Droplet discharging head and droplet discharging device

Abstract

A droplet discharging head according to the present disclosure comprises a flow path member, a branch flow path member, and a reservoir. The flow path member has a plurality of discharge holes from which droplets are discharged. The branch flow path member is positioned above the flow path member and has a branch flow path which is connected to the flow path member. The reservoir is positioned above the branch flow path member and supplies a liquid to the branch flow path member. The branch flow path member has a box shape.

Description

Droplet ejection head and droplet ejection device

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

[0002] Conventionally, liquid ejection heads that perform various types of printing by ejecting liquid onto a recording medium have been known as printing heads. Patent Document 1 discloses an inkjet head having a flat laminated flow path unit that has an ink flow path that guides ink supplied from an ink supply port to an ink outlet.

[0003] Japanese Patent Application Laid-Open No. 2004-114404

[0004] A droplet ejection head according to one aspect of the present disclosure includes a flow path member, a branch flow path member, and a reservoir. The flow path member has a plurality of ejection holes from which droplets are ejected. The branch flow path member is located above the flow path member and has a branch flow path connected to the flow path member. The reservoir is located above the branch flow path member and supplies liquid to the branch flow path member. The branch flow path member is box-shaped.

[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 an enlarged cross-sectional view taken along line IV-IV shown in FIG. 3. FIG. 5 is a perspective view illustrating the structure of a branch flow path member according to the first embodiment. FIG. 6 is a schematic plan view of a branch flow path member according to the first embodiment. FIG. 7 is a schematic front view of a droplet ejection head according to the first embodiment. FIG. 8 is a schematic front view of a droplet ejection head according to the first embodiment. FIG. 9 is an enlarged perspective view of a droplet ejection head according to the first embodiment. FIG. 10 is an exploded perspective view showing a schematic configuration of a droplet ejection head according to a second embodiment. FIG. 11 is a schematic perspective view showing the configuration of a wiring board, a first support member, and a second support member according to the second embodiment. FIG. 12 is a schematic perspective view showing the configuration of a pressing member according to the second embodiment. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 10. FIG. 14 is a schematic cross-sectional view showing the configuration of one end of a droplet ejection head according to a modified example of 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 the drawings referred to below, for ease of understanding, the X-axis, Y-axis, and Z-axis directions are defined as being orthogonal to each other, and an orthogonal coordinate system is shown in which the positive Z-axis direction is the vertically upward direction. The rotation direction around the vertical axis is also referred to as the θ direction.

[0009] Conventionally, liquid ejection heads that perform various types of printing by ejecting liquid onto a recording medium have been known as printing heads. Patent Document 1 discloses an inkjet head having a flat laminated flow path unit that has an ink flow path that guides ink supplied from an ink supply port to an ink outlet.

[0010] However, there is room for further improvement in terms of increasing the rigidity of a droplet ejection head having a flow path unit configured by stacking multiple flat plates, as in the technology described in Patent Document 1. If the rigidity of the droplet ejection head is low, for example, the amount of deflection of the nozzle surface may increase, which may result in ejection defects or reduced printing accuracy.

[0011] Therefore, there is a need for a technology that can increase the rigidity of the droplet ejection head.

[0012] (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.

[0013] As shown in FIG. 1, the printer 1 includes a paper feed roller 2, a guide roller 3, an applicator 4, a head case 5, a plurality of conveying rollers 6, a plurality of frames 7, a plurality of droplet ejection heads 8, a conveying roller 9, a dryer 10, a conveying roller 11, a sensor unit 12, and a recovery roller 13.

[0014] Furthermore, the printer 1 has a control unit 14 that controls the paper feed roller 2, guide roller 3, coater 4, head case 5, multiple conveying rollers 6, multiple frames 7, multiple droplet ejection heads 8, conveying roller 9, dryer 10, conveying roller 11, sensor unit 12, and recovery roller 13.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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."

[0021] 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.

[0022] 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.

[0023] 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 the longitudinal direction is perpendicular to the transport direction of the printing paper P.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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 .

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] The printer 1 may also print wiring patterns for electronic devices by discharging droplets containing conductive particles from the droplet discharging head 8. The printer 1 may also produce chemicals by discharging a predetermined amount of liquid chemicals or droplets containing chemicals from the droplet discharging head 8 toward a reaction vessel or the like.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] <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 Figures 3 and 4. Figure 3 is an exploded perspective view showing the schematic configuration of the droplet ejection head 8 according to the first embodiment. Figure 4 is an enlarged cross-sectional view taken along line IV-IV shown in Figure 3.

[0041] The droplet ejection head 8 includes a head body 20, a wiring section 30, a head cover 40, and two heat sinks 45. 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.

[0042] 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."

[0043] 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) which is one main surface, and a second surface 21b (see FIG. 4) located on the opposite side of the first surface. The first surface 21a has an opening (not shown), and liquid is supplied from a reservoir 24 to the inside of the flow path member 21 through this opening.

[0044] The second surface 21b has a plurality of ejection holes (not shown) that eject droplets onto the printing paper P. The flow path member 21 has therein a flow path that allows the liquid to flow from the first surface 21a to the second surface 21b.

[0045] The piezoelectric actuator substrate 22 is located on the first surface 21a 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.

[0046] The branch flow path member 23 is located on the flow path member 21. The branch flow path member 23 has therein a branch flow path 231 (see FIG. 6 ) that connects to the flow path of the flow path member 21. The branch flow path member 23 is made of a highly rigid material such as stainless steel. Details of the branch flow path member 23 will be described later using FIG. 4 .

[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 flow path member 21. The reservoir 24 also stores the liquid supplied to the flow path member 21.

[0048] When printing, the liquid may be supplied from one opening 24a while the other opening 24a is closed. Alternatively, the liquid may be supplied from both openings 24a. When initially introducing the liquid into the droplet ejection head 8, if the liquid is supplied from one opening 24a and collected from the other opening 24a, air and storage liquid that were in the flow path inside the reservoir 24 can easily escape from the flow path, making it easier to introduce the 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 that accommodates a fixing member 50 (see FIG. 8) is formed on the side of the reservoir 24 that faces 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 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 attached to the head body 20 and is arranged so as to cover the wiring section 30, such as the flexible substrate 31, the wiring substrate 32, and the pressing member 34, located on the head body 20. This allows the head cover 40 to seal the wiring section 30. The head cover 40 is made of, for example, resin or metal.

[0059] The head cover 40 has a box shape that extends long 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.

[0060] The two heat sinks 45 are attached to 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-shaped member that is long in the longitudinal direction of the droplet ejection head 8, and is made of a metal or alloy with high heat dissipation properties. The heat sink 45 is provided so as to be in contact with the driver IC 33, and dissipates heat generated by the driver IC 33.

[0062] Each of the two heat sinks 45 has a plurality of through holes 46 that accommodate fixing members 50 (see FIG. 8 ). The head cover 40 has a plurality of through holes 41 that accommodate the fixing members 50. The two heat sinks 45 are each fixed to the head cover 40 by the fixing members 50 (see FIG. 8 ). The head cover 40 with the heat sinks 45 attached has a box shape in which the first opening 40 a and the second opening 40 b are closed and the third opening 40 c and the fourth opening 40 d are open.

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

[0064] The fourth opening 40d is provided for inserting a connector (not shown) provided on the wiring board 32. 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 head cover 40 may also have a heat insulating portion (not shown) between the heat sink 45 and the head body 20. By providing the head cover 40 with a heat insulating portion, heat generated by the driver IC 33 is less likely to be transmitted to the head body 20 via the heat sink 45.

[0066] 3 shows an example of the configuration of the droplet ejection head 8, and the droplet ejection head 8 may further include members other than those shown in FIG.

[0067] Next, details of the branch flow path member 23 according to the first embodiment will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a perspective view for explaining the structure of the branch flow path member 23 according to the first embodiment. Fig. 6 is a schematic plan view of the branch flow path member 23 according to the first embodiment.

[0068] As shown in Figure 5, 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, a peripheral wall 234 that stands up from the bottom 233, and two slits 235. The bottom 233 is located above the flow path member 21. The bottom 233 has an opposing surface 233a that faces the flow path member 21, and a box bottom surface 233b that is located opposite the opposing surface 233a (see Figure 4). The box bottom surface 233b is surrounded by the peripheral wall 234.

[0069] The box-shaped branch flow path member 23 can increase the rigidity of the branch flow path member 23 compared to when the branch flow path member 23 is in a flat plate shape. This can reduce the amount of deflection of the nozzle surface of the flow path member 21 joined to the branch flow path member 23.

[0070] In the branch flow path member 23 according to the first embodiment, the height H1 (see FIG. 4) of the peripheral wall portion 234 relative to the box bottom surface 233b is greater than 20% of the width W1 (see FIG. 4) in the short direction of the bottom portion 233. This allows the rigidity of the branch flow path member 23 to be further increased.

[0071] The peripheral wall portion 234 of the branch flow path member 23 further has an eaves portion 234a that protrudes outward from the branch flow path member 23. This makes it possible to prevent droplets discharged from the discharge holes of the flow path member 21 from scattering onto the heat sink 45, fixing materials 70a to 70d (described later), and the like.

[0072] A portion of the reservoir 24 is located in an area surrounded by the bottom 233 and peripheral wall 234 of the branch flow path member 23. In other words, a portion of the reservoir 24 is housed inside the box-shaped branch flow path member 23. This allows the droplet discharge head 8 to be made smaller in the height direction (Z-axis direction) than when the reservoir 24 is provided on the flat branch flow path member 23.

[0073] 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.

[0074] In the first embodiment, an elastic member 60 is located between the branch flow path member 23 and the reservoir 24. The elastic member 60 is a plate-shaped member that extends long in the longitudinal direction (Y-axis direction) of the droplet ejection head 8 in a plan view, and is located on the bottom 233 of the branch flow path member 23 (see FIG. 4 ). The elastic member 60 may be made of, for example, silicone rubber. The elastic member 60 may have a higher thermal conductivity than the branch flow path member 23. This allows heat from the heater substrate 24c of the reservoir 24 to be efficiently transferred to the branch flow path member 23, making it possible to make the temperature distribution on the nozzle surface more uniform.

[0075] In the first embodiment, a plurality of O-rings 80 that seal the connection between the branch flow path member 23 and the reservoir 24 are positioned between the branch flow path member 23 and the reservoir 24. This can further improve the sealing performance of the droplet ejection head 8.

[0076] Furthermore, in the droplet ejection head 8 according to the first embodiment, even if stress is generated by providing the elastic member 60 or the O-ring 80, the rigidity of the branch flow path member 23 is high, so the amount of deflection of the nozzle surface of the flow path member 21 joined to the branch flow path member 23 can be reduced.

[0077] In the first embodiment, the branch flow path member 23 and the reservoir 24 are fixed at both longitudinal ends of the droplet ejection head 8. For example, as shown in FIG. 6 , the branch flow path member 23 and the reservoir 24 are fixed by fixing materials 90a and 90b (an example of a first fixing material). The fixing materials 90a and 90b are, for example, waterproof double-sided tape. However, the fixing materials 90a and 90b are not limited to this, and gel, sealing resin, or the like may also be used. This can improve the sealing performance of the branch flow path member 23 and the reservoir 24 and prevent liquid from leaking.

[0078] Next, details of the fixing locations of the heat sink 45, the branch flow path member 23, and the reservoir 24 will be described with reference to FIGS. 7 to 9. FIGS. 7 and 8 are schematic front views of the droplet ejection head 8 according to the first embodiment. FIG. 9 is an enlarged perspective view of the droplet ejection head 8 according to the first embodiment. For ease of understanding, the heat sink 45 and the fixing member 50 are omitted from FIG. 7. Furthermore, the recess 47 of the heat sink 45 and the fixing member 50 are omitted from FIG. 9.

[0079] 7 and 8 , in the first embodiment, the heat sink 45, the branch flow path member 23, and the reservoir 24 are fixed by a fixing material 70d (an example of a second fixing material). The fixing material 70d may be, for example, double-sided tape, gel, or sealing resin. When the fixing material 70d is waterproof double-sided tape, one adhesive surface of the fixing material 70d is positioned so as to straddle the branch flow path member 23 and the reservoir 24, and the other adhesive surface is positioned on the heat sink 45. This can further improve the sealing performance of the droplet ejection head 8, making it less likely for liquid to leak.

[0080] Furthermore, in the first embodiment, the head cover 40 and the heat sink 45 may be fixed by fixing materials 70a to 70c (an example of a third fixing material). Similar to the fixing material 70c, the fixing materials 70a to 70c may be made of waterproof double-sided tape, gel, or sealing resin. When the fixing materials 70a to 70c are waterproof double-sided tape, one adhesive surface of each of the fixing materials 70a to 70c is positioned on the flange portion (the portion where the through-hole 41 is provided) located on the periphery of the first opening 40a and the second opening 40b (FIG. 3) of the head cover 40, and the other adhesive surface is positioned on the heat sink 45. This can further improve the sealing performance of the droplet ejection head 8.

[0081] In the first embodiment, the reservoir 24, the head cover 40, and the heat sink 45 are partially sealed with a caulking material. Specifically, as shown in FIG. 9 , the droplet ejection head 8 has a region P1 in which neither the fixing material 70c nor the fixing material 70d is present in a portion of the gap between the reservoir 24, the head cover 40, and the heat sink 45. The caulking material is located in this region P1. That is, the caulking material is positioned across the reservoir 24 and the heat sink 45 so as to fill the gap between the reservoir 24 and the heat sink 45 where neither the fixing material 70c nor the fixing material 70d is present. The caulking material may be, for example, a resin. This allows the reservoir 24 and the heat sink 45 to be fixed even between adjacent fixing materials, thereby further improving the sealing performance of the droplet ejection head 8.

[0082] 8, the portion of the heat sink 45 that faces the branch flow path member 23 and the reservoir 24 protrudes in the longitudinal direction (Y-axis direction) of the head body 20 further than the portion that faces the head cover 40. The upper surface 45a of the portion that faces the branch flow path member 23 and the reservoir 24 is located below the above-mentioned region P1. As a result, even if the pre-hardened caulking material applied to the region P1 drips due to gravity during the manufacture of the droplet ejection head 8, for example, the upper surface 45a can receive the caulking material, thereby more reliably sealing the region P1 with the caulking material.

[0083] Furthermore, the branch flow path member 23, the reservoir 24, and the heat sink 45 are partially sealed with a caulking material. Specifically, as shown in FIG. 9 , the droplet ejection head 8 has a region P2 where the fixing material 90a and the fixing material 70d contact each other in a portion of the gap between the branch flow path member 23, the reservoir 24, and the heat sink 45. The caulking material is located in this region P2. In region P2, the side surface (the non-adhesive surface) of the fixing material 90a contacts the fixing material 70d, which may result in insufficient sealing. Therefore, by sealing the gap between the fixing material 90a and the fixing material 70d with a caulking material, the sealing ability of the droplet ejection head 8 can be further improved. This allows the branch flow path member 23, the reservoir 24, and the heat sink 45 to be fixed together even in areas where the fixing materials contact each other perpendicularly, thereby further improving the sealing ability of the droplet ejection head 8.

[0084] 8, the upper surface 23a of the overhanging portion 234a of the branch flow path member 23 is located below the above-mentioned region P2. As a result, even if the pre-hardened caulking material applied to the region P2 drips due to gravity during the manufacture of the droplet discharge head 8, the upper surface 23a can receive the caulking material, thereby ensuring the sealing of the region P2 with the caulking material.

[0085] In the first embodiment, the reservoir 24 and the heat sink 45 are fixed by a fixing member 50. Specifically, the reservoir 24 and the heat sink 45 are fixed by the fixing member 50 at both longitudinal ends of the droplet ejection head 8. The fixing member 50 has a shaft portion having a spiral groove on the outer periphery and a head portion located at the end of the shaft portion. The fixing member 50 may be, for example, a screw, a bolt, or a machine screw. This makes it possible to fix the periphery of the portions fixed by the fixing members 70a to 70d or the caulking material, thereby further improving the sealing performance of the droplet ejection head 8.

[0086] Furthermore, in the first embodiment, the heat sink 45 has a plurality of recesses 47 that accommodate the heads of the fixing members 50. This allows the amount of protrusion of the fixing members 50 to be reduced compared to when the recesses 47 are not provided, and allows the droplet ejection head 8 to be made smaller in size in the short direction.

[0087] Second Embodiment Next, a droplet ejection head 8a according to a second embodiment will be described with reference to FIGS. 10 to 13. FIG. 10 is an exploded perspective view showing the general configuration of the droplet ejection head 8a according to the second embodiment. FIG. 11 is a schematic perspective view showing the configuration of the wiring substrate 32, first support member 161, and second support member 162 according to the second embodiment. FIG. 12 is a schematic perspective view showing the configuration of the pressing member 163 according to the second embodiment. FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 10. In other words, FIG. 13 is a cross-sectional view of one end of the head main body 20 in the longitudinal direction. Note that, for ease of understanding, the support member 160 is omitted from FIG. 10. Furthermore, in the second embodiment below, parts that are the same as those in the first embodiment are designated by the same reference numerals, and redundant description will be omitted.

[0088] The droplet discharge head 8a shown in FIG. 10 differs from the droplet discharge head 8 according to the first embodiment shown in FIG. 3 mainly in the configuration of the wiring section 30.

[0089] The droplet ejection head 8a according to the second embodiment, like the droplet ejection head 8 according to the first embodiment shown in Figure 3, comprises a head body 20a, a wiring section 30a, a head cover 40, and two heat sinks 45.

[0090] The head main body 20 a includes a flow path member 21 , a piezoelectric actuator substrate (not shown), a branch flow path member 51 , and a reservoir 52 .

[0091] The wiring section 30 a includes a flexible substrate 31 , a wiring substrate 32 , a plurality of support members 160 , a plurality of driver ICs 33 , and a pressing member 163 .

[0092] 11 , the plurality of support members 160 support the wiring substrate 32. Specifically, the plurality of support members 160 include a first support member 161 and a second support member 162.

[0093] The first support member 161 is located at one end of the wiring substrate 32 in the longitudinal direction of the head main body 20a. Specifically, the first support member 161 has a base 161b, a support portion 161a extending perpendicularly from one longitudinal end of the base 161b, and a fixing portion 161c extending perpendicularly from the other longitudinal end of the base 161b. The wiring substrate 32 is located so that its bottom surface is located on the base 161b and one main surface is in contact with the support portion 161a.

[0094] A through hole 161d is formed in the support portion 161a. The wiring board 32 has through holes 32b that penetrate both main surfaces at positions corresponding to the through holes 161d. Fixing members (not shown) such as bolts or screws are inserted into the through holes 161d and the through holes 32b and screwed together, thereby fixing the wiring board 32 and the first support member 161. A through hole 161e is formed in the base portion 161b. Details of the fixing portion 161c will be described later.

[0095] The second support member 162 is located at the other end of the wiring substrate 32 in the longitudinal direction of the head main body 20a. Specifically, the second support member 162 has a base 162b, a support portion 162a extending perpendicularly from one longitudinal end of the base 162b, and a fixing portion 162c extending perpendicularly from the other longitudinal end of the base 162b. The wiring substrate 32 is located so that its bottom surface is located on the base 162b and one main surface is in contact with the support portion 162a.

[0096] A through hole 162d is formed in the support portion 162a. The wiring board 32 has through holes 32b that penetrate both main surfaces at positions corresponding to the through holes 161d. Fixing members (not shown) such as bolts or screws are inserted into the through holes 161d and the through holes 32b and screwed together, thereby fixing the wiring board 32 and the second support member 162. A through hole 162e is formed in the base portion 162b. Details of the fixing portion 162c will be described later.

[0097] As shown in FIG. 12, the pressing member 163 includes two side walls 163a and 163b, a bottom 163c, and two fixing portions 163d.

[0098] The bottom portion 163c connects the lower ends of the two side wall portions 163a, 163b. The bottom portion 163c has a plurality of through holes 165 at both longitudinal ends of the head main body 20. The reservoir 52 has through holes (not shown) located at positions corresponding to the through holes 165. The branch flow path member 51 has screw holes (not shown) located at positions corresponding to the through holes 165. Fixing members (not shown) such as bolts or screws are inserted through the through holes 165 in the bottom portion 163c of the pressing member 163 and the through holes in the reservoir 52. The fixing members (not shown) are screwed into the screw holes in the branch flow path member 51. As a result, the pressing member 163 is fixed to the branch flow path member 51, which is made of a highly rigid material, via the reservoir 52.

[0099] Furthermore, the bottom portion 163c has a through hole 166a formed at a position corresponding to the through hole 161e (see FIG. 11 ) in the base portion 161b of the first support member 161. A fixing member (not shown), such as a bolt or a screw, is inserted through the through hole 166a and the through hole 161e. The fixing member (not shown) is threaded into, for example, a thread groove formed in the through hole 161e. This fixes the first support member 161 to the pressing member 163. Similarly, the bottom portion 163c has a through hole 166b formed at a position corresponding to the through hole 162e in the base portion 162b of the second support member 162. A fixing member (not shown), such as a bolt or a screw, is inserted through the through hole 166b and the through hole 162e. The fixing member (not shown) is threaded into, for example, a thread groove formed in the through hole 162e. This fixes the second support member 162 to the pressing member 163. In this way, the first support member 161 is fixed to the pressing member 163, and is thereby fixed to the branch flow path member 51 made of a highly rigid material via the pressing member 163 and the reservoir 52.

[0100] The two fixing portions 163d are provided at both ends of one of the two side wall portions 163a, 163b (here, the side wall portion 163b). In other words, the two fixing portions 163d are provided at both ends of the pressing member 163 in the longitudinal direction of the head main body 20. The fixing portions 163d will be described in detail later.

[0101] As described above, the pressing member 163 and the plurality of support members 160 according to the second embodiment are fixed to the branch flow path member 51 made of a highly rigid material. The heat sink 45 according to the second embodiment is fixed to the pressing member 163 and the plurality of support members 160 at both longitudinal ends of the head main body 20. In the droplet ejection head 8a having such a configuration, the head cover 40 is unlikely to fall over even when an external force is applied to the heat sink 45.

[0102] The details of the fixing points between the head cover 40, the pressing member 163, and the plurality of support members 160 will be described below with reference to Fig. 13. Fig. 13 shows the configuration of the fixing point at one end in the longitudinal direction of the droplet ejection head 8a, and the configuration of the fixing point at the other end is omitted, but the fixing point at the other end has the same configuration as the fixing point at one end.

[0103] First, the fixing location at one end in the width direction of the droplet ejection head 8a, specifically the negative X-axis direction side, will be described. A through hole 163e is formed in the fixing portion 163d of the pressing member 163. A through hole 41 is located in the head cover 40 at a position corresponding to the through hole 163e. One of the two heat sinks 45 has a through hole 46 located at a position corresponding to the through hole 163e. A fixing member 180 is inserted through the through holes 163e, 41, and 46 and screwed together, thereby fixing the pressing member 163, head cover 40, and heat sink 45 at one longitudinal end of the head main body 20.

[0104] Next, the fixing location on the other end side in the width direction of the droplet ejection head 8a, specifically the side on the positive X-axis direction, will be described. A through hole 161f is formed in the fixing portion 161c of the first support member 161. A through hole 41 is located in the head cover 40 at a position corresponding to the through hole 161f. The other of the two heat sinks 45 has a through hole 46 located at a position corresponding to the through hole 161f. A fixing member 181 is inserted through and screwed into the through holes 161f, 41, and 46, thereby fixing the first support member 161, head cover 40, and heat sink 45 at one longitudinal end of the head main body 20.

[0105] Similarly, at the other longitudinal end of the head body 20, the pressing member 163 or the second support member 162, the head cover 40, and the heat sink 45 are fixed by fixing members. Thus, the heat sink 45 and the head cover 40 according to the second embodiment are fixed to members (here, the pressing member 163, the first support member 161, and the second support member 162) directly or indirectly fixed to the branch flow path member 51 at both longitudinal ends of the head body 20. This makes it possible to make the head cover 40 less likely to tip over even when an external force is applied to the droplet ejection head 8a. If the head cover 40 were to tip over, there is a risk that the resin seal between the head cover 40 and the reservoir 52 would come off. In contrast, with the droplet ejection head 8a according to the second embodiment, the head cover 40 is less likely to tip over, making the seal less likely to be broken.

[0106] In the droplet ejection head 8a according to the second embodiment, the branch flow path member 51 may be box-shaped, as in the droplet ejection head 8 according to the first embodiment. This increases the rigidity of the branch flow path member 51 compared to when the branch flow path member 51 is flat. This reduces the amount of deflection of the nozzle surface of the flow path member 21 joined to the branch flow path member 51.

[0107] The droplet ejection head 8 a according to the second embodiment may further include two plate members 170 that join the heat sink 45 and the head main body 20 together.

[0108] The plate member 170 is made of resin and joins the heat sink 45 and the branch flow path member 51 of the head main body 20. The plate member 170 is a member that extends long in the main scanning direction (Y-axis direction). The width of the plate member 170 in the longitudinal direction is approximately the same as the width of the heat sink 45 in the longitudinal direction. The thermal conductivity of the plate member 170 may be lower than the thermal conductivity of the heat sink 45. By providing the plate member 170, heat generated in the driver IC 33 is less likely to be transmitted to the head main body 20 via the heat sink 45.

[0109] The plate member 170, the heat sink 45, and the branch flow path member 51 of the head main body 20 may be bonded together with double-sided tape or adhesive.

[0110] As described above, the droplet ejection head 8a according to the second embodiment is fixed at both longitudinal ends of the head body 20 to the branch flow path member 51 and the member fixed directly or indirectly to the heat sink 45. This increases the rigidity of the droplet ejection head 8a.

[0111] While the example described above uses the pressing member 163 and the support member 160 as the components fixed to the heat sink 45 at both longitudinal ends of the head main body 20, these components need only be components fixed directly or indirectly to at least the branch flow path member 51, and do not necessarily have to be the pressing member 163 and the support member 160. For example, the pressing member 163 may be the only component fixed to the heat sink 45 at both longitudinal ends of the head main body 20. In this case, the pressing member 163 may be provided on both of the two side wall portions 163a, 163b (see FIG. 12 ). Furthermore, the supporting member 160 may be the only component fixed to the heat sink 45 at both longitudinal ends of the head main body 20, or another component may be provided.

[0112] <Modification of Second Embodiment> A modification of the droplet ejection head 8a according to the second embodiment will be described with reference to Fig. 14. Fig. 14 is a schematic cross-sectional view showing the configuration of one end of the droplet ejection head 8a according to the modification of the second embodiment. Note that in the following modification, the same parts as in the second embodiment are designated by the same symbols, and redundant explanations will be omitted.

[0113] The fixing member for fixing the heat sink 45 to the pressing member 163 and the fixing member for fixing the heat sink 45 to the support member 160 may be fastened to the same member.

[0114] Specifically, as shown in FIG. 14 , the first support member 161 may have a tubular portion 167 with a thread groove formed on its inner circumferential surface. The tubular portion 167 is, for example, cylindrical. For example, the tubular portion 167 may be inserted into a notch 161g provided in the support portion 161a of the first support member 161. Alternatively, the tubular portion 167 may be formed integrally with the first support member 161. A first male screw 190 is inserted into the through-hole 46 of one of the two heat sinks 45, the through-hole 41 of the head cover 40, and the through-hole 163e of the fixing portion 163d of the pressing member 163. The first male screw 190 is threadedly engaged with the tubular portion 167. As a result, one of the two heat sinks 45, the head cover 40, and the pressing member 163 are fixed at one end of the head main body 20 in the longitudinal direction.

[0115] Similarly, a second male screw 191 is inserted through the through-hole 46 of the other of the two heat sinks 45, the through-hole 41 of the head cover 40, and the through-hole 161e of the fixing portion 161c of the first support member 161. The second male screw 191 is screwed into the cylindrical portion 167, whereby the other of the two heat sinks 45, the head cover 40, and the first support member 161 are fixed at one end of the head body 20 in the longitudinal direction.

[0116] Similarly, at the other longitudinal end of the head body 20, the second support member 162 may have a cylindrical portion (not shown) with a threaded groove formed on its inner surface, and a first male screw (not shown) that fixes one of the two heat sinks 45 and the pressing member 163, and a second male screw (not shown) that fixes the other of the two heat sinks 45 and the second support member 162 may be fastened to the same cylindrical portion.

[0117] In this way, in the droplet ejection head 8a according to the second embodiment, the first male screw 190 and the second male screw 191 are fastened to the same cylindrical portion 167, thereby further increasing the rigidity of the droplet ejection head 8a.

[0118] In one embodiment, (1) a droplet ejection head (for example, droplet ejection head 8) has a flow path member (for example, flow path member 21), a branch flow path member (for example, branch flow path member 23), and a reservoir (for example, reservoir 24). The flow path member has a plurality of ejection holes from which droplets are ejected. The branch flow path member is located above the flow path member and has a branch flow path (for example, branch flow path 231) connected to the flow path member. The reservoir is located above the branch flow path member and supplies liquid to the branch flow path member. The branch flow path member is box-shaped.

[0119] (2) In the droplet ejection head of (1) above, the branch flow path member has a bottom (for example, bottom 233) located on the flow path member and a peripheral wall portion (for example, peripheral wall 234) standing up from the bottom, and the bottom has a contact surface with the flow path member and a box bottom surface located opposite the contact surface, and the height of the peripheral wall portion based on the box bottom surface may be greater than 20% of the width in the short direction of the bottom.

[0120] (3) In the droplet ejection head of (2) above, the peripheral wall portion may further have an eave portion (eave portion 234a, for example) that protrudes outward from the branch flow path member.

[0121] (4) Any one of the droplet ejection heads (1) to (3) above may have an elastic member (for example, the elastic member 60) between the branch flow path member and the reservoir.

[0122] (5) Any one of the droplet ejection heads described above in (1) to (4) may have an O-ring (e.g., O-ring 80) between the branch flow path member and the reservoir to seal the connection between the branch flow path and the reservoir.

[0123] (6) In the droplet ejection head according to any one of (1) to (5) above, the branch flow path member and the reservoir may be fixed to both ends of the droplet ejection head in the longitudinal direction.

[0124] (7) In any one of the droplet ejection heads (1) to (6) above, the branch flow path member and the reservoir may be fixed by a waterproof fixing material (for example, fixing materials 90a and 90b).

[0125] (8) Any one of the droplet ejection heads (1) to (7) above may further have a plate-shaped heat sink that is long in the longitudinal direction of the droplet ejection head, and the heat sink, branch flow path member, and reservoir may be fixed by a waterproof fixing material (for example, fixing material 70d).

[0126] (9) Any one of the droplet ejection heads (1) to (8) above further has a plate-shaped heat sink that is long in the longitudinal direction of the droplet ejection head, and the branch flow path member and the reservoir are fixed by a first fixing material (for example, fixing materials 90a and 90b) that is waterproof, and the branch flow path member and the reservoir and the heat sink are fixed by a second fixing material (for example, fixing material 70d) that is waterproof, and the area of ​​the gap between the branch flow path member and the reservoir and the heat sink where the first fixing material and the second fixing material come into contact may be sealed with a caulking material.

[0127] (10) Any one of the droplet ejection heads (1) to (9) above further has a head cover attached to the head body and a plate-shaped heat sink that is long in the longitudinal direction of the droplet ejection head, the reservoir and the heat sink are fixed by a second fixing material that is waterproof, the head cover and the heat sink are fixed by a third fixing material that is waterproof (for example, fixing materials 70a to 70c), and areas of the gaps between the reservoir and the head cover and the heat sink that do not have both the second fixing material and the third fixing material may be sealed with caulking material.

[0128] (11) Any one of the droplet ejection heads (1) to (10) above further has a plate-shaped heat sink that is long in the longitudinal direction of the droplet ejection head, and the heat sink and the reservoir are fixed by a fixing member (for example, fixing member 50) that has a shaft portion with a spiral groove on its outer periphery and a head portion located at the end of the shaft portion, and the heat sink may have a recess (for example, recess 47) that accommodates the head portion.

[0129] (12) In the droplet ejection head of any one of (2) to (11) above, a portion of the reservoir may be located in an area surrounded by the bottom and peripheral wall of the branch flow path member.

[0130] (13) Any one of the droplet ejection heads (1) to (12) above has a driver IC that controls the driving of the head body, a heat sink that dissipates heat generated by the driver IC, and a fixed part (for example, fixed parts 161c, 162c, 163d) that is fixed directly or indirectly to the branch flow path member, and the heat sink and the fixed part may be fixed at both longitudinal ends of the head body.

[0131] (14) The droplet ejection head of (13) above may further include a pressing member that presses the driver IC against the heat sink, and the fixing portions may be provided at both ends of the pressing member in the longitudinal direction of the droplet ejection head.

[0132] (15) The droplet ejection head of (13) above has a flexible substrate on which a driver IC is mounted and which is electrically connected to the head body, a wiring substrate (for example, wiring substrate 32) which is electrically connected to the flexible substrate, and a plurality of support members (for example, support member 160) which support the wiring substrate, and the plurality of support members include a first support member (for example, first support member 161) which supports one end of the wiring substrate in the longitudinal direction of the droplet ejection head, and a second support member (for example, second support member 162) which supports the other end of the wiring substrate in the longitudinal direction of the droplet ejection head, and the fixing portion may be provided on the first support member and the second support member.

[0133] (16) The droplet ejection head of (15) above has two heat sinks located at both ends of the head body in the width direction, at least two first male screws (for example, first male screw 190) inserted into one of the two heat sinks, and at least two second male screws (for example, second male screw 191) inserted into the other of the two heat sinks, and the first support member and the second support member have a cylindrical portion (for example, cylindrical portion 167) that is open at both ends in the width direction of the head body and has a threaded groove formed on its inner surface, and the first male screw and the second male screw may be fastened to the same cylindrical portion.

[0134] (17) The droplet ejection head according to any one of (13) to (16) above may further include a resin plate member (for example, plate member 170) that joins the heat sink and the branch flow path member.

[0135] (18) A droplet ejection device may have any one of the droplet ejection heads described above in (1) to (17) and a control unit that controls the droplet ejection head.

[0136] 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.

[0137] 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 231 branch flow path 233 bottom portion 234 peripheral wall portion 24 reservoir 30 wiring portion 40 head cover 41 through hole 45 heat sink 46 through hole 47 recess 50 fixing member 60 elastic member 70a to 70d fixing material 80 O-ring

Claims

1. a flow path member having a plurality of discharge holes through which droplets are discharged; a branch flow path member located above the flow path member and having a branch flow path connected to the flow path member; a reservoir located above the branch flow path member and supplying liquid to the branch flow path member; A plate-shaped heat sink that is long in the longitudinal direction of the droplet ejection head and The branch flow path member has a box shape, the branch flow path member and the reservoir are fixed by a first fixing material having waterproof properties, the branch flow path member, the reservoir, and the heat sink are fixed by a second fixing material having waterproof properties; The droplet ejection head, wherein a region in which the first fixing material and the second fixing material contact each other in the gap between the branch flow path member and the heat sink and the reservoir is sealed with a caulking material.

2. A flow path member having a plurality of discharge holes through which droplets are discharged; a branch flow path member located above the flow path member and having a branch flow path connected to the flow path member; a reservoir located above the branch flow path member and supplying liquid to the branch flow path member; A head cover that can be attached to the head body; A plate-shaped heat sink that is long in the longitudinal direction of the droplet ejection head and The branch flow path member has a box shape, the reservoir and the heat sink are fixed by a second fixing material having waterproof properties; the head cover and the heat sink are fixed together by a third fixing material having waterproof properties, A droplet ejection head, wherein a region of the gap between the reservoir and the heat sink, and between the head cover and the heat sink and in which neither the second fixing material nor the third fixing material is present, is sealed with a caulking material.

3. A flow path member having a plurality of discharge holes through which droplets are discharged; a branch flow path member located above the flow path member and having a branch flow path connected to the flow path member; a reservoir located above the branch flow path member and supplying liquid to the branch flow path member; a driver IC that controls the driving of the head body; a heat sink for radiating heat generated by the driver IC; a fixing portion fixed directly or indirectly to the branch flow path member; a flexible substrate on which the driver IC is mounted and which is electrically connected to the head body; a wiring board electrically connected to the flexible board; a plurality of support members for supporting the wiring substrate; and The plurality of support members include: a first support member that supports one end of the wiring substrate in the longitudinal direction of the droplet ejection head; a second support member that supports the other end of the wiring substrate in the longitudinal direction of the droplet ejection head; Including, The branch flow path member has a box shape, the heat sink and the fixing portion are fixed to both ends of the droplet ejection head in the longitudinal direction, The fixing portion is provided on the first support member and the second support member.

4. the branch flow path member has a bottom portion located on the flow path member and a peripheral wall portion standing upright from the bottom portion, the bottom portion has a contact surface with the flow path member and a box bottom surface located opposite the contact surface, 4. The droplet ejection head according to claim 1, wherein the height of the peripheral wall portion relative to the bottom surface of the box is greater than 20% of the width of the bottom portion in the short direction.

5. The droplet ejection head according to claim 4 , wherein the peripheral wall portion further includes an eave portion that projects outward from the branch flow path member.

6. 4. The droplet ejection head according to claim 1, further comprising an elastic member between the branch flow path member and the reservoir.

7. 4. The droplet ejection head according to claim 1, further comprising an O-ring between the branch flow path member and the reservoir, the O-ring sealing the connection between the branch flow path and the reservoir.

8. 4. The droplet discharge head according to claim 1, wherein the branch flow path member and the reservoir are fixed at both ends of the droplet discharge head in the longitudinal direction.

9. The droplet ejection head according to claim 8 , wherein the branch flow path member and the reservoir are fixed together by a waterproof fixing material.

10. A droplet ejection head described in any one of claims 1 to 3, wherein the heat sink, the branch flow path member, and the reservoir are fixed by a waterproof fixing material.

11. The branch flow path member and the reservoir are fixed by a first fixing material having waterproof properties, the branch flow path member, the reservoir, and the heat sink are fixed by a second fixing material having waterproof properties; The droplet ejection head according to claim 3 , wherein the branch flow path member and the gap between the reservoir and the heat sink include a region where the first fixing material and the second fixing material come into contact, and the region is sealed with a caulking material.

12. A head cover attached to the head body. and the reservoir and the heat sink are fixed by a second fixing material having waterproof properties; the head cover and the heat sink are fixed together by a third fixing material having waterproof properties, The droplet ejection head according to claim 3 , wherein the gap between the reservoir and the head cover and the heat sink, in an area where neither the second fixing material nor the third fixing material is present, is sealed with a caulking material.

13. The heat sink and the reservoir are fixed by a fixing member having a shaft portion with a spiral groove on the outer periphery and a head portion located at the end of the shaft portion, 4. The droplet ejection head according to claim 1, wherein the heat sink has a recess for accommodating the head.

14. The droplet ejection head according to claim 4 , wherein a portion of the reservoir is located in a region surrounded by the bottom and the peripheral wall of the branch flow path member.

15. a driver IC that controls the driving of the head body; a fixing portion fixed directly or indirectly to the branch flow path member; and The droplet ejection head according to claim 1 , wherein the heat sink and the fixing portion are fixed to both ends of the droplet ejection head in the longitudinal direction.

16. a pressing member that presses the driver IC against the heat sink; The droplet ejection head according to claim 15 , wherein the fixing portions are provided at both ends of the pressing member in the longitudinal direction of the droplet ejection head.

17. a flexible substrate on which the driver IC is mounted and which is electrically connected to the head body; a wiring board electrically connected to the flexible board; a plurality of support members for supporting the wiring substrate; and The plurality of support members include: a first support member that supports one end of the wiring substrate in the longitudinal direction of the droplet ejection head; a second support member that supports the other end of the wiring substrate in the longitudinal direction of the droplet ejection head; Including, The droplet ejection head according to claim 15 , wherein the fixing portion is provided on the first support member and the second support member.

18. two heat sinks located at both ends of the droplet ejection head in the width direction; at least two first male screws inserted into one of the two heat sinks; at least two second male screws inserted into the other of the two heat sinks; and the first support member and the second support member each have a cylindrical portion that is open at both ends in the width direction of the droplet ejection head and has a thread groove formed on an inner circumferential surface; The droplet ejection head according to claim 3 , wherein the first male screw and the second male screw are fastened to the same cylindrical portion.

19. The droplet ejection head according to claim 15 , further comprising a resin plate member that joins the heat sink and the branch flow path member.

20. A droplet ejection head according to any one of claims 1 to 3; a control unit that controls the droplet ejection head; A droplet ejection device having: