Liquid container and inkjet recording apparatus including the same

Abstract

To prevent air bubbles from flowing into a liquid supply destination from a liquid container.SOLUTION: A liquid container includes a main body portion that has a bottom portion and a side wall portion erected upward from the bottom portion and stores a liquid in a storage area that is an area surrounded by the bottom portion and the side wall portion, a lid portion that is attached to the main body portion and covers the storage area from above, a liquid inlet that allows the liquid to flow into the storage area, a liquid outlet that allows the liquid to flow out from the storage area to a supply destination, and an air bubble discharge port that discharges air bubbles in the storage area. The first portion is a portion having a larger upward inclination angle with respect to the horizontal direction than the second portion, and the bubble outlet is provided at an uppermost portion of the first portion.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a liquid container and an inkjet recording apparatus equipped with the same. [Background technology]

[0002] An inkjet recording apparatus forms an image using ink as a liquid. In other words, the ink is circulated within the inkjet recording apparatus. Such an inkjet recording apparatus is disclosed, for example, in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-114611 Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional inkjet recording device, ink is temporarily stored in a liquid container (referred to as a buffer tank in Patent Document 1). The ink is then supplied from the liquid container to a recording head. The recording head ejects the ink supplied from the liquid container onto a sheet, forming an image made of ink on the sheet.

[0005] In this configuration, if air bubbles flow from the liquid reservoir into the print head, ink ejection failure may occur in the print head, which in turn reduces the quality of the ink image formed on the sheet.

[0006] The present invention has been made in view of the above points, and has as its object to prevent air bubbles from flowing into a destination of liquid supplied from a liquid container. [Means for solving the problem]

[0007] To solve the above problems, a liquid container according to a first aspect of the present invention is a liquid container arranged in a liquid flow path, and includes: a main body having a bottom and sidewalls extending upward from the bottom, and configured to store liquid in a storage area defined by the bottom and sidewalls; a lid attached to the main body and covering the storage area from above; a liquid inlet for allowing liquid to flow into the storage area; a liquid outlet for allowing liquid to flow out of the storage area to a destination; and a bubble outlet for discharging air bubbles from the storage area. The ceiling surface of the lid defining the upper side of the storage area has a first portion and a second portion. The first portion has a larger angle of inclination upward relative to the horizontal than the second portion. The bubble outlet is provided at the top of the first portion.

[0008] An inkjet recording apparatus according to a second aspect of the present invention includes the liquid container described above, an ink storage container for storing ink, and a recording head. The liquid container stores the ink flowing from the ink storage container. The recording head forms an image on a sheet using the ink supplied from the liquid container. [Effects of the Invention]

[0009] According to the configuration of the present invention, it is possible to prevent air bubbles from flowing into the destination of the supply of liquid from the liquid container. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an inkjet recording apparatus according to an embodiment. [Figure 2] 1 is a schematic diagram of a printing unit of an inkjet printing apparatus according to an embodiment. [Figure 3] FIG. 2 is a schematic diagram of an ink supply system according to one embodiment. [Figure 4] FIG. 1 is a perspective view of a mini-tank according to an embodiment, seen from above. [Figure 5] FIG. 1 is a perspective view of a mini-tank according to an embodiment, seen from below. [Figure 6] FIG. 1 is a cross-sectional view of a mini-tank according to one embodiment. [Figure 7]1A and 1B are diagrams illustrating the flow of ink (including air bubbles) in a mini-tank according to an embodiment. [Figure 8] FIG. 10 is a diagram showing the planar positions of each opening provided in the lid of the mini-tank according to one embodiment. [Figure 9] FIG. 10 is a diagram showing the angle of inclination provided on the ceiling surface of the lid of the mini-tank according to one embodiment. [Figure 10] 10A and 10B are diagrams showing the positions of the parts of the lid of the mini-tank according to one embodiment, which correspond to the first and second parts. DETAILED DESCRIPTION OF THE INVENTION

[0011] <Configuration of Inkjet Recording Apparatus> As shown in FIG. 1, the inkjet recording device 7 of this embodiment is an inkjet recording type printer. The inkjet recording device 7 forms (records) an image on a recording medium using ink. Ink corresponds to "liquid." The recording medium is, for example, paper P. However, the recording medium is not limited to this, and various sheets such as cloth can also be used.

[0012] The inkjet recording device 7 includes a recording unit 700. The recording unit 700 forms an image at a recording position. The recording unit 700 forms an image on the paper P by ejecting ink onto the paper P. The inkjet recording device 7 also includes a paper feed unit 71, a first conveying unit 72, and a second conveying unit 73.

[0013] The paper feed unit 71 stores paper sheets P and feeds them one by one. The paper feed unit 71 transports the paper sheets P toward a recording position. The first transport unit 72 and the second transport unit 73 each include an endless belt that is rotatably stretched. The first transport unit 72 and the second transport unit 73 each suction-hold the paper sheets P on the outer circumferential surface of the belt and rotate the belt in this state. In this way, the paper sheets P are transported.

[0014] The recording unit 700 is located above the first conveying unit 72. The recording unit 700 forms an image on the paper P being conveyed by the first conveying unit 72 (i.e., the paper P on the belt). After the image is formed on the paper P, the paper P is sent from the first conveying unit 72 to the second conveying unit 73. While the paper P is being conveyed by the second conveying unit 73, the image (i.e., the ink) formed on the paper P is dried.

[0015] 2, the recording unit 700 includes three recording heads 70B, 70C, 70M, and 70Y corresponding to the colors black, cyan, magenta, and yellow, respectively. In the following description, when it is not necessary to distinguish between the recording heads 70B, 70C, 70M, and 70Y, the alphabets at the end of the reference numerals will be omitted.

[0016] Each recording head 70 has a plurality of ink ejection nozzles 70a. Each recording head 70 ejects ink toward the paper P on the first transport section 72. In this way, an image is formed on the paper P.

[0017] As shown in FIG. 1, the inkjet recording device 7 includes a reverse conveyance section 74. When images are formed on both sides of the paper P, after an image is formed on one side of the paper P, the paper P is guided to the reverse conveyance section 74 by a branching section 740. The reverse conveyance section 74 switches back the paper P and returns the paper P to the upstream side in the paper conveyance direction from the recording position. This reverses the paper P. In other words, it becomes possible to form an image on the other side of the paper P.

[0018] The inkjet recording apparatus 7 also includes a control unit 75. The control unit 75 includes various electronic components such as a processing circuit (such as a CPU) and a memory. The control unit 75 controls the operation of each component provided in the inkjet recording apparatus 7 based on a control program and control data.

[0019] <Ink supply system configuration> The inkjet recording device 7 includes ink supply systems 8 as shown in Fig. 3. There are four ink supply systems 8, one for each of the colors black, cyan, magenta, and yellow. In other words, one ink supply system 8 is assigned to each of the recording heads 70B, 70C, 70M, and 70Y.

[0020] 3 shows only the ink supply system 8 of a certain color. The ink supply systems 8 of the other colors have the same configuration. Therefore, the following description will be used to cite the configurations of the ink supply systems 8 of the other colors, and therefore will not be provided.

[0021] The ink supply system 8 includes an ink container 81. The ink container 81 is detachable from the main body of the inkjet recording device 7. The ink container 81 stores ink. When the inkjet recording device 7 forms an image on paper P, the ink in the ink container 81 is used.

[0022] The ink supply system 8 includes a sub-tank 82. The sub-tank 82 corresponds to an "ink storage container." For example, a container pump 80 is disposed on the ink distribution path between the ink container 81 and the sub-tank 82. The container pump 80 sucks ink from the ink container 81 and ejects it into the sub-tank 82.

[0023] The control unit 75 controls the container pump 80. For example, the subtank 82 is provided with an ink storage amount sensor (not shown) that outputs a value corresponding to the amount of ink stored in the subtank 82. Various types of ink storage amount sensors can be used, such as optical, capacitance, electrode, differential pressure, and float types. The control unit 75 monitors the output value of the ink storage amount sensor. Then, when the amount of ink stored in the subtank 82 falls below a predetermined amount, the control unit 75 uses the container pump 80 to supply ink from the ink container 81 to the subtank 82.

[0024] The subtank 82 temporarily stores ink supplied from the ink container 81. The ink in the subtank 82 is supplied to the recording head 70. The positional relationship between the subtank 82 and the recording head 70 is set so that an ink meniscus is formed at the ejection-side opening of the ink ejection nozzle 70a. In other words, ink is supplied from the subtank 82 to the recording head 70 by the action of head pressure.

[0025] The ink supply system 8 also includes a mini-tank 100. The mini-tank 100 corresponds to a "liquid container." The mini-tank 100 is disposed on the ink distribution path between the sub-tank 82 and the recording head 70. In other words, the destination of the ink flowing out of the mini-tank 100 is the recording head 70.

[0026] The mini-tank 100 suppresses sudden pressure fluctuations in the ink distribution path from the sub-tank 82 to the print head 70. The mini-tank 100 also branches the ink distribution path into three. Ink is supplied from a single mini-tank 100 to three print heads 70 that eject ink of the same color.

[0027] <Mini Tank Configuration> In this embodiment, a mini-tank 100 as shown in Figures 4 to 6 is used. The vertical direction of the mini-tank 100 is the up-down direction. The up-down direction of the mini-tank 100 coincides with the up-down direction of the inkjet recording device 7.

[0028] The mini-tank 100 comprises a main body 1 and a lid 2. The main body 1 and the lid 2 are each a resin molded product manufactured using a resin molding die. The mini-tank 100 is constructed by assembling the main body 1 and the lid 2 together. The main body 1 constitutes the lower part of the mini-tank 100, and the lid 2 constitutes the upper part of the mini-tank 100.

[0029] The main body 1 has a storage area 10 that stores ink. Specifically, the main body 1 has a bottom 11 and sidewalls 12. The bottom 11 is circular when viewed from the top-bottom direction. The sidewalls 12 extend upward from the edge of the bottom 11 when viewed from the top-bottom direction around the entire periphery. The main body 1 has a storage area 10 that is an area surrounded by the bottom 11 and the sidewalls 12. The storage area 10 is a circular area when viewed from the top-bottom direction.

[0030] In the following description, the center of the storage area 10 when viewed from the top-bottom direction is designated by the symbol CP, and the central axis that passes through the center CP of the storage area 10 in the top-bottom direction is designated by the symbol CA. Also, the direction perpendicular to the central axis CA (i.e., the top-bottom direction) is referred to as the radial direction. Within the radial direction, the direction approaching the central axis CA is referred to as the radially inward direction, and the direction away from the central axis CA is referred to as the radially outward direction.

[0031] The lid part 2 is disposed above the main body part 1. The lid part 2 covers the storage area 10 from above. In other words, the lid part 2 closes the upper opening of the main body part 1.

[0032] The lid 2 is attached to the main body 1. Specifically, the main body 1 has a main body-side attachment portion 1a that surrounds the side wall 12 (i.e., the storage area 10) when viewed from the top-bottom direction. The main body-side attachment portion 1a has a substantially rectangular outer shape when viewed from the top-bottom direction. The lid 2 has a lid-side attachment portion 2a, which is a portion that overlaps the main body-side attachment portion 1a in the top-bottom direction. The lid 2 is attached to the main body 1 by fastening the lid-side attachment portion 2a to the main body-side attachment portion 1a with a fastening member.

[0033] The mini-tank 100 has an ink inlet 3. The ink inlet 3 is provided in the lid portion 2. The ink inlet 3 is the same member as the lid portion 2. In other words, the lid portion 2 has the ink inlet 3 integrally therewith.

[0034] The ink inlet 3 has an outer tube portion 31 that protrudes upward from the lid portion 2. The outer tube portion 31 is cylindrical and extends linearly in the vertical direction. The ink inlet 3 has the internal space of the outer tube portion 31 as a flow path for ink.

[0035] The ink inlet 3 allows ink to flow from the subtank 82 into the storage area 10. Specifically, the ink inlet 3 is connected to a conduit 30 (see FIG. 3). The conduit 30 is attached to the tip of the outer tube portion 31. The conduit 30 is connected to the subtank 82 and allows ink from the subtank 82 to flow. This allows the ink from the subtank 82 to flow into the storage area 10 via the conduit 30.

[0036] The mini-tank 100 also has an ink outlet 4. The ink outlet 4 is provided in the lid portion 2. The ink outlet 4 is the same member as the lid portion 2. In other words, the lid portion 2 has the ink outlet 4 integrally therewith.

[0037] The ink outlet 4 has an outer tube portion 41 that protrudes upward from the lid portion 2. The outer tube portion 41 is cylindrical and extends linearly in the vertical direction. The ink outlet 4 has the internal space of the outer tube portion 41 as a flow path for ink.

[0038] The ink outlet 4 allows ink to flow from the storage area 10 to the recording head 70 (i.e., the ink supply destination). Three recording heads 70 are assigned to each color. On the other hand, there is one mini-tank 100 for each color. Therefore, the mini-tank 100 has three ink outlets 4 corresponding to the three recording heads 70, respectively.

[0039] Each ink outlet 4 is connected to a conduit 40. The conduit 40 is attached to the tip of the outer tube portion 41. Each ink outlet 4 allows ink to flow from the containing region 10 to a corresponding recording head 70 via the conduit 40. Each recording head 70 forms an image using ink supplied from the mini-tank 100.

[0040] The mini-tank 100 also includes a bubble discharge port 5. The bubble discharge port 5 is provided in the lid portion 2. The bubble discharge port 5 is the same member as the lid portion 2. In other words, the lid portion 2 has the bubble discharge port 5 integrally therewith.

[0041] The bubble discharge port 5 has an outer tubular part 51 that protrudes upward from the lid part 2. The outer tubular part 51 is cylindrical and extends linearly in the vertical direction. The bubble discharge port 5 has the internal space of the outer tubular part 51 as a flow path for bubbles.

[0042] The bubble discharge port 5 discharges air bubbles in the storage area 10 into the sub-tank 82. Specifically, the bubble discharge port 5 is connected to a conduit 50 (see FIG. 3). The conduit 50 is attached to the tip of the outer tubular portion 51. The conduit 50 is connected to the sub-tank 82. As a result, the air bubbles in the storage area 10 are discharged into the sub-tank 82 via the conduit 50.

[0043] In this embodiment, air bubbles can be discharged from within the storage area 10, making it difficult for air bubbles to flow into the recording head 70. The recording head 70 forms an image using ink, and if air bubbles flow into the recording head 70, poor ink ejection will occur in the recording head 70, reducing the quality of the image formed using the ink. For this reason, it is preferable to discharge air bubbles from within the storage area 10.

[0044] The flow of ink (including air bubbles) within the storage area 10 is shown schematically in Figure 7. In Figure 7, the flow of ink (including air bubbles) is indicated by arrows. Air bubbles within the storage area 10 are indicated by white circles. Note that in Figure 7, some reference numerals from Figure 6 are used and have been omitted.

[0045] <Inner cylinder of ink outlet> In this embodiment, as shown in FIG. 6 , the ink outlet 4 has an inner tubular portion 42. The inner tubular portion 42 protrudes downward from the lid portion 2 in a cylindrical shape and is disposed in the storage area 10. The inner tubular portion 42 is cylindrical and extends linearly in the vertical direction. The ink outlet 4 has the inner space of the inner tubular portion 42 as an ink flow path in addition to the inner space of the outer tubular portion 41. In other words, the inner space of the inner tubular portion 42 communicates with the inner space of the outer tubular portion 41. In other words, the ink outlet 4 is cylindrical and penetrates the lid portion 2 in the vertical direction.

[0046] As a result, the ink in the storage area 10 flows into the internal space of the inner tube portion 42 from the lower end opening of the inner tube portion 42 (i.e., the opening of the ink outlet 4 on the storage area 10 side). Then, the ink in the storage area 10 flows out from the upper end opening of the outer tube portion 41 (i.e., the opening of the ink outlet 4 on the opposite side from the storage area 10 side).

[0047] In this embodiment, the inner cylindrical portion 42 does not contact the side wall portion 12 of the main body portion 1. In other words, a gap G is provided between the inner cylindrical portion 42 and the side wall portion 12 in the radial direction. In other words, the inner cylindrical portion 42 is disposed at a position spaced apart from the inner surface of the side wall portion 12 radially inward.

[0048] In this configuration, even if air bubbles in the storage area 10 move toward the ink outlet 4, the air bubbles pass through the lower end opening of the inner tubular portion 42 and reach the gap G (see FIG. 7). Because the air bubbles in the storage area 10 move further upward, the air bubbles in the gap G are less likely to flow into the ink outlet 4 (i.e., the lower end opening of the inner tubular portion 42). As a result, it is possible to prevent air bubbles from flowing out of the ink outlet 4. In other words, it is possible to prevent air bubbles from flowing into the recording head 70, which is the destination of the ink supply.

[0049] Suppressing the inflow of air bubbles into the recording head 70 can suppress ink ejection defects from occurring in the recording head 70. This can suppress deterioration in the quality of images formed using ink.

[0050] Furthermore, in this embodiment, since the ink outlet 4 has the inner tubular portion 42, the opening of the ink outlet 4 on the storage area 10 side (i.e., the lower end opening of the inner tubular portion 42) is positioned closer to the bottom 11 than the opening of the ink inlet 3 on the storage area 10 side. In other words, the vertical distance W1 between the opening of the ink outlet 4 on the storage area 10 side and the bottom 11 is smaller than the vertical distance W2 between the opening of the ink inlet 3 on the storage area 10 side and the bottom 11.

[0051] With this configuration, air bubbles present around the opening of the ink inlet 3 on the side of the storage area 10 are less likely to reach the opening of the ink outlet 4 on the side of the storage area 10 (i.e., the lower end opening of the inner tubular portion 42). In other words, air bubbles move upward on the way from the ink inlet 3 to the ink outlet 4, making it less likely for ink to flow into the ink outlet 4 (i.e., the lower end opening of the inner tubular portion 42). As a result, air bubbles can be further prevented from flowing out from the ink outlet 4.

[0052] For example, the vertical distance W1 between the opening of the ink outlet 4 on the storage area 10 side (i.e., the lower end opening of the inner tubular portion 42) and the bottom 11 is set to be equal to or larger than the inner diameter D of the ink outlet 4. This can reduce the flow resistance of the ink.

[0053] As a modified example, a difference in height may be provided in the ceiling of the storage area 10 (i.e., the underside of the lid 2). Then, the ink inlet 3 may be provided on the side with the higher ceiling, and the ink outlet 4 may be provided on the side with the lower ceiling (i.e., the part of the lid 2 closer to the bottom 11). This also allows the opening of the ink outlet 4 on the storage area 10 side to be positioned closer to the bottom 11 than the opening of the ink inlet 3 on the storage area 10 side.

[0054] <Height positions of the ink inlet, ink outlet, and bubble outlet> 6, of the ink inlet 3, ink outlet 4, and bubble outlet 5, the ink outlet 4 is closest to the bottom 11 in the vertical direction, and the bubble outlet 5 is farthest from the bottom 11 in the vertical direction. In other words, the opening of the bubble outlet 5 on the storage area 10 side is located farther from the bottom 11 than the opening of the ink inlet 3 on the storage area 10 side.

[0055] In this configuration, the bubble discharge port 5 is located in the location in the storage area 10 where bubbles are likely to accumulate (i.e., the highest position). This allows bubbles in the storage area 10 to be efficiently discharged from the bubble discharge port 5. When bubbles are efficiently discharged from the bubble discharge port 5, it is possible to prevent bubbles from flowing into the ink outlet 4.

[0056] <Plane positions of the ink inlet, ink outlet, and bubble outlet> 8, in this embodiment, a total of four openings, including one ink inlet 3 and three ink outlets 4, are evenly spaced around the same imaginary circle VC centered at the center CP of the storage area 10 when viewed from the top-bottom direction. When there are four openings in total, they are evenly spaced at 90° intervals around the circumference of the imaginary circle VC. Although not shown, for example, when there is one ink inlet 3 and two ink outlets 4 (a total of three openings), they are evenly spaced at 120° intervals around the circumference of the imaginary circle VC.

[0057] 8, the imaginary circle VC is indicated by a two-dot chain line, and the outer edge of the accommodation area 10 as viewed from above and below is indicated by a broken line.

[0058] In this configuration, the openings of the cover 2 (one ink inlet 3 and three ink outlets 4) are separated when viewed from above and below. This allows the ink that flows into the containing area 10 from the ink inlet 3 to be appropriately agitated before reaching each ink outlet 4.

[0059] By stirring the ink, the air bubbles tend to move upward. That is, the air bubbles tend to move toward the air bubble discharge port 5. This promotes the discharge of air bubbles from the air bubble discharge port 5, and prevents air bubbles from flowing into the ink outlet 4 (that is, preventing air bubbles from flowing out from the ink outlet 4). As a result, it is possible to prevent air bubbles from flowing into the recording head 70, which is the destination of the ink supply.

[0060] Furthermore, with this configuration, the ink in the storage area 10 is appropriately stirred, thereby preventing the ink in the storage area 10 from becoming highly viscous. This prevents highly viscous ink from flowing out of the ink outlet 4. As a result, it is possible to prevent highly viscous ink from flowing into the recording head 70, which is the destination of the ink supply.

[0061] By suppressing the inflow of air bubbles into the recording head 70 and suppressing the increase in viscosity of the ink flowing into the recording head 70, it is possible to suppress the occurrence of ink ejection defects in the recording head 70. This makes it possible to suppress the degradation of the image quality of images formed using the ink.

[0062] Furthermore, in this embodiment, the bubble discharge port 5 is disposed at a position that overlaps with the center CP of the storage area 10 of the lid part 2 (i.e., the center CP of the imaginary circle VC) when viewed from the top and bottom. This allows bubbles to be efficiently collected at the bubble discharge port 5. As a result, bubbles can be efficiently discharged from the bubble discharge port 5.

[0063] In this embodiment, the ink inlet 3 is disposed at a position away from the position of the lid 2 where it overlaps with the side wall 12 toward the storage area 10 (i.e., radially inward) when viewed from the top-bottom direction. This results in the shape of the lid 2 being the shape shown in Fig. 4. In other words, this makes it easier to mold from resin.

[0064] <Shape of main body> 6, the inner surfaces of at least some of the corners 10a of the storage area 10, which is formed by the bottom 11 and the sidewalls 12, are rounded. In other words, the inner surfaces of at least some of the corners 10a of the storage area 10 are curved.

[0065] This configuration can prevent ink from accumulating in the corners 10a of the storage area 10, promoting agitation of the ink. As a result, the ink in the storage area 10 can be prevented from becoming highly viscous. By preventing the ink in the storage area 10 from becoming highly viscous, it is possible to prevent highly viscous ink from flowing out from the ink outlet 4 (i.e., it is possible to prevent highly viscous ink from flowing into the recording head 70, which is the destination of the ink). Furthermore, because the agitation of the ink is promoted, it is possible to prevent air bubbles from flowing out from the ink outlet 4 (i.e., it is possible to prevent air bubbles from flowing into the recording head 70, which is the destination of the ink).

[0066] In this embodiment, the corners 10a of the storage area 10 are formed in an R-shape over the entire circumferential direction surrounding the storage area 10. This can further promote the agitation of ink in the storage area 10.

[0067] In this embodiment, at least a portion of the ink inlet 3 overlaps with the rounded corner 10a of the storage area 10 when viewed from the top and bottom. In this configuration, ink flowing in from the ink inlet 3 flows toward the rounded corner 10a. This makes it easier to agitate the ink in the storage area 10.

[0068] In this embodiment, at least a portion of the ink outlet 4 overlaps with the rounded corner 10a of the ink containing area 10 when viewed from the top and bottom. With this configuration, the ink is more likely to be agitated at the rounded corner 10a immediately before it flows out of the ink outlet 4.

[0069] As a modified example (not shown), only some corners 10a of the containing area 10 may be formed in an R-shape. For example, only the portion of the corner 10a of the containing area 10 that overlaps at least a portion of the ink inlet 3 may be formed in an R-shape, or only the portion that overlaps at least a portion of the ink outlet 4 may be formed in an R-shape.

[0070] <Lid shape> In this embodiment, as shown in Fig. 6, an inclined surface 20 is provided on the underside of the lid portion 2. The inclined surface 20 of the lid portion 2 is inclined upward in the radially inward direction. In other words, the underside of the lid portion 2, which is the surface that defines the storage area 10, has the inclined surface 20 that is inclined upward toward the center CP (central axis CA) of the storage area 10.

[0071] Here, when viewed from the top-bottom direction, the bubble discharge port 5 is positioned so as to overlap the center CP, and the ink inlet 3 and ink outlet 4 are each positioned radially outward from the bubble discharge port 5. As a result, the underside of the lid part 2 is inclined upward from the positions of the ink inlet 3 and ink outlet 4 on the lid part 2 toward the position of the bubble discharge port 5.

[0072] With this configuration, air bubbles in the storage area 10 can easily move along the inclined surface 20 of the lid portion 2. That is, the air bubbles in the storage area 10 can easily move toward the air bubble discharge port 5. This makes it easier for the air bubbles to be discharged from the air bubble discharge port 5.

[0073] <Directions of the ink inlet, ink outlet, and bubble outlet> In this embodiment, the ink inlet 3, ink outlet 4, and bubble outlet 5 are all provided in the lid portion 2. Specifically, the ink inlet 3, ink outlet 4, and bubble outlet 5 have outer tubular portions 31, 41, and 51, respectively. Each of the outer tubular portions 31, 41, and 51 has its own internal space as an ink flow path. Each of the outer tubular portions 31, 41, and 51 protrudes upward from the lid portion 2 in a cylindrical shape. That is, each of the outer tubular portions 31, 41, and 51 protrudes in the same direction as each other. Conduits 30, 40, and 50, which allow ink to flow, are attached to the outer tubular portions 31, 41, and 51, respectively.

[0074] In this configuration, the attachment points of the conduits 30, 40, and 50 are concentrated on the upper side of the mini-tank 100. This increases the flexibility of the installation location of the mini-tank 100. In other words, other components can be placed below the mini-tank 100. In other words, it is possible to prevent excess space from being created around the mini-tank 100. As a result, it is possible to reduce the size of the inkjet recording device 7 equipped with the mini-tank 100.

[0075] <Ceiling of containment area> The storage area 10 has the underside of the lid 2 as its ceiling surface. The ceiling surface of the lid 2 covers the upper opening of the storage area 10 from above, blocking the upper opening of the storage area 10 from above. As a result, a portion of the storage area 10 is defined by the ceiling surface of the lid 2. In other words, the underside of the lid 2 is the ceiling surface that defines the upper area of ​​the storage area 10.

[0076] In the following description, the ceiling surface of the lid portion 2 (that is, the lower surface of the lid portion 2) will be denoted by the reference numeral 200. The inclined surface 20 (see FIG. 6) is a part of the ceiling surface 200.

[0077] As shown in Fig. 9, the ceiling surface 200 has a first portion 201 and a second portion 202. Looking at the plan view of the lid portion 2 shown in Fig. 10 (a plan view of the lid portion 2 seen from above), the underside of portion 2001 of the lid portion 2 corresponds to the first portion 201, and the underside of portion 2002 of the lid portion 2 corresponds to the second portion 202. In Fig. 10, the boundary between portion 2001 and portion 2002 of the lid portion 2 is indicated by a dashed dotted line. Note that in Fig. 9, the left-right direction of the drawing is the horizontal direction.

[0078] The first portion 201 is a circular portion located in the center of the storage area 10 when viewed from the top-bottom direction. The center of the first portion 201 when viewed from the top-bottom direction coincides with the center CP. In the perspective view shown in FIG. 4, the underside of the portion 2001 of the lid 2 that protrudes upward in a conical shape corresponds to the first portion 201.

[0079] The first portion 201 is inclined upward relative to the horizontal direction. Specifically, the first portion 201 is inclined upward from the outer periphery toward the center (i.e., the center CP of the accommodation area 10) when viewed from the top-bottom direction of the first portion 201. The inclination angle of the first portion 201 relative to the horizontal direction is angle θa (see FIG. 9).

[0080] The second portion 202 is annular when viewed from the top-bottom direction, and surrounds the first portion 201. When viewed from the top-bottom direction, the second portion 202 is connected to the outer periphery of the first portion 201. In the perspective view shown in FIG. 4 , the lower surface of the portion 2002 on the outer edge side of the conical portion 2001 of the lid portion 2 corresponds to the second portion 202.

[0081] Similar to the first portion 201, the second portion 202 is inclined upward with respect to the horizontal direction. Specifically, the second portion 202 is inclined upward from the outer circumferential edge of the second portion 202 when viewed from the top-bottom direction toward the connection side with the first portion 201. The inclination angle of the second portion 202 with respect to the horizontal direction is angle θb (see FIG. 9).

[0082] The tilt angles θa and θb are different from each other. The tilt angle θa is larger than the tilt angle θb. That is, the first portion 201 has a larger upward tilt angle with respect to the horizontal direction than the second portion 202. For example, the tilt angle θa is approximately 45°, and the tilt angle θb is approximately 10° to 20°.

[0083] In this embodiment, the bubble discharge outlet 5 is disposed at a position that overlaps with the center CP of the storage area 10 of the lid part 2 when viewed from the top-bottom direction. In other words, the bubble discharge outlet 5 is disposed at a position that overlaps with the center of the first part 201 when viewed from the top-bottom direction. In other words, the bubble discharge outlet 5 is provided at the top of the first part 201.

[0084] The bubbles in the storage area 10 tend to flow upward along the inner surfaces that define the storage area 10 (such as the inner surfaces of the bottom 11, the inner surfaces of the sidewalls 12, and the ceiling surface 200). If the inclination angle θa of the first portion 201 is greater than the inclination angle θb of the second portion 202, the bubbles flowing along the ceiling surface 200 will be more likely to reach the top of the first portion 201.

[0085] This improves the efficiency of air bubbles being discharged from the bubble discharge port 5 in this embodiment. When air bubbles are efficiently discharged from the bubble discharge port 5, air bubbles are less likely to flow into the ink outlet 4. As a result, air bubbles can be prevented from flowing out from the ink outlet 4. In other words, air bubbles can be prevented from flowing into the recording head 70, which is the destination of ink supply.

[0086] In this embodiment, the ink inlet 3 and the ink outlet 4 are provided in the second portion 202. Furthermore, in this embodiment, the second portion 202 is inclined upward from the outer periphery of the second portion 202 when viewed from the top-bottom direction toward the connecting side with the first portion 201. This makes it easier for air bubbles around the openings of the ink inlet 3 and the ink outlet 4 to move toward the bubble outlet 5 (i.e., the top of the first portion 201). As a result, air bubbles are more easily discharged from the bubble outlet 5.

[0087] Furthermore, in this embodiment, the inclination angle of the ceiling surface 200 gradually increases toward the center CP of the storage area 10. In other words, the ceiling surface 200 is formed so that the second portion 202 and the first portion 201 are arranged in this order toward the top. This allows the upper end position of the outer tubular portion 51 of the bubble discharge port 5 to be lower than when the inclination angle of the ceiling surface 200 suddenly increases from the outer peripheral edge of the storage area 10. In other words, the vertical size of the mini-tank 100 can be prevented from increasing.

[0088] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0089] 1 Main body 2 Lid 3 Ink inlet 4 Ink outlet 5 Air bubble outlet 7. Inkjet recording device 10 Containment Area 11 Bottom 12 Side wall 70 Recording head (supply destination) 82 Subtank (ink storage container) 100 Mini Tank (Liquid Container) 200 Ceiling 201 Part 1 202 Part 2

Claims

1. A liquid container disposed on a liquid flow path, a main body portion having a bottom portion and a side wall portion extending upward from the bottom portion, the main body portion containing liquid in a containing area surrounded by the bottom portion and the side wall portion; a lid portion attached to the main body portion and covering the storage area from above; a liquid inlet for allowing liquid to flow into the storage area; a liquid outlet for discharging liquid from the storage area to a supply destination; a bubble discharge port for discharging bubbles from the storage area, a ceiling surface of the lid portion defining an upper portion of the storage area has a first portion and a second portion; the first portion has a larger upward inclination angle with respect to the horizontal direction than the second portion, The bubble discharge port is provided at the top of the first portion.

2. The first portion is disposed in a central portion of the storage area when viewed from the top-bottom direction, and is inclined upward from an outer peripheral edge of the first portion toward a center when viewed from the top-bottom direction, The liquid container according to claim 1 , wherein the bubble discharge port is disposed at a position that overlaps with the center of the first portion when viewed from above.

3. the second portion surrounds the first portion when viewed from the top-bottom direction and is connected to an outer periphery of the first portion; The liquid container according to claim 2 , wherein the liquid inlet and the liquid outlet are provided in the second portion.

4. The liquid container according to claim 3 , wherein the second portion is inclined upward from an outer periphery of the second portion when viewed from the top-bottom direction toward a connecting side with the first portion.

5. A liquid container according to any one of claims 1 to 4; an ink storage container for storing ink; a recording head; the liquid container stores the ink flowing in from the ink storage container; The recording head forms an image on a sheet using ink supplied from the liquid container.

Images