Droplet ejection head and droplet ejection device

Abstract

A droplet ejection head according to the present disclosure comprises: a head body; a cover member; a plate-like member; and an intermediate member. The head body has, on a first surface thereof, a plurality of ejection holes through which droplets can be ejected. The cover member is positioned on the opposite side of the head body from the first surface. The plate-like member is positioned on a side surface part of the cover member. The intermediate member is positioned between the head body and the plate-like member. The head body and the intermediate member are fitted to each other.

Description

Droplet ejection head and droplet ejection device

[0001] The present disclosure relates to a droplet ejection head and a droplet ejection device.

[0002] 2. Description of the Related Art Conventionally, as a printing head, for example, a droplet ejection head that ejects a liquid onto a recording medium to perform various printing operations is known (see Patent Document 1).

[0003] WO 2016 / 104480

[0004] A droplet ejection head according to one aspect of the present disclosure has a head body, a cover member, a plate-like member, and an intermediate member. The head body has a first surface having a plurality of ejection holes capable of ejecting droplets. The cover member is located on the side of the head body opposite the first surface. The plate-like member is located on a side portion of the cover member. The intermediate member is located between the head body and the plate-like member. The head body and the intermediate member are fitted together.

[0005] FIG. 1 is a schematic side view of a printer according to the first embodiment. FIG. 2 is a schematic plan view of the printer according to the first embodiment. FIG. 3 is an exploded perspective view showing a schematic configuration of a droplet ejection head according to the first embodiment. FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. 3. FIG. 5 is an enlarged cross-sectional view of the droplet ejection head according to the first embodiment. FIG. 6 is a perspective view illustrating the structure of an intermediate member according to the first embodiment. FIG. 7 is a perspective view illustrating the structure of an intermediate member according to the first embodiment. FIG. 8 is a perspective view illustrating the structure of an intermediate member according to a second embodiment. FIG. 9 is a perspective view showing another example of an intermediate member according to the second embodiment.

[0006] Hereinafter, a detailed description will be given of a droplet ejection head and a droplet ejection device according to the present disclosure (hereinafter referred to as an "embodiment") with reference to the drawings. Note that the present disclosure is not limited to the embodiment. Furthermore, the embodiments can be appropriately combined as long as the processing content is not contradictory. Furthermore, the same components in the following embodiments are designated by the same reference numerals, and redundant explanations will be omitted.

[0007] Furthermore, in the following embodiments, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in the strict sense. In other words, the above expressions allow for deviations due to, for example, manufacturing precision or installation precision.

[0008] In addition, in the drawings referred to below, for ease of understanding, an orthogonal coordinate system may be shown in which the X-axis direction, Y-axis direction, and Z-axis direction, which are perpendicular to each other, are defined, and the positive Z-axis direction is the vertically upward direction.

[0009] The structure of a conventional droplet ejection head has room for improvement, for example, in terms of improving sealing performance. The present disclosure has been made in view of the above, and provides a droplet ejection head and a droplet ejection device that can improve sealing performance.

[0010] (First embodiment) <Printer configuration> First, an overview of a printer 1, which is an example of a recording apparatus according to a first embodiment, will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a schematic side view of the printer 1 according to the first embodiment, and Fig. 2 is a schematic plan view of the printer 1 according to the first embodiment. The printer 1 according to the first embodiment is, for example, a color inkjet printer.

[0011] 1 , the printer 1 includes a paper feed roller 2, a guide roller 3, a coater 4, a head case 5, a plurality of transport rollers 6, a plurality of frames 7, and a plurality of droplet ejection heads 8. The printer 1 further includes a transport roller 9, a dryer 10, a transport roller 11, a sensor unit 12, and a recovery roller 13.

[0012] The printer 1 further includes a control unit 14. The control unit 14 controls the paper feed roller 2, the guide roller 3, the coater 4, the head case 5, the plurality of transport rollers 6, the plurality of frames 7, the plurality of droplet ejection heads 8, the transport roller 9, the dryer 10, the transport roller 11, the sensor unit 12, and the recovery roller 13.

[0013] The printer 1 records images or characters on the printing paper P by causing droplets to land on the printing paper P. The printing paper P is an example of a recording medium. Before use, the printing paper P is wound around a paper feed roller 2. The printer 1 then transports the printing paper P from the paper feed roller 2, via a guide roller 3 and a coater 4, into the interior of a head case 5.

[0014] The coater 4 applies the coating agent evenly to the printing paper P. This allows the printing paper P to be surface treated, thereby improving the printing quality of the printer 1.

[0015] The head case 5 houses a plurality of transport rollers 6, a plurality of frames 7, and a plurality of droplet ejection heads 8. Inside the head case 5, a space is formed that is isolated from the outside, except for a portion that is connected to the outside, such as a portion where the printing paper P enters and leaves.

[0016] At least one of the control factors such as temperature, humidity, and air pressure of the internal space of the head case 5 is controlled by the control unit 14 as necessary. The transport rollers 6 transport the printing paper P inside the head case 5 to the vicinity of the droplet ejection heads 8.

[0017] The frame 7 is a rectangular flat plate, and is positioned above and in close proximity to the print paper P being transported by the transport rollers 6. As shown in Figure 2, the frame 7 is positioned so that its longitudinal direction is perpendicular to the transport direction of the print paper P. Inside the head case 5, multiple (for example, four) frames 7 are positioned along the transport direction of the print paper P.

[0018] In the following description, the transport direction of the printing paper P is also referred to as the "sub-scanning direction," and the direction perpendicular to the sub-scanning direction and parallel to the printing paper P is also referred to as the "main scanning direction."

[0019] A liquid, such as ink, is supplied from a liquid tank (not shown) to the droplet discharge head 8. The droplet discharge head 8 discharges droplets of liquid supplied from the liquid tank.

[0020] The control unit 14 controls the droplet ejection head 8 based on data such as images or characters, and ejects droplets toward the printing paper P. The distance between the droplet ejection head 8 and the printing paper P is, for example, about 0.5 to 20 mm.

[0021] The droplet ejection head 8 is fixed to the frame 7. For example, both ends of the droplet ejection head 8 in the longitudinal direction are fixed to the frame 7. The droplet ejection head 8 is positioned so that its longitudinal direction is perpendicular to the transport direction of the printing paper P.

[0022] That is, the printer 1 according to the first embodiment is a so-called line printer in which the droplet ejection head 8 is fixed inside the printer 1. Note that the printer 1 according to the first embodiment is not limited to a line printer, and may also be a so-called serial printer. A serial printer is a printer that alternates between recording while moving the droplet ejection head 8 back and forth in a direction intersecting the transport direction of the printing paper P, for example, in a direction substantially perpendicular to the direction, and transporting the printing paper P.

[0023] As shown in Fig. 2, a plurality of (for example, five) droplet ejection heads 8 are fixed to one frame 7. Fig. 2 shows an example in which three droplet ejection heads 8 are positioned in front and two in the rear in the transport direction of the printing paper P, and the droplet ejection heads 8 are positioned in the transport direction of the printing paper P so that the centers of the droplet ejection heads 8 do not overlap.

[0024] A head group 8A is made up of multiple droplet ejection heads 8 positioned on one frame 7. The four head groups 8A are positioned along the transport direction of the printing paper P. The same color ink is supplied to droplet ejection heads 8 belonging to the same head group 8A. This allows the printer 1 to print with four colors of ink using the four head groups 8A.

[0025] The colors of ink ejected from each head group 8A are, for example, magenta (M), yellow (Y), cyan (C), and black (K). The control unit 14 controls each head group 8A to eject ink of multiple colors onto the printing paper P, thereby printing a color image on the printing paper P.

[0026] In order to treat the surface of the printing paper P, a coating agent may be ejected onto the printing paper P from the droplet ejection head 8 .

[0027] Furthermore, the number of droplet ejection heads 8 included in one head group 8A, or the number of head groups 8A mounted on the printer 1, can be changed as appropriate depending on the object to be printed or the printing conditions. For example, if a single color is printed on the printing paper P and the printing area is to be printed with one droplet ejection head 8, the number of droplet ejection heads 8 mounted on the printer 1 may be one.

[0028] The printing paper P that has been printed inside the head case 5 is transported to the outside of the head case 5 by transport rollers 9 and passes through the inside of a dryer 10. The dryer 10 dries the printing paper P that has been printed. The printing paper P that has been dried in the dryer 10 is transported by transport rollers 11 and collected by a collection roller 13.

[0029] In the printer 1, by drying the printing paper P in the dryer 10, it is possible to reduce adhesion between overlapping printing paper P wound up on the recovery roller 13 and rubbing of undried liquid.

[0030] The sensor unit 12 is configured with a position sensor, a speed sensor, a temperature sensor, etc. The control unit 14 can determine the state of each part of the printer 1 based on information from the sensor unit 12 and control each part of the printer 1.

[0031] The printer 1 described so far uses printing paper P as the printing object (i.e., recording medium), but the printing object of the printer 1 is not limited to printing paper P. For example, the printing object may be a roll of cloth or the like.

[0032] Furthermore, the printer 1 may transport the printing paper P on a conveyor belt instead of directly transporting the printing paper P. By using a conveyor belt, the printer 1 can print on sheets of paper, cut pieces of cloth, wood, tiles, etc.

[0033] The printer 1 may also print wiring patterns for electronic devices by ejecting droplets containing conductive particles from the droplet ejection head 8. The printer 1 may also produce chemical agents by ejecting a predetermined amount of liquid chemical agents or droplets containing chemical agents from the droplet ejection head 8 toward a reaction vessel or the like.

[0034] The printer 1 may also include a cleaning unit that cleans the droplet ejection head 8. The cleaning unit cleans the droplet ejection head 8 by, for example, wiping or capping.

[0035] The wiping process is a process of removing liquid adhering to the droplet ejection head 8 by wiping the surface of the area where droplets are ejected with a flexible wiper, for example.

[0036] The capping process is performed, for example, as follows: First, a cap is placed over the surface of the portion onto which droplets are to be ejected (this process is called capping). As a result, a nearly sealed space is formed between the surface onto which droplets are to be ejected and the cap.

[0037] Next, droplets are repeatedly ejected in this sealed space, which makes it possible to remove liquid with a higher viscosity than normal or foreign matter that has clogged the ejection holes (nozzles) that eject droplets.

[0038] <Configuration of droplet ejection head> Next, the configuration of the droplet ejection head 8 according to the first embodiment will be described with reference to Fig. 3 to Fig. 5. Fig. 3 is an exploded perspective view showing the schematic configuration of the droplet ejection head 8 according to the first embodiment. Fig. 4 is a cross-sectional view taken along line IV-IV shown in Fig. 3. Fig. 5 is an enlarged cross-sectional view of the droplet ejection head 8 according to the first embodiment.

[0039] The droplet ejection head 8 includes a head body 20, a wiring section 30, a head cover 40, two heat sinks 45, and two intermediate members 50. The head body 20 includes a flow path member 21, a piezoelectric actuator substrate 22 (see FIG. 4), a branch flow path member 23, and a reservoir 24.

[0040] In the following description, for convenience, the direction in which the head body 20 is provided in the droplet ejection head 8 may be referred to as "downward," and the direction in which the head cover 40 is provided relative to the head body 20 may be referred to as "upward."

[0041] The flow path member 21 of the head main body 20 has a generally flat plate shape and has a first surface 21a (see FIG. 4) and a second surface 21b (see FIG. 4) located on the opposite side of the first surface 21a.

[0042] The first surface 21a has a plurality of ejection holes (not shown) that can eject droplets onto the printing paper P. The second surface 21b has openings (not shown), and liquid is supplied from a reservoir 24 to the inside of the flow path member 21 through these openings. The flow path member 21 has a flow path therein that allows liquid to flow from the second surface 21b to the first surface 21a.

[0043] The piezoelectric actuator substrate 22 is located on the second surface 21b of the flow path member 21. The piezoelectric actuator substrate 22 has a plurality of displacement elements (not shown). The piezoelectric actuator substrate 22 is electrically connected to a flexible substrate 31 of the wiring section 30.

[0044] The branch flow path member 23 is located above the flow path member 21. The branch flow path member 23 has a branch flow path (not shown) inside that connects to the flow path of the flow path member 21. The branch flow path member 23 is made of a metal such as stainless steel (SUS430). The thermal conductivity of the branch flow path member 23 is, for example, 26 (W / m°C). The branch flow path member 23 is a box-shaped member that extends long in the main scanning direction (Y-axis direction) and has an open top. The branch flow path member 23 has a bottom 233 and a peripheral wall 234 that stands up from the bottom 233 (see FIG. 4 ). The bottom 233 is located above the flow path member 21.

[0045] The peripheral wall portion 234 further has a recess 234a. The recess 234a is located on the upper surface of the peripheral wall portion 234 and extends along the longitudinal direction (Y-axis direction) of the branch flow path member 23. The recess 234a will be described in detail later.

[0046] The slit portion 235 is a groove-shaped gap extending along the longitudinal direction (Y-axis direction) of the branch flow path member 23. The two slit portions 235 are provided so as to sandwich the bottom portion 233 in a plan view. The flexible substrate 31 connected to the piezoelectric actuator substrate 22 is inserted into the slit portion 235.

[0047] The reservoir 24 is located on the branch flow path member 23. The reservoir 24 has openings 24a at both ends in the main scanning direction (Y-axis direction). That is, the reservoir 24 has two openings 24a. The reservoir 24 has a flow path inside, and liquid is supplied from the outside through the openings 24a. The reservoir 24 supplies liquid to the branch flow path member 23. The reservoir 24 also stores the liquid supplied to the branch flow path member 23.

[0048] When printing, liquid may be supplied from one opening 24a while the other opening 24a is closed. Alternatively, liquid may be supplied from both openings 24a. When initially introducing liquid into the droplet ejection head 8, the liquid may be supplied from one opening 24a and collected from the other opening 24a. This allows air or storage liquid that was in the flow path inside the reservoir 24 to easily escape from the flow path, making it easier to introduce liquid into the droplet ejection head 8.

[0049] Furthermore, during printing, liquid may be supplied from one opening 24a and recovered from the other opening 24a. In this way, air bubbles are less likely to accumulate in the flow path inside the reservoir 24. Furthermore, by supplying liquid adjusted to a constant temperature, the temperature of the droplet discharge head 8 can be stabilized. The recovered liquid may be passed through a filter or the like and then supplied again to the droplet discharge head 8. In other words, the liquid may be circulated. The supply and recovery of liquid to the droplet discharge head 8, or the circulation of the liquid, may be controlled by the control unit 14.

[0050] Furthermore, liquid may be supplied from the reservoir 24 to the flow path member 21, and liquid may be recovered from the flow path member 21 to the reservoir 24. Furthermore, liquid may be supplied to and recovered from the flow path facing the nozzles (ejection holes) within the flow path member 21, so that liquid is less likely to stagnate within the nozzles and their surroundings. In such an embodiment, liquid is supplied from the outside to the droplet ejection head 8 as a whole, some of the liquid is ejected from the ejection holes, and the liquid that is not ejected is recovered externally.

[0051] 4, the reservoir 24 may further include a heater substrate 24c and a heating resistor 24d. The heater substrate 24c brings the liquid flowing through the head body 20 closer to a predetermined temperature. In addition, a hole 24b for accommodating a screw (not shown) or the like is formed on the side of the reservoir 24 facing the heat sink 45.

[0052] The wiring section 30 has a flexible substrate 31, a wiring board 32, a plurality of driver ICs 33, and a pressing member 34. The flexible substrate 31 is a flexible wiring board, and transmits a predetermined signal sent from the outside to the head main body 20. As shown in Fig. 3, the droplet ejection head 8 according to the first embodiment has two flexible substrates 31.

[0053] One end of the flexible substrate 31 is electrically connected to the piezoelectric actuator substrate 22 of the head body 20 (see FIG. 4). The other end of the flexible substrate 31 is drawn out above the reservoir 24 and is electrically connected to the wiring substrate 32. This allows the piezoelectric actuator substrate 22 of the head body 20 to be electrically connected to the outside.

[0054] The wiring board 32 is located above the head body 20. The wiring board 32 distributes signals to a plurality of driver ICs 33.

[0055] The plurality of driver ICs 33 are located on one main surface of the flexible substrate 31. As shown in Fig. 3, in the droplet ejection head 8 according to the first embodiment, two driver ICs 33 are provided on each flexible substrate 31. Note that the number of driver ICs 33 provided on each flexible substrate 31 is not limited to two.

[0056] The driver IC 33 drives each displacement element on the piezoelectric actuator substrate 22 of the head main body 20 based on a drive signal sent from the control unit 14 (see FIG. 1 ). In this way, the driver IC 33 drives the droplet ejection head 8.

[0057] The pressing member 34 is, for example, a leaf spring having a substantially U-shaped cross section. The pressing member 34 is located between the two flexible substrates 31 and presses the driver IC 33 on the flexible substrate 31 toward the heat sink 45. This brings the driver IC 33 into close contact with the heat sink 45, allowing heat generated when the driver IC 33 is driven to be efficiently dissipated to the heat sink 45.

[0058] The head cover 40 is located on the side of the head main body 20 opposite to the first surface 21a of the flow path member 21. The head cover 40 is arranged to cover the wiring portion 30 located on the head main body 20, such as the flexible substrate 31, the wiring substrate 32, and the pressing member 34. This allows the head cover 40 to seal the wiring portion 30. The head cover 40 is made of, for example, resin or metal.

[0059] The head cover 40 has a box shape that extends elongately in the main scanning direction, and has a first opening 40a and a second opening 40b on two side surfaces that face each other in the sub-scanning direction. In the example of Fig. 3, the first opening 40a is provided on the side surface located on the positive side of the X axis, and the second opening 40b is provided on the side surface located on the negative side of the X axis. The head cover 40 also has a third opening 40c on its bottom surface and a fourth opening 40d on its top surface. The head cover 40 is an example of a cover member.

[0060] The two heat sinks 45 are located on the side surfaces of the head cover 40. One of the two heat sinks 45 is disposed so as to cover the first opening 40a, and the other is disposed so as to cover the second opening 40b.

[0061] The heat sink 45 is, for example, a plate-like member that is long in the longitudinal direction of the droplet ejection head 8, and is made of a metal or alloy such as aluminum that has high heat dissipation properties. The heat sink 45 has a thermal conductivity of, for example, 236 (W / m°C). The heat sink 45 is in contact with the driver IC 33 and dissipates heat generated by the driver IC 33. The heat sink 45 is an example of a plate-like member.

[0062] Each of the two heat sinks 45 has a plurality of first through holes 46 that accommodate screws (not shown). The head cover 40 has a plurality of through holes 41 that accommodate such screws. The two heat sinks 45 are each fixed to the head cover 40 with screws. The head cover 40 with the heat sinks 45 attached has a box shape in which the first opening 40a and the second opening 40b are closed and the third opening 40c and the fourth opening 40d are open.

[0063] The third opening 40c is positioned opposite the reservoir 24. The flexible substrate 31 and the pressing member 34 are inserted through the third opening 40c.

[0064] A connector (not shown) provided on the wiring board 32 is inserted through the fourth opening 40d. If the space between the connector and the fourth opening 40d is sealed with resin or the like, it becomes difficult for liquid or dust to enter the inside of the head cover 40.

[0065] The intermediate member 50 is located between the heat sink 45 and the head main body 20. The intermediate member 50 is made of, for example, an epoxy-based resin. The thermal conductivity of the intermediate member 50 may be lower than that of the heat sink 45. The thermal conductivity of the intermediate member 50 is, for example, 0.19 (W / m°C). By providing the intermediate member 50, heat generated in the driver IC 33 is less likely to be transmitted to the head main body 20 via the heat sink 45. Details of the intermediate member 50 will be described later.

[0066] 3 shows an example of the configuration of the droplet ejection head 8, and the droplet ejection head 8 may further include components other than those shown in Fig. 3. The intermediate member 50 may have a lower thermal conductivity than the heat sink 45, or may have a thermal conductivity that is approximately 1 / 1000 of that of the heat sink 45.

[0067] Next, details of the intermediate member 50 according to the first embodiment will be described with reference to Figures 6 and 7. Figures 6 and 7 are perspective views for explaining the structure of the intermediate member 50 according to the first embodiment.

[0068] 6, the intermediate member 50 is a member that extends long in the main scanning direction (Y-axis direction). The intermediate member 50 has a first portion 51, a second portion 52, and a third portion 53.

[0069] The first portion 51 and the second portion 52 are positioned with a difference in the X-axis direction, with the first portion 51 being the portion positioned closer to the reservoir 24 and the second portion 52 being the portion farther away from the reservoir 24. The first portion 51 has a first bonding surface 51a (see FIG. 5 ) at a position facing the plate surface (side surface) of the heat sink 45. The intermediate member 50 and the heat sink 45 are bonded to each other at the first bonding surface 51a and the plate surface of the heat sink 45.

[0070] The second portion 52 is located at a position corresponding to the recess 234a of the branch flow path member 23. The second portion 52 is an example of a protrusion that fits into the recess 234a of the branch flow path member 23. The second portion 52 may have a rib 55. Specifically, the rib 55 may be located on a side surface of the second portion 52 that is closer to the first portion 51. The intermediate member 50 may be positioned with respect to the branch flow path member 23 by the rib 55.

[0071] The third portion 53 connects the lower portion of the first portion 51 and the upper portion of the second portion 52. A portion of the third portion 53 protrudes outward from the intermediate member 50.

[0072] In the droplet ejection head 8 according to the first embodiment, the head main body 20 and the intermediate member 50 are fitted together. Specifically, as shown in Fig. 5, the recess 234a of the branch flow path member 23 of the head main body 20 may be fitted together with the second portion 52 of the intermediate member 50. Here, "fitted together" is not limited to fitting together without any gaps or misalignment and being fixed to each other.

[0073] By fitting the head main body 20 and the intermediate member 50 together in this way, the head main body 20 and the intermediate member 50 can be fixed more firmly than when they are simply fixed together with a caulking material or double-sided tape, thereby improving the sealing performance of the droplet ejection head 8. Furthermore, the robustness of the droplet ejection head 8 can be improved.

[0074] Furthermore, as described above, the second portion 52 of the intermediate member 50 according to the first embodiment may fit into the recess 234a of the branch flow path member 23 of the head main body 20. The intermediate member 50 is produced, for example, by heating and melting resin, pouring it into a mold to form a predetermined shape, and then cooling and solidifying it. If a recess were to be formed in the intermediate member 50, the mold would need to have a protrusion, which could reduce the strength of the mold. On the other hand, in the droplet ejection head 8 according to the first embodiment, the mold has a recess in order to form a protrusion in the intermediate member 50, so the mold strength is less likely to be reduced compared to when the mold has a protrusion.

[0075] Furthermore, the branch flow path member 23 is made of, for example, stainless steel (SUS430). In the droplet ejection head 8 according to the first embodiment, the branch flow path member 23 has the recessed portion 234a, so that fewer portions need to be cut when manufacturing the branch flow path member 23 than when the branch flow path member 23 has a protruding portion, thereby reducing costs.

[0076] As shown in FIG. 5 , a gap S1 may be formed between the head main body 20 and the intermediate member 50. Specifically, as shown in FIGS. 4 and 5 , a gap S1 may be formed between the upper end surface of the peripheral wall portion 234 of the branch flow path member 23, one of the side surfaces of the second portion 52 of the intermediate member 50 that is farther from the first portion 51, and the lower end surface of the third portion 53. The gap S1 may be formed outward from the fitting portion between the branch flow path member 23 and the intermediate member 50. A sealing member 60 may be located in the gap S1. In other words, the branch flow path member 23 and the intermediate member 50 may be partially sealed by the sealing member 60. The sealing member 60 may be made of, for example, a resin.

[0077] In this way, by positioning the gap S1 between the head main body 20 and the intermediate member 50, the sealing member 60 can be filled into this gap S1, thereby improving the sealing performance of the droplet ejection head 8 and making it less likely for liquid to leak. Furthermore, when filling the gap S1 with the sealing member 60, the intermediate member 50 is positioned between the heat sink 45 and the gap S1, making it less likely for heat to be transferred from the heat sink 45 to the sealing member 60, and reducing the linear expansion of the sealing member 60.

[0078] 5, the second portion 52 of the intermediate member 50 may be fitted with a gap between it and the inner surface of the recess 234a of the branch flow path member 23 that is closest to the gap S1. The second portion 52 of the intermediate member 50 may be fitted with a gap between it and the bottom surface of the recess 234a of the branch flow path member 23. By positioning the sealing member 60 in this gap as well, sealing can be made more reliable. For example, during the manufacture of the droplet ejection head 8, the sealing member 60 can be formed by applying the sealing member 60 to the gap S1 before hardening and pouring it into the recess 234a of the branch flow path member 23.

[0079] 4 and 5, in the first embodiment, a surface 51b of the first portion 51 located opposite the first bonding surface 51a faces the inside of the droplet ejection head 8 and may be inclined downward from the outside to the inside of the droplet ejection head 8. This makes it possible to ensure a large space for passing the flexible substrate 31.

[0080] The droplet ejection head 8 may have a waterproof member 70a between the intermediate member 50 and the heat sink 45. This can prevent the liquid from leaking out of the droplet ejection head 8.

[0081] The waterproofing member 70a may be adhesive. The intermediate member 50 and the heat sink 45 may be bonded by the waterproofing member 70a. The waterproofing member 70a may be, for example, double-sided tape, gel, or sealing resin. When the waterproofing member 70a is double-sided tape, one adhesive surface of the waterproofing member 70a is located on the wall surface of the heat sink 45, and the other adhesive surface is located on the first bonding surface 51a of the first part 51 of the intermediate member 50. This can further improve the sealing performance of the droplet ejection head 8, making it less likely for liquid to leak.

[0082] As described above, the droplet ejection head 8 according to the first embodiment has the head main body 20 fitted to the intermediate member 50. This configuration allows the head main body 20 and the intermediate member 50 to be fixed more firmly than when they are simply fixed with caulking material or double-sided tape, thereby improving the sealing performance of the droplet ejection head 8.

[0083] Note that, here, an example has been shown in which the second portion 52 of the intermediate member 50 is fitted with a gap between it and the inner surface of the recess 234a of the branch flow path member 23 that is closest to the gap S1 or between it and the bottom surface. However, this is not the only possible way to fit the intermediate member 50 to the branch flow path member 23. For example, the second portion 52 of the intermediate member 50 may be fitted in contact with two inner surfaces of the recess 234a of the branch flow path member 23. Furthermore, the second portion 52 of the intermediate member 50 may be fitted in contact with the bottom surface of the recess 234a of the branch flow path member 23.

[0084] Second Embodiment Fig. 8 is a perspective view for explaining the structure of an intermediate member 50 according to a second embodiment. Fig. 9 is a perspective view showing another example of the intermediate member 50 according to the second embodiment.

[0085] The intermediate member 50 may have a plurality of projections and recesses on the surface that forms the gap S1 (see FIG. 5 ). Specifically, as shown in FIG. 8 , a plurality of projections 54 may be formed on the side surface of the second portion 52 of the intermediate member 50. Furthermore, as shown in FIG. 9 , the plurality of projections 54 may be formed across the side surface of the second portion 52 and the lower end surface of the third portion 53 of the intermediate member 50. The plurality of projections 54 may be arranged at equal intervals along the extension direction (Y-axis direction) of the intermediate member 50.

[0086] In this way, by providing multiple irregularities on the surface forming the gap S1 (see FIG. 5), when filling the gap S1 with the sealing member 60 (see FIG. 5), the contact area between the sealing member 60 and the intermediate member 50 increases compared to when there are no irregularities, making it difficult for the sealing member 60 to peel off. This makes it possible to more reliably seal with the sealing member 60.

[0087] The present technology may also be configured as follows. (1) A droplet ejection head (for example, the droplet ejection head 8) has a head body (for example, the head body 20), a cover member (for example, the head cover 40), a plate-shaped member (for example, a heat sink 45), and an intermediate member (for example, the intermediate member 50). The head body has a plurality of ejection holes capable of ejecting droplets on a first surface (for example, the first surface 21a). The cover member is located on the side of the head body opposite the first surface. The plate-shaped member is located on a side portion of the cover member. The intermediate member is located between the head body and the plate-shaped member. The head body and the intermediate member are fitted together. (2) In the droplet ejection head described in (1) above, the head body may have a recess (for example, the recess 234a), and the intermediate member may have a protrusion (for example, the second portion 52) that fits into the recess. (3) In the droplet ejection head described in (1) or (2) above, a gap may be located between the head main body and the intermediate member. (4) In the droplet ejection head described in (3) above, the intermediate member may have a plurality of irregularities on the surface that forms the gap. (5) In the droplet ejection head described in any one of (1) to (4) above, a waterproof member (e.g., waterproof member 70a) may be provided between the intermediate member and the plate-like member. (6) In the droplet ejection head described in (5) above, the waterproof member may have adhesive properties, and the intermediate member and the plate-like member may be bonded by the waterproof member. (7) A droplet ejection device (e.g., printer 1) may have the droplet ejection head described in any one of (1) to (6) above and a control unit (e.g., control unit 14) that controls the droplet ejection head.

[0088] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0089] REFERENCE SIGNS LIST 1 printer 6 transport roller 7 frame 8 droplet ejection head 20 head body 21 flow path member 22 piezoelectric actuator substrate 23 branch flow path member 24 reservoir 30 wiring portion 40 head cover 45 heat sink 50 intermediate member 51 first portion 52 second portion 53 third portion 70a waterproof member 234a recess

Claims

1. A droplet ejection head comprising: a head body having a plurality of ejection holes on a first surface capable of ejecting droplets; a cover member located on the side of the head body opposite the first surface; a plate-like member located on a side of the cover member; and an intermediate member located between the head body and the plate-like member, wherein the head body and the intermediate member are fitted together.

2. The droplet ejection head according to claim 1, wherein the head body has a recess, and the intermediate member has a protrusion that fits into the recess.

3. The droplet ejection head according to claim 1 or 2, wherein a gap is positioned between the head main body and the intermediate member.

4. The droplet ejection head according to claim 3, wherein the intermediate member has a plurality of projections and recesses on the surface that forms the gap.

5. The droplet ejection head according to any one of claims 1 to 4, further comprising a waterproof member between the intermediate member and the plate-like member.

6. The droplet ejection head according to claim 5, wherein the waterproof member has adhesive properties, and the intermediate member and the plate-like member are bonded together by the waterproof member.

7. A droplet ejection device comprising: a droplet ejection head according to any one of claims 1 to 6; and a control unit that controls the droplet ejection head.

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