Flow channel unit and liquid discharge device

Abstract

To suitably remove gas contained in liquid flowing in a flow passage.SOLUTION: A flow passage unit 100 includes a flow passage 50 in which liquid I flows to be supplied to a discharge section 3 for discharging the liquid I. The flow passage unit includes a removal section 110 which can remove gas G. The removal section 110 has an inner wall 112 which is provided with an opening 113 continuous to the flow passage 50 and is in contact with the liquid I and a storage tank 111 which has the inner wall 112 and stores the liquid I, removes the gas G contained in the liquid I flowing in the flow passage 50 in the storage tank 111, and has a lyophobic member 120 having lyophilic property smaller than that of the inner wall 112 with respect to the liquid I at a position in contact with the liquid I of the storage tank 111.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a flow path unit and a liquid ejection device.

Background Art

[0002] Conventionally, a flow path unit for supplying liquid to a discharge part that discharges liquid has been used. Among such flow path units, there is one provided with a removal part for removing gas contained in the liquid flowing through the flow path. For example, Patent Document 1 discloses a liquid injection device including a decompression chamber that houses a cylindrical hollow fiber membrane, and by passing the liquid through the decompression chamber, gas contained in the liquid flowing through the flow path is removed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional flow path unit provided with a removal part for removing gas contained in the liquid flowing through the flow path, it has been difficult to suitably remove the gas contained in the liquid flowing through the flow path. For example, in the liquid injection device of Patent Document 1, gas adheres as bubbles to a part that comes into contact with the liquid, such as a hollow fiber membrane, and there is a risk that the bubbles adhering to the part that comes into contact with the liquid grow without moving and flow out into the flow path.

Means for Solving the Problems

[0005] The present invention provides a flow path unit for solving the above problems, having a flow path through which a liquid supplied to a discharge section discharges a liquid flows, comprising a removal section capable of removing gas contained in the liquid flowing through the flow path, the removal section comprising an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, wherein the storage tank has a hydrophobic member in a position in contact with the liquid that removes the gas and has a hydrophilicity to the liquid less than that of the inner wall.

[0006] Furthermore, the flow path unit of the present invention for solving the above problems is a flow path unit having a flow path through which the liquid supplied to a discharge section discharges the liquid flows, and includes a removal section capable of removing gas contained in the liquid, an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, wherein the gas is removed in the storage tank, and the inner wall has a hydrophobic region at a position in the storage tank that is in contact with the liquid, where the hydrophilicity to the liquid is smaller than that of the adjacent region adjacent to the opening.

[0007] Furthermore, the present invention provides a liquid dispensing device for solving the above problems, comprising a dispensing section for dispensing liquid and a flow path through which the liquid supplied to the dispensing section flows, wherein the device includes a removal section capable of removing gas contained in the liquid flowing through the flow path, the removal section includes an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, the storage tank having a hydrophobic member in a position in contact with the liquid that removes the gas and has a hydrophilicity to the liquid less than that of the inner wall.

[0008] Furthermore, the present invention provides a liquid dispensing device for solving the above problems, comprising a dispensing section for dispensing liquid and a flow path through which the liquid supplied to the dispensing section flows, wherein the device includes a removal section capable of removing gas contained in the liquid flowing through the flow path, the removal section includes an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, the gas being removed in the storage tank, and the inner wall having a hydrophobic region at a position in the storage tank that is in contact with the liquid, where the hydrophilicity to the liquid is smaller than that of an adjacent region adjacent to the opening. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic perspective view showing a liquid dispensing device according to Embodiment 1 of the present invention. [Figure 2] A schematic plan cross-sectional view showing the removal section of the flow path unit of the liquid discharge device in Figure 1. [Figure 3] A schematic side cross-sectional view showing the removal section of the flow path unit of the liquid discharge device in Figure 1. [Figure 4] A schematic plan cross-sectional view showing the removal section of the flow path unit of the liquid discharge device according to Embodiment 2 of the present invention. [Figure 5] A schematic side cross-sectional view showing the removal section of the flow path unit of the liquid discharge device according to Embodiment 2 of the present invention. [Figure 6] A schematic side cross-sectional view showing the removal section of the flow path unit of the liquid discharge device according to Embodiment 3 of the present invention. [Figure 7] A schematic side cross-sectional view showing the removal section of the flow path unit of the liquid discharge device according to Embodiment 4 of the present invention. [Figure 8] A schematic side cross-sectional view showing the removal section of the flow path unit of the liquid discharge device according to Embodiment 5 of the present invention. [Figure 9] A schematic side cross-sectional view showing the removal section of the flow path unit of the liquid discharge device according to Embodiment 6 of the present invention. [Figure 10] A schematic side cross-sectional view showing the removal section of the flow path unit of the liquid discharge device according to Embodiment 7 of the present invention. [Figure 11] A schematic side cross-sectional view showing the removal section of the flow path unit of a liquid discharge device in a reference example. [Modes for carrying out the invention]

[0010] The present invention will be described in general terms below. A first aspect of the present invention for solving the above problems is a flow channel unit having a flow channel through which a liquid supplied to a discharge section discharges a liquid flows, comprising a removal section capable of removing gas contained in the liquid flowing through the flow channel, wherein the removal section includes an inner wall having an opening connected to the flow channel and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, and wherein the storage tank has a hydrophobic member in a position in contact with the liquid that removes the gas and has a hydrophilicity to the liquid less than that of the inner wall.

[0011] According to this embodiment, the removal unit has a hydrophobic member at a position that contacts the liquid in the storage tank. The less hydrophilic the contact surface with the liquid, the more likely gases contained in the liquid are to appear as bubbles on the contact surface. Therefore, the hydrophobic member can suitably cause gases contained in the liquid to appear as bubbles. Consequently, gases contained in the liquid flowing through the channel can be suitably removed.

[0012] A flow path unit according to a second aspect of the present invention is characterized in that, in the first aspect, the removal unit has a recovery unit that collects bubbles detached from the liquid, located above the hydrophobic member in the direction of gravity.

[0013] According to this embodiment, a collection section for collecting bubbles detached from the liquid is provided above the hydrophobic member in the direction of gravity. Therefore, by collecting the bubbles that appear due to the hydrophobic member, it is possible to prevent the bubbles from entering the flow path.

[0014] A flow path unit according to a third aspect of the present invention is characterized in that, in the first or second aspect, it comprises at least one heating unit for heating the liquid stored in the storage tank.

[0015] According to this aspect, a heating unit for heating the liquid stored in the storage tank is provided. By heating the liquid, the gas contained in the liquid can be efficiently made into bubbles, so that the gas contained in the liquid flowing through the flow path can be efficiently removed.

[0016] In the flow path unit according to the fourth aspect of the present invention, in the third aspect, the at least one heating unit includes a first heating unit provided on the inner wall and a second heating unit provided on the liquid-repellent member.

[0017] According to this aspect, the removal unit has a first heating unit provided on the inner wall as a heating unit and a second heating unit provided on the liquid-repellent member. Therefore, the gas contained in the liquid can be removed particularly efficiently in the storage tank.

[0018] The flow path unit according to the fifth aspect of the present invention is characterized in that, in any one of the first to fourth aspects, an ultrasonic wave applying unit for applying ultrasonic waves to the liquid stored in the storage tank is provided.

[0019] According to this aspect, an ultrasonic wave applying unit for applying ultrasonic waves to the liquid stored in the storage tank is provided. By applying ultrasonic waves to the liquid, the gas contained in the liquid can be efficiently made into bubbles, so that the gas contained in the liquid flowing through the flow path can be efficiently removed.

[0020] In the flow path unit according to the sixth aspect of the present invention, in the fifth aspect, the ultrasonic wave applying unit is provided on the liquid-repellent member.

[0021] According to this aspect, the ultrasonic wave applying unit is provided on the liquid-repellent member. Therefore, the gas contained in the liquid can be removed particularly efficiently in the storage tank.

[0022] A flow path unit according to a seventh aspect of the present invention is characterized in that, in any one of the first to sixth aspects, the storage tank has a reservoir portion that is located upward in the direction of gravity and accumulates the gas removed from the liquid, and the liquid-repellent member extends to the reservoir portion.

[0023] When the entire hydrophobic member is submerged in a liquid, bubbles attached to the hydrophobic member tend to move upward along the hydrophobic member in the direction of gravity, but they are less likely to detach from the upper end of the hydrophobic member in the direction of gravity. In contrast, according to this embodiment, the hydrophobic member extends to the reservoir where gas accumulates. With this configuration, bubbles attached to the hydrophobic member can be efficiently moved to the air reservoir, and it is possible to suppress the bubbles from reaching the flow path.

[0024] A flow path unit according to an eighth aspect of the present invention is a flow path unit having a flow path through which a liquid supplied to a discharge section discharges a liquid flows, and comprising a removal section capable of removing gas contained in the liquid flowing through the flow path, wherein the removal section includes an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, wherein the gas is removed in the storage tank, and the inner wall has a hydrophobic region in the storage tank at a position in contact with the liquid where its hydrophilicity to the liquid is smaller than that of an adjacent region adjacent to the opening.

[0025] According to this embodiment, the inner wall has a hydrophobic region at a position that contacts the liquid in the storage tank, where its hydrophilicity to the liquid is smaller than that of the adjacent region. The smaller the hydrophilicity of the contact surface with the liquid, the more likely gases contained in the liquid are to appear as bubbles on the contact surface. Therefore, the hydrophobic region can suitably cause gases contained in the liquid to appear as bubbles. Consequently, gases contained in the liquid flowing through the channel can be suitably removed.

[0026] A flow path unit according to the ninth aspect of the present invention is characterized in that, in the eighth aspect, the removal unit has a recovery unit that recovers the gas removed from the liquid, located above the hydrophobic region in the direction of gravity.

[0027] According to this embodiment, a collection unit is provided above the hydrophobic region in the direction of gravity to collect bubbles that have detached from the liquid. Therefore, by collecting the bubbles that appear in the hydrophobic region, it is possible to prevent the bubbles from entering the flow path.

[0028] A flow path unit according to a tenth aspect of the present invention is characterized in that, in the eighth or ninth aspect, it comprises a heating unit for heating the liquid stored in the storage tank.

[0029] According to this embodiment, the storage tank is equipped with a heating unit for heating the liquid stored in the storage tank. By heating the liquid, the gas contained in the liquid can be efficiently converted into bubbles, and thus the gas contained in the liquid flowing through the channel can be efficiently removed.

[0030] An eleventh embodiment of the present invention is a flow path unit characterized in that, in any one of the eighth to tenth embodiments, it includes an ultrasonic application unit for applying ultrasonic waves to the liquid stored in the storage tank.

[0031] According to this embodiment, the system includes an ultrasonic application unit that applies ultrasonic waves to the liquid stored in the storage tank. By applying ultrasonic waves to the liquid, gases contained in the liquid can be efficiently converted into bubbles, thus efficiently removing gases contained in the liquid flowing through the channel.

[0032] A flow path unit according to a twelfth aspect of the present invention, in any one of the eighth to eleventh aspects, is characterized in that the storage tank has a reservoir portion that is located upward in the direction of gravity and accumulates the gas removed from the liquid, and the hydrophobic region is provided spanning the interface between the liquid stored in the storage tank and the gas accumulated in the reservoir portion.

[0033] When the entire hydrophobic region is located in a liquid, bubbles attached to the hydrophobic region tend to move upward along the hydrophobic region in the direction of gravity, but they are less likely to detach from the upper end of the hydrophobic region in the direction of gravity. In contrast, according to this embodiment, the hydrophobic region is provided across the gas-liquid interface. With this configuration, bubbles attached to the hydrophobic region can be efficiently moved to an air pocket, and it is possible to suppress the bubbles from reaching the flow path.

[0034] A liquid dispensing device according to a thirteenth aspect of the present invention is a liquid dispensing device comprising a dispensing section for dispensing liquid and a flow path through which the liquid supplied to the dispensing section flows, wherein the device comprises a removal section capable of removing gas contained in the liquid flowing through the flow path, the removal section includes an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, wherein the storage tank has a hydrophobic member in a position in contact with the liquid that removes the gas and has a hydrophilicity to the liquid less than that of the inner wall.

[0035] According to this embodiment, the removal unit has a hydrophobic member at a position that comes into contact with the liquid in the storage tank. Therefore, the hydrophobic member can suitably cause the gas contained in the liquid to appear as bubbles, and the gas contained in the liquid flowing through the channel can be suitably removed.

[0036] A liquid dispensing device according to a fourteenth aspect of the present invention is a liquid dispensing device comprising a dispensing section for dispensing liquid and a flow path through which the liquid supplied to the dispensing section flows, wherein the device comprises a removal section capable of removing gas contained in the liquid flowing through the flow path, the removal section includes an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, the gas being removed in the storage tank, and the inner wall having a hydrophobic region in contact with the liquid in the storage tank where its hydrophilicity to the liquid is smaller than that of an adjacent region adjacent to the opening.

[0037] According to this embodiment, the inner wall has a hydrophobic region at a position in contact with the liquid in the storage tank, where its hydrophilicity to the liquid is smaller than that of the adjacent region. Therefore, the hydrophobic region can suitably cause gas contained in the liquid to appear as bubbles, and gas contained in the liquid flowing through the channel can be suitably removed.

[0038] [Example 1] A liquid dispensing device equipped with a flow path unit according to one embodiment of the present invention will be described in detail below with reference to the attached drawings. First, an overview of the liquid dispensing device according to Embodiment 1 of the present invention will be described.

[0039] In this embodiment, the liquid dispensing device 1 performs recording by reciprocating a carriage 2, which has an ink dispensing unit 3 on the side facing the medium P, in a scanning direction B that intersects with the transport direction A, relative to a medium P transported in the transport direction A by a transport unit (not shown). Specifically, the medium P is intermittently driven in the transport direction A, and the dispensing unit 3 is moved back and forth (reciprocating scan) in the scanning direction B via the carriage 2, dispensing ink from a plurality of nozzles (not shown) formed on the dispensing unit 3 to perform recording. Here, one direction of scanning direction B is referred to as direction B1, and the other direction of scanning direction B is referred to as direction B2.

[0040] The ejection unit 3 in this embodiment is an inkjet head equipped with a piezoelectric element. However, the configuration is not limited to this, and a thermal head equipped with a heater instead of a piezoelectric element may be used. The carriage 2 is connected to an ink cartridge 4 containing black ink, cyan ink, magenta ink, and yellow ink via an ink tube 5 that forms part of the flow path unit 100 and the ink flow path 50. The flow path unit 100 is located on the B1 side of the carriage 2, and the detailed configuration of the flow path unit 100 will be described later. The ejection unit 3 is capable of ejecting black ink, cyan ink, magenta ink, and yellow ink, and nozzle rows corresponding to each ink are formed along the transport direction A. The number of ink colors is not limited to these four colors, and may be more or less, or other colors may be used.

[0041] Next, the detailed configuration of the flow path unit 100 (flow path unit 100A) in the liquid dispensing device 1 of this embodiment will be described with reference to Figure 1, as well as Figures 2, 3, and 11. The flow path unit 100A of this embodiment is a flow path unit that supplies ink to the dispensing unit 3, which dispenses liquid ink, as shown in Figure 1. As shown in Figures 2 and 3, it comprises a flow path 50 through which ink I flows, and a removal unit 110 capable of removing gas G contained in the ink I flowing through the flow path 50. As shown in Figure 1, the flow path unit 100A of this embodiment is equipped with a removal unit 110 for each of the four ink tubes 5 corresponding to black ink, cyan ink, magenta ink, and yellow ink. The four removal units 110 all have the same configuration. As shown in Figures 2 and 3, each removal unit 110 includes an opening 113 connected to the flow path 50 and an inner wall 112 that contacts the ink I, and a storage tank 111 that has the inner wall 112 and stores the ink I. The storage tank 111 is configured to remove gas G contained in the ink I flowing through the flow path 50. The opening 113 includes an opening 113A corresponding to an inlet for the ink I to flow into the storage tank 111 and an opening 113B corresponding to an outlet for the ink I to flow out of the storage tank 111. The storage tank 111 can also be considered as part of the flow path 50.

[0042] Here, as shown in Figures 2 and 3, in the flow channel unit 100A of this embodiment, the removal section 110 has a hydrophobic member 120 that is less hydrophilic to the ink I than the inner wall 112, at a position that contacts the ink I in the storage tank 111. Generally, the less hydrophilic the contact surface with a liquid, the more likely gas G contained in the liquid is to appear on the contact surface as bubbles GB. Therefore, in the flow channel unit 100A of this embodiment, the hydrophobic member 120 can suitably cause the gas G contained in the ink I to appear as bubbles GB. Thus, gas contained in the liquid flowing through the flow channel 50 can be suitably removed.

[0043] As shown in Figures 2 and 3, in the flow path unit 100A of this embodiment, bubbles GB selectively adhere to the hydrophobic member 120 which is prone to bubble formation. On the other hand, in the flow path unit 101 of the reference example shown in Figure 11, the hydrophobic member 120 is not provided in the storage tank 111. Therefore, in the flow path unit 101 of the reference example, bubbles GB adhere to the inner wall 112. When bubbles GB adhere to the inner wall 112, they adhere to a position close to the opening 113, and there is a risk that the flow F of ink I in the storage tank 111, which acts as a flow path 50, will cause bubbles GB to enter the ink tube 5 from the outlet opening 113 in the storage tank 111. If bubbles GB enter the ink tube 5 and reach the discharge section 3, it may cause a discharge failure.

[0044] From the perspective of a liquid dispensing device, the liquid dispensing device 1 of this embodiment is a liquid dispensing device that includes a flow path unit 100 having the above-described features, a dispensing unit 3 for dispensing liquid ink I, and a flow path 50 for supplying ink I to the dispensing unit 3. Therefore, the hydrophobic member 120 can suitably cause the gas G contained in the ink I to appear as bubbles GB, and the gas G contained in the ink I flowing through the flow path 50 can be suitably removed.

[0045] The hydrophilicity of ink I (liquid) can be evaluated by applying ink I to a flat surface such as the hydrophobic member 120 or inner wall 112 that is the subject of the hydrophilicity evaluation, and measuring the contact angle of ink I with respect to the flat surface. The more difficult it is for ink I to wet the flat surface subject to the hydrophilicity evaluation and the larger the contact angle, the more hydrophobic the material is. Conversely, the more easily ink I wets the flat surface subject to the hydrophilicity evaluation and the smaller the contact angle, the more hydrophilic the material is. Specifically, for example, the hydrophilicity evaluation can be performed using the actual liquid and the actual member subject to the hydrophilicity evaluation, in accordance with the surface free energy measurement method of JIS R 3257 (1999).

[0046] Furthermore, as shown in Figure 3, the flow path unit 100A of this embodiment has a depressurization chamber 131 located above the storage tank 111 in the direction of gravity. As shown in Figure 3, the depressurization chamber 131 is connected to a tube 6 connected to a depressurization pump (not shown), and is partitioned from the storage tank 111 by a permeable membrane 130 that does not allow liquid to pass through but allows gas to pass through. The depressurization pump is an example of a suction mechanism that sucks gas from inside the depressurization chamber 131. The air pressure inside the depressurization chamber 131 is lower than the air pressure outside the depressurization chamber 131, i.e., atmospheric pressure. In other words, the removal section 110 of the flow path unit 100A of this embodiment has a depressurization chamber 131 located above the hydrophobic member 120 in the direction of gravity, which serves as a recovery section for recovering air bubbles GB detached from the ink I. Therefore, the flow path unit 100A of this embodiment can prevent the air bubbles GB that appear due to the hydrophobic member 120 from reaching the ink tube 5, which serves as the flow path 50.

[0047] In the flow path unit 100A of this embodiment, the hydrophobic members 120 are arranged as shown in Figures 2 and 3. Specifically, as shown in Figure 2, multiple flat, plate-shaped hydrophobic members 120 are formed along the general transport direction A of the storage tank 111, with varying heights along the general direction B2, as shown in Figure 3. Within the storage tank 111, the ink I flows F as shown in Figures 2 and 3. However, the hydrophobic members 120 are not limited to this configuration. Preferably, the hydrophobic members 120 have a shape and arrangement that does not obstruct the ink I flow F within the storage tank 111.

[0048] [Example 2] The flow path unit 100B of the liquid dispensing device of Example 2 will be described below with reference to Figures 4 and 5. Figure 4 corresponds to Figure 2 of the liquid dispensing device 1 of Example 1, and Figure 5 corresponds to Figure 3 of the liquid dispensing device 1 of Example 1. Furthermore, the liquid dispensing device of this example is the same as the liquid dispensing device of Example 1, except for the configuration described below. In detail, only the configuration of the hydrophobic member 120 differs from the liquid dispensing device of Example 1. For this reason, it has the same characteristics as the liquid dispensing device of Example 1. Therefore, in Figures 4 and 5, components common to Example 1 are indicated by the same reference numerals, and detailed explanations are omitted.

[0049] In the flow path unit 100B of this embodiment, as shown in Figure 4, a plurality of flat, plate-shaped hydrophobic members 120 are provided alternately in a direction generally aligned with the transport direction A in a plan view. As shown in Figure 5, the upper end portion of each hydrophobic member 120 in the direction of gravity extends into the accumulation portion 114 within the storage tank 111. In other words, in the flow path unit 100B of this embodiment, the storage tank 111 has an accumulation portion 114 above in the direction of gravity, and the hydrophobic members 120 extend into the accumulation portion 114.

[0050] When the entire hydrophobic member 120 is submerged in liquid, bubbles GB attached to the hydrophobic member 120 tend to move upward along the hydrophobic member 120 in the direction of gravity, but they are less likely to detach from the upper end of the hydrophobic member 120 in the direction of gravity. However, by configuring the fluid channel unit 100B in this embodiment so that the hydrophobic member 120 protrudes into the accumulation portion 114, bubbles GB attached to the hydrophobic member 120 can be efficiently moved to the accumulation portion 114, thereby preventing the bubbles GB from reaching the ink tube 5 which serves as the fluid channel 50.

[0051] [Example 3] The flow path unit 100C of the liquid dispensing device of Example 3 will be described below with reference to Figure 6. Figure 6 corresponds to Figure 3 of the liquid dispensing device 1 of Example 1. Furthermore, the liquid dispensing device of this example is the same as the liquid dispensing devices of Example 1 and Example 2, except for the configuration described below. Specifically, the only difference from the liquid dispensing device of Example 2 is that it is equipped with a heating unit 160. For this reason, it has the same characteristics as the liquid dispensing devices of Example 1 and Example 2. Therefore, in Figure 6, components common to Example 1 and Example 2 are indicated by the same reference numerals, and detailed explanations are omitted.

[0052] As shown in Figure 6, the flow path unit 100C of this embodiment includes a heating unit 160 that heats the liquid (ink I) stored in the storage tank 111. By heating the liquid, the gas G contained in the liquid can be efficiently converted into bubbles GB, so the flow path unit 100C of this embodiment can efficiently remove the gas G contained in the ink I flowing through the flow path 50. Here, "liquid stored in the storage tank 111" means not only the liquid stored in the storage tank 111 but also the liquid that will be stored in the storage tank 111 in the future. For this reason, in this embodiment, the heating unit 160 is provided in the storage tank 111, but the heating unit 160 may also be provided upstream of the storage tank 111 in the direction of liquid flow, that is, in any part of the flow path 50 at a position between the ink cartridge 4 and the removal unit 110.

[0053] More specifically, as shown in Figure 6, in the flow path unit 100C of this embodiment, the removal unit 110 has a first heating unit 160A provided on the inner wall 112 as a heating unit 160 and a second heating unit 160B provided on the hydrophobic member 120. Therefore, the flow path unit 100C of this embodiment can remove gas G contained in the ink I particularly efficiently in the storage tank 111.

[0054] [Example 4] The flow path unit 100D of the liquid dispensing device of Example 4 will be described below with reference to Figure 7. Figure 7 corresponds to Figure 3 of the liquid dispensing device 1 of Example 1. Furthermore, the liquid dispensing device of this example is the same as the liquid dispensing devices of Examples 1 to 3, except for the configuration described below. In detail, the only difference from the liquid dispensing device of Example 2 is that it is equipped with a heating unit 160. For this reason, it has the same characteristics as the liquid dispensing devices of Examples 1 to 3. Therefore, in Figure 7, components common to Examples 1 to 3 are indicated by the same reference numerals, and detailed explanations are omitted.

[0055] As shown in Figure 7, the flow path unit 100D of this embodiment includes an ultrasonic application unit 170 that applies ultrasonic waves to the ink I stored in the storage tank 111. By applying ultrasonic waves to the liquid, the gas G contained in the liquid can be efficiently converted into bubbles GB, so the flow path unit 100D of this embodiment can efficiently remove the gas G contained in the ink I flowing through the flow path 50.

[0056] More specifically, as shown in Figure 7, in the flow path unit 100D of this embodiment, the ultrasonic application unit 170 is provided on the hydrophobic member 120. Therefore, the flow path unit 100D of this embodiment can remove gas G contained in the ink I particularly efficiently in the storage tank 111. However, the configuration is not limited to this. The ultrasonic application unit 170 may be provided on the inner wall 112, or it may be provided in any part of the flow path 50 at a position between the ink cartridge 4 and the removal unit 110.

[0057] [Example 5] The flow path unit 100E of the liquid dispensing device of Example 5 will be described below with reference to Figure 8. Figure 8 corresponds to Figure 3 of the liquid dispensing device 1 of Example 1. Furthermore, the liquid dispensing device of this example is the same as the liquid dispensing devices of Examples 1 to 4, except for the configuration described below. Therefore, it has the same characteristics as the liquid dispensing devices of Examples 1 to 4. Accordingly, in Figure 8, components common to Examples 1 to 4 are indicated by the same reference numerals, and detailed explanations are omitted.

[0058] As described above, the liquid dispensing devices of Examples 1 to 4 had a hydrophobic member 120 in the storage tank 111. On the other hand, in the liquid dispensing device of this embodiment, as shown in Figure 8, the storage tank 111 does not have a hydrophobic member 120, and instead, a hydrophobic region 112B is provided on the inner wall 112, which is formed by roughening the surface, for example by UV irradiation. However, there are no particular limitations on the method of forming the hydrophobic region 112B. Note that in Figure 8 and other figures, the hydrophobic region 112B is shown as raised relative to the inner wall 112 for clarity, but in reality, it is formed almost flush with the rest of the inner wall 112. In this embodiment, the hydrophobic region 112B is formed continuously so as to encircle the inner wall 112 in a plan view.

[0059] Here, the flow path unit 100E of this embodiment is a flow path unit that supplies ink I, which is a liquid, to a discharge unit 3 that discharges ink I, and is equipped with a flow path 50 through which the ink I flows, similar to the liquid discharge devices of Embodiments 1 to 4. Furthermore, the flow path unit 100E of this embodiment, similar to the liquid discharge devices of Embodiments 1 to 4, includes an inner wall 112 that has an opening 113 connected to the flow path 50 and is in contact with the ink I, and a storage tank 111 that stores the ink I, and is equipped with a removal unit 110 that can remove gas G contained in the ink I flowing through the flow path 50 in the storage tank 111. However, unlike the liquid discharge devices of Embodiments 1 to 4, the flow path unit 100E of this embodiment does not have a hydrophobic member 120 in the storage tank 111. Instead, as shown in Figure 8, the inner wall 112 has a hydrophobic region 112B at a position in the storage tank 111 that is in contact with the ink I, where the hydrophilicity to the ink I is smaller than that of the adjacent region 112A adjacent to the opening 113.

[0060] Thus, in the flow channel unit 100E of this embodiment, the inner wall 112 has a hydrophobic region 112B at a position in contact with the liquid in the storage tank 111, where its hydrophilicity to the liquid (ink I) is smaller than that of the adjacent region 112A. The smaller the hydrophilicity of the contact surface with the liquid, the more likely the gas G contained in the liquid is to appear as bubbles GB on the contact surface. Therefore, the flow channel unit 100E of this embodiment can suitably cause the gas G contained in the ink I to appear as bubbles GB through the hydrophobic region 112B. Consequently, the flow channel unit 100E of this embodiment can suitably remove the gas G contained in the ink I flowing through the flow channel 50. Furthermore, preferred examples of "having a hydrophobic region 112B in a position that comes into contact with the liquid in the storage tank 111, where its hydrophilicity to the liquid is smaller than that of the adjacent region 112A" include, as in this embodiment, providing one hydrophobic region 112B in a position different from the adjacent region 112A, providing multiple hydrophobic regions 112B in positions different from the adjacent region 112A, and forming the inner wall 112 such that its hydrophilicity to the liquid decreases as it moves away from the opening 113.

[0061] From the perspective of a liquid dispensing device, the liquid dispensing device 1 of this embodiment is a liquid dispensing device that includes a flow path unit 100 having the above-described features, a dispensing unit 3 for dispensing liquid ink I, and a flow path 50 for supplying ink I to the dispensing unit 3. Therefore, the hydrophobic member 120 can suitably cause the gas G contained in the ink I to appear as bubbles GB, and the gas G contained in the ink I flowing through the flow path 50 can be suitably removed.

[0062] Furthermore, as shown in Figure 8, in the flow path unit 100E of this embodiment, the removal unit 110 has a reduced pressure chamber 131 as a recovery unit for recovering air bubbles GB detached from the ink I, located above the hydrophobic region 112B in the direction of gravity. Therefore, the flow path unit 100E of this embodiment can prevent air bubbles GB that appear in the hydrophobic region 112B from reaching the ink tube 5, which serves as the flow path 50, by recovering the air bubbles GB. The reduced pressure chamber 131 of the flow path unit 100E of this embodiment has the same configuration as the reduced pressure chamber 131 of the liquid discharge devices of Embodiments 1 to 4, but there are no particular limitations on the configuration of the recovery unit.

[0063] Furthermore, as shown in Figure 8, in the flow path unit 100E of this embodiment, the storage tank 111 stores ink I with an accumulation portion 114 located above in the direction of gravity, and the hydrophobic region 112B is provided spanning the gas-liquid interface with the accumulation portion 114. When the entire hydrophobic region 112B is located in the liquid, bubbles GB attached to the hydrophobic region 112B tend to move upward along the hydrophobic region 112B in the direction of gravity, but they are difficult to detach from the upper end of the hydrophobic region 112B in the direction of gravity. In contrast, as shown in Figure 8, by providing the hydrophobic region 112B spanning the interface between the ink I stored in the storage tank 111 and the gas G accumulated in the accumulation portion 114, bubbles GB attached to the hydrophobic region 112B can be efficiently moved to the accumulation portion 114, and it is possible to suppress the bubbles GB from reaching the ink tube 5 which serves as the flow path 50.

[0064] As shown in Figure 8, in the flow path unit 100E of this embodiment, the opening 113A is provided above in the direction of gravity and the opening 113B is provided below in the direction of gravity, so that the flow F of ink I in the storage tank 111 is directed from above to below in the direction of gravity when viewed from the side. With this configuration, it is possible to suppress the air bubbles GB from reaching the ink tube 5, which serves as the flow path 50, through at least one of the openings 113A and 113B. However, the configuration is not limited to this.

[0065] [Example 6] The flow path unit 100F of the liquid dispensing device of Example 6 will be described below with reference to Figure 9. Note that Figure 9 corresponds to Figure 3 in the liquid dispensing device 1 of Example 1. Furthermore, the liquid dispensing device of this example is the same as the liquid dispensing devices of Examples 1 to 5, except for the configuration described below. Specifically, the only difference from the liquid dispensing device of Example 5 is that it is equipped with a heating unit 160. For this reason, it has the same characteristics as the liquid dispensing devices of Examples 1 to 5. Therefore, in Figure 9, components common to Examples 1 to 5 are indicated by the same reference numerals, and detailed explanations are omitted.

[0066] As shown in Figure 9, the flow path unit 100F of this embodiment includes a heating unit 160 that heats the ink I stored in the storage tank 111. By heating the liquid, the gas G contained in the liquid can be efficiently converted into bubbles GB, so the flow path unit 100F of this embodiment can efficiently remove the gas G contained in the ink I flowing through the flow path 50. However, the embodiment is not limited to this configuration, and the heating unit 160 may be provided in any part of the flow path 50 at a position between the ink cartridge 4 and the removal unit 110.

[0067] [Example 7] The flow path unit 100G of the liquid dispensing device of Example 7 will be described below with reference to Figure 10. Figure 10 corresponds to Figure 3 of the liquid dispensing device 1 of Example 1. Furthermore, the liquid dispensing device of this example is the same as the liquid dispensing devices of Examples 1 to 6, except for the configuration described below. Specifically, the only difference from the liquid dispensing device of Example 5 is the inclusion of an ultrasonic application unit 170. Therefore, it has the same characteristics as the liquid dispensing devices of Examples 1 to 6. Accordingly, in Figure 10, components common to Examples 1 to 6 are indicated by the same reference numerals, and detailed explanations are omitted.

[0068] As shown in Figure 10, the flow path unit 100G of this embodiment includes an ultrasonic application unit 170 that applies ultrasonic waves to the ink I stored in the storage tank 111. By applying ultrasonic waves to the liquid, the gas G contained in the liquid can be efficiently converted into bubbles GB, so the flow path unit 100G of this embodiment can efficiently remove the gas G contained in the ink I flowing through the flow path 50. However, the configuration is not limited to this, and the ultrasonic application unit 170 may be provided in any part of the flow path 50 at a position between the ink cartridge 4 and the removal unit 110.

[0069] It should be noted that the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention described in the claims, and these modifications are also included within the scope of the present invention. [Explanation of symbols]

[0070] 1…Liquid dispensing device, 2…Carriage, 3…Dispensing unit, 4…Ink cartridge, 5…Ink tube, 50…Flow path, 100…Flow path unit, 100A…Flow path unit, 100B…Flow path unit, 100C…Flow path unit, 100D…Flow path unit, 100E…Flow path unit, 100F…Flow path unit, 100G…Flow path unit, 101…Flow path unit, 110…Removal unit, 111…Storage tank, 112…Inner wall, 112A…Adjacent area, 112B…Hydrophobic area, 113…Opening, 114…Accumulation area, 120…Hydrophobic member, 130…Permeable membrane, 131…Depressurization chamber (recovery unit), 160…Heating unit, 160A…First heating unit, 160B…Second heating unit, 170…Ultrasonic application unit, G…Gas, GB…Bubble, I…Ink (liquid)

Claims

1. A flow path unit having a flow path through which the liquid supplied to a discharge section for discharging liquid flows, The system includes a removal unit capable of removing gas contained in the liquid flowing through the aforementioned channel, The removal section is, The system includes an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, wherein the gas is removed in the storage tank. A hydrophobic member, whose hydrophilicity to the liquid is less than that of the inner wall, is provided at a position in the storage tank that comes into contact with the liquid. The removal unit has a collection unit located above the hydrophobic member in the direction of gravity for collecting the bubbles that have detached from the liquid. The storage tank is equipped with at least one bubble-promoting unit that promotes the formation of bubbles in the gas contained in the liquid stored in the storage tank, A flow path unit characterized in that at least one of the bubble-promoting components is provided on the liquid-repellent member.

2. In the flow channel unit according to claim 1, The flow path unit is characterized in that the bubble-promoting unit is a heating unit that heats the liquid stored in the storage tank.

3. In the flow channel unit according to claim 2, The flow path unit is characterized in that the heating section includes a first heating section provided on the inner wall and a second heating section provided on the hydrophobic member.

4. In the flow path unit according to any one of claims 1 to 3, The flow path unit is characterized in that the bubble-promoting unit is an ultrasonic application unit that applies ultrasonic waves to the liquid stored in the storage tank.

5. In the flow path unit according to any one of claims 1 to 4, The storage tank has a reservoir portion at the top in the direction of gravity where the gas removed from the liquid accumulates. The fluid-repellent member is characterized by extending to the reservoir portion.

6. In the flow path unit according to any one of claims 1 to 4, The flow path unit is characterized in that the flow path is configured such that the liquid flows without penetrating the liquid-repellent member.

7. A liquid dispensing device comprising a dispensing section for dispensing liquid, and a flow path through which the liquid supplied to the dispensing section flows, The system includes a removal unit capable of removing gas contained in the liquid flowing through the aforementioned channel, The removal section is, The system includes an inner wall having an opening connected to the flow path and in contact with the liquid, and a storage tank having the inner wall and storing the liquid, wherein the gas is removed in the storage tank. A hydrophobic member, whose hydrophilicity to the liquid is less than that of the inner wall, is provided at a position in the storage tank that comes into contact with the liquid. The removal unit has a collection unit located above the hydrophobic member in the direction of gravity for collecting the bubbles that have detached from the liquid. The storage tank is equipped with at least one bubble-promoting unit that promotes the formation of bubbles in the gas contained in the liquid stored in the storage tank, A liquid dispensing device characterized in that at least one of the bubble-promoting components is provided on the liquid-repellent member.

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