Droplet dispensing head and droplet dispensing device
The droplet ejection head's manifold design with widened sections and dampers addresses pressure loss and stagnation issues, enhancing ejection efficiency and reducing failure risks.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KYOCERA CORP
- Filing Date
- 2023-10-25
- Publication Date
- 2026-07-23
AI Technical Summary
Conventional liquid ejection heads experience pressure loss, constriction flow, and liquid stagnation due to wide connection regions, leading to reduced ejection efficiency and potential ejection failure.
The droplet ejection head features a manifold design with widened inlet and outlet sections, connected by narrower transition sections, and includes dampers and tabs to manage pressure fluctuations and flow efficiency, reducing energy loss and stagnation.
This configuration enhances liquid ejection efficiency by minimizing pressure loss and stagnation, improving droplet dispensing performance.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a droplet ejection head and a droplet ejection device.
Background Art
[0002] Conventionally, as a printing head, for example, a liquid ejection head that performs various types of printing by ejecting a liquid onto a recording medium is known. Patent Document 1 discloses a liquid ejection head including an integrated flow path extending in a predetermined direction, a plurality of common flow paths connected to the integrated flow path, a plurality of individual flow paths connected to each of the plurality of common flow paths, and a plurality of ejection holes connected to at least one corresponding one of the plurality of individual flow paths.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
[0004] A droplet ejection head according to an aspect of the present disclosure includes a plurality of ejection holes, a plurality of individual flow paths, and a manifold. The plurality of ejection holes eject droplets. The plurality of individual flow paths are respectively connected to the plurality of ejection holes. The manifold is connected to the plurality of individual flow paths. The manifold has an inflow portion, a flow path portion, and a first connection portion. The inflow portion allows a liquid to flow in. The flow path portion is located downstream of the inflow portion and is connected to the plurality of individual flow paths. The first connection portion connects the inflow portion and the flow path portion. The inflow portion has a first widened portion that is wider than the width of the flow path portion. The first connection portion is narrower than the width of the flow path portion.
Brief Description of the Drawings
[0005] [Figure 1] FIG. 1 is a diagram schematically showing a configuration example of a droplet ejection device according to the first embodiment. [Figure 2] FIG. 2 is a perspective view schematically showing an external configuration of a droplet ejection head according to the first embodiment. [Figure 3] Figure 3 is a schematic plan view showing the internal flow path of the droplet dispensing head according to the first embodiment. [Figure 4] Figure 4 is a schematic perspective view showing the internal flow path of the droplet dispensing head according to the first embodiment. [Figure 5] Figure 5 is a schematic plan perspective view showing the manifold according to the first embodiment. [Figure 6] Figure 6 is a schematic plan view showing a supply manifold according to the first embodiment. [Figure 7] Figure 7 is a cross-sectional view taken along the line VII-VII in Figure 6. [Figure 8] Figure 8 is a schematic plan view showing a recovery manifold according to the first embodiment. [Figure 9] Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 8. [Figure 10] Figure 10 is a cross-sectional view taken along the arrow XX in Figure 5. [Figure 11] Figure 11 is a schematic plan view showing a recovery manifold according to the second embodiment. [Figure 12] Figure 12 is a schematic plan view showing a recovery manifold according to the second embodiment. [Figure 13] Figure 13 is a schematic cross-sectional view showing a tab according to the third embodiment. [Modes for carrying out the invention]
[0006] The embodiments for implementing the droplet dispensing head and droplet dispensing device according to this disclosure (hereinafter referred to as "embodiments") will be described in detail below with reference to the drawings. However, this disclosure is not limited by these embodiments. Furthermore, each embodiment can be combined as appropriate, provided that the processing content is not inconsistent. Also, the same parts are denoted by the same reference numerals in each of the following embodiments, and redundant descriptions are omitted.
[0007] Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not require strict adherence to "constant," "orthogonal," "perpendicular," or "parallel" conditions. In other words, each of the above expressions allows for deviations such as manufacturing accuracy or installation accuracy.
[0008] Furthermore, in the drawings referenced below, for the sake of clarity, mutually orthogonal X, Y, and Z axis directions are sometimes defined, and a Cartesian coordinate system is shown with the positive Z axis pointing vertically upward.
[0009] Furthermore, the droplet ejection head disclosed herein can be applied to inkjet printers and inkjet plotters that utilize an inkjet recording method, as well as various other devices that eject droplets using an inkjet method.
[0010] Conventionally, a liquid ejection head is known as a printing head that performs various types of printing by ejecting a liquid onto a recording medium. Patent Document 1 discloses a liquid ejection head having an integrated channel extending in a predetermined direction, a plurality of common channels connected to the integrated channel, a plurality of individual channels connected to each of the plurality of common channels, and a plurality of ejection holes connected to at least one corresponding individual channel.
[0011] Furthermore, the liquid discharge head described in Patent Document 1 has a wide section in the connection region where the integrated channel and the common channel are connected, the length in a predetermined direction being greater than that of other sections, and a damper is provided in this wide section, which is a section with thinner walls than other sections. By providing a damper in this wide section, or in other words, by making the area where the damper is provided wider, it is possible to reduce the transmission of pressure fluctuations generated in the liquid in the integrated channel to the liquid in the discharge hole, and to enhance the damping effect of the damper.
[0012] However, since the liquid ejection head described in Patent Document 1 has a wide portion in the connection region, a constriction flow is likely to occur in the inlet portion where the liquid flows from the integrated flow path into the common flow path, and separation is likely to occur in the outlet portion where the liquid flows out from the common flow path into the integrated flow path. As a result, in the liquid ejection head described in Patent Document 1, a pressure loss due to such constriction flow or separation may occur, which may reduce the liquid ejection efficiency. In particular, in the outlet portion, due to the influence of separation, liquid may accumulate and the liquid may adhere to the flow path, which may also cause ejection failure.
[0013] Therefore, a technique for improving the liquid ejection efficiency is expected.
[0014] (First Embodiment) <Example of the external configuration of the droplet ejection device> The configuration example of the droplet ejection device according to the first embodiment will be described with reference to FIG. 1. FIG. 1 is a diagram schematically showing the configuration example of the droplet ejection device according to the first embodiment.
[0015] As shown in FIG. 1, the droplet ejection device 100 includes a robot arm 1, a circulation mechanism 2, a droplet ejection head 3, and a control device 4.
[0016] The robot arm 1 is assembled to a base 5 placed on, for example, a horizontal floor surface indoors or outdoors. The robot arm 1 holds the droplet ejection head 3. The robot arm 1 is, for example, a vertical multi-joint robot. The robot arm 1 has an arm portion 11. The arm portion 11 is composed of a plurality of components assembled so as to be bendable, extendable, and rotatable. The arm portion 11 can move the droplet ejection head 3 mounted at the tip of the arm portion 11, and change the position, posture, and angle of the droplet ejection head 3 according to a command from a control unit 41 described later. The arm portion 11 illustrated in FIG. 1 is not particularly limited to the configuration shown in FIG. 1 as long as it has a degree of freedom that allows changes in movement, position, posture, and angle necessary for the droplet ejection head 3.
[0017] The robot arm 1 can be moved vertically (in the Z-axis direction) by moving, for example, the circulation mechanism 2 and droplet dispensing head 3 mounted at the tip of the arm 11 along a predetermined axis of rotation. This allows the circulation mechanism 2 and droplet dispensing head 3 to assume a position where the liquid dispensing surface 3SF of the droplet dispensing head 3 faces parallel to the spraying surface 6SF of the object 6, as shown in Figure 1. Furthermore, the robot arm 1 can rotate, for example, the circulation mechanism 2 and droplet dispensing head 3 assembled at the tip of the arm 11 around a predetermined axis of rotation. This allows the circulation mechanism 2 and droplet dispensing head 3 to, for example, swap their longitudinal and transverse positions, or reverse their vertical positions.
[0018] The circulation mechanism 2 is installed at the tip of the arm portion 11 of the robot arm 1. The circulation mechanism 2 supplies liquid to the droplet dispensing head 3 while controlling the circulation flow rate of the liquid circulating between it and the droplet dispensing head 3.
[0019] The droplet dispensing head 3 is assembled to a circulation mechanism 2 installed at the tip of the arm portion 11 of the robot arm 1. The droplet dispensing head 3 dispenses liquid in droplet form onto the object 6. The liquid is, for example, a liquid that can be applied to the object 6 to color it. Examples of liquids that can be used include ink or paint. The liquid may also have a higher viscosity than standard.
[0020] The control device 4 is, for example, a computer and comprises a control unit 41 such as a processor and a storage unit 42 such as memory. The storage unit 42 stores programs that control various processes performed in the droplet dispensing device 100. The control unit 41 controls the operation of the droplet dispensing device 100 by reading and executing the programs stored in the storage unit 42.
[0021] Such a program may have been recorded on a computer-readable storage medium and installed from that storage medium to the storage unit 42 of the control device 4. Examples of computer-readable storage mediums include hard disks (HDs), flexible disks (FDs), compact disks (CDs), magnetic optical disks (MOs), or memory cards.
[0022] <Example configuration of a droplet dispensing head> Next, an example of the configuration of the droplet dispensing head 3 according to the first embodiment will be described using Figures 2 to 4. Figure 2 is a schematic perspective view showing the external configuration of the droplet dispensing head according to the first embodiment. Figure 3 is a schematic plan view showing the internal flow path of the droplet dispensing head according to the first embodiment. Figure 4 is a schematic perspective view showing the internal flow path of the droplet dispensing head according to the first embodiment.
[0023] As shown in Figure 2, the droplet dispensing head 3 has a housing that includes a box-shaped member 31 and a substantially flat-shaped member 32. The housing of the droplet dispensing head 3 is provided with a supply port 321 for supplying liquid into the inside of the droplet dispensing head 3 and a recovery port 322 for recovering liquid from inside the droplet dispensing head 3. A first flow path RT1 for supplying liquid from the circulation mechanism 2 into the inside of the head is connected to the supply port 321. A second flow path RT2 for sending the liquid recovered inside the head back to the circulation mechanism 2 is connected to the recovery port 322.
[0024] As shown in Figure 3, the droplet discharge head 3 has a reservoir 10, a plurality of manifolds 20, and a plurality of individual flow paths 30. The reservoir 10 includes a supply reservoir 12 and a recovery reservoir 13. The manifolds 20 include a supply manifold 21 and a recovery manifold 22.
[0025] The supply reservoir 12 is a flow channel member having an elongated shape that extends in the longitudinal direction (Y-axis direction) of the droplet discharge head 3. The supply reservoir 12 is connected to a plurality of supply manifolds 21. As shown in Figure 4, liquid is supplied to the supply reservoir 12 through the first flow channel RT1 and the supply port 321, and the liquid stored in the flow channel of the supply reservoir 12 is sent to the supply manifolds 21.
[0026] The recovery reservoir 13 has an elongated shape that extends in the longitudinal direction (Y-axis direction) of the droplet discharge head 3 and is connected to the recovery manifold 22. The recovery reservoir 13 has a flow path inside. As shown in Figure 4, the liquid that is sent from the recovery manifold 22 to the recovery reservoir 13 and stored in the flow path of the recovery reservoir 13 is sent back to the circulation mechanism 2 through the recovery port 322 and the second flow path RT2.
[0027] The supply reservoir 12 is located at one end of the droplet dispensing head 3 in the short direction (in this case, the positive X-axis direction), and the recovery reservoir 13 is located at the other end of the droplet dispensing head 3 in the short direction (in this case, the negative X-axis direction).
[0028] The supply manifold 21 and the recovery manifold 22 are arranged to extend along the short direction (X-axis direction) of the droplet discharge head 3. As shown in Figure 4, the multiple supply manifolds 21 and the multiple recovery manifolds 22 are spaced apart along the longitudinal direction (Y-axis direction) of the droplet discharge head 3 so that the supply manifolds 21 and the recovery manifolds 22 are positioned alternately. The supply manifolds 21 and the recovery manifolds 22 are connected to multiple individual flow paths 30, and adjacent supply manifolds 21 and recovery manifolds 22 are connected to each other via the multiple individual flow paths 30.
[0029] The supply manifold 21 has an elongated shape, with one end (in this case, the end on the positive X-axis side) located below the supply reservoir 12, extending from this end to just before the recovery reservoir 13. The supply manifold 21 is connected to the supply reservoir 12 and the individual flow channels 30. As shown in Figure 4, the liquid sent from the supply reservoir 12 to the supply manifold 21 is then sent from the supply manifold 21 to the individual flow channels 30.
[0030] The recovery manifold 22 has an elongated shape, with its other end (in this case, the end on the negative X-axis side) located below the recovery reservoir 13, extending from this other end to just before the supply reservoir 12. The recovery manifold 22 has internal flow paths that communicate with the flow paths of the recovery reservoir 13 and the individual flow paths 30. As shown in Figure 4, liquid that is not discharged to the outside from the individual flow paths 30 (discharge holes 30h) is sent to the recovery manifold 22.
[0031] The individual flow paths 30 are flow paths connecting the supply manifold 21 and the recovery manifold 22. Multiple individual flow paths 30 are connected to multiple discharge holes 30h that discharge droplets toward the object 6. Each of the multiple individual flow paths 30 has multiple piezoelectric elements (not shown). These piezoelectric elements, for example, draw liquid from the supply manifold 21 by negative pressure generated in a pressure chamber (not shown), and discharge the drawn liquid toward the object 6 from the discharge holes 30h by positive pressure generated in the pressure chamber (not shown).
[0032] Next, a specific example of the configuration of the manifold 20 according to the first embodiment will be described using Figure 5. Figure 5 is a schematic plan perspective view showing the manifold 20 according to the first embodiment. As shown in Figure 5, the supply manifold 21 has an inlet 210, a flow path 220, and a first connection 230. The recovery manifold 22 has an outlet 240, a flow path 250, and a second connection 260. Multiple third connection 60 are located in the flow path 220 of the supply manifold 21 and the flow path 250 of the recovery manifold 22. The third connection 60 is a place where it connects to an individual flow path 30 (not shown in Figure 5).
[0033] The droplet discharge head 3 also has a plurality of dampers 40 and a plurality of tabs 50. The plurality of dampers 40 are located at the bottom of the supply manifold 21 and the recovery manifold 22. The plurality of tabs 50 are located inside the supply manifold 21 and the recovery manifold 22. Details of these dampers 40 and tabs 50 will be described later.
[0034] Next, an example of the configuration of the supply manifold 21 according to the first embodiment will be described using Figures 6 and 7. Figure 6 is a schematic plan perspective view of the supply manifold 21 according to the first embodiment. Figure 7 is a cross-sectional view taken along the line VII-VII in Figure 6. Note that Figure 6 is a plan perspective view of the supply manifold 21 viewed from above.
[0035] The supply manifold 21 has an inlet 210, a flow path 220, and a first connection 230. The inlet 210 is where the liquid supplied from the supply reservoir 12 flows in. Specifically, as shown in Figures 6 and 7, the inlet 210 has an inlet 211 into which the liquid flows and a first wide section 212. The inlet 211 is located at the top of the inlet 210 and is connected to the supply reservoir 12.
[0036] The first wide section 212 is a portion that is wider than the width of the flow channel section 220. For example, as shown in Figure 6, the width W1 of the upstream side (the widest part) of the first wide section 212 is wider than the width W2 of the flow channel section 220. Here, "width" refers to the width in the direction perpendicular to the liquid flow direction, i.e., the flow channel width. The downstream side wall 212a of the first wide section 212 is curved so as it narrows towards the first connection section 230, which will be described later.
[0037] The flow channel section 220 is located downstream of the inlet section 210 and extends in a straight line. The flow channel section 220 has a plurality of third connection sections 60 (see Figure 5), and each third connection section 60 connects to an individual flow channel 30. The width W2 of the flow channel section 220 is the width at the locations where no third connection sections 60 are provided.
[0038] The first connection section 230 is the part that connects the inlet section 210 and the flow path section 220. The width of the first connection section 230 is narrower than the width of the flow path section 220. Specifically, as shown in Figure 6, the side wall of the first connection section 230 is curved so that it narrows temporarily and then widens as it approaches the flow path section 220, and the width W3 of the first connection section 230 near the center (the narrowest point) is narrower than the width W2 of the flow path section 220.
[0039] As an example, the cross-sectional area of the first wide section 212 is A1, the cross-sectional area of the flow channel section 220 is A2, and the minimum cross-sectional area at the first connecting section 230 is A C In that case, A1, A2, A C The relationship may also satisfy the following equation.
number
[0040] This configuration reduces energy loss due to flow contraction that occurs when the flow path narrows rapidly, improves the efficiency of liquid outflow, and reduces liquid stagnation and adhesion to the flow path.
[0041] As shown in Figure 7, the sidewall of the manifold 20, which includes the supply manifold 21 and the recovery manifold 22, is composed of a plurality of stacked plates 20a to 20h. As an example, eight plates, from plate 20a to plate 20h, are stacked in order from the inlet 211 side of the supply manifold 21. Numerous holes or grooves are formed in these plates. The holes or grooves can be formed, for example, by etching each plate made of metal. The thickness of each plate is approximately 10 to 300 μm, which allows for high accuracy in forming the holes or grooves. The plates are stacked in alignment so that these holes or grooves communicate with each other to constitute the supply manifold 21.
[0042] As shown in Figure 7, the first wide section 212 of the inlet section 210 is composed of the plate 20h located at the bottom of the multiple plates 20a to 20h. For example, the first wide section 212 is composed of plate 20h and plate 20g located above plate 20h. The portion of the inlet section 210 located above the first wide section 212 is narrower than the first wide section 212. For example, the width of the portion located above the first wide section 212 is the same as the width of the flow channel section 220.
[0043] Next, an example of the configuration of the recovery manifold 22 according to the first embodiment will be described with reference to Figures 8 and 9. Figure 8 is a schematic plan perspective view showing the recovery manifold 22 according to the first embodiment. Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 8.
[0044] The recovery manifold 22 has an outlet section 240, a flow path section 250, and a second connection section 260. The outlet section 240 is where the liquid flows out. Specifically, as shown in Figures 8 and 9, the outlet section 240 has an outlet 241 through which the liquid flows out and a second wide section 242. The outlet 241 is located at the top of the outlet section 240 and is connected to the recovery reservoir 13.
[0045] The second wide section 242 is wider than the width of the flow channel section 250. For example, as shown in Figure 8, the second wide section 242 is formed in a tapered shape, becoming wider as it moves downstream (negative X-axis direction), and the width W4 of the second wide section 242 at its furthest downstream end (widest point) is wider than the width W5 of the flow channel section 250.
[0046] The flow channel section 250 is located upstream of the outflow section 240 and extends in a straight line. The flow channel section 250 has a plurality of third connection sections 60 (see Figure 5), and each third connection section 60 connects to an individual flow channel 30. The width W5 of the flow channel section 250 is the width at the locations where no third connection sections 60 are provided.
[0047] The second connection section 260 is the part that connects the outflow section 240 and the flow path section 250. Here, of the outflow section 240 and the second connection section 260, the area facing the damper 40, which will be described later in a plan view, is referred to as the outflow section 240, and the area not facing the damper 40 is referred to as the second connection section 260 (see Figure 5).
[0048] The second connecting portion 260 has a third wide portion 261. The third wide portion 261 is wider than the width of the flow channel portion 250 and less than or equal to the width of the second wide portion 242. For example, as shown in Figure 8, the third wide portion 261 is formed in a tapered shape, becoming wider towards the second wide portion 242 of the flow channel portion 250. In this case, the width W4 at the downstream end of the third wide portion 261 is wider than the width W5 of the flow channel portion 250 and less than or equal to the width W6 of the second wide portion 242.
[0049] This configuration reduces pressure loss caused by vortices (separation) that occur when the flow path rapidly expands, thereby increasing the efficiency of liquid outflow and reducing liquid stagnation and clogging of the flow path.
[0050] In the example shown in Figure 8, the recovery manifold 22 has a continuous tapered shape from the second connection section 260 to the outlet section 240. However, the shapes of the outlet section 240 and the second connection section 260 are not limited to the illustrated example. This point will be discussed later.
[0051] As shown in Figure 9, the side wall of the recovery manifold 22 is composed of multiple stacked plates 20a to 20h, similar to the supply manifold 21. As an example, eight plates, from plate 20a to plate 20h, are stacked in order from the outlet 241 side of the recovery manifold 22.
[0052] As shown in Figure 9, the second wide section 242 of the outflow section 240 includes the plate 20h located at the bottom of the multiple plates 20a to 20h. For example, the second wide section 242 is composed of plate 20h and plate 20g located above plate 20h. The portion of the outflow section 240 located above the second wide section 242 is narrower than the second wide section 242. For example, the width of the portion located above the second wide section 242 is the same as the width of the flow channel section 250.
[0053] Returning to Figure 5, the configuration of the dampers 40 and tabs 50 will be described. As shown in Figure 5, the multiple dampers 40 are located below the manifold 20. As shown in Figures 5 and 7, one of the three dampers 40 is located below the inlet 210 of the supply manifold 21 and faces multiple first wide sections 212 of the supply manifold 21. Another of the three dampers 40 is located below the outlet 240 of the recovery manifold 22 and faces multiple second wide sections 242 of the recovery manifold 22. The remaining damper 40 is located below the flow path 220 of the supply manifold 21 and the flow path 250 of the recovery manifold 22 and faces multiple flow path sections 220 and 250.
[0054] As shown in Figures 7 and 9, each damper 40 comprises a damper wall 43 that is thinner than the rest of the unit, and a damper chamber 44 separated from the manifold 20 by the damper wall 43.
[0055] One main surface of the damper wall 43 faces the manifold 20, and the other main surface of the damper wall 43 faces the damper chamber 44. The damper wall 43 is positioned opposite the bottom wall of the damper chamber 44. The damper 40 can deform toward the bottom wall of the damper chamber 44 due to the pressure applied from the manifold 20. The damper wall 43 vibrates in response to pressure waves transmitted to the manifold 20 from a piezoelectric element (not shown), thereby attenuating pressure fluctuations of the liquid in the supply manifold 21. By separating the manifold 20 and the damper chamber 44 via the damper wall 43, pressure fluctuations of the liquid in the manifold 20 are reduced.
[0056] Furthermore, as described above, the damper 40 faces multiple first wide sections 212, multiple second wide sections 242, or multiple flow path sections 220 in multiple manifolds 20. With this configuration, the damping effect of the damper 40 can be further enhanced.
[0057] As shown in Figure 5, in a plan view, the first connection portion 230 of the supply manifold 21 does not face the damper 40. In other words, the damper 40 is not located below the first connection portion 230. With this configuration, the flow of liquid in the first connection portion 230 can be made more efficient without reducing the damping function of the damper 40.
[0058] Furthermore, the droplet discharge head 3 is not limited to the above example, and only needs to have a damper 40 facing at least one of the inlet 210 of the supply manifold 21 and the outlet 240 of the recovery manifold 22. Also, the droplet discharge head 3 is only needed to have a damper 40 facing at least one of the first wide portion 212 of the inlet 210 and the second wide portion 242 of the outlet 240.
[0059] Multiple tabs 50 connect the side walls of adjacent flow channels 220 and 250. The presence of tabs 50 reduces deformation of the plates constituting the flow channels 220 and 250, thereby improving the strength of the manifold 20.
[0060] Here, the positional relationship between the adjacent flow channels 220 and 250, the damper 40, and the tab 50 will be explained with reference to Figure 10. Figure 10 is a cross-sectional view taken along the XX arrow in Figure 5. Although Figure 10 shows the cross-sectional structure of the flow channel 250 of the recovery manifold 22, the cross-sectional structure of the flow channel 220 of the supply manifold 21 is the same.
[0061] As shown in Figure 10, the tab 50 may be positioned in contact with the damper 40. Specifically, the lower surface of the tab 50 may be in contact with the upper surface of the damper wall 43 of the damper 40. With this configuration, the tab 50 is integrated with the bottom wall of the flow channel 250, thereby reducing the obstruction of the fluid flow in the flow channel 250 by the tab 50.
[0062] (Modification of the first embodiment) In the first embodiment described above, an example was described in which the first wide section 212 and the second wide section 242 are composed of plate 20g and plate 20h. However, the first wide section 212 and the second wide section 242 may be composed only of plate 20h located at the bottom, or they may be composed of all plates 20a to 20h.
[0063] Furthermore, in a plan view as shown in Figure 8, the downstream side wall of the outflow section 240 of the recovery manifold 22 may be curved. In other words, the corners of the outflow section 240 in the plan view may be curved. With this configuration, it is possible to reduce liquid stagnation and solidification at the corners of the outflow section 240.
[0064] (Second Embodiment) Figures 11 and 12 are schematic plan views showing a recovery manifold according to the second embodiment. As shown in Figures 11 and 12, the shapes of the outflow section 240 and the second connection section 260 of the recovery manifold 22 are not limited to the shapes shown in Figure 8.
[0065] For example, as shown in Figure 11, the second wide portion 242 of the outlet portion 240 of the recovery manifold 22 may have a constant width along the longitudinal direction of the recovery manifold 22. In this case, the side wall constituting the third wide portion 261 of the second connecting portion 260 may extend linearly, as shown in Figure 11, or curved, as shown in Figure 12.
[0066] (Third embodiment) Figure 13 is a cross-sectional view of the droplet discharge head 3 according to the third embodiment, taken from the same location as in Figure 10. As shown in Figure 13, the tab 50 may be separated from the damper 40. Specifically, there may be a space between the lower surface of the tab 50 and the upper surface of the damper wall 43 of the damper 40. With this configuration, the movable range of the damper 40 provided below the manifold 20 can be secured.
[0067] (1) In one embodiment, a droplet dispensing head (for example, droplet dispensing head 3) has a plurality of dispensing holes (for example, dispensing holes 30h), a plurality of individual flow paths (for example, individual flow paths 30), and a manifold (for example, manifold 20). The plurality of dispensing holes dispense droplets. The plurality of individual flow paths are each connected to the plurality of dispensing holes. The manifold is connected to the plurality of individual flow paths. The manifold has an inlet (for example, inlet 210), a flow path section (for example, flow path sections 220, 250), and a first connection section (for example, first connection section 230). Liquid flows into the inlet. The flow path section is located downstream of the inlet and is connected to the plurality of individual flow paths. The first connection section connects the inlet and the flow path section. The inlet section has a first wide section (for example, first wide section 212) that is wider than the width of the flow path section. The first connection section is narrower than the width of the flow path section.
[0068] (2) In the droplet discharge head described in (1) above, the manifold has an outlet section from which the liquid flows out and a second connecting section that connects the flow path section and the outlet section, the outlet section has a second wide section that is wider than the width of the flow path section, and the second connecting section may have a third wide section that is wider than the width of the flow path section and less than or equal to the width of the second wide section.
[0069] (3) In the droplet dispensing head of (1) or (2) above, the width of the third wide portion may increase as it approaches the second wide portion.
[0070] (4) Any of the droplet dispensing heads described in (1) to (3) above may have a damper facing at least one of the inlet and outlet portions.
[0071] (5) In any of the droplet discharge heads described in (1) to (4) above, the damper may face at least one of the first wide portion in the inlet and the second wide portion in the outlet.
[0072] (6) Any droplet discharge head described in (1) to (5) above may have a plurality of manifolds, and the damper may face a plurality of the first wide portions in the plurality of manifolds.
[0073] (7) Any droplet discharge head described in (1) to (5) above may have a plurality of manifolds, and the damper may face a plurality of the second wide portions in the plurality of manifolds.
[0074] (8) In any of the droplet dispensing heads described in (1) to (7) above, the side wall of the first wide portion may be curved in a plan view such that it becomes narrower towards the first connection portion, and the side wall of the first connection portion may be curved in such that it becomes narrower and then wider towards the flow path portion.
[0075] (9) In any of the droplet dispensing heads described in (1) to (8) above, the side wall of the manifold is composed of a plurality of stacked plates, and the first wide portion may include the plate located at the bottom of the plurality of plates.
[0076] (10) In any of the droplet dispensing heads described in (1) to (9) above, the cross-sectional area of the first wide portion is A1, the cross-sectional area of the flow path portion is A2, and the minimum cross-sectional area of the first connecting portion is A C In that case, the following equation may also be satisfied.
number
[0077] (11) Any droplet discharge head described in (1) to (10) above has a plurality of manifolds, a damper facing across a plurality of flow channels in the plurality of manifolds, and a tab connecting the side walls of the flow channels, the tabs may be in contact with the damper.
[0078] (12) Any droplet discharge head described in (1) to (10) above has a plurality of manifolds, and has dampers facing across a plurality of flow channels in the plurality of manifolds, and tabs connecting the side walls of the flow channels, wherein the tabs may be separated from the dampers.
[0079] (13) In a plan view, the first connection portion of any of the droplet dispensing heads described in (1) to (12) above does not have to face the damper.
[0080] (14) The droplet dispensing device may have one of the droplet dispensing heads described in (1) to (13) above, and a control unit that controls the droplet dispensing head.
[0081] (15) The droplet dispensing device described in (14) above may have a robotic arm that holds the droplet dispensing head.
[0082] Therefore, according to the droplet dispensing head of the embodiment, the liquid dispensing efficiency can be improved.
[0083] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Indeed, the embodiments described above can be embodied in a variety of forms. Furthermore, the embodiments described above may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of Symbols]
[0084] 1. Robot arm 2 Circulation mechanism 3. Droplet dispensing head 4. Control device 20 Manifold 20a~20h Plate 21 Supply Manifold 22 Recovery Manifold 30 individual channels 30h Discharge hole 40 dampers 41 Control Unit 42 Storage section 50 tabs 100 Droplet discharge device 210 Inlet 211 Inlet 212 First wide section 220 Flow channel section 230 First connection section 240 Outlet 241 Outlet 242 Second wide section 250 Flow channel section 260 Second connection section 261 Third wide section
Claims
1. Multiple ejection holes for ejecting droplets, Multiple individual flow paths connected to each of the multiple discharge holes, The manifold connected to the aforementioned multiple individual flow paths It has, The aforementioned manifold is The inlet into which the liquid flows, A flow channel section located downstream of the aforementioned inflow section and connected to the plurality of individual flow channels, A first connecting portion that connects the inlet portion and the flow path portion. It has, The inlet section has a first wide section that is wider than the width of the flow path section. The first connection portion is narrower than the width of the flow path portion. The first wide portion is configured to include the lower end of the inlet portion, A droplet dispensing head wherein the portion of the inlet located above the first wide portion is narrower than the first wide portion.
2. The aforementioned manifold is The outlet from which the aforementioned liquid flows out, A second connecting section that connects the flow channel section and the outflow section. It has, The outflow section has a second wide section that is wider than the width of the flow channel section. The droplet dispensing head according to claim 1, wherein the second connecting portion has a third wide portion that is wider than the width of the flow path portion and less than or equal to the width of the second wide portion.
3. The droplet dispensing head according to claim 2, wherein the width of the third wide portion increases as it approaches the second wide portion.
4. The droplet dispensing head according to claim 2, having a damper facing at least one of the inlet and outlet portions.
5. The droplet discharge head according to claim 4, wherein the damper faces at least one of the first wide portion in the inlet and the second wide portion in the outlet.
6. Having multiple of the aforementioned manifolds, The droplet discharge head according to claim 5, wherein the damper faces across a plurality of first wide portions in the plurality of manifolds.
7. Having multiple of the aforementioned manifolds, The droplet discharge head according to claim 5, wherein the damper faces across a plurality of the second wide portions in the plurality of manifolds.
8. In a planar perspective view, the side wall of the first wide portion is curved such that it becomes narrower towards the first connecting portion. The droplet dispensing head according to claim 1, wherein the side wall of the first connection portion is curved such that it narrows and then widens as it approaches the flow path portion.
9. The side wall of the manifold is composed of multiple stacked plates, The droplet dispensing head according to claim 1, wherein the first wide portion includes the plate located at the lowest position among the plurality of plates.
10. The cross-sectional area of the first wide portion is A １ The cross-sectional area of the flow channel is A ２ , the minimum cross-sectional area at the first connection part is A Ｃ In this case, the droplet dispensing head according to claim 1 satisfies the following formula. [Math 1]
11. Having multiple of the aforementioned manifolds, A damper facing across multiple flow path sections in the multiple manifolds, A tab connecting the two side walls of the aforementioned flow channel section It has, The droplet dispensing head according to claim 1, wherein the tab is in contact with the damper.
12. Having multiple of the aforementioned manifolds, A damper facing across multiple flow path sections in the multiple manifolds, A tab connecting the two side walls of the aforementioned flow channel section It has, The droplet dispensing head according to claim 1, wherein the tab is separated from the damper.
13. A plurality of discharge holes for discharging droplets, Multiple individual flow paths connected to each of the multiple discharge holes, The manifold connected to the aforementioned multiple individual flow paths It has, The aforementioned manifold is The inlet into which the liquid flows, The outlet from which the aforementioned liquid flows out, A flow channel section located downstream of the aforementioned inflow section and connected to the plurality of individual flow channels, A first connecting section that connects the inlet section and the flow path section, A second connecting section that connects the flow channel section and the outflow section. It has, The inlet section has a first wide section that is wider than the width of the flow path section. The outflow section has a second wide section that is wider than the width of the flow channel section. The first connection portion is narrower than the width of the flow path portion. The second connecting portion has a third wide portion that is wider than the width of the flow path portion and less than or equal to the width of the second wide portion. The damper has a damper facing at least one of the inlet and outlet portions. In a planar perspective view, the first connection portion is a droplet dispensing head that does not face the damper.
14. A droplet dispensing head according to any one of claims 1 to 13, A control unit that controls the droplet dispensing head and A droplet dispensing device having the following features.
15. The droplet dispensing device according to claim 14, further comprising a robotic arm for holding the droplet dispensing head.