Liquid injection head unit and liquid injection device

Abstract

To solve such a problem that the inserting / extracting property of an external wiring member is bad.SOLUTION: A liquid jet head unit having a first connector for connection with an external wiring member comprises: a wiring board which has the first connector; a housing of the liquid jet head unit which has an opening for exposing the first connector to the outside and stores the wiring board in a storage space; and a flexible member which is arranged in the storage space. The flexible member sections the storage space into the first space including at least a portion of the first connector and the opening and the second space larger than the first space.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a liquid ejecting head unit and a liquid ejecting apparatus. [Background Art]

[0002] For example, the liquid discharging head described in Patent Document 1 below includes a wiring board provided with an internal connector, and a housing that accommodates the wiring board. The housing is formed with an opening for connecting the internal connector connected to the internal wiring board and a connector that is an external wiring member. Further, a cover member formed of a flexible member is attached to the housing, and the cover member is formed with an opening through which an external wiring member is inserted. In the liquid discharging head described in Patent Document 1, the inner peripheral surface of the opening of the cover member is in contact with the external wiring member inserted through the opening to prevent mist from entering the housing. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2014-4767 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] For example, in the conventional technology, a slit is formed in a portion of the cover member that covers the internal connector so that the opening of the cover member, into which an external wiring member is inserted, is widened. In the conventional technology, although a slit is formed in the cover member, the internal connector is covered by the cover member, resulting in poor insertability and extractability of the external wiring member. Specifically, since the inner peripheral surface of the opening of the cover member is in contact with the external wiring member, the insertability and extractability of the external wiring member is poor. [Means for Solving the Problem]

[0005] The liquid injection head unit according to the present invention is a liquid injection head unit equipped with a first connector for connecting to an external wiring member, comprising: a wiring board having the first connector; a housing for the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space; and a flexible member disposed within the housing space, wherein the flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space.

[0006] The liquid injection device according to the present invention comprises a liquid injection head unit and an external wiring member located outside the liquid injection head unit and connected to a first connector. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram showing a liquid injection device according to the first embodiment. [Figure 2] This is an exploded perspective view showing the head unit. [Figure 3] This is a bottom view showing the injection surface of the head unit. [Figure 4] This is a plan view showing the base component and the wiring board. [Figure 5] This is a plan view showing the head unit 20 with the cover not yet attached. [Figure 6] This is a plan view showing a part of the head unit. [Figure 7] This is a plan view showing a magnified view of the opening in the cover and the connector exposed through the opening. [Figure 8] This is an enlarged cross-sectional view showing a close-up of a portion of the head unit. [Figure 9] This is an enlarged cross-sectional view showing the main part of the head unit according to the second embodiment. [Figure 10] This is a cross-sectional view showing an enlarged view of the main part of the head unit according to the third embodiment. [Figure 11]This is a plan view showing a magnified view of the opening in the cover and the connector exposed through the opening. [Figure 12] This is an enlarged cross-sectional view showing the main part of the head unit 20 according to the fourth embodiment. [Figure 13] This is a close-up cross-sectional view showing an opening in the cover and the connector exposed through the opening. [Figure 14] This is a side view showing the housing of the liquid injection device that houses the head unit.

[0008] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scale of each part have been appropriately changed from those of the actual parts. Furthermore, the embodiments described below are preferred specific examples of the present invention and are subject to various technically preferred limitations, but the scope of the present invention is not limited to these embodiments unless otherwise stated in the following description.

[0009] In the following explanation, the three intersecting directions may be referred to as the X-axis, Y-axis, and Z-axis directions. The X-axis direction includes the X1 and X2 directions, which are opposite to each other. The Y-axis direction includes the Y1 and Y2 directions, which are opposite to each other. The Z-axis direction includes the Z1 and Z2 directions, which are opposite to each other. The X-axis, Y-axis, and Z-axis directions are orthogonal.

[0010] <1. First Embodiment> Figure 1 is a schematic diagram showing a liquid ejection device 1 according to the first embodiment. The liquid ejection device 1 is an inkjet printing device that ejects ink, which is an example of a "liquid," as droplets onto a medium PA. The liquid ejection device 1 of this embodiment is a so-called line-type printing device in which a plurality of nozzles that eject ink are distributed over the entire width of the medium PA. The medium PA is typically printing paper. However, the medium PA is not limited to printing paper and may be any material to be printed on, for example, a resin film or a cloth.

[0011] As shown in FIG. 1, the liquid ejecting apparatus 1 includes a liquid container 2, a control unit 3, a medium conveying mechanism 4, a circulation mechanism 5, and a head unit 20. The head unit 20 has a plurality of liquid ejecting heads 10.

[0012] The liquid container 2 stores ink. Specific aspects of the liquid container 2 include, for example, a cartridge detachable from the liquid ejecting apparatus 1, a bag-shaped ink pack formed of a flexible film, and an ink tank capable of being refilled with ink. The type of ink stored in the liquid container 2 is arbitrary. The liquid ejecting apparatus 1 includes a plurality of liquid containers 2 corresponding to respective types of ink. The liquid ejecting apparatus 1 may also be configured to include one liquid container 2.

[0013] The control unit 3 controls operations of each element of the liquid ejecting apparatus 1. The control unit 3 includes, for example, a processing circuit such as a CPU or an FPGA, and a storage circuit such as a semiconductor memory. Various programs and various data are stored in the storage circuit. The processing circuit implements various controls by executing the programs and appropriately using the data. CPU is an abbreviation for Central Processing Unit. FPGA is an abbreviation for Field Programmable Gate Array.

[0014] The medium conveying mechanism 4 is controlled by the control unit 3 and conveys a medium PA in a conveying direction DM. The medium conveying mechanism 4 includes a conveying roller that is long along the width direction of the medium PA, and a motor that rotates the conveying roller. The medium conveying mechanism 4 is not limited to a configuration using a conveying roller, and for example, may be configured to use a drum or an endless belt that conveys the medium PA in a state where the medium PA is adsorbed to an outer peripheral surface by electrostatic force or the like.

[0015] The liquid ejecting head 10 is controlled by the control unit 3, and ejects ink supplied from the liquid container 2 via the circulation mechanism 5 onto the medium PA from each of a plurality of nozzles. The plurality of liquid ejecting heads 10 are arranged in a direction intersecting the conveying direction DM to constitute a line head 6.

[0016] The ink stored in the liquid container 2 is supplied to the liquid ejecting head 10 via the circulation mechanism 5. The circulation mechanism 5 supplies ink to the liquid ejecting head 10 and collects the ink discharged from the liquid ejecting head 10. The circulation mechanism 5 supplies the collected ink to the liquid ejecting head 10 again. The circulation mechanism 5 includes a supply flow path 7 for supplying ink to the liquid ejecting head 10, a discharge flow path 8 for collecting ink discharged from the liquid ejecting head 10, a sub-tank 2b for storing the collected ink, a pump for transferring ink, and the like. The supply flow path 7 and the discharge flow path 8 are, for example, pipes, tubes, or the like. The supply flow path 7 and the discharge flow path 8 may be a structure formed with grooves, recesses or the like through which liquid flows.

[0017] Next, the head unit 20 will be described with reference to FIGS. 2 to 8. FIG. 2 is an exploded perspective view showing the head unit 20. FIG. 3 is a cross-sectional view showing a part of the head unit 20. The head unit 20 includes a plurality of liquid ejecting heads 10, a housing 23, a common flow path member 30, and a circuit board portion 40. The housing 23 includes a cover 21 and a base member 22. FIG. 3 shows an upper portion of the head unit 20, and does not show a lower portion of the base member 22 and a lower portion of the liquid ejecting head 10. The base member 22 is an example of "a first member", and the cover 21 is an example of "a second member stacked on the first member". Note that the phrase "stacked on the first member" includes "disposed on the first member", and an object stacked on the first member is not limited to a layered one.

[0018] The housing 23 forms an accommodation space S10 therein. The accommodation space S10 of the housing 23 includes an accommodation space inside the cover 21 and an accommodation space inside the base member 22. The plurality of liquid ejecting heads 10, the common flow path member 30, and the circuit board portion 40 are accommodated in the accommodation space S10.

[0019] The base member 22 supports a plurality of liquid injection heads 10 and a common flow path member 30. The circuit board portion 40 and the cover 21 are fixed to the base member 22. As shown in Figure 3, the cover 21 is positioned in the Z2 direction relative to the base member 22. The cover 21 is stacked on the base member 22. The cover 21 is not limited to being directly attached to the base member 22, but may be attached via other members. Also, the cover 21 may be composed of multiple members. Similarly, the base member 22 may be composed of multiple members.

[0020] Most of the liquid injection head 10 is housed in the housing space S10 within the base member 22. The portion of the liquid injection head 10 in the Z1 direction, including the injection surface F1, may be located outside the base member 22. Figure 4 shows the injection surfaces F1 of multiple liquid injection heads 10. The injection surfaces F1 are exposed to the outside.

[0021] The base member 22 shown in Figures 2 and 3 includes a frame portion 22a. The frame portion 22a is rectangular in shape when viewed in the Z-axis direction. The frame portion 22a has side walls 24 to 27. Side walls 24 and 25 are spaced apart in the Y-axis direction. The thickness direction of side walls 24 and 25 is along the Y-axis direction. Side wall 25 is located in the Y2 direction relative to side wall 24. Side walls 26 and 27 are spaced apart in the X-axis direction. The thickness direction of side walls 26 and 27 is along the X-axis direction. Side wall 27 is located in the X2 direction relative to side wall 26.

[0022] The common flow channel member 30 has, for example, a plurality of flow channel substrates 31 to 33. The thickness direction of the plurality of flow channel substrates 31 to 33 is along the Z-axis direction. The flow channel substrates 31 to 33 are stacked in the Z-axis direction. As shown in Figure 3, a plurality of common flow channels 50 are formed inside the common flow channel member 30. At least one of grooves and through holes is formed in the flow channel substrates 32 and 33. The flow channel substrate 31 has a through hole that communicates with the groove in the flow channel substrate 32. The flow channel substrate 32 has a through hole that communicates with the groove in the flow channel substrate 33. These grooves and through holes constitute the common flow channels 50 through which the ink flows.

[0023] The common flow path member 30 is positioned in the Z2 direction relative to the multiple liquid injection heads 10. In the Z-axis direction, the common flow path member 30 is positioned between the circuit board portion 40 and the liquid injection heads 10. The flow path substrate 31 is positioned closer to the liquid injection heads 10 than the flow path substrate 32 in the Z-axis direction. The flow path substrate 33 is positioned in the Z2 direction relative to the flow path substrate 32. In this embodiment, the common flow path member 30 is composed of three flow path substrates 31 to 33, but the common flow path member 30 may also be constructed by stacking two flow path substrates 31 and 32.

[0024] The flow path substrate 32 has a main body portion 32a and a projection portion 32b that protrudes from the main body portion 32a in the Y2 direction. The main body portion 32a is substantially rectangular when viewed in the Z-axis direction. The main body portion 32a of the flow path substrate 32 is positioned between the flow path substrate 31 and the flow path substrate 33 in the Z-axis direction. The projection portion 32b of the flow path substrate 32 is positioned so as not to overlap with the flow path substrates 31 and 33 in the Z-axis direction. Figure 5 is a plan view showing the head unit 20 with the cover 21 not attached. As shown in Figure 5, the projection portion 32b of the flow path substrate 32 is exposed to the outside when viewed in the Z-axis direction. The flow path substrate 32 is provided with a plurality of flow path pipes 35 that protrude in the Z2 direction. The plurality of flow path pipes 35 are positioned on the projection portion 32b of the flow path substrate 32 and are exposed to the outside. The plurality of flow path pipes 35 communicate with a common flow path 50 in the common flow path member 30.

[0025] The common channel 50 of the common channel member 30 is connected to the supply channel 7 and discharge channel 8 shown in Figure 1 via the flow channel pipe 35. Ink flowing through the supply channel 7 flows through the common channel 50 in the common channel member 30 and is supplied to the multiple liquid spray heads 10. Ink discharged from the multiple liquid spray heads 10 flows through the common channel 50 in the common channel member 30 and flows into the discharge channel 8. Ink that has flowed through the discharge channel 8 is collected in the sub-tank 2b.

[0026] The circuit board section 40 includes a relay board 41 and a control board 42. The thickness direction of the relay board 41 and the control board 42 is aligned with the Z-axis direction. The relay board 41 is located in the Z2 direction relative to the common flow path member 30. The control board 42 is located in the Z2 direction relative to the relay board 41. The relay board 41 and the control board 42 are spaced apart in the Z-axis direction.

[0027] The relay board 41 is mounted on the base member 22. The base member 22 is provided with a stepped surface 22b on which the relay board 41 is placed. The stepped surface 22b is formed at the Z2 direction end of the frame portion 22a of the base member 22. The stepped surface 22b is positioned offset in the Z1 direction from the Z2 direction end face 22c of the frame portion 22a. The peripheral edge of the Z1 direction facing surface 41b of the base member 22 is positioned to be in contact with the stepped surface 22b.

[0028] The relay board 41 is fixed to the base member 22. The relay board 41 is screwed to the base member 22. The control board 42 is screwed to the base member 22. The relay board 41 and the control board 42 are electrically connected by wiring (not shown). The relay board 41 extends across the multiple liquid spray heads 10 in the X-axis direction. The relay board 41 is positioned to overlap the multiple liquid spray heads 10 when viewed in the Z-axis direction.

[0029] The relay board 41 is electrically connected to the connector 19 of the liquid injection head 10 via a flexible wiring board 43. The relay board 41 is, for example, a rigid board. The flexible wiring board 43 may be, for example, an FFC. The relay board 41 is provided with a connector 44 that connects to the flexible wiring board 43. As shown in Figure 3, the relay board 41 includes a surface 41a and a surface 41b. Surface 41a is the surface facing the Z2 direction, and surface 41b is the surface facing the Z1 direction. Surface 41b is the surface opposite to surface 41a. The connector 44 of the relay board 41 is located on surface 41a. Surface 41a is an example of a "first surface of the wiring board", and surface 41b is an example of a "second surface of the wiring board".

[0030] The relay board 41 divides the housing space S10 within the housing 23 in the Z-axis direction. In other words, the housing space S10 within the housing 23 includes housing spaces S11 and S12 located in the Z2 direction relative to the relay board 41, and housing space S13 located in the Z1 direction relative to the relay board 41.

[0031] As shown in Figures 2 and 5, the control board 42 is provided with one or more IC chips 47 and a heat sink 45. The control board 42 is, for example, a rigid board. The IC chip 47 includes a drive signal generation circuit. The drive signal generation circuit can generate a drive signal for driving the piezoelectric element of the liquid spray head 10. The IC chip 47 may also include a step-down circuit or a step-up circuit that can generate a reference voltage signal which will be the reference potential when ink is sprayed from the liquid spray head 10. The relay board 41 and the control board 42 include circuit elements 48, wiring, connectors and other electrical components. At least one or more circuit elements 48 are stacked on the relay board 41. The circuit elements 48 include, for example, discrete components such as resistors, capacitors, transistors and coils.

[0032] The longitudinal direction of the relay board 41, the control board 42, and the heat sink 45 is along the X-axis direction. The short direction of the relay board 41, the control board 42, and the heat sink 45 is along the Y-axis direction. In the X-axis, the relay board 41 is longer than the control board 42. When viewed in the Z-axis direction, the relay board 41 protrudes further in the X2 direction than the control board 42. In other words, the relay board 41 extends closer to the side wall 27 of the base member 22 than the control board 42.

[0033] The heatsink 45 is positioned in approximately the same location as the control board 42 in the X-axis direction. Viewed in the Z-axis direction, the relay board 41 protrudes further in the X2 direction than the heatsink 45.

[0034] The relay board 41 has a main body portion 41c and a protruding portion 41d that protrudes from the main body portion 41c in the Y2 direction. The main body portion 41c is substantially rectangular in shape when viewed in the Z-axis direction. The protruding portion 41d is substantially rectangular in shape when viewed in the Z-axis direction. The protruding portion 41d is positioned near the end in the X2 direction and protrudes in the Y2 direction. When viewed in the Z-axis direction, the protruding portion 41d is positioned in the X2 direction relative to the protruding portion 32b of the flow channel board 32. When viewed in the Z-axis direction, the protruding portion 41d is positioned in the X2 direction relative to the heat sink 45 and the control board 42.

[0035] The relay board 41 is provided with connectors 46A and 46B for connecting to the external electrical wiring 49A and 49B of the head unit 20. Connector 46A is an example of a "first connector". Connector 46B is an example of a "second connector". The relay board 41 is an example of a "wiring board having a first connector". Note that connector 46B may be the "first connector" and connector 46A may be the "second connector".

[0036] Connectors 46A and 46B are provided on the protruding portion 41d of the relay board 41. Connectors 46A and 46B are positioned on the surface 41a of the protruding portion 41d of the relay board 41 facing the Z2 direction. An opening for inserting electrical wiring 49A is formed on the surface of connector 46A facing the Z2 direction. Similarly, an opening for inserting electrical wiring 49B is formed on the surface of connector 46B facing the Z2 direction.

[0037] The cover 21 is fixed to the base member 22. The cover 21 is screwed to the base member 22. As shown in Figure 2, the cover 21 has a first part 70 and a second part 80. The first part 70 is positioned to cover a portion of the relay board 41, the control board 42, and the heat sink 45. Here, "a portion of the relay board 41" refers to the portion that overlaps with the control board 42 when viewed in the Z-axis direction. The second part 80 covers the remaining portion of the relay board 41 and the connectors 46A and 46B. The connectors 46A and 46B are positioned to be exposed to the outside through openings 55A and 55B, which will be described later, but are covered by the second part 80 of the cover 21.

[0038] The cover 21 has an air intake port 91 and an exhaust port 92. The air intake port 91 is formed at the X1 direction end of the first portion 70 of the cover 21. An opening, which is the air intake port 91, is formed at the X1 direction end of the first portion 70 of the cover 21. Air from outside the cover 21 flows into the interior of the cover 21 through the air intake port 91. The air that flows in from the air intake port 91 flows in the X2 direction inside the first portion 70 of the cover 21 and flows into the second portion 80 of the cover 21. The air that flows inside the first portion 70 of the cover 21 cools the IC chip 47 and the like via the heat sink 45.

[0039] Figure 6 is a plan view showing a part of the head unit 20. As shown in Figures 2 and 6, the exhaust port 92 is formed in the wall 80b in the Y1 direction of the second part 80 of the cover 21. Also, as shown in Figure 6, a part of the exhaust port 92 may be formed in the portion of the wall 80a in the Z2 direction of the second part 80 that is close to the wall 80b. The thickness direction of the wall 80a is along the Z-axis direction. The thickness direction of the wall 80b is along the Y-axis direction. When viewed in the Z-axis direction, the exhaust port 92 is located in the Y1 direction with respect to the connectors 46A and 48B. Air flowing from the first part 70 into the interior of the second part 80 changes direction in the Y1 direction and is discharged to the outside of the cover 21 through the exhaust port 92.

[0040] Next, the openings 55A and 55B provided in the cover 21 will be described. Figure 7 is a plan view showing an enlarged view of the openings 55A and 55B provided in the cover 21, and the connectors 46A and 46B exposed from the openings 55A and 55B. Figure 8 is an enlarged cross-sectional view showing an enlarged view of a part of the head unit 20. As shown in Figures 6 to 8, the cover 21 has openings 55A and 55B. The openings 55A and 55B are aligned in the X-axis direction. Opening 55A is located in the X1 direction of opening 55B. Opening 55A exposes connector 46A to the outside. Opening 55B exposes connector 46B to the outside.

[0041] The openings 55A and 55B are formed in the wall 80c of the cover 21. The wall 80c includes a surface facing the Z2 direction. The thickness direction of the wall 80c is aligned with the Z-axis direction. Viewed in the Z-axis direction, the wall 80c is positioned in the Y2 and Z1 directions relative to the wall 80a. The Z2-direction tip of the opening 55A is located Z2 further than the Z2-direction end of the connector 46A. Similarly, the Z2-direction tip of the opening 55B is located Z2 further than the Z2-direction end of the connector 46B.

[0042] As shown in Figure 8, the cover 21 is provided with ribs 28. The ribs 28 protrude from the wall 80c of the cover 21 in the Z1 direction. The thickness direction of the ribs 28 is along the Y-axis direction. The ribs 28 extend in the X-axis direction. Connectors 46A and 46B are positioned in the Y2 direction relative to the ribs 28.

[0043] Next, the flexible member 65 will be described. The head unit 20 is equipped with a flexible member 65. As shown in Figure 8, the flexible member 65 is located in the housing space S10 of the housing 23 of the head unit 20. The housing space S10 includes a first space S11 which includes connectors 46A, 46B and openings 55A, 55B, and a second space S12 which is larger than the first space S11. The flexible member 65 divides the housing space S10 into the first space S11 and the second space. Note that "dividing" is not limited to complete division. For example, even if a small gap is formed between the first space S11 and the second space S12, if resistance is formed so that mist or paper dust does not move through the gap, this is also included in "dividing". Here, "the first space S11 includes openings 55A, 55B" means that each of the openings 55A, 55B defines the first space S11.

[0044] In this embodiment, the rib 28 is located between the first space S11 and the second space S12. The first space S11 is located in the Y2 direction relative to the rib 28. The second space S12 is located in the Y1 direction relative to the rib 28. The flexible member 65 is sandwiched between the rib 28 and the intermediate substrate 41 in the X-axis direction. The flexible member 65 is on the surface 41a of the intermediate substrate 41 and is arranged in the Z1 direction relative to the rib 28. The multiple circuit elements 48 are arranged in the second space S12 and are not present in the first space S11. Note that the circuit elements 48 may be located in positions that overlap with the flexible member 65 when viewed in the Z-axis direction.

[0045] As shown in Figure 5, the flexible member 65 is linear in shape along the boundary between the protrusion 41d and the main body 41c when viewed in the Z-axis direction. The flexible member 65 overlaps the boundary line between the protrusion 41d and the main body 41c when viewed in the Z-axis direction. In the X-axis direction, the flexible member 65 is provided across both connectors 46A and 46B and is longer than the protrusion 41d.

[0046] As shown in Figure 8, the flexible member 65, together with the rib 28, demarcates the first space S11 and the second space S12. However, the flexible member 65 is not limited to demarcating the first space S11 and the second space S12 together with the rib 28. For example, the flexible member 65 may be positioned differently from the rib 28 when viewed in the Z-axis direction, and the first space S11 and the second space S12 may be demarcated by the flexible member 65 alone.

[0047] Furthermore, the first space S11 does not necessarily have to accommodate all of the connectors 46A and 46B. For example, the first space S11 may include an opening 55A and include at least a portion of the connector 46A. That is, the end of the connector 46A on the +Z2 direction side may protrude to the outside of the cover 21 through the opening 55A. Similarly, the first space S11 may include an opening 55B and include at least a portion of the connector 46B. Alternatively, the first space S11 may include openings 55A and 55B and include at least a portion of the connector 46A and at least a portion of the connector 46B.

[0048] Furthermore, the accommodation space S10 may include a plurality of first spaces S11. For example, the accommodation space S10 may include a first space S11 including at least a part of the connector 46A and the opening 55A, a first space S11 including at least a part of the connector 46B and the opening 55B, and a second space S12. In this case, where a plurality of first spaces S11 are included, the second space S12 may have a volume greater than the sum of the volumes of the plurality of first spaces S11. Also, the second space S12 may have a volume greater than the first space S11 with the largest volume among the plurality of first spaces S11.

[0049] The flexible member 65 is elastic and compressible. The flexible member 65 is deformable when sandwiched between the rib 28 and the intermediate substrate 41. The flexible member 65 can be crushed in the Z1 direction by the rib 28 to seal the gap between the rib 28 and the intermediate substrate 41. The flexible member 65 can suppress the transmission of mist and paper dust. Mist may be generated by separation from the ink sprayed from the liquid spray head 10. Paper dust may be generated by some of the medium PA becoming pulverized.

[0050] The flexible member 65 may be an insulating Thermon sheet. Thermon sheet is a registered trademark. Thermon sheet is a silicone sheet that has thermal conductivity, electrical insulation, and flame retardancy. If the flexible member 65 has electrical insulation properties, problems are less likely to occur even if the flexible member 65 comes into contact with the metal wiring or circuit elements 48 of the relay substrate 41.

[0051] The flexible member 65 may be, for example, an elastomer. The flexible member 65 may also be other resins or rubbers.

[0052] Furthermore, the thermal conductivity of the flexible member 65 may be, for example, 1.0 W / m·K or higher. When the thermal conductivity of the flexible member 65 is 1.0 W / m·K or higher, the heat from the relay substrate 41 can be transferred to the cover 21 via the flexible member 65.

[0053] Furthermore, when the flexible member 65 is positioned to straddle a part of the circuit element 48, it is preferable that the flexible member 65 be a gel-type or putty-type silicone sheet so that it can follow the irregularities of the outer shape of the circuit element 48. The flexible member 65 may also be, for example, a rubber-type silicone sheet. A flexible member 65 that is a gel-type or putty-type silicone sheet has better conformability to the shape of the circuit element 48 than a rubber-type silicone sheet.

[0054] Next, with reference to Figure 6, the duct 93 and fan 94 connected to the exhaust port 92 of the cover 21 will be described. The duct 93 and fan 94 are connected to the exhaust port 92 of the cover 21. The duct 93 extends in the Y1 direction relative to the exhaust port 92. The fan 94 is positioned in the Y1 direction relative to the duct 93. The fan 94 draws in air from inside the cover 21. As described above, the air that flows into the cover 21 from the intake port 91 flows in the X2 direction, passes through the exhaust port 92, and is discharged into the duct 93. The air inside the duct 93 passes through the fan 94 and is discharged to the outside.

[0055] Since the first space S11 and the second space S12 of the containment space S10 inside the cover 21 are separated by the flexible member 65, the flow of air from the first space S11 to the second space S12 is suppressed. As a result, the intrusion of mist and foreign matter such as paper dust from the first space S11 to the second space is suppressed.

[0056] Furthermore, the flexible member 65 is positioned so as not to come into contact with the electrical wiring 49A and 49B, which are external wiring components, when connecting them to the connectors 46A and 46B. Therefore, in the head unit 20, the flexible member 65 does not get in the way when connecting the electrical wiring 49A and 49B to the connectors 46A and 46B, improving the ease of inserting and removing the electrical wiring 49A and 49B.

[0057] As described above, the head unit 20 of this embodiment is a head unit 20 equipped with connectors 46A and 46B for connecting to external electrical wiring 49A and 49B, comprising a relay board 41 having connectors 46A and 46B, a housing 23 of the head unit 20 having openings 55A and 55B for exposing the connectors 46A and 46B to the outside and housing the relay board 41 in a housing space S10, and a flexible member 65 disposed within the housing space S10, wherein the flexible member 65 divides the housing space S10 into a first space S11 including at least a part of the connector 46 and the openings 55A and 55B, and a second space S12 which is larger than the first space S11.

[0058] With this head unit 20, the flexible member 65 positioned near the connectors 46A and 46B can suppress the intrusion of mist and paper dust, and since the flexible member 65 does not cover the openings 55A and 55B, it does not impair the insertion and removal of the external electrical wiring 49A and 49B. Also, because mist tends to accumulate around the connectors 46A and 46B due to the Leonard effect, isolating the first space S11 where the connectors 46A and 46B are located with the flexible member 65 effectively suppresses the intrusion of mist into the second space S12. Preferably, the volume of the second space S12 is five times or more the volume of the first space S11, and more preferably ten times or more the volume of the first space S11. In this way, the first space S11 for arranging the connectors 46A and 46B can be made smaller, thus suppressing the enlargement of the relay board 41.

[0059] The relay board 41 defines the first space S11 and the second space S12, respectively. The portion of the relay board 41 defining the first space S11 does not have any circuit elements 48, while the portion of the relay board 41 defining the second space S12 has one or more circuit elements 48. With a head unit 20 configured in this way, since no circuit elements 48 are provided in the first space S11, even if mist or paper dust enters the first space S11 through the openings 55A and 55B, there is no risk of the mist or paper dust coming into contact with the circuit elements 48. Furthermore, in the head unit 20, the circuit elements 48 are located in the second space S12, and the first space S11 and the second space S12 are separated by a flexible member 65. Therefore, the intrusion of mist or paper dust from the first space S11 into the second space S12 is suppressed, protecting the circuit elements 48 in the second space S12. As a result, the head unit 20 suppresses the occurrence of adverse effects caused by mist or paper dust coming into contact with the circuit elements 48. Here, "the portion of the relay substrate 41 that defines the first space S11" refers to the portion of the surface 41a of the relay substrate 41 that faces the first space S11, and "the portion of the relay substrate 41 that defines the first space S12" refers to the portion of the surface 41a of the relay substrate 41 that faces the second space S12.

[0060] Connectors 46A and 46B are stacked on the surface 41a of the relay board 41. The housing 23 has a base member 22 and a cover 21 stacked on the base member 22. The base member 22 has ribs 28 that protrude from the wall 80c of the cover 21 toward the surface 41a, defining the housing space S10. The flexible member 65 is sandwiched between the surface 41a of the relay board 41 and the ribs 28. With a head unit 20 configured in this way, the cover 21 is laminated on the base member 22, making it easy to remove the cover 21 from the base member 22. Since the cover 21 is placed on the base member 22 and secured with screws, it is easy to remove the cover 21 from the base member 22. In the Z-axis direction, which is the direction in which the cover 21 is laminated on the base member 22, the gap between the cover 21 and the base member 22 may be approximately 0 mm. Specifically, this gap is the gap between the end face 22c of the frame portion 22a of the base member 22 and the cover 21. Also, as can be seen from Figure 5, this gap is provided so as to surround the entire circumference, or almost the entire circumference, of the circuit board portion 40 when viewed in the Z-axis direction. This gap is a tolerance that includes manufacturing errors and is only a small gap. Therefore, there is little risk of mist or paper dust entering the storage space S10 through this gap.

[0061] Furthermore, in the head unit 20 of this embodiment, the flexible member 65 prevents mist and paper dust from entering the second space S12 from the first space S11. Therefore, compared to, for example, a case where the storage space S10 is divided into the first space S11 and the second space S12 with a filler such as adhesive instead of the flexible member 65, the cover 21 is easier to remove from the base member 22. Also, if the cover 21 is fixed to the base member 22 using adhesive, it is not easy to remove the cover 21. However, in the head unit 20 of this embodiment, the cover 21 is fixed to the base member 22 without using adhesive, so the cover 21 is easy to remove.

[0062] The relay substrate 41 has a surface 41b opposite to surface 41a, and the surface 41b of the relay substrate 41 is laminated on the base member 22, thereby separating the first space S11 from the space of the housing space S10 that surface 41b faces.

[0063] In the head unit 20, a third space S13 located in the Z1 direction relative to the surface 41b of the relay substrate 41 contains a plurality of liquid injection heads 10 and a common flow path member 30. The entire outer circumference of the relay substrate 41, excluding the vicinity of the joint of the common flow path member 30, is in contact with the base member 22. The gap between the relay substrate 41 and the base member 22 may be approximately 0 mm. This gap is a tolerance including manufacturing errors and is only a small gap. The gap between the relay substrate 41 and the base member 22 is small, and there is little risk of mist or paper dust entering the first space S11 and the second space S12 through this gap. Even if mist or paper dust were to enter through the gap between the relay substrate 41 and the base member 22, it would be negligible in relation to the problem of suppressing the entry of mist or paper dust into the second space S12.

[0064] According to the head unit 20 of this embodiment, the intrusion of mist and paper dust from the space located in the Z1 direction with respect to the surface 41b of the relay substrate 41 into the first space S11 and the second space S12 on the relay substrate 41 is suppressed.

[0065] When viewed from above towards the relay board 41, the relay board 41 has a main body portion 41c and a protruding portion 41d that protrudes from the main body portion 41c. Connectors 46A and 46B are provided on the protruding portion 41d, a first space S11 is defined by the protruding portion 41d, a second space S12 is defined by the main body portion 41c, and the flexible member 65 is in a straight line along the boundary between the protruding portion 41d and the main body portion 41c when viewed from above.

[0066] In a head unit 20 with this configuration, a linear flexible member 65 is provided, which simplifies and miniaturizes the shape of the flexible member 65. The length of the flexible member 65 in the X-axis direction is slightly longer than the length of the protruding portion 41d in the X-axis direction, and is sufficiently shorter than the length of the main body portion 41c in the X-axis direction. The length of the flexible member 65 along the X-axis direction is preferably 50% or less, and more preferably 30% or less, of the length of the main body portion 41c of the relay substrate 41 in the X-axis direction.

[0067] Furthermore, the flexible member 65 is not limited to being linear. In particular, if the relay substrate 41 is not provided with a protruding portion 41d as in this embodiment, and the relay substrate 41 is formed only by a substantially rectangular main body portion 41c, the first space S11 and the second space S12 can be partitioned by making the flexible member 65 U-shaped, L-shaped, or U-shaped, while suppressing an increase in the size of the flexible member 65 compared to the case where the flexible member 65 is linear.

[0068] The housing 23 has an intake port 91 for drawing air into the second space S12 from the outside, and an exhaust port 92 for discharging air from the second space S12 to the outside. The openings 55A and 55B and the exhaust port 92 face each other via a flexible member 65 with respect to the short direction perpendicular to the longitudinal direction of the relay substrate 41. In this embodiment, the longitudinal direction of the relay substrate 41 is the X-axis direction, and the short direction is the Y-axis direction. It is sufficient that at least a portion of the openings 55A and 55B and the exhaust port 92 overlap in the Y-axis direction.

[0069] In this configuration of the head unit 20, the airflow directed towards the exhaust port 92 in the Y1 direction makes it easier to draw in gas containing mist and paper dust from the openings 55A and 55B into the first space S11. However, the head unit 20 of this embodiment is equipped with a flexible member 65 that separates the first space S11 and the second space S12, so the inflow of gas from the first space S11 to the second space S12 is suppressed.

[0070] Furthermore, in the head unit 20, the air intake port 91 is located outside the printing area created by the multiple liquid spray heads 10 in the X-axis direction. The printing area is narrower in the X-axis direction than the width of the media PA in the X-axis direction. Therefore, there is little risk of mist or paper dust entering the second space S12 from the air intake port 91.

[0071] Furthermore, in the head unit 20, the storage space S10 is divided in the Z-axis direction by the relay board 41. When the Z-axis direction is aligned with the direction of gravity, the storage space S10 is divided vertically by the relay board 41. The connectors 46A, 46B and the exhaust port 92 are located in the storage space S10 divided by the relay board 41, specifically in the storage space S10 that is closer to surface 41a than surface 41b of the relay board 41. In the head unit 20 with this configuration, a flexible member 65 is placed between the first space S11 and the second space S12, so that the intrusion of air from the first space S11, including the openings 55A, 55B, into the second space S12, including the exhaust port 92, is suppressed. As a result, the intrusion of mist and paper dust into the second space S12 is suppressed.

[0072] Furthermore, the liquid injection device 1 includes a head unit 20 and external electrical wiring 49A and 49B connected to connectors 46A and 46B, which are located outside the head unit 20.

[0073] Furthermore, the liquid injection device 1 is equipped with a fan 94 located on the exhaust port 92 side, and the relay board 41 located in the housing space S10 is cooled by the fan 94. The exhaust port 92 side refers to a position closer to the exhaust port 92 than to the intake port 91. The fan 94 may also be located closer to the intake port 91. For example, the fan 94 may be located in the X1 direction relative to the intake port 91.

[0074] <2. Second Embodiment> Next, the head unit 20 according to the second embodiment will be described with reference to Figure 9. Figure 9 is an enlarged cross-sectional view showing the main part of the head unit 20 according to the second embodiment. The difference between the head unit 20 of the second embodiment and the head unit 20 of the first embodiment is that a recess 29 is formed on the tip surface 28a of the rib 28 of the cover 21, and a part of the flexible member 65B is arranged in the recess 29. Note that in the description of the second embodiment, explanations similar to those of the first embodiment may be omitted.

[0075] The cover 21 includes a rib 28 with a recess 29 formed on its tip surface 28a. The tip surface 28a is the surface facing in the Z1 direction. The tip surface 28a is positioned in the Z2 direction relative to the surface 41a of the relay substrate 41. The recess 29 is recessed from the tip surface 28a in the Z2 direction. The recess 29 is continuous in the X-axis direction. Although not shown in the figures, it is preferable that the entire circumference of the flexible member 65B is surrounded by the inner wall surface of the recess 29 when viewed in the Z-axis direction, which is the protruding direction of the rib 28. The length of the recess 29 in the X-axis direction is approximately the same as the length of the flexible member 65B in the X-axis direction. The recess 29 only needs to be able to hold the flexible member 65B.

[0076] The head unit 20 includes a flexible member 65B. The flexible member 65B is located between the first space S11 and the second space S12. Together with the rib 28, the flexible member 65B divides the first space S11 and the second space S12.

[0077] A portion of the flexible member 65B is positioned within the recess 29, and a portion of the flexible member 65B protrudes in the Z1 direction beyond the tip surface 28a.

[0078] A recess 29 is formed on the tip surface 28a of the rib 28, which is recessed away from the surface 41a, and the flexible member 65B is positioned within the recess 29 of the rib 28 so as to protrude from the tip surface 28a of the rib 28.

[0079] According to the head unit 20 of this second embodiment, the flexible member 65B is positioned relative to the tip surface 28a of the rib 28, so that the flexible member 65B does not shift. Also, when removing the cover 21 from the base member 22, the base member 22 can be removed together with the cover 21, so that the cover 21 can be easily replaced. When attaching the cover 21 to the base member 22, the flexible member 65B can also be positioned together with the cover 21.

[0080] Furthermore, it is preferable that the tackiness of the surface of the flexible member 65B that contacts the rib 28 is greater than the tackiness of the surface of the flexible member 65B that contacts the surface 41a of the intermediate substrate 41. Note that tackiness may also refer to the property that the flexible member 65B is less likely to separate from the surface of other members. When tackiness is high, it is less likely to separate from other members compared to when tackiness is low.

[0081] Furthermore, the flexible member 65B may be formed integrally with the rib 28 by two-color molding or the like.

[0082] <3. Third Embodiment> Next, the head unit 20 according to the third embodiment will be described with reference to Figures 10 and 11. Figure 10 is an enlarged cross-sectional view showing the main part of the head unit 20 according to the third embodiment. Figure 11 is an enlarged plan view showing an opening provided in the cover and a connector exposed from the opening. The differences between the head unit 20 of the third embodiment and the head unit 20 of the first embodiment are the arrangement of the flexible members 65C and 65D, and the ranges of the first space S21 and the second space S22. Note that in the description of the third embodiment, explanations similar to those of the first embodiment may be omitted.

[0083] The head unit 20 includes flexible members 65C and 65D. Flexible member 65C is positioned around connector 46A, and flexible member 65D is positioned around connector 46B. When viewed in the Z-axis direction, the flexible members 65C and 65D form a rectangular frame. The inner circumferential surface 65e of flexible member 65C abuts against the outer circumferential surface 46e of connector 46A. The outer circumferential surface 65f of flexible member 65C abuts against the inner circumferential surface 55f of opening 55A. The inner circumferential surface 65g of flexible member 65D abuts against the outer circumferential surface 46g of connector 46B. The outer circumferential surface 65h of flexible member 65D abuts against the inner circumferential surface 55h of opening 55B.

[0084] The flexible members 65C and 65D have a predetermined thickness in the Z-axis direction. The openings 55A and 55B may have a predetermined length in the Z-axis direction. The flexible member 65C is positioned in the Z1 direction relative to the Z2 end face 46j of the connector 46A. The flexible member 65D is positioned in the Z1 direction relative to the Z2 end face 46k of the connector 46B. The flexible members 65C and 65D are positioned so as not to interfere with the attachment of external electrical wiring 49A and 49B to the connectors 46A and 46B. The flexible members 65C and 65D are not positioned in the Z2 direction relative to the connectors 46A and 46B.

[0085] The flexible members 65C and 65D divide the housing space S10 into a first space S21 and a second space S22. In the Z-axis direction, the first space S21 includes a space located in the Z2 direction relative to the flexible members 65C and 65D. The second space S22 includes a space located in the Z1 direction relative to the flexible members 65C and 65D. The first space S21 includes at least a portion of the connectors 46A and 46B and the openings 55A and 55B. The first space S21 has a space including at least a portion of the connector 46A and the opening 55A, and a space including at least a portion of the connector 46B and the opening 55B. The first space S21 may have a plurality of separate spaces.

[0086] In the head unit 20 according to the third embodiment, the flexible member 65 is not placed between the tip surface 28a of the rib 28 and the surface 41a of the relay substrate 41, but the flexible member 65 may be further placed between the rib 28 and the relay substrate 41. Also, although the flexible members 65C and 65 are placed spaced apart from the surface 41a of the relay substrate 41 in the Z-axis direction, the flexible members 65C and 65D may be placed so as to abut against the outer peripheral surfaces 46e and 46g of the connectors 46A and 46B, as well as abut against the surface 41a of the relay substrate 41.

[0087] The flexible member 65C is sandwiched between the inner circumferential surface 55f of the opening 55A and the outer circumferential surface 46e of the connector 46A. The flexible member 65D is sandwiched between the inner circumferential surface 55h of the opening 55B and the outer circumferential surface 46g of the connector 46B. The head unit 20 may be equipped with such flexible members 65C and 65D. The head unit 20 according to the third embodiment provides the same effects as the head unit 20 according to the first embodiment.

[0088] Opening 55A is a through-hole formed in the housing 23, and the flexible member 65C is sandwiched between the entire inner circumferential surface 55f of opening 55A and the entire outer circumferential surface 46e of connector 46A, when viewed in the direction in which the external electrical wiring 49A is inserted into connector 46A. Opening 55B is a through-hole formed in the housing 23, and the flexible member 65D is sandwiched between the entire inner circumferential surface 55h of opening 55B and the entire outer circumferential surface 46g of connector 46B, when viewed in the direction in which the external electrical wiring 49B is inserted into connector 46B. "The entire inner circumferential surface 55f" and "the entire inner circumferential surface 55h" include the entire circumference when viewed in the Z-axis direction. "The entire outer circumferential surface 46e" and "the entire outer circumferential surface 46g" include the entire circumference when viewed in the Z-axis direction. Insertion of electrical wiring 49A into connector 46A includes electrical connection between electrical wiring 49A and connector 46A. The insertion of electrical wiring 49B into connector 46B includes the electrical connection between electrical wiring 49B and connector 46B. The direction in which electrical wiring 49A is inserted into connector 46A is along the Z-axis direction. The direction in which electrical wiring 49B is inserted into connector 46B is along the Z-axis direction.

[0089] With this head unit 20, the intrusion of mist and paper dust into the second space S22 on the opposite side of the openings 55A and 55B into the flexible members 65C and 65D can be reduced. For example, if the terminals 46m of connectors 46A and 46B are provided on the surface 41a of the relay board 41, these terminals 46m will be located in the second space S22. In the head unit 20 according to the third embodiment, the inflow of air from the first space S21 to the second space S22 is suppressed by the flexible members 65C and 65D, so there is a low risk of mist and paper dust adhering to the terminals 46m of connectors 46A and 46B in the second space S22. Although the terminals 46m of connector 46A are shown in Figure 10, the terminals 46m of connector 46B are formed in a similar manner.

[0090] <4. Fourth Embodiment> Next, the head unit 20 according to the fourth embodiment will be described with reference to Figures 12 and 13. Figure 12 is an enlarged cross-sectional view showing the main part of the head unit 20 according to the fourth embodiment. Figure 13 is an enlarged plan view showing the opening 55C provided in the cover 21 and the connector 46C exposed from the opening 55C. The differences between the head unit 20 of the fourth embodiment and the head unit 20 of the first embodiment are the arrangement of the connector 46C, the arrangement of the opening 55C, the arrangement of the flexible member 65I, and the ranges of the first space S31 and the second space S32. Note that in the description of the fourth embodiment, explanations similar to those of the first to third embodiments may be omitted.

[0091] The head unit 20 is equipped with a connector 46C. The connector 46C is connected to an external electrical wiring 49C. An opening for inserting the external electrical wiring 49C is formed on the Y2-facing side of the connector 46C. The direction in which the electrical wiring 49C is inserted into the connector 46C is along the Y-axis. When connecting the electrical wiring 49C to the connector 46C, the electrical wiring 49C is moved in the Y1 direction.

[0092] The cover 21 has an opening 55C formed therein for exposing the connector 46C to the outside. The opening 55C is positioned in the Y2 direction relative to the connector 46C.

[0093] The head unit 20 includes a flexible member 65I. The flexible member 65I is positioned around the connector 46C. When viewed in the Y-axis direction, the flexible member 65I includes a portion 65i1 extending in the X-axis direction, portions 65i2 and 65i3 extending in the Z1 direction from both ends of portion 65i1 in the X-axis direction, a portion 65i4 extending in the X1 direction from the Z1 end of portion 65i2, and a portion 65i5 extending in the X2 direction from the Z1 end of portion 65i3. When viewed in the Y-axis direction, portion 65i1 is positioned in the Z2 direction relative to the connector 46C, portion 65i2 is positioned in the X1 direction relative to the connector 46C, and portion 65i3 is positioned in the X2 direction relative to the connector 46C. Since the surface of connector 46C facing the Z1 direction is in contact with surface 41a of the relay board 41, there is no need to position the flexible member 65I in the Z1 direction of connector 46C.

[0094] The inner circumferential surfaces 65e of the flexible member 65C, specifically the inner circumferential surfaces 65e of portions 65i1, 65i2, and 65i3, abut against the outer circumferential surface 46e of the connector 46C. The outer circumferential surface 65f of the flexible member 65C abuts against the inner circumferential surface 55f of the opening 55C.

[0095] The flexible member 65I has a predetermined thickness in the Y-axis direction. The opening 55C may have a predetermined length in the Y-axis direction. The flexible member 65I is positioned in the Y1 direction relative to the Y2 direction end face 46n of the connector 46C. The flexible member 65I is positioned so as not to interfere with the attachment of external electrical wiring 49C to the connector 46C. The flexible member 65C is not positioned in the Y2 direction relative to the connector 46C.

[0096] The flexible member 65I divides the housing space S10 into a first space S31 and a second space S32. In the Z-axis direction, the first space S31 includes a space located in the Y2 direction relative to the flexible member 65I. The second space S32 includes a space located in the Y2 direction relative to the flexible member 65I. The first space S31 includes at least a portion of the connector 46C and the opening 55C.

[0097] The flexible member 65I is sandwiched between the inner circumferential surface 55f of the opening 55C and the outer circumferential surface 46e of the connector 46C. The head unit 20 may be equipped with such a flexible member 65I. The head unit 20 according to the third embodiment provides the same effects as the head unit 20 according to the first embodiment.

[0098] In the head unit 20 according to the third embodiment, the connector 46C is laminated on the surface 41a of the relay board 41, the housing 23 has a cover 21 and a base member 22 laminated on the cover 21, and the flexible member 65C is sandwiched between the surface 41a of the relay board 41, the outer peripheral surface 46e of the connector 46C and the inner peripheral surface 55f of the opening 55C.

[0099] In the head unit 20 with this configuration, the cover 21 can be easily removed from the base member 22 by moving it in the Z2 direction. Also, when attaching the cover 21 to the base member 22, the cover 21 can be easily stacked on the base member 22 by moving it in the Z1 direction. Therefore, in the head unit 20 according to the third embodiment, the cover 21 is easy to attach and detach.

[0100] Furthermore, the opening 55C has a notched shape and is open in the Z1 direction with no peripheral edge.

[0101] <5. Fifth Embodiment> Next, the housing 1a of the liquid injection device 1, which houses the head unit 20 according to the above embodiment, will be described. Figure 14 is a side view showing the housing 1a of the liquid injection device 1, which houses the head unit 20. As shown in Figure 14, the head unit 20 and the media transport mechanism 4 are housed inside the housing 1a. The control unit 3 may also be housed inside the housing 1a. The housing 1a is, for example, box-shaped. The housing 1a has, for example, an openable and closable door.

[0102] For example, the user can open the door and plug the electrical wiring 49A and 49B, which are located outside the head unit 20 and inside the housing 1a, into connectors 46A and 46B to connect the control unit 3 and the head unit 20. Also, for example, when replacing the head unit 20, the user can disconnect the electrical wiring 49A and 49B from connectors 46A and 46B.

[0103] The liquid injection device 1 of this embodiment includes a housing 1a that houses a head unit 20, and the openings 55A and 55B face into the housing 1a of the liquid injection device 1. Facing into the housing 1a means that when the head unit 20 is housed inside the housing 1a, the openings 55A and 55B are located inside the housing 1a.

[0104] When the liquid ejection device 1 is in use, the head unit 20 is housed inside the housing 1a. Ink is ejected from the liquid ejection head 10, and there is a risk that mist separated from the ink may float inside the housing 1a. However, in the head unit 20, the inflow of air from the first space S11 to the second space S12 is suppressed by the flexible member 65. Therefore, there is no risk of mist or paper dust adhering to the circuit elements 48 in the second space S12. As a result, the reliability of the head unit 20 can be improved.

[0105] Furthermore, for example, during maintenance, when attaching or detaching the external electrical wiring 49A and 49B to the head unit 20, the flexible member 65 does not get in the way, thus not impairing the ease of inserting and removing the electrical wiring 49A and 49B.

[0106] <6. Variation> The embodiments described above merely represent typical forms of the present invention, and the present invention is not limited to the embodiments described above. Various modifications and additions are possible without departing from the spirit of the present invention.

[0107] [Example 1] In the above embodiment, the case in which the thickness direction of the relay substrate 41 is aligned with the Z-axis direction is described, but the thickness direction of the relay substrate 41 is not limited to the Z-axis direction. The thickness direction of the relay substrate 41 may be aligned with the X-axis direction, the Y-axis direction, or other directions. The relay substrate 41 may also be arranged vertically so as to be aligned with the Y-axis direction.

[0108] [Differentiation 2] In the above embodiment, the case in which connectors 46A and 46B are arranged on the surface 41a of the relay board 41 is described, but connectors 46A and 46B may also be arranged on the surface 41b of the relay board 41. For example, connector 46A may be arranged on the surface 41a of the relay board 41, and connector 46B may be arranged on the surface 41b of the relay board 41. It is also possible to have a configuration in which connectors 46A and 46B are arranged on both sides of the relay board 41.

[0109] [Difference 3] In the above embodiment, the case in which the first space S11 and the second space S12 are arranged in the Z2 direction with respect to the surface 41a of the relay substrate 41 has been described. However, the first space S11 and the second space S12 may be arranged in the Z1 direction with respect to the surface 41b of the relay substrate 41.

[0110] [Differentiation Example 4] Although the above embodiment describes a case where there is one relay board 41, the head unit 20 may also have multiple relay boards 41.

[0111] [Difference 5] In the above embodiment, a case is described in which one opening 55A is formed for one connector 46A, but for example, an opening common to multiple connectors 46A, 46B may be formed. In other words, a configuration in which multiple connectors are exposed to the outside from a single opening is also possible.

[0112] [Modification 6] In the above embodiment, the case in which the exhaust port 92 is formed in the wall 80b of the cover 21 is described, but for example, it may be formed in the wall 80a of the cover 21 or in a wall facing the X2 direction.

[0113] In the embodiments described above, a line-type liquid injection device 1 equipped with a line head 6 is illustrated, but the present invention may also be applied to a serial-type liquid injection device in which a carriage equipped with a liquid injection head 10 is reciprocated in the width direction of the medium PA.

[0114] The liquid spraying device 1 illustrated in the above-described embodiment can be used in various devices such as facsimile machines and photocopiers, in addition to equipment dedicated to printing. However, the applications of the liquid spraying device of the present invention are not limited to printing. For example, a liquid spraying device that dispenses a colorant solution can be used as a manufacturing device for forming color filters for display devices such as liquid crystal display panels. A liquid spraying device that dispenses a conductive material solution can be used as a manufacturing device for forming wiring and electrodes on a wiring board. A liquid spraying device that dispenses a solution of organic matter related to living organisms can be used, for example, as a manufacturing device for producing biochips. [Explanation of Symbols]

[0115] 1...Liquid injection device, 1a...Housing of liquid injection device, 10...Liquid injection head, 20...Head unit, 21...Cover, 22...Base member, 23...Housing, 28...Rib, 28a...Tip surface, 29...Recess, 41...Intermediate board, 41a...Surface, 41b...Surface, 41c...Main body, 41d...Protruding part, 46A...Connector, 46B...Connector, 48...Circuit element, 49A,49B...External electrical wiring, 55A,55B,55C...Opening, 65,65B,65C,65D,65I...Flexible member, 91...Intake port, 92...Exhaust port, 94...Fan, S10...Accommodation space, S11,S21,S31...First space, S12,S22,S32...Second space, X...X-axis direction, Y...Y-axis direction, Z...Z-axis direction.

Claims

1. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. It is equipped with a second connector for connecting to external wiring components, The second connector is provided on the wiring board and is exposed to the outside through the opening. The flexible member defines the first space so as to include at least a portion of the second connector. A liquid injection head unit characterized by the following features.

2. The aforementioned wiring board defines the first space and the second space, No circuit elements are provided in the portion of the wiring board that defines the first space. One or more circuit elements are provided in the portion of the wiring board that defines the second space. The liquid injection head unit according to feature 1.

3. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. The aforementioned wiring board defines the first space and the second space, No circuit elements are provided in the portion of the wiring board that defines the first space. One or more circuit elements are provided in the portion of the wiring board that defines the second space. A liquid injection head unit characterized by the following features.

4. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. The first connector is laminated on the first surface of the wiring board, The housing comprises a first member and a second member stacked on the first member. The second member has ribs that protrude from the inner wall defining the accommodation space toward the first surface, The flexible member is sandwiched between the first surface of the wiring board and the rib. A liquid injection head unit characterized by the following features.

5. The first connector is laminated on the first surface of the wiring board, The housing comprises a first member and a second member stacked on the first member. The second member has ribs that protrude from the inner wall defining the accommodation space toward the first surface, The flexible member is sandwiched between the first surface of the wiring board and the rib. A liquid spray head unit according to any one of claims 1 to 3.

6. The aforementioned wiring board has a second surface opposite to the first surface, The second surface of the wiring board is laminated onto the first member, thereby separating the first space from the space within the housing space that the second surface faces. The liquid injection head unit according to claim 4 or 5, characterized by the above.

7. A recess is formed on the tip surface of the rib, which is recessed in a direction away from the first surface. The flexible member is positioned within the recess of the rib so as to protrude from the tip surface of the rib. A liquid injection head unit according to any one of claims 4 to 6, characterized by the features described herein.

8. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. The first connector and the flexible member do not come into contact with each other. A liquid injection head unit characterized by the following features.

9. The first connector is laminated on the first surface of the wiring board, The housing comprises a first member and a second member stacked on the first member. The flexible member is sandwiched between the first surface and the second member. The direction in which the first surface, the flexible member, and the second member are aligned is along the direction in which the external wiring is inserted into the first connector. A liquid spray head unit according to feature 8.

10. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside, and an inner circumferential surface defining the opening, and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. The flexible member is sandwiched between the inner circumferential surface of the opening and the outer circumferential surface of the first connector. A liquid injection head unit characterized by the following features.

11. The flexible member is sandwiched between the inner circumferential surface of the opening and the outer circumferential surface of the first connector. A liquid spray head unit according to feature 1 or 2.

12. The aforementioned opening is a through hole formed in the housing, The flexible member is sandwiched between the entire inner surface of the opening and the entire outer surface of the first connector, when viewed in the direction in which the external wiring is inserted into the first connector. The liquid injection head unit according to claim 10 or 11, characterized in that it is a liquid injection head unit according to the present invention.

13. The first connector is laminated on the first surface of the wiring board, The housing comprises a first member and a second member stacked on the first member. The flexible member is sandwiched between the first surface of the wiring board and the outer peripheral surface of the first connector and the inner peripheral surface of the opening. The liquid injection head unit according to claim 10 or 11, characterized in that it is a liquid injection head unit according to the present invention.

14. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. The flexible member is sandwiched between the inner circumferential surface of the opening and the outer circumferential surface of the first connector. The first connector is laminated on the first surface of the wiring board, The housing comprises a first member and a second member stacked on the first member. The flexible member is sandwiched between the first surface of the wiring board and the outer peripheral surface of the first connector and the inner peripheral surface of the opening. A liquid injection head unit characterized by the following features.

15. It is equipped with a second connector for connecting to external wiring components, The second connector is provided on the wiring board and is exposed to the outside through the opening. The flexible member defines the first space so as to include at least a portion of the second connector. A liquid injection head unit according to any one of claims 1 to 14.

16. When viewed in plan toward the aforementioned wiring board, the wiring board has a main body and a protruding portion that extends from the main body. The first connector is provided on the protruding portion, The first space is defined by the aforementioned protrusion, The main body defines the second space, The flexible member is, in the plan view, in a straight line along the boundary between the protruding portion and the main body portion. A liquid spray head unit according to any one of claims 1 to 15.

17. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. When viewed in plan toward the aforementioned wiring board, the wiring board has a main body and a protruding portion that extends from the main body. The first connector is provided on the protruding portion, The first space is defined by the aforementioned protrusion, The main body defines the second space, The flexible member is, in the plan view, in a straight line along the boundary between the protruding portion and the main body portion. A liquid injection head unit characterized by the following features.

18. The aforementioned flexible member has insulating properties. A liquid injection head unit according to any one of claims 1 to 17.

19. The housing has an air intake port for drawing air into the second space from the outside, and an exhaust port for discharging air from the second space to the outside. The opening and the exhaust port face each other via the flexible member with respect to the short direction perpendicular to the longitudinal direction of the wiring board, A liquid injection head unit according to any one of claims 1 to 18.

20. A liquid injection head unit comprising a first connector for connecting to an external wiring component, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. The housing has an air intake port for drawing air into the second space from the outside, and an exhaust port for discharging air from the second space to the outside. The opening and the exhaust port face each other via the flexible member with respect to the short direction perpendicular to the longitudinal direction of the wiring board, A liquid injection head unit characterized by the following features.

21. A liquid injection head unit according to any one of claims 1 to 20, An external wiring member, located outside the liquid injection head unit and connected to the first connector, A liquid injection device characterized by being equipped with the following features.

22. The housing comprises the aforementioned liquid injection head unit, The opening faces into the housing of the liquid injection device, The liquid injection device according to feature 21.

23. A liquid injection device comprising a liquid injection head unit, an external wiring member disposed outside the liquid injection head unit, and a housing that houses the liquid injection head unit inside, The aforementioned liquid injection head unit is A first connector for connecting to the aforementioned external wiring member, A wiring board having the first connector, The housing of the liquid injection head unit, having an opening for exposing the first connector to the outside and housing the wiring board in a housing space, A flexible member arranged within the aforementioned containment space, Equipped with, The flexible member divides the housing space into a first space including at least a part of the first connector and the opening, and a second space larger than the first space. The external wiring member is connected to the first connector. The opening faces into the housing of the liquid injection device, A liquid injection device characterized by the following features.

24. The fan provided on the exhaust port side, The fan cools the wiring board provided in the housing space. The liquid injection device according to claim 21 or 22, which refers to claim 19 or 20.

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