzles, communicates with a plurality of pressure chambers arranged along one direction, and the pressure chambers, and extends along the arrangement direction of the pressure chambers. And a manifold. Ink is supplied to the pressure chambers belonging to one pressure chamber row from one manifold extending along the arrangement direction of the pressure chamber rows. Such an ink jet head is configured such that ink is ejected from the nozzles by applying pressure to the ink in the pressure chamber with a piezoelectric actuator.

  As described above, when ink is supplied from one manifold to pressure chambers belonging to one pressure chamber row, pressure fluctuation in one pressure chamber propagates to another adjacent pressure chamber via the manifold. So-called crosstalk is likely to occur. When crosstalk occurs, the ejection stability of the inkjet head is impaired.

On the other hand, Patent Document 2 discloses an inkjet head in which ink is supplied from two different manifolds to two adjacent pressure chambers among pressure chambers belonging to one pressure chamber row. More specifically, in the ink jet head of Patent Document 2, an ink inflow port into which ink supplied from a manifold flows is orthogonal to the arrangement direction of the pressure chambers in the odd-numbered pressure chambers among the plurality of pressure chambers. It is formed at one end along the direction. In addition, in the even-numbered pressure chamber, an ink inlet is formed at the other end with respect to the one end. Manifolds extending along the direction in which the pressure chambers are arranged are arranged on both sides of the pressure chamber row, and each pressure chamber has a manifold arranged on the end side where the ink inlet is formed. Ink is supplied from. In such an ink jet head, it is possible to prevent the pressure fluctuation in the pressure chamber from propagating to the adjacent pressure chamber via the manifold, so that the occurrence of crosstalk can be suppressed.
JP 2006-68941 A (FIG. 2) Japanese Patent Laying-Open No. 2001-301167 (FIG. 2)

  However, as in the ink jet head disclosed in Patent Document 2, the ink inlets of the odd-numbered pressure chambers and the ink inlets of the even-numbered pressure chambers conflict with each other in the direction perpendicular to the direction in which the pressure chambers are arranged. If it is formed at such a position, it is difficult to arrange the two manifolds in which ink to be supplied to the pressure chambers are stored close to each other. Accordingly, there arises a problem that the ink jet head is enlarged.

  Accordingly, an object of the present invention is to provide a droplet discharge device that can suppress the occurrence of crosstalk and can be miniaturized.

  The droplet discharge device of the present invention includes a plurality of pressure chambers arranged along a predetermined arrangement direction, a plurality of nozzles communicating with the plurality of pressure chambers, respectively, for discharging droplets, and the arrangement direction A first manifold communicating with an odd-numbered pressure chamber from the pressure chamber at the end of the plurality of pressure chambers, and extending along the arrangement direction A second manifold communicating with the even numbered pressure chamber from the pressure chamber at the extreme end, formed in the odd numbered pressure chamber, and the liquid supplied from the first manifold An inflowing liquid inflow port and a liquid inflowing port into which the liquid supplied from the second manifold flows are located on the same straight line along the arrangement direction. There.

  According to this configuration, the liquid is supplied from the first and second manifolds different from each other to two pressure chambers adjacent to each other in the arrangement direction. Therefore, it is possible to prevent the pressure fluctuation in the pressure chamber from propagating to the pressure chambers adjacent in the arrangement direction via the manifold, and it is possible to suppress the occurrence of crosstalk. Furthermore, since the liquid inlet formed in the odd-numbered pressure chambers and the liquid inlet formed in the even-numbered pressure chambers are located on a straight line along the arrangement direction, the liquid inlets extend along the arrangement direction. It is easy to place the two manifolds close to each other. Therefore, it is possible to reduce the size of the droplet discharge device.

  In the droplet discharge device according to the present invention, the liquid droplet discharge port is formed in the first manifold, and is formed in the liquid manifold and the second manifold through which the liquid supplied to the odd-numbered pressure chambers flows out. It is preferable that the liquid outflow port from which the liquid supplied to the pressure chamber corresponding to the even number is outflow is positioned on the same straight line along the arrangement direction.

  The channel resistance in the channel through which the liquid flows depends on the channel area (area of the cross section orthogonal to the liquid flow direction) and the length of the channel. Therefore, in order to make the channel resistances of the channels having different lengths uniform, it is necessary to change the channel areas. In such a case, the overall flow path shape becomes complicated, which is not preferable. According to the above-described configuration, the lengths of the plurality of flow paths communicating the liquid inlets formed in the plurality of pressure chambers and the liquid outlets formed in the first and second manifolds are made uniform. Can do. Therefore, the flow path resistances of a plurality of flow paths that connect the liquid inlet and the liquid outlet can be made uniform without complicating the overall flow path shape.

  In the droplet discharge device of the present invention, the first and second manifolds are adjacent to each other, and a portion corresponding to the odd-numbered pressure chamber in the first manifold is provided on the second manifold side. A first protrusion protruding to the second manifold is formed, and a portion corresponding to the even-numbered pressure chamber in the second manifold is overlapped with the first protrusion along the arrangement direction. A second projecting portion projecting toward the first manifold is formed, and the liquid outlet is formed in a portion of the first and second projecting portions that overlaps in the arrangement direction. Good. According to this configuration, the liquid outlets can be reliably arranged on the same straight line along the arrangement direction.

  In the droplet discharge device of the present invention, the flow path of the flow path that connects the liquid inlet of the odd-numbered pressure chamber and the liquid outlet from which the liquid supplied to the pressure chamber flows out from the first manifold. The shape and the channel shape of the channel that connects the liquid inlet of the even-numbered pressure chamber and the liquid outlet from which the liquid supplied to the pressure chamber flows from the second manifold are equal to each other. It is preferable. According to this configuration, the channel resistances of the plurality of channels that connect the liquid inlets formed in the plurality of pressure chambers and the liquid outlets formed in the first and second manifolds are reliably aligned. be able to.

  In the droplet discharge device of the present invention, it is preferable that the first and second manifolds are disposed so as to overlap the plurality of pressure chambers in a direction perpendicular to an arrangement plane of the plurality of pressure chambers. According to this configuration, the droplet discharge device can be reliably downsized.

  In the droplet discharge device of the present invention, the first and second manifolds and the pressure chamber are formed in a plate laminate formed by laminating a plurality of metal plates and diffusion bonding them. The first and second manifolds may be formed on the same plate among the plurality of metal plates.

  Here, “(the first and second manifolds are formed on the same plate)” is not only the case where the first and second manifolds are formed on one plate, but also a plurality of The case where it is formed across the plate is also included.

  When forming a plate stack by diffusion bonding in which multiple metal plates are stacked and high pressure is applied in the stacking direction at high temperatures to join the metal plates, the manifold width (manifold extension direction and metal plate stacking) When the length along the direction orthogonal to the direction) is long, pressure may not be sufficiently applied to the area overlapping the manifold in the stacking direction due to the space of the manifold. In such a case, the metal plates are not appropriately joined at the portion overlapping the manifold. According to the above configuration, the width of the manifold can be shortened without changing the volume of the manifold per unit pressure chamber, compared to the case where one manifold is provided for one pressure chamber row. Therefore, it is possible to suitably perform diffusion bonding while ensuring a sufficient volume of the manifold.

  In the droplet discharge device of the present invention, the plurality of nozzles may be arranged on the same straight line along the arrangement direction. According to this configuration, the nozzles can be arranged at a higher density along the arrangement direction than when a plurality of nozzles are not arranged on the same straight line along the arrangement direction.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The present embodiment is an example in which the present invention is applied to an inkjet head that ejects ink onto a recording sheet. FIG. 1 is a diagram illustrating a schematic configuration of an inkjet printer including an inkjet head according to the present embodiment.

  As shown in FIG. 1, an inkjet printer 1 includes a carriage 10 that can be moved in a scanning direction (left and right direction in FIG. 1), a serial that is supported by the carriage 10 so as to face a recording sheet, and that ejects ink. The ink jet head 20 of the type and a transport roller 60 for transporting the recording paper in a paper feed direction (a direction from the right back to the left front in FIG. 1) perpendicular to the scanning direction are mainly provided. In the ink jet printer 1, the ink jet head 20 ejects ink onto the recording paper while moving in the scanning direction integrally with the carriage 10. Then, the recording paper recorded by the inkjet head 20 is discharged in the paper feeding direction by the transport roller 60.

  Next, the inkjet head 20 will be described in detail with reference to FIGS. FIG. 2 is a top view of the inkjet head 20 (viewed from the side opposite to the side facing the recording paper). FIG. 3 is a partially enlarged view of FIG. 4A is a cross-sectional view taken along line IVa-IVa in FIG. 3, and FIG. 4B is a cross-sectional view taken along line IVb-IVb in FIG. FIG. 5 is an exploded perspective view of the flow path unit included in the inkjet head.

  As shown in FIGS. 2 to 4, the inkjet head 20 includes a channel unit 40 in which an individual ink channel including a pressure chamber 21 is formed, and a piezoelectric actuator 50 stacked on the upper surface of the channel unit 40. It has.

  Here, the flow path unit 40 will be described. As shown in FIGS. 4 and 5, the flow path unit 40 includes a cavity plate 41, a base plate 42, an aperture plate 43, a supply plate 44, a manifold plate 45, a cover plate 46, and a nozzle plate 47. The plane shapes of these seven plates are all rectangular so that the sides along the scanning direction are short sides and the sides along the paper feed direction are long sides. And the plates 41-47 are mutually joined by the lamination state.

  Among the plates 41 to 47 constituting the flow path unit 40, the six plates 41 to 46 excluding the nozzle plate 47 are stainless steel plates. Therefore, ink passages such as manifolds 25a and 25b and pressure chambers 21 to be described later can be easily formed in these six plates 41 to 46 by etching. And these six plates 41-46 are heated to about 1000 degreeC in the state pressurized by the lamination direction with the jig | tool which is not shown in figure, and are joined by diffusion bonding. At this time, as shown in FIG. 4, a plate laminate 48 is constituted by the six plates 41 to 46 joined to each other. The nozzle plate 47 is made of, for example, a polymer synthetic resin material such as polyimide. The nozzle plate 47 is bonded to the lower surface of the plate laminate 48, that is, the lower surface of the cover plate 46 by an adhesive. Alternatively, the nozzle plate 47 is also formed of a metal material such as stainless steel like the plates 41 to 46 and may be diffusion bonded together with the plates 41 to 46.

  A plurality of pressure chambers 21 arranged in the longitudinal direction (paper feeding direction) are formed in the cavity plate 41 in a staggered manner. That is, two pressure chamber rows adjacent in the scanning direction are formed by the plurality of pressure chambers 21. The plurality of pressure chambers 21 are open on the upper surface of the flow path unit 40 (the upper surface of a cavity plate 41 to which a diaphragm 51 described later is joined). Each pressure chamber 21 is formed in a substantially elliptical shape in plan view, and the long axis direction thereof coincides with the short direction (scanning direction) of the cavity plate 41. In the following description, the arrangement direction of the pressure chambers 21 is simply referred to as “the arrangement direction”.

  As shown in FIGS. 2 and 5, two through-holes are formed on one end side in the longitudinal direction of the cavity plate 41 (upward side in the drawing in FIG. 2). The through hole constitutes an ink supply path 35 communicating with the manifolds 25a and 25b formed in the manifold plate 45 as will be described in detail later. That is, the through holes constituting the ink supply path 35 are similarly formed at positions where the base plate 42, the aperture plate 43, and the supply plate 44 overlap the through holes of the cavity plate 41 in plan view. The ink supply path 35 is connected to an ink tank (not shown).

  One end of the pressure chamber 21 in the long axis direction in plan view of the base plate 42 (the end on the side where the pressure chamber row adjacent to the pressure chamber row to which the pressure chamber 21 belongs: hereinafter, simply referred to as “one end”) ) A through hole is formed at a position overlapping the vicinity. The through hole constitutes a communication path 28 that allows the pressure chamber 21 and the nozzle 29 formed in the nozzle plate 47 to communicate with each other as described in detail later. That is, the through holes constituting the communication path 28 are also formed in the aperture plate 43, the supply plate 44, the manifold plate 45, and the cover plate 46 at positions overlapping the through holes of the base plate 42 in plan view. . As shown in FIG. 4, the communication passage 28 extends along the stacking direction of the plates.

  Further, when viewed in plan view of the base plate 42, the position overlaps with the vicinity of the other end in the major axis direction of the pressure chamber 21 (the end opposite to the side where the communication path 28 is connected: hereinafter simply referred to as “the other end”). Is formed with a substantially circular through-hole 22. That is, the base plate 42 is formed with a plurality of through holes 22 communicating with the other end portions of the plurality of pressure chambers 21 arranged in a line on the same straight line along the arrangement direction. The diameters of the plurality of through holes 22 are all equal.

  In the aperture plate 43, the pressure chamber 21 extends from a position overlapping the through hole 22 of the base plate 42 in a plan view (in other words, a position overlapping the other end of the pressure chamber 21) to a position overlapping the substantially central portion of the pressure chamber 21. A long and narrow aperture 23 extending along the long axis direction is formed. That is, the aperture plate 43 is formed with a plurality of apertures 23 communicating with the other end portions of the plurality of pressure chambers 21 arranged in a row through the through holes 22. Furthermore, the lengths along the extending direction of the plurality of apertures 23 are all equal. Here, the flow path area of the aperture 23 (the area of the vertical cross section orthogonal to the ink flow direction) is sufficiently smaller than the flow path area of the pressure chamber 21. Further, the flow areas of the plurality of apertures 23 are all equal. Since the aperture 23 is formed by full etching, the height of the aperture 23 (length along the plate stacking direction) matches the thickness of the aperture plate 43. Therefore, by adjusting only the width of the aperture 23 (the length along the longitudinal direction of the aperture plate 43), the flow path areas of the plurality of apertures 23 can be made uniform.

  A through hole 24 is formed in the supply plate 44 at a position that overlaps the substantially central portion of the pressure chamber 21 in plan view, that is, a position that overlaps one end of the aperture 23 opposite to the side communicating with the through hole 22. . That is, the supply plate 44 is formed with a plurality of through holes 24 communicating with the plurality of apertures 23 connected to the other ends of the plurality of pressure chambers 21 arranged in a line on the same straight line along the arrangement direction. ing. The diameters of the plurality of through holes 24 are all equal.

  Here, a throttle channel 27 is configured by the through hole 22, the aperture 23, and the through hole 24 formed in the base plate 42, the aperture plate 43, and the supply plate 44, respectively. As shown in FIGS. 2 to 4, in the present embodiment, the throttle channel 27 is formed at a position overlapping the pressure chamber 21 in plan view. The function of the throttle channel 27 will be described in detail later.

  In the manifold plate 45, two manifolds 25 a and 25 b extending along the arrangement direction are adjacent to each other in the major axis direction of the pressure chamber 21 at a position overlapping the plurality of pressure chambers 21 arranged in a line in a plan view. Is formed. More specifically, the two manifolds 25a and 25b are arranged without protruding from one end and the other end of each pressure chamber 21 in plan view. Here, of the two manifolds 25a and 25b, the one located on the right side in FIG. 2 to FIG. 4 is the manifold 25a, and the one located on the left side in FIG. The two manifolds 25a and 25b are formed to have the same width in the scanning direction (direction perpendicular to the arrangement direction). As shown in FIG. 2, the two manifolds 25a and 25b are connected to one end side in the longitudinal direction of the manifold plate 45 (the upper side in the drawing in FIG. 2). The ink supply path 35 is connected to a connection portion between the two manifolds 25a and 25b.

  Among the plurality of pressure chambers 21 arranged in a row, the manifold 25a has an odd number of pressure chambers 21 (hereinafter simply referred to as “odd number of pressure chambers 21”) from the pressure chamber 21 located at the lowest position in FIG. Is formed on a portion corresponding to the adjacent manifold 25b (left side in FIG. 2). On the other hand, among the plurality of pressure chambers 21 arranged in a row, the manifold 25b has an even-numbered pressure chamber 21 (hereinafter simply referred to as an “even-numbered pressure chamber”) from the pressure chamber 21 located at the lowest position in FIG. A protruding portion 26b that protrudes to the adjacent manifold 25a side (the right side in FIG. 2) is formed at a portion corresponding to “21”. As shown in FIGS. 2, 3, and 5, the protrusions 26 a and 26 b are formed at positions that overlap each other along the arrangement direction. Further, the overlapping portions of the protruding portions 26 a and 26 b along the arrangement direction overlap with the through holes 24 constituting the throttle channel 27 in plan view. The two manifolds 25a and 25b described in detail above have the same width in the direction (scanning direction) orthogonal to the arrangement direction. Moreover, the shape in planar view of the protrusion part 26a and the protrusion part 26b is equal. Further, in the arrangement direction, the formation interval between the adjacent protrusions 26a is equal to the formation interval between the adjacent protrusions 26b. Accordingly, the two manifolds 25a and 25b have the same flow path resistance.

  As described above, the cover plate 46 is formed with only a through hole that constitutes the communication passage 28 that allows the pressure chamber 21 and the nozzle 29 to communicate with each other.

  In the nozzle plate 47, a nozzle 29 is formed at a position overlapping the communication path 28, that is, near one end of the pressure chamber 21 in plan view. That is, the nozzles 29 communicating with the pressure chambers 21 arranged in a row are arranged on the same straight line along the arrangement direction. As a result, a plurality of nozzles 29 arranged in two rows are arranged in a staggered pattern on the nozzle plate 47. The nozzle 29 is formed, for example, by performing excimer laser processing on a polymer synthetic resin substrate such as polyimide.

  As shown in FIG. 4A, the manifold 25 a communicates with the odd-numbered pressure chambers 21 via the throttle channel 27. Further, as shown in FIG. 4B, the manifold 25 b communicates with the even-numbered pressure chambers 21 via the throttle channel 27. A plurality of ink outlets 31 through which ink to be supplied to the plurality of pressure chambers 21 arranged in a line from the manifold 25a or the manifold 25b is located on the same straight line along the arrangement direction. The ink inlet 32 into which the ink supplied from the manifold 25a or the manifold 25b flows into the pressure chamber 21 is located on the same straight line along the arrangement direction. Furthermore, the flow path shapes of the plurality of throttle flow paths 27 that communicate the ink outlet 31 and the ink inlet 32 are all the same. In addition, the pressure chamber 21 communicates with the nozzle 29 via the communication path 28. In this way, an individual ink flow path is formed in the flow path unit 40 from the manifold 25a or the manifold 25b to the nozzle 29 through the throttle flow path 27 and the pressure chamber 21.

  Here, the function of the throttle channel 27 will be described. In the inkjet head 20, pressure is applied to the ink in the pressure chamber 21 supplied from the manifolds 25 a and 25 b by the piezoelectric actuator 50 as will be described in detail later, and from the nozzle 29 communicating with the pressure chamber 21. Ink droplets are ejected. At this time, as described above, the flow path area in the aperture 23 of the throttle channel 27 is sufficiently smaller than the flow channel area of the pressure chamber 21, so that the pressure wave generated in the pressure chamber 21 passes through the throttle channel 27. Propagation to the manifolds 25a and 25b can be suppressed. As a result, the discharge pressure (discharge energy) applied to the pressure chamber 21 can be efficiently transmitted to the nozzle 29 side.

  Next, the piezoelectric actuator 50 will be described. As shown in FIG. 4, the piezoelectric actuator 50 includes a conductive vibration plate 51 disposed on the upper surface of the flow path unit 40 (the upper surface of the cavity plate 41), and a plurality of pressure chambers 21 on the surface of the vibration plate 51. And a plurality of individual electrodes 53 respectively formed on the surface of the piezoelectric layer 52 so as to correspond to the plurality of pressure chambers 21, respectively.

  The vibration plate 51 is a stainless steel plate having a rectangular shape that is equal to the plates 41 to 47 constituting the flow path unit 40 in plan view, and the upper surface of the cavity plate 41 in a state of closing the openings of the plurality of pressure chambers 21. Are laminated and bonded together. The diaphragm 51 also serves as a common electrode that opposes the plurality of individual electrodes 53 and applies an electric field to the piezoelectric layer 52 between the individual electrodes 53 and the diaphragm 51. The diaphragm 51 is grounded and is always held at the ground potential.

  On the surface of the diaphragm 51, there is formed a piezoelectric layer 52 mainly composed of lead zirconate titanate (PZT) which is a solid solution and is a ferroelectric substance of lead titanate and lead zirconate. The piezoelectric layer 52 is continuously formed across the plurality of pressure chambers 21. Here, the piezoelectric layer 52 can be formed by using, for example, an aerosol deposition method (AD method) in which an ultrafine particle material is deposited by colliding at high speed. For the piezoelectric layer 52, a sol-gel method, a sputtering method, a hydrothermal synthesis method, or a CVD (chemical vapor deposition) method can also be used. Furthermore, the piezoelectric layer 52 can also be formed by attaching a piezoelectric sheet obtained by firing a PZT green sheet to the surface of the diaphragm 51.

  A plurality of individual electrodes 53 having an elliptical planar shape that is slightly smaller than the pressure chamber 21 are formed on the surface of the piezoelectric layer 52. The individual electrodes 53 are respectively formed at positions overlapping the central portion of the corresponding pressure chamber 21 in plan view. Here, the individual electrode 53 is made of a conductive material such as gold. Further, on the surface of the piezoelectric layer 52, terminal portions 54 are respectively formed at one end portions of the plurality of individual electrodes 53 (end portions on the other end portion side of the pressure chamber 21 corresponding to the plan view). The terminal portion 54 is connected to a driving circuit such as a driver IC via a flexible wiring member such as a flexible printed wiring board, and a driving potential is selectively applied to the plurality of individual electrodes 53. It is configured as follows.

  Here, the operation of the piezoelectric actuator 50 will be described. When a driving potential is selectively applied to the plurality of individual electrodes 53, the individual electrode 53 to which the driving potential is applied is opposed to the individual electrode 53 and held at the ground potential, and functions as a common electrode. Thus, the electric field in the thickness direction is generated in the portion of the piezoelectric layer 52 sandwiched between the individual electrode 53 and the diaphragm 51. The portion of the piezoelectric layer 52 corresponding to the individual electrode 53 to which the drive potential is applied contracts in the horizontal direction orthogonal to the thickness direction that is the polarization direction. At this time, since the diaphragm 51 is deformed so as to protrude toward the pressure chamber 21 as the piezoelectric layer 52 contracts, the volume in the pressure chamber 21 decreases and pressure is applied to the ink in the pressure chamber 21. Is done. As a result, ink droplets are ejected from the nozzles 29 communicating with the pressure chamber 21.

  As described above, the inkjet head 20 of the present embodiment communicates with the manifold 25a that communicates with the odd-numbered pressure chambers 21 and the even-numbered pressure chambers 21 among the plurality of pressure chambers 21 arranged in a row. And a manifold 25b. The ink inlet 32 into which the ink supplied from the manifold 25a or the manifold 25b flows into the pressure chamber 21 is located on the same straight line along the arrangement direction. Accordingly, since ink is supplied from two different manifolds 25a and 25b to two pressure chambers 21 adjacent to each other in the arrangement direction, pressure fluctuations in the pressure chambers 21 cause the manifolds 25a and 25b to flow. Propagation to the pressure chambers 21 adjacent to each other in the arrangement direction can be prevented. Therefore, occurrence of crosstalk can be suppressed. Furthermore, since the ink inlet 32 is located on a straight line along the arrangement direction, it is easy to arrange the two manifolds 25a and 25b extending along the arrangement direction close to each other. As a result, the inkjet head 20 can be reduced in size.

  Further, in the inkjet head 20 of the present embodiment, the plurality of ink outlets 31 through which the ink supplied to the plurality of pressure chambers 21 arranged in a row from the manifold 25a or the manifold 25b flows out along the arrangement direction. Located on the same straight line. Therefore, the lengths of the plurality of throttle channels 27 that communicate the ink inlets 32 provided in the plurality of pressure chambers 21 and the ink outlets 31 provided in the first and second manifolds are made uniform. Can do. Therefore, as in the case where the lengths of the plurality of throttle channels 27 are different, the plurality of throttle channels 27 are changed without changing the channel area of each throttle channel 27 and complicating the overall channel shape. The flow path resistance can be made uniform.

  Furthermore, in the inkjet head 20 of the present embodiment, the two manifolds 25a and 25b are adjacent to each other, and a portion corresponding to the odd-numbered pressure chamber 21 in the manifold 25a has a protruding portion 26a protruding toward the manifold 25b. Is formed. On the other hand, in the portion corresponding to the even-numbered pressure chambers 21 in the manifold 25b, a protruding portion 26b protruding toward the manifold 25a is formed so as to overlap the protruding portion 26a along the arrangement direction. And the ink outlet 31 is formed in the part which overlaps along the sequence direction in protrusion part 26a, 26b. Therefore, the ink outlet 31 can be reliably arranged on the same straight line along the arrangement direction.

  In addition, in the inkjet head 20 of the present invention, the shape of the throttle channel 27 that communicates the ink inlet 32 of the odd-numbered pressure chamber 21 and the ink outlet 31 of the manifold 25a, and the ink of the even-numbered pressure chamber 21. The shape of the throttle channel 27 that communicates the inlet 32 and the ink outlet 31 of the manifold 25b is equal to each other. Therefore, the flow resistances of the plurality of throttle channels 27 that communicate the ink inlets 32 formed in the plurality of pressure chambers 21 with the ink outlets 31 formed in the manifolds 25a and 25b are reliably aligned. Can do.

  Further, in the inkjet head 20 of the present invention, the manifolds 25a and 25b are arranged so as to overlap with the plurality of pressure chambers 21 arranged in a row in a plan view. Therefore, the inkjet head 20 can be reliably downsized.

  Further, in the inkjet head 20 of the present invention, the manifolds 25a and 25b and the pressure chambers are formed inside the plate laminate 48 which is produced by joining the six plates 41 to 46, which are all metal plates, by diffusion bonding. 21 is formed, and two manifolds 25 a and 25 b are formed on one manifold plate 45. Therefore, compared with the case where one manifold is provided for a plurality of pressure chambers 21 arranged in a row, the widths of the manifolds 25a and 25b (manifolds are not changed) without changing the manifold volume per unit pressure chamber. The length along the direction perpendicular to the extending direction of 25a and 25b and the stacking direction of the plates can be shortened. Therefore, it is possible to suitably perform diffusion bonding while sufficiently securing the volumes of the manifolds 25a and 25b.

  Furthermore, in the inkjet head 20 of the present invention, the nozzles 29 communicating with the pressure chambers 21 arranged in a row are arranged on the same straight line along the arrangement direction. Therefore, compared with the case where the plurality of nozzles 29 are not arranged on the same straight line along the arrangement direction, the nozzles 29 can be arranged at a high density along the arrangement direction.

  Next, a second embodiment of the present invention will be described with reference to FIGS. 6 is a partially enlarged view of a top view of the ink jet head according to the present embodiment, FIG. 7A is a cross-sectional view taken along line VIIa-VIIa in FIG. 6, and FIG. 6 is a cross-sectional view taken along line VIIb-VIIb in FIG. The present embodiment is the same as the first embodiment except for the configuration of the inkjet head 120. The main difference between the configuration of the inkjet head 120 according to the second embodiment and the configuration of the inkjet head 20 according to the first embodiment is that, in the inkjet head 20, the throttle channel 27 is a pressure in a plan view. In the inkjet head 120 of the present embodiment, the throttle channel 127 is formed at a position that does not overlap with the pressure chamber 21 in plan view. In the following description, components having the same configurations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted as appropriate.

  As shown in FIG. 7, the flow path unit 140 according to the present embodiment includes two cavity plates 141 and 142, a supply plate 144, a manifold plate 145, a cover plate 146, and a nozzle plate 147. Of these six plates, the five plates 141, 142, 144 to 146 excluding the nozzle plate 147 are made of stainless steel, and are joined together by diffusion bonding to form a plate laminate 148. The nozzle plate 147 is made of a polymer resin material and is bonded to the lower surface of the plate laminate 148 with an adhesive.

  As shown in FIG. 7, the pressure chamber 121 is formed across the two cavity plates 141 and 141. An aperture 123 extending along the major axis direction of the pressure chamber 121 is formed in the plate 142 positioned below the two cavity plates 141 and 142. As shown in FIGS. 6 and 7, the aperture 123 communicates with one end portion (the right end portion in FIGS. 6 and 7) of the through hole constituting the pressure chamber 121 in the cavity plate 142. Similar to the first embodiment, the flow path resistance in the aperture 123 is larger than the flow path resistance in the pressure chamber 121.

  The supply plate 144, the manifold plate 145, and the cover plate 146 include a pressure chamber 121 (more specifically, the vicinity of the end of the pressure chamber 121 opposite to the end that is in communication with the aperture 123), A through-hole forming a communication path 128 that communicates with the nozzle 129 is formed.

  A through hole 124 is formed at a position overlapping the end of the supply plate 144 opposite to the side communicating with the pressure chamber 121 of the aperture 123 in plan view. The aperture 123 and the through hole 124 formed in the cavity plate 142 and the supply plate 144 constitute a throttle channel 127. As shown in FIGS. 6 and 7, the throttle channel 127 is formed at a position that does not overlap the pressure chamber 121 in plan view.

  On the manifold plate 145, two manifolds 125a and 125b extending in the arrangement direction are formed adjacent to the long axis direction of the pressure chamber 121. 6 and 7, the manifold 125 a located on the right side of the drawing is formed at a position that does not overlap the pressure chamber 121 in plan view. On the other hand, the manifold 125b located on the left side in FIG. 6 and 7 is formed at a position that partially overlaps the vicinity of the right end of the pressure chamber 121 in plan view.

  In the manifold 125a, a protrusion 126a that protrudes toward the adjacent manifold 125b is formed at a portion corresponding to the odd-numbered pressure chamber 121. On the other hand, the manifold 125b is formed with a protruding portion 126b protruding toward the manifold 125a so as to overlap the protruding portion 126a along the arrangement direction at a portion corresponding to the even pressure chamber 121. A throttle channel 127 is connected to the overlapping portions of the protruding portions 126a and 126b along the arrangement direction.

  The nozzle plate 147 is formed at a position overlapping the communication path 128 in plan view, and a plurality of nozzles 129 respectively communicating with the plurality of pressure chambers 121 arranged in a row are on the same straight line along the arrangement direction. Has been placed.

  As shown in FIGS. 7A and 7B, an individual ink flow path from the manifold 125 a or the manifold 125 b to the nozzle 129 through the throttle flow path 127 and the pressure chamber 121 is provided inside the flow path unit 40. It is formed. Here, the plurality of ink outlets 131 from which the ink supplied to the plurality of pressure chambers 121 arranged in a line from the manifold 125a or the manifold 125b flows out are positioned on the same straight line along the arrangement direction. Further, the ink inlets 132 into which the ink supplied from the manifold 125a or the manifold 125b flows into the pressure chamber 121 are located on the same straight line along the arrangement direction. Further, the flow path shapes of the plurality of narrowed flow paths 127 communicating the ink outlet 131 and the ink inlet 132 are all equal.

  As described above, the inkjet head 120 of the present embodiment can be miniaturized while suppressing the occurrence of crosstalk, similarly to the inkjet head 20 of the first embodiment.

  Further, in the inkjet head 120 of the present embodiment, the throttle channel 127 is formed at a position that does not overlap the pressure chamber 121 in plan view. Therefore, the number of plates constituting the flow path unit 140 can be reduced as compared with the case where the throttle flow path 127 is formed at a position overlapping the pressure chamber 121 in plan view.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. Is. For example, in the above-described first and second embodiments, the case where the manifolds 25a and 25b (125a and 125b) are formed on the single manifold plate 45 and 145 has been described, but the manifolds 25a and 25b ( 125a and 125b) may be formed across a plurality of plates.

  In the first and second embodiments described above, the ink supplied to the plurality of pressure chambers 21 (121) arranged in a line from the manifold 25a (125a) or the manifold 25b (125b) flows out. Although the case where the plurality of ink outlets 31 (131) are located on the same straight line along the arrangement direction has been described, the ink outlets 31 (131) may not be located on a straight line.

  Further, in the first and second embodiments described above, the two manifolds 25a and 25b (125a and 125b) are adjacent to each other, and the portion corresponding to the odd-numbered pressure chambers 21 in the manifold 25a (125a). Is formed with a protruding portion 26a (126a) protruding toward the manifold 25b (125b), and a portion corresponding to the even-numbered pressure chamber 21 in the manifold 25b (125b) has a protruding portion along the arrangement direction. A protruding portion 26b (126b) protruding toward the manifold 25a (125a) is formed so as to overlap with 26a (126a). And although the case where the ink outlet 31 (131) was formed in the part which overlaps along the sequence direction in protrusion part 26a, 26b (126a, 126b) was demonstrated, it is not restricted to this. For example, a recessed portion that is recessed on the opposite side to the manifold 25a (125a) side is formed in a portion corresponding to the odd-numbered pressure chamber 21 in the manifold 25b (125b), and is formed in the manifold 25b (125b). Manifolds 125a and 25b (125a and 125b) may be arranged so that the depressions fit into the protrusions 26a (126a) formed in the manifold 25a (125a).

  In addition, in the first and second embodiments described above, the ink inlet 32 (132) of the odd-numbered pressure chamber 21 (121) communicates with the ink outlet 31 (131) of the manifold 25a (125a). Of the throttle channel 27 (127) to be connected, and the throttle channel that connects the ink inlet 32 (132) of the even-numbered pressure chamber 21 (121) and the ink outlet 31 (131) of the manifold 25b (125b). Although the case where the shape of 27 (127) is equal to each other has been described, the shape of the throttle channel 27 (127) may be different from each other. At this time, the length and channel area of each throttle channel 27 (127) may be adjusted so that the channel resistances of the plurality of throttle channels 27 (127) are equal, or the plurality of throttle channels 27 27 (127) may have different channel resistances.

  In the first embodiment described above, the two manifolds 25a and 25b extending along the arrangement direction of the pressure chambers 21 do not protrude from one end and the other end of each pressure chamber 21 in plan view. The case where it is arranged has been described. Furthermore, in the second embodiment, one of the two manifolds 125a (125b) is arranged so as to partially overlap with the vicinity of the end of the pressure chamber 121 in plan view, and the other in plan view. The case where the pressure chamber 121 and the pressure chamber 121 do not overlap with each other has been described. However, the positional relationship between the pressure chamber 21 (121) and the manifolds 25a and 25b (125a and 125b) is not limited to these. For example, the manifolds 25a and 25b (125a and 125b) may be arranged at positions that do not overlap the pressure chamber 21 (121).

  In the first and second embodiments described above, the manifolds 25a and 25b (125a and 125b) and the pressure chamber 21 (121) include a plurality of plates 41 to 46 (141, 142, 144 to 146). Are laminated and diffusion-bonded to form a plate laminate 48 (148). The case where the two manifolds 25a and 25b (125a and 125b) are formed on the same manifold plate 45 (145) has been described, but the present invention is not limited to this. For example, the two manifolds 25a and 25b (125a and 125b) may be formed on different plates among the plurality of plates forming the plate stack 48 (148). Further, two manifolds 25a and 25b (125a and 125b) and a pressure chamber 21 (121) may be formed inside a resin member formed by injection molding.

  In addition, in the above-described first and second embodiments, the nozzles 29 (129) communicating with the pressure chambers 21 (121) arranged in a row are arranged on the same straight line along the arrangement direction. However, the present invention is not limited to this. For example, the nozzles 29 (129) communicating with the pressure chambers 21 (121) arranged in a row may be arranged in a staggered manner.

  In the first and second embodiments described above, the ink inlet 32 (132) of the pressure chamber 21 (121) and the ink outlet 31 (131) of the manifolds 25a and 25b (125a and 125b) are throttled. Although the case where the ink flow path 27 (127) communicates with the flow path 27 (127) has been described, the flow path that connects the ink inlet 32 (132) and the ink outlet 31 (131) is a flow path that does not have a restriction function. It may be. Further, the ink inflow port 32 (132) and the ink outflow port 31 (131) coincide with each other, and a flow path that connects these may not be formed.

1 is a diagram illustrating a schematic configuration of an inkjet printer including an inkjet head according to a first embodiment of the present invention. It is a top view of the inkjet head shown in FIG. FIG. 3 is a partially enlarged view of FIG. 2. (A) is sectional drawing which follows the IVa-IVa line of FIG. 3, (b) is sectional drawing which follows the IVb-IVb line of FIG. FIG. 5 is an exploded perspective view of the flow path unit shown in FIG. 4. It is the elements on larger scale of the top view in the inkjet head concerning the 2nd Embodiment of this invention. (A) is sectional drawing which follows the VIIa-VIIa line of FIG. 6, (b) is sectional drawing which follows the VIIb-VIIb line of FIG.

Explanation of symbols

1 Inkjet printer 20, 120 Inkjet head (droplet ejection device)
21, 121 Pressure chamber 25a, 125a Manifold (first manifold)
25b, 125b Manifold (second manifold)
26a, 126a Projection (first projection)
26b, 126b Protruding part (second projecting part)
27, 127 Restricted flow path 29, 129 Nozzle 31, 131 Ink outlet (liquid outlet)
32, 132 Ink inlet (liquid inlet)
40, 140 Channel unit 41, 141, 142 Cavity plate 42 Base plate 43 Aperture plate 44, 144 Supply plate 45, 145 Manifold plate 46, 146 Cover plate 47, 147 Nozzle plate 48, 148 Plate laminate 50 Piezoelectric actuator

Claims (7)

A plurality of pressure chambers arranged along a predetermined arrangement direction;
A plurality of nozzles respectively communicating with the plurality of pressure chambers and discharging droplets;
A first manifold that extends along the arrangement direction and communicates with an odd-numbered pressure chamber from an endmost pressure chamber of the plurality of pressure chambers;
A second manifold that extends along the arrangement direction and communicates with the even pressure chambers from the pressure chambers at the extreme ends,
Formed in the odd-numbered pressure chambers, formed in the liquid inlet into which the liquid supplied from the first manifold flows, and in the even-numbered pressure chambers, supplied from the second manifold And a liquid inflow port into which the liquid flowing in is located on the same straight line along the arrangement direction.   A liquid outlet formed in the first manifold through which liquid supplied to the odd-numbered pressure chambers flows out, and a liquid formed in the second manifold and supplied to the even-numbered pressure chambers 2. The droplet discharge device according to claim 1, wherein the liquid outlet from which the liquid flows out is located on the same straight line along the arrangement direction.   The first and second manifolds are adjacent to each other, and a portion corresponding to the odd-numbered pressure chamber in the first manifold has a first protrusion that protrudes toward the second manifold. A portion corresponding to the even-numbered pressure chambers in the second manifold protrudes toward the first manifold so as to overlap the first protrusion along the arrangement direction. 3. The liquid outflow port is formed in a portion where a second protrusion is formed and the first and second protrusions overlap in the arrangement direction. 4. Droplet discharge device.   The channel shape of the channel that connects the liquid inlet of the odd-numbered pressure chamber and the liquid outlet from which the liquid supplied to the pressure chamber flows from the first manifold, and the even-numbered pressure chamber The flow path shapes of the flow paths communicating the liquid inlet and the liquid outlet from which the liquid supplied to the pressure chamber flows out from the second manifold are equal to each other. 4. The droplet discharge device according to 3.   The first and second manifolds are arranged so as to overlap with the plurality of pressure chambers in a direction perpendicular to an arrangement plane of the plurality of pressure chambers. The droplet discharge device according to 1. The first and second manifolds and the pressure chamber are formed in a plate laminate formed by laminating a plurality of metal plates and diffusion bonding,
6. The droplet discharge device according to claim 1, wherein the first and second manifolds are formed on the same plate among the plurality of metal plates.   The liquid droplet ejection apparatus according to claim 1, wherein the plurality of nozzles are arranged on the same straight line along the arrangement direction.

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