Filter unit, liquid ejecting apparatus, and maintenance method of liquid ejecting head

Abstract

To provide a filter unit in which air bubbles in a filter chamber are easily discharged, a liquid ejecting apparatus, and a maintenance method of a liquid ejecting head.SOLUTION: A filter unit 2 that is used in a posture in which a gravity direction and an imaginary plane along a filter F intersect, the filter unit 2 including the filter F, a filter chamber 30 having an upstream chamber 31 and a downstream chamber 32 that are partitioned by the filter F, an inlet port 33a for introducing a liquid from outside the filter unit 2, and an outlet port 35a for discharging the liquid inside the filter chamber 30 to outside the filter unit 2 via the downstream chamber 32, the introduction port 33a opens toward a second direction intersecting a first direction perpendicular to an imaginary plane along the filter F, the lead-out port 35a opens toward a third direction opposite to the second direction, and the introduction port 33a overlaps the lead-out port 35a when viewed in the third direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a filter unit having a filter therein that removes foreign matter contained in liquid, a liquid ejection device that includes the filter unit and a liquid ejection head that ejects liquid supplied from the filter unit, and a maintenance method for the liquid ejection head that ejects liquid supplied from a filter chamber. [Background technology]

[0002] The liquid ejection device includes a liquid ejection head that ejects liquid such as ink supplied from a liquid storage unit such as an ink tank as droplets from a plurality of nozzles by changing the pressure generated by a pressure generating means. The liquid ejection device also includes a filter unit having a flow path that supplies the ink from the liquid storage unit to the liquid ejection head, and a filter chamber that is provided midway along the flow path and that has a filter that captures foreign matter such as dust and air bubbles contained in the liquid (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-101347 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a filter unit, it is desirable to make it easier to expel air bubbles from the filter chamber when performing an initial filling operation in which liquid is initially filled from the liquid storage section to the liquid ejection head via the filter chamber, or when performing a cleaning operation in which air bubbles remaining in the filter chamber are expelled. [Means for solving the problem]

[0005] An aspect of the present invention that solves the above problem is a filter unit used in an orientation where the direction of gravity and an imaginary plane along the filter intersect, comprising: the filter; a filter chamber having an upstream chamber and a downstream chamber partitioned by the filter; an inlet for introducing liquid from outside the filter unit; and an outlet for discharging liquid in the filter chamber to the outside of the filter unit via the downstream chamber, wherein the inlet opens toward a second direction that intersects with a first direction perpendicular to the imaginary plane along the filter, and the outlet opens toward a third direction opposite to the second direction, and the inlet overlaps with the outlet when viewed in the third direction.

[0006] Another aspect of the present invention is a liquid ejection device comprising: a liquid ejection head for ejecting liquid; a liquid storage section for storing liquid to be supplied to the liquid ejection head; and a filter unit according to claim 1, which is arranged midway along a supply flow path for supplying liquid from the liquid storage section to the liquid ejection head.

[0007] Another aspect of the present invention is a maintenance method for a liquid ejection head having a plurality of nozzles that eject liquid supplied from a filter chamber having an upstream chamber and a downstream chamber partitioned by a filter, characterized in that the liquid ejection head performs a printing operation in which the liquid ejection head ejects liquid onto a medium when the filter chamber is in a first position such that the lower surface that defines the downstream chamber of the filter faces the direction of gravity, and performs maintenance in which the filter chamber is in a second position such that the lower surface faces in the opposite direction to the direction of gravity, discharging liquid from the plurality of nozzles to the outside through the filter chamber. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing a schematic configuration of a liquid ejecting apparatus according to a first embodiment of the present invention. [Figure 2] 1 is a schematic diagram of a liquid ejecting device according to a first embodiment of the present invention. [Figure 3] FIG. 1 is a cross-sectional view of a filter unit according to a first embodiment of the present invention. [Figure 4] FIG. 1 is a cross-sectional view of a filter unit according to a first embodiment of the present invention. [Figure 5] 1 is a functional block diagram of a liquid ejecting device according to a first embodiment of the present invention. [Figure 6] FIG. 4 is a cross-sectional view of a filter unit according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view of a filter unit according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a plan view of a main part of a filter unit according to a third embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of a filter unit according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below based on embodiments. However, the following description illustrates one aspect of the present invention and can be modified as desired within the scope of the present invention. In each drawing, the same reference numerals indicate the same components, and their description will be omitted as appropriate. In each drawing, X, Y, and Z represent three spatial axes that are orthogonal to each other. In this specification, the directions along these axes are referred to as the X, Y, and Z directions. In each drawing, the direction indicated by the arrows is the positive (+) direction, and the direction opposite the arrow is the negative (-) direction. The Z direction indicates the vertical direction, and the +Z direction is the direction of gravity, i.e., vertically downward, while the -Z direction is the direction opposite to the direction of gravity, i.e., vertically upward. Furthermore, the directions of the three spatial axes, which are not limited to positive and negative directions, will be described as the X-axis direction, Y-axis direction, and Z-axis direction.

[0010] (Embodiment 1) Fig. 1 is a diagram showing a schematic configuration of a liquid ejecting apparatus 1 of the present invention. Fig. 2 is a schematic diagram of a liquid storage section 3, a filter unit 2, and a liquid ejecting head H.

[0011] As shown in the figure, the liquid ejection device 1 is a so-called serial printer that includes a liquid ejection head H and prints by conveying a medium S in the X-axis direction while moving the liquid ejection head H back and forth in the Y-axis direction and ejecting (also called discharging) liquid from the liquid ejection head H toward the medium S in the +Z direction. Note that the medium S can be made of any material, such as recording paper, resin film, cloth, etc.

[0012] The liquid ejecting device 1 includes a liquid ejecting head H, a filter unit 2, a liquid storage section 3, a control device 4, a transport mechanism 5 that feeds out the medium S, and a moving mechanism 6.

[0013] The liquid jet head H jets the liquid supplied from the liquid storage section 3 in the form of droplets in the +Z direction.

[0014] The liquid storage unit 3 individually stores multiple types of ink with different colors and ingredients to be ejected from the liquid ejection head H. Examples of the liquid storage unit 3 include a cartridge that is detachable from the liquid ejection device 1, a bag-shaped ink pack made of flexible film, and an ink tank that can be refilled with ink. FIG. 1 illustrates a single liquid storage unit 3. The liquid storage unit 3 may be a liquid storage unit 3 having separate chambers that individually store multiple types of ink, or may be multiple liquid storage units 3 that are individually provided corresponding to the multiple types of ink. The liquid storage unit 3 may also be divided into a main tank and a sub-tank. A configuration may be adopted in which the sub-tank is connected to the liquid ejection head H, and ink consumed when ink is ejected from the liquid ejection head H is replenished from the main tank to the sub-tank.

[0015] A supply tube T is connected to the liquid storage section 3. Although one supply tube T is shown in Fig. 1, a supply tube T is provided for each different type of ink.

[0016] The supply tube T is a tube that supplies the ink in the liquid storage section 3 , which has been pressurized to a predetermined pressure by the pump 7 , to the liquid jet head H via the filter unit 2 .

[0017] The control device 4 includes, for example, a control device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage device such as a semiconductor memory. The control device 4 also includes a power supply device that supplies power from an external power source such as a commercial power source to each element of the liquid ejection device 1. The control device 4 is electrically connected to the liquid ejection head H via external wiring (not shown). The control device 4 comprehensively controls each element of the liquid ejection device 1 by the control device executing a program stored in the storage device.

[0018] The transport mechanism 5 transports the medium S in the X-axis direction, and includes, for example, a transport roller 5a that is rotated by a transport motor that is driven under the control of the control device 4.

[0019] The movement mechanism 6 is a mechanism for reciprocating the liquid jet head H in the Y-axis direction, and includes a holder 6a that holds the liquid jet head H, and a conveyor belt 6b that is an endless belt that is installed along the Y-axis direction. The control device 4 controls the drive of a conveyor motor (not shown), thereby rotating the conveyor belt 6b and moving the liquid jet head H back and forth in the Y-axis direction together with the holder 6a fixed to the conveyor belt 6b. The filter unit 2 can also be mounted on the holder 6a together with the liquid jet head H. The liquid storage section 3 can also be mounted on the holder 6a together with the liquid jet head H and the filter unit 2. The holder 6a holds one liquid jet head H, but the holder 6a may hold two or more liquid jet heads H.

[0020] The liquid jet head H performs a jetting operation to jet ink supplied from the liquid storage unit 3 as ink droplets from each of the multiple nozzles N in the +Z direction under the control of the control device 4. The control device 4 functions as a jetting control unit that controls the jetting of ink by the liquid jet head H. This jetting operation by the liquid jet head H is performed in parallel with the transport of the medium S in the X-axis direction by the transport mechanism 5 and the reciprocating movement of the liquid jet head H in the Y-axis direction by the movement mechanism 6, thereby applying ink to the medium S, i.e., performing so-called printing.

[0021] The filter unit 2 captures foreign matter such as dust and air bubbles contained in the ink supplied from the liquid storage section 3, and supplies the ink to the liquid jet head H. In other words, the filter unit 2 is disposed between the liquid storage section 3 and the liquid jet head H. In this embodiment, the portion of the supply tube T between the liquid storage section 3 and the filter unit 2 is referred to as the supply tube T1, and the portion between the filter unit 2 and the liquid jet head H is referred to as the supply tube T2.

[0022] A plurality of filter units 2 are provided corresponding to the types of ink stored in the liquid storage section 3. Figures 1 and 2 show one filter unit 2. Furthermore, one filter unit 2 is provided for one ink, but two or more filter units 2 may be provided for one ink by branching the same type of ink, for example.

[0023] Fig. 3 is a cross-sectional view showing a first posture of the filter unit 2 during printing. Fig. 4 is a cross-sectional view showing a second posture of the filter unit 2 during cleaning. The configuration of the filter unit 2 will be described below using the X-axis, Y-axis, and Z-axis directions with the posture during printing shown in Fig. 3 as a reference.

[0024] 3, the filter unit 2 includes a first flow path member 10 and a second flow path member 20. The first flow path member 10 and the second flow path member 20 are stacked together along the Z-axis direction, and the first flow path member 10 is disposed in the −Z direction relative to the second flow path member 20.

[0025] A filter chamber 30 is defined inside the filter unit 2. The filter chamber 30 is formed by aligning the openings of a first recess 11, which is provided in the first flow path member 10 and opens onto a surface facing the +Z direction, with a second recess 21, which is provided in the second flow path member 20 and opens onto a surface facing the -Z direction. The first recess 11 has a larger volume than the second recess 21.

[0026] A filter F is fixed to the opening of the second recess 21 of the second flow path member 20. The filter F is disposed so that the in-plane direction of the main surface Fa (also referred to as the upper surface Fa) on which the filter F extends is perpendicular to the Z-axis direction, which is the stacking direction of the first flow path member 10 and the second flow path member 20, i.e., along the XY plane defined by the X-axis and Y-axis. That is, the lower surface Fb of the filter F is disposed facing the +Z direction. Such a filter F traps foreign matter contained in ink, such as air bubbles and dust. For example, a sheet-like filter having multiple micropores formed by finely weaving fibers of metal or resin can be used. Alternatively, a plate-like filter F made of metal or resin with multiple microscopic through-holes can be used. Furthermore, the filter F may be made of a nonwoven fabric or the like, and the material is not particularly limited. The method of fixing the filter F to the second flow path member 20 is not particularly limited, and examples include adhesion with an adhesive and heat welding.

[0027] The filter chamber 30 is divided by the filter F into an upstream chamber 31 located upstream of the filter F and a downstream chamber 32 located downstream of the filter F. Specifically, the upstream chamber 31 is defined by the upper surface Fa of the filter F. The downstream chamber 32 is defined by the lower surface Fb of the filter F. When viewed from the Z-axis direction, the filter chamber 30 and the filter F have a so-called rounded rectangular shape (also known as a track shape) or an elongated hole shape, which is based on a circular or rectangular shape with semicircular longitudinal ends. Incidentally, an elongated hole shape refers to an elliptical shape or a shape similar to an ellipse, such as a chicken egg shape or an oval shape. Of course, the filter chamber 30 and the filter F may be square, rectangular, parallelogram, polygonal, or sector-shaped. However, because corners tend to trap air bubbles in the corners of shapes with corners, the aforementioned corner-less shapes, which make it difficult for air bubbles to trap, are preferred. Furthermore, in this embodiment, the first recess 11 has a larger volume than the second recess 21, and therefore the upstream chamber 31 has a larger volume than the downstream chamber 32. By making the volume of the upstream chamber 31 relatively large in this way, it is possible to retain a large number of air bubbles within the upstream chamber 31. Incidentally, if the volume of the upstream chamber 31 is small, air bubbles will clog the filter F, reducing the effective area of ​​the filter F and increasing flow path resistance, resulting in poor ink supply to the liquid ejection head H and requiring frequent cleaning to remove the air bubbles, which increases wasteful consumption of ink. By making the volume of the upstream chamber 31 relatively large as in this embodiment, it is possible to retain a large number of air bubbles within the upstream chamber 31, thereby preventing poor ink supply and reducing wasteful consumption of ink.

[0028] The filter unit 2 also has an inlet passage 33 communicating with the upstream chamber 31 of the filter chamber 30, a first outlet passage 34 communicating with the downstream chamber 32 of the filter chamber 30, and a second outlet passage 35 communicating with the first outlet passage 34.

[0029] A cylindrical first flow path connecting portion 12 that protrudes in the -Y direction is provided on the surface of the first flow path member 10 facing the -Y direction. The inflow path 33 extends along the Y axis direction so that one end opens into the tip surface of the first flow path connecting portion 12 and the other end opens into the inner wall surface on the -Y direction side of the upstream chamber 31. In this embodiment, the opening of the inflow path 33 at the tip surface of the first flow path connecting portion 12 is referred to as an inlet 33a. Ink from outside the filter unit 2 is introduced via the inlet 33a.

[0030] A cylindrical second flow path connecting portion 22 that protrudes in the +Z direction is provided on a surface of the second flow path member 20 facing the +Z direction. The first outflow path 34 is provided along the Z axis direction so that one end opens to the tip surface of the second flow path connecting portion 22 and the other end opens to the bottom surface of the downstream chamber 32 in the +Z direction. An outflow port 34a is provided at the boundary between the first outflow path 34 and the downstream chamber 32. In other words, the outflow port 34a, which allows ink to flow out from the downstream chamber 32, opens in the +Z direction.

[0031] Furthermore, a cylindrical third flow path connecting portion 23 protruding in the +Z direction is provided on a surface of the second flow path member 20 facing the +Z direction. Furthermore, a cylindrical fourth flow path connecting portion 24 protruding in the +Y direction is provided on a surface of the first flow path member 10 facing the +Y direction. The second outflow path 35 includes a first portion 36 provided along the Z axis direction across the first flow path member 10 and the second flow path member 20, and a second portion 37 provided on the second flow path member 20 along the Y axis direction. An end of the first portion 36 opposite to one end communicating with the second portion 37 opens into the tip surface of the third flow path connecting portion 23, and an end of the second portion 37 opposite to the one end communicating with the first portion 36 opens into the tip surface of the fourth flow path connecting portion 24. The opening of the second outflow path 35 in the tip surface of the fourth flow path connecting portion 24 is referred to as an outlet 35a. The ink in the filter chamber 30 passes through the downstream chamber 32 and is discharged to the outside from the discharge port 35a.

[0032] Furthermore, the second flow path connecting portion 22 and the third flow path connecting portion 23 are connected via a tubular communicating pipe 40 having a communicating passage 41 provided therein. That is, the first outflow path 34 and the second outflow path 35 are connected via the communicating passage 41. In such a filter unit 2, ink from the liquid storage portion 3 is supplied from the inlet 33a to the inflow path 33. The ink in the inflow path 33 is supplied to the upstream chamber 31, and the ink in the upstream chamber 31 is supplied to the downstream chamber 32 via the filter F. The ink in the downstream chamber 32 is supplied to the liquid jet head H from the outlet 35a via the first outflow path 34, the communicating passage 41, and the second outflow path 35.

[0033] As described above, the inlet 33a opens in a direction perpendicular to an imaginary plane along the filter F, i.e., an XY plane defined by the X-axis and Y-axis, i.e., a direction intersecting the Z-axis direction, which is the -Y direction in this embodiment. The outlet 35a opens toward the +Y direction, which is the opposite direction to the -Y direction. The inlet 33a is disposed at a position overlapping with the outlet 35a when viewed in the +Y direction. In this embodiment, a virtual center line that passes through the center of the inlet 33a and extends in the +Y direction also passes through the center of the outlet 35a. In other words, the inlet 33a is disposed at a position where the center of the inlet 33a and the center of the outlet 35a overlap when viewed in the +Y direction. Note that, although the +Y direction has been exemplified in this embodiment as a direction intersecting with a direction perpendicular to an imaginary plane along the filter F, this is not particularly limited. If the direction intersecting an imaginary plane along the filter F is defined as the first direction and the direction intersecting the first direction is defined as the second direction, then when viewed along the intersection of a first straight line extending in the first direction and a second straight line extending in the second direction, the smaller of the angles formed by the two straight lines is preferably 45 degrees or greater, more preferably 60 degrees or greater, and even more preferably 75 degrees or greater. In this embodiment, the +Z direction is an example of the "first direction" and the +Y direction is an example of the "second direction," so the angle formed above is 90 degrees.

[0034] By arranging the inlet 33a and the outlet 35a in a position where they overlap when viewed in the +Y direction, the filter unit 2 can rotate about a rotation axis C that extends along a line connecting the portion where the inlet 33a is provided and the portion where the outlet 35a is provided. Furthermore, in this embodiment, by arranging the inlet 33a and the outlet 35a in a position where the centers of the inlet 33a and the outlet 35a overlap when viewed in the +Y direction, the filter unit 2 can be easily rotated about the rotation axis C that extends along a line connecting the centers of the inlet 33a and the outlet 35a. Of course, the filter unit 2 can be rotated even when the inlet 33a and the outlet 35a are positioned so that their centers do not coincide when viewed in the +Y direction.

[0035] Furthermore, in this embodiment, inlet 33a is positioned so as to overlap with filter chamber 30 when viewed in the +Y direction. By positioning inlet 33a so as to overlap with filter chamber 30 when viewed in the +Y direction in this manner, filter unit 2 can be made smaller in size in the Z axis direction compared to when inlet 33a is positioned so as not to overlap with filter chamber 30 when viewed in the +Y direction, thereby reducing the space required to rotate filter unit 2. Similarly, outlet 35a is positioned so as to overlap with filter chamber 30 when viewed in the +Y direction. This also allows filter unit 2 to be made smaller in size in the Z axis direction, thereby reducing the space required to rotate filter unit 2.

[0036] Furthermore, the inlet 33a is positioned so as to overlap the upstream chamber 31 when viewed in the +Y direction. By positioning the inlet 33a so as to overlap the upstream chamber 31, which has a larger volume than the downstream chamber 32, the upstream chamber 31 and the inlet 33a can be formed in the same member, in this embodiment, the first flow path member 10, and ink leakage can be suppressed compared to when the inlet is formed from two members. Similarly, the outlet 35a is positioned so as to overlap the upstream chamber 31 when viewed in the +Y direction. This also suppresses ink leakage.

[0037] Here, the first flow path connection part 12 of the filter unit 2 is connected to the supply tube T1 via a tubular first connecting pipe 50 and a rotary joint 60. In addition, the fourth flow path connection part 24 of the filter unit 2 is connected to the supply tube T2 via a tubular second connecting pipe 51 and a rotary joint 60.

[0038] The rotary joint 60, also called a rotary joint or a swivel joint, is a joint that rotatably connects two tubes. By connecting the filter unit 2 to the supply tubes T1 and T2 via the rotary joint 60, the filter unit 2 becomes rotatable about a rotation axis C that connects the first flow path connector 12, where the inlet 33a is provided, and the fourth flow path connector 24, where the outlet 35a is provided, and that is along the Y-axis in this embodiment.

[0039] The rotary joint 60 includes a first body 62 having a first flow path 61 extending therethrough along the Y-axis direction and a second body 64 having a second flow path 63 extending therethrough along the Y-axis direction. One end of a plain bearing 65 is fixed to the second flow path 63 of the second body 64. The other end of the plain bearing 65 is fixed to the first flow path 61 of the first body 62 via a ball bearing 66. A first seal member 67 is provided between the plain bearing 65 on the outer side of the ball bearing 66 and the inner wall of the first body 62, and the first seal member 67 prevents liquid in the first flow path 61 from penetrating into the ball bearing 66. A second seal member 68, such as an O-ring, is provided between the plain bearing 65 and the inner wall of the second body 64, and the second seal member 68 prevents liquid in the second flow path 63 from leaking out of the second flow path 63.

[0040] In such a rotary joint 60, the first body 62 and the second body 64 rotate relative to each other via the sliding bearing portion 65. The rotation axis of the rotary joint 60 is in a direction along the extension direction of the first flow path 61 and the second flow path 63, i.e., in a direction along the Y-axis direction. Furthermore, the rotation axis C is disposed at a position passing through the centers of the first flow path 61 and the second flow path 63 when viewed in the Y-axis direction.

[0041] Furthermore, by connecting the filter unit 2 and the supply tubes T1, T2 via the rotary joint 60, the filter unit 2 can rotate relative to the supply tubes T1, T2 about the rotation axis C. Note that the supply tube T1 may be connected directly to the first flow path connecting part 12 without using the rotary joint 60, and the supply tube T2 may be connected directly to the fourth flow path connecting part 24 without using the rotary joint 60.

[0042] As shown in Figure 2, the rotation mechanism 70 that rotates the filter unit 2 around the rotation axis C includes a pair of bearings 71 that support the filter unit 2 so that it can rotate around the rotation axis C, a cylindrical gear 72 provided at the -Y direction end of the filter unit 2, and an electric motor 73.

[0043] A pinion gear 73a provided on the rotation shaft of the electric motor 73 is disposed to mesh with a gear 72 provided on the filter unit 2, and the driving force of the electric motor 73 causes the pinion gear 73a to rotate the gear 72, causing the filter unit 2 to rotate about the rotation axis C. Of course, the rotation mechanism 70 may also include other gears that transmit the driving force of the electric motor 73. Furthermore, the rotation mechanism 70 is not limited to being driven by the electric motor 73, and may be, for example, a mechanism that combines electromagnet, hydraulic, or pneumatic power with a gear that transmits the power.

[0044] By using such a rotation mechanism 70, the filter unit 2 can be rotated between a first position during printing shown in FIG. 3 and a second position during maintenance shown in FIG.

[0045] The rotation of the filter unit 2 by the rotation mechanism 70 and the printing by the liquid ejecting head H are controlled by the control device 4.

[0046] 5 is a functional block diagram of the liquid ejection device 1. The control device 4 is an element that controls the entire liquid ejection device 1, and includes a control unit 100, a storage unit 101, an external I / F (interface) 102, and an internal I / F 103. Print data indicating an image to be printed on the medium S is transmitted from an external device 110 (e.g., a host computer) to the external I / F 102, and the liquid ejection head H, a movement mechanism 6, and a transport mechanism 5 are connected to the internal I / F 103. The liquid ejection head H, the movement mechanism 6, and the transport mechanism 5 are elements that record an image on the medium S under the control of the control device 4. The control unit 100 is also connected to the rotation mechanism 70 via the internal I / F 103.

[0047] The storage unit 101 includes a ROM that stores control programs and the like, and a RAM that temporarily stores various types of data necessary for printing an image (ejection of ink droplets from each nozzle N). The control unit 100 executes the control programs stored in the storage unit 101 to comprehensively control each element of the liquid ejection device 1, such as the transport motor of the transport mechanism 5 and the transport motor of the movement mechanism 6. The control unit 100 also converts print data sent from the external device 110 to the external I / F 102 into ejection data that instructs each nozzle N of the liquid ejection head H to eject / not eject ink droplets, and sends the data to the liquid ejection head H.

[0048] Furthermore, during printing, the control device 4 controls the rotation mechanism 70 to rotate the filter unit 2 about the rotation axis C and move it to the first position shown in FIG. 3. In this first position, the lower surface Fb of the filter F faces the direction of gravity, i.e., the +Z direction. In this first position, the liquid ejection head H performs a printing operation to eject ink onto the medium S. In other words, the first position is also referred to as the printing position.

[0049] Furthermore, during maintenance, the control device 4 controls the rotation mechanism 70 to rotate the filter unit 2 around the rotation axis C and move it to the second position shown in FIG. 4. In this second position, the lower surface Fb of the filter F faces in the direction opposite to gravity, i.e., in the -Z direction. In this second position, maintenance is performed to discharge ink from the multiple nozzles N to the outside via the filter chamber 30. In other words, the second position is also referred to as the maintenance position.

[0050] 3 , the air bubbles 200 contained in the ink captured by the filter F move due to buoyancy to the ceiling of the upstream chamber 31, i.e., toward the wall surface in the −Z direction. Even if maintenance of the liquid jet head H is performed in this first position, the air bubbles cannot be successfully discharged. Examples of maintenance of the liquid jet head H include suction cleaning, in which a concave-shaped cap (not shown) is placed in contact with the nozzle face of the liquid jet head H, and a closed space within the cap, where the nozzles N of the liquid jet head H are open, is subjected to negative pressure via a tube (not shown) connected to the cap by a negative pressure generating mechanism (not shown), thereby sucking the ink together with the air bubbles 200 from the nozzles N of the liquid jet head H; and pressure cleaning, in which ink is pressurized from the upstream side of the upstream chamber 31 by a pressure mechanism such as the pump 7, thereby discharging the air bubbles 200 in the filter chamber 30 from the nozzles N. Any type of pressure mechanism, such as a tube pump, a diaphragm pump, or a piston pump, can be used as the pressure mechanism. Furthermore, maintenance of the liquid jet head H includes so-called initial filling, which is the initial filling of ink into the liquid jet head H. In other words, maintenance of the liquid jet head H involves applying pressure from the upstream chamber 31 toward the downstream chamber 32 at a pressure higher than that during printing. Even if maintenance is performed in the first position, the air bubbles 200 cannot be pressed against the filter F, and therefore the air bubbles 200 cannot pass through the filter F, making it difficult to expel the air bubbles 200 from the filter chamber 30.

[0051] For this reason, during maintenance of the liquid ejection head H, the filter unit 2 is rotated about the rotation axis C from the first position shown in FIG. 3 to the second position shown in FIG. 4 . That is, the filter unit 2 is rotated so that the lower surface Fb of the filter F faces in the direction opposite to the +Z direction, which is the direction of gravity, i.e., the -Z direction. Maintenance such as cleaning and initial filling is performed with the filter unit 2 in this second position. In this second position, the air bubbles 200 in the upstream chamber 31 move in the -Z direction due to buoyancy and are positioned in contact with the filter F. Therefore, by performing maintenance in the second position, pressure can be applied from the upstream chamber 31 to the downstream chamber 32 while the air bubbles 200 are pressed against the filter F. Therefore, by performing maintenance in the second position, the air bubbles 200 pass through the filter F and are easily discharged from the filter chamber 30. In this way, the air bubbles 200 inside the filter chamber 30 can be easily discharged by maintenance, which prevents the air bubbles 200 remaining inside the filter chamber 30 from flowing into the liquid jet head H at an unexpected timing during printing, thereby preventing problems such as poor ejection of ink droplets from the liquid jet head H. In this embodiment, the outlet 34a opens in the +Z direction of the downstream chamber 32 in the first position shown in Fig. 3. Therefore, in the second position shown in Fig. 4, the outlet 34a opens in the -Z direction of the downstream chamber 32, making it easier for the buoyancy of the air bubbles to discharge the air bubbles from the downstream chamber 32 through the outlet 34a.

[0052] Furthermore, by performing printing in the first position shown in FIG. 3 , the air bubbles 200 remain on the −Z direction surface of the upstream chamber 31 due to buoyancy, as described above, so the air bubbles 200 do not clog the filter F, and a decrease in the effective area of ​​the filter F can be suppressed. This prevents the air bubbles 200 from clogging the filter F, thereby suppressing an increase in the flow path resistance of the filter F and suppressing poor ink supply to the liquid ejection head H. Furthermore, if the air bubbles 200 come into contact with the filter F, frequent cleaning operations are required to remove the air bubbles 200, which increases the wasteful consumption of ink. By performing printing in the first position, frequent cleaning operations are not necessary, and thus wasteful consumption of ink can be suppressed. Incidentally, if printing is performed in the second position, the air bubbles 200 come into contact with the filter F and clog the filter F, which increases the wasteful consumption of ink due to poor ink supply and frequent cleaning. In this manner, in this embodiment, printing in the first position prevents poor ink supply and reduces wasteful consumption, and maintenance in the second position improves bubble removal.

[0053] In this embodiment, the +Z direction is an example of the "gravity direction," the +Z direction is an example of the "first direction," the -Y direction is an example of the "second direction," and the +Y direction is an example of the "third direction."

[0054] In this embodiment, the second direction is a direction perpendicular to the first direction, but is not limited to this and may be any direction intersecting the first direction. In other words, the second direction may be a direction inclined at an angle of less than 90 degrees with respect to the -Y direction, which is perpendicular to the +Z direction, which is the first direction. Of course, the second direction is not limited to the -Y direction or a direction inclined relative to it, and may be either one of the directions in the X-axis direction or a direction inclined relative to it.

[0055] Furthermore, in this embodiment, the first posture is defined as a posture in which the lower surface Fb of the filter F faces the +Z direction, but is not particularly limited to this. "The lower surface Fb of the filter F faces the direction of gravity" includes a case in which a vector normal to the lower surface Fb of the filter F has a component in the direction of gravity. That is, the normal to the lower surface Fb may be inclined at an angle of less than 90 degrees with respect to the +Z direction. Similarly, the second posture is defined as a posture in which the lower surface Fb of the filter F faces the -Z direction, but is not particularly limited to this. "The lower surface Fb of the filter F faces the opposite direction to the direction of gravity" includes a case in which a vector normal to the lower surface Fb of the filter F has a component in the opposite direction to the direction of gravity. That is, the normal to the lower surface Fb may be inclined at an angle of less than 90 degrees with respect to the -Z direction. Even in this second posture, buoyancy can move the air bubbles 200 toward the upper surface Fa of the filter F, making it easier for the air bubbles 200 to pass through the filter F and be discharged to the outside during initial filling and cleaning.

[0056] (Embodiment 2) 6 is a cross-sectional view showing the posture of the filter unit 2 during printing according to the second embodiment of the present invention. Note that the same members as those in the above-described embodiments are given the same reference numerals, and redundant explanations will be omitted.

[0057] As shown in FIG. 6, the filter unit 2 includes a first flow path member 10, a second flow path member 20, and a third flow path member 80.

[0058] The third flow path member 80 is laminated on the surface facing the +Z direction of the second flow path member 20. A communicating passage 42 is provided at the lamination interface between the second flow path member 20 and the third flow path member 80. That is, in this embodiment, the third flow path member 80 is provided in place of the communicating pipe 40 of the first embodiment described above.

[0059] The communicating passage 42 is formed by providing a recess that opens into the surface of the third flow path member 80 facing the -Z direction and covering the opening of this recess with the second flow path member 20. Of course, the communicating passage 42 may be formed by providing a recess in the second flow path member 20 and covering this recess with the third flow path member 80, or by providing recesses in both the second flow path member 20 and the third flow path member 80. Furthermore, the communicating passage 42 is not limited to being provided at the lamination interface between the second flow path member 20 and the third flow path member 80, and may be provided midway in the Z-axis direction of the third flow path member 80. However, by providing the communicating passage 42 at the lamination interface between the second flow path member 20 and the third flow path member 80, the number of parts can be reduced and the communicating passage 42 can be easily formed.

[0060] In such a filter unit 2, the inlet 33a is disposed at the center of the filter unit 2 in a direction perpendicular to the +Y direction, which in this embodiment is the +Z direction. Here, as shown in FIG. 6, if the filter unit 2 is divided into four equal regions in the +Z direction, and the regions are designated Pa1 to Pa4 in the +Z direction, the center of the filter unit 2 refers to the two central regions Pa2 and Pa3 of the four regions Pa1 to Pa4. Furthermore, if the filter unit 2 is divided into three regions in the +Z direction, and the regions are designated Pb1 to Pb3 in the +Z direction, the center of the filter unit 2 refers to the central region Pb2 of the three regions Pb1 to Pb3. Similarly, the outlet 35a is disposed at the center of the filter unit 2 in the +Z direction. The center defining the position of the outlet 35a here is the same as the center of the inlet 33a.

[0061] In this way, by arranging the inlet 33a and the outlet 35a in the center of the filter unit 2 in the +Z direction, it is possible to reduce the space required for rotating the filter unit 2 between the first position and the second position. Therefore, the space wasted for rotating the filter unit 2 is reduced, and the liquid ejecting device 1 can be made more compact.

[0062] In this embodiment, the +Z direction is an example of the "gravity direction," the +Z direction is an example of the "first direction," the -Y direction is an example of the "second direction," and the +Y direction is an example of the "third direction."

[0063] In this embodiment, the second direction is a direction perpendicular to the first direction, but is not limited to this and may be any direction intersecting the first direction. In other words, the second direction may be a direction inclined at an angle of less than 90 degrees with respect to the -Y direction, which is perpendicular to the +Z direction, which is the first direction. Of course, the second direction is not limited to the -Y direction or a direction inclined relative to it, and may be either one of the directions in the X-axis direction or a direction inclined relative to it.

[0064] In this embodiment, the first posture is defined as a posture in which the lower surface Fb of the filter F faces the +Z direction, but is not limited to this. The phrase "the lower surface Fb of the filter F faces the direction of gravity" includes a case in which a vector normal to the lower surface Fb of the filter F has a component in the direction of gravity. That is, the normal to the lower surface Fb may be inclined at an angle of less than 90 degrees with respect to the +Z direction. Similarly, the second posture is defined as a posture in which the lower surface Fb of the filter F faces the -Z direction, but is not limited to this. The phrase "the lower surface Fb of the filter F faces the direction opposite to the direction of gravity" includes a case in which a vector normal to the lower surface Fb of the filter F has a component in the direction opposite to the direction of gravity. That is, the normal to the lower surface Fb may be inclined at an angle of less than 90 degrees with respect to the -Z direction. Even in this second posture, buoyancy can move the air bubbles 200 toward the upper surface Fa of the filter F, making it easier for the air bubbles 200 to pass through the filter F and be discharged to the outside during initial filling and cleaning.

[0065] (Embodiment 3) Fig. 7 is a cross-sectional view of a filter unit 2 according to a third embodiment of the present invention. Fig. 8 is a plan view of second flow path connecting portion 22 of filter unit 2 according to the third embodiment, viewed in the -Z direction. Note that the same members as those in the above-described embodiments are denoted by the same reference numerals, and redundant description will be omitted.

[0066] 7, the filter unit 2 of this embodiment includes a first flow path member 10 and a second flow path member 20. The filter unit 2 has a filter chamber 30 with a filter F provided therein, and the filter chamber 30 is divided by the filter F into an upstream chamber 31 and a downstream chamber 32.

[0067] The filter unit 2 is provided with an inflow channel 33 communicating with the upstream chamber 31, and a first outflow channel 34 and a second outflow channel 35 communicating with the downstream chamber 32, similar to the embodiment described above.

[0068] The filter unit 2 is also provided with a discharge path 38 that connects the upstream chamber 31 to the outside. One end of the discharge path 38 opens to an inner wall surface on the -Z direction side of the upstream chamber 31, and the other end opens to a surface of the first flow path member 10 facing the +Z direction. In this embodiment, the other end of the discharge path 38 is referred to as a discharge port 38a.

[0069] The discharge port 38a is connected to a waste liquid tube 14. The waste liquid tube 14 is connected to a waste liquid tank (not shown), and the liquid discharged from the discharge port 38a is discharged into the waste liquid tank via a flow path in the waste liquid tube 14 when cleaning is performed to discharge air bubbles from the upstream chamber 31.

[0070] It is preferable to provide a valve mechanism (not shown) in the waste liquid flow path between the upstream chamber 31 and the waste liquid tank so that ink does not flow from the upstream chamber 31 toward the waste liquid tank during printing. This valve mechanism can be a solenoid valve or a diaphragm valve that can be opened and closed under the control of the control device 4. The valve mechanism may also be a differential pressure valve that closes the waste liquid flow path during printing and opens during maintenance when the pressure downstream of the valve body (on the waste liquid tank side) falls below a predetermined pressure. The valve mechanism may be provided as part of the filter unit 2, or may be provided separately from the filter unit 2.

[0071] The first outflow path 34 also includes a check valve. Specifically, the check valve includes a small-diameter portion 34b that communicates with the downstream chamber 32 and a large-diameter portion 34c that is located downstream of the small-diameter portion 34b and has a larger inner diameter than the small-diameter portion 34b. A ball 26 made of a spherical elastic material is provided within the large-diameter portion 34c. The outer diameter of the ball 26 is larger than the inner diameter of the small-diameter portion 34b but smaller than the inner diameter of the large-diameter portion 34c. When ink flows in the opposite direction from the first outflow path 34 toward the downstream chamber 32, a so-called backflow, the ball 26 abuts against the step between the large-diameter portion 34c and the small-diameter portion 34b due to the flow of ink, thereby blocking the first outflow path 34. Furthermore, when ink flows in the forward direction from the downstream chamber 32 toward the first outflow path 34, the flow of ink causes the ball 26 to move in the +Z direction, forming a gap with the step, and ink flows between the large diameter portion 34c and the ball 26. In other words, the ball 26 functions as a check valve that allows ink to flow from the downstream chamber 32 toward the outlet 35a and prevents ink from flowing from the outlet 35a toward the downstream chamber 32. As shown in FIG. 8, the opening edge of the second flow path connecting portion 22 is provided with four protrusions 27 that protrude inward. These protrusions 27 can prevent the ball 26 from moving toward the communicating path 41, which is downstream of the first outflow path 34, due to the weight of the ball 26 and the flow of ink.

[0072] During printing, such a filter unit 2 closes the waste liquid flow path with the aforementioned valve mechanism, allowing ink to flow from the inlet 33a to the outlet 35a via the filter chamber 30. At this time, the ball 26 does not obstruct the forward flow of ink.

[0073] During maintenance, the ink in the upstream chamber 31 can be discharged to a waste liquid tank outside the filter unit 2 together with air bubbles 200 remaining in the upstream chamber 31 by performing cleaning, which involves sucking the liquid in the upstream chamber 31 from the waste liquid tube 14 side using a negative pressure generating mechanism (not shown), or by performing cleaning which involves pressurizing the liquid from upstream of the upstream chamber 31 using a pump 7 or the like. At this time, the discharge path 38 opens to the inner wall surface on the -Z direction side of the upstream chamber 31, so the air bubbles 200 remain near the discharge path 38 due to buoyancy. This makes it easy to discharge the air bubbles 200 from the discharge path 38 during maintenance. If the valve mechanism is a solenoid valve or a diaphragm valve, the control device 4 controls the valve mechanism to open the waste liquid flow path during maintenance and to close the waste liquid flow path during printing. Furthermore, when the valve mechanism is a differential pressure valve, in cleaning in which liquid in the upstream chamber 31 is sucked from the waste liquid tube 14 side by a negative pressure generating mechanism (not shown), the valve opens when cleaning is performed due to negative pressure being generated downstream of the valve element, and the waste liquid flow path is closed when cleaning is not performed, eliminating the need for control to open and close the valve mechanism. Furthermore, when the valve mechanism is a differential pressure valve, if a mechanism is provided that applies an external force to move the valve element of the differential pressure valve in response to a control signal from the control device 4, the waste liquid flow path can be opened even when cleaning is performed by pressurizing liquid from the upstream side of the upstream chamber 31 with the pump 7 or the like, similar to a solenoid valve or diaphragm valve. Note that, during maintenance, it is preferable to perform cleaning in which liquid in the upstream chamber 31 is sucked from the waste liquid tube 14 side by a negative pressure generating mechanism (not shown) so that the check valve functions during cleaning.

[0074] Note that, by blocking the outlet 38a with a cap 13 made of an elastic material such as an elastomer that is detachably attached to the outlet 38a, the filter unit 2 of this embodiment can be used in the same manner as in the first embodiment described above, that is, in a first position in which the bottom surface Fb of the filter F faces the +Z direction during printing, and in a second position in which the bottom surface Fb of the filter F faces the +Z direction during maintenance. Also, by removing the cap 13 from the outlet 38a, connecting a waste liquid tube 14 to the outlet 38a, and providing a valve (the aforementioned valve mechanism) midway along the waste liquid tube 14 that can open and close the flow path, both printing and maintenance can be performed with the waste liquid tube 14 connected to the outlet 38a by simply opening and closing the valve provided on the waste liquid tube 14, without having to replace the waste liquid tube 14 and cap 13 during printing.

[0075] (Embodiment 4) 9 is a cross-sectional view of a filter unit 2 according to a fourth embodiment of the present invention. Note that the same members as those in the above-described embodiments are given the same reference numerals, and redundant explanations will be omitted.

[0076] 9, the filter unit 2 of this embodiment has a filter chamber 30 in which a filter F is provided. The filter unit 2 is disposed so that the lower surface Fb of the filter F faces the -Y direction. The filter chamber 30 is divided by the filter F into an upstream chamber 31 and a downstream chamber 32.

[0077] The filter unit 2 also has an inlet channel 33 , a first outlet channel 34 and a bypass channel 39 .

[0078] One end of the inflow channel 33 communicates with the inner wall surface of the upstream chamber 31 in the +Y direction, and the other end opens to a surface of the filter unit 2 facing the +Y direction. The opening at this other end is called an inlet 33a. A supply tube T1 is connected to the inlet 33a, and ink is supplied from the liquid storage section 3.

[0079] One end of the first outflow path 34 communicates with the inner wall surface of the downstream chamber in the +Z direction, and the other end opens to a surface of the filter unit 2 facing the -Y direction. The opening at this other end is referred to as an outlet 35a. A supply tube T2 is connected to the outlet 35a, and ink from the outlet 35a is supplied to the liquid jet head H. In addition, a valve 43 that opens and closes the first outflow path 34 is provided midway along the first outflow path 34. The valve 43 may be, for example, an electromagnetic valve, a manual valve, or the like.

[0080] One end of the bypass flow channel 39 is connected to the inner wall surface of the downstream chamber 32 in the -Z direction, and the other end is connected to the first outflow channel 34 downstream of the valve 43. The bypass flow channel 39 has a higher flow resistance than the first outflow channel 34. That is, the bypass flow channel 39 has a smaller cross-sectional area in a direction intersecting the ink flow than the first outflow channel 34 and has a longer path. Therefore, when the valve 43 is open, the ink in the downstream chamber 32 flows out to the outside from the outlet 35a via the first outflow channel 34. At this time, ink is unlikely to flow in the bypass flow channel 39, and air bubbles 200 that have accumulated in the downstream chamber 32 in the -Z direction due to buoyancy are unlikely to be discharged downstream from the bypass flow channel 39. In contrast, when the valve 43 is closed, the ink in the downstream chamber 32 flows out to the outside from the outlet 35a via the bypass flow channel 39. Therefore, the air bubbles 200 that have accumulated in the downstream chamber 32 in the -Z direction due to buoyancy can be discharged to the outside from the outlet 35a via the bypass flow path 39. In other words, during printing, the valve 43 is opened to prevent the air bubbles 200 in the downstream chamber 32 from being sent to the liquid jet head H, and during maintenance, the valve 43 is closed to send the air bubbles 200 in the downstream chamber 32 to the liquid jet head H, and the air bubbles 200 can be discharged to the outside from the nozzles N of the liquid jet head H. Of course, even during initial filling when ink is first filled into the liquid jet head H, closing the valve 43 allows the air bubbles 200 in the filter chamber 30 to be discharged from the outlet 35a via the bypass flow path 39, thereby improving bubble discharge performance.

[0081] In this embodiment, the +Z direction is an example of the "gravity direction," the +Z direction is an example of the "first direction," the +Y direction is an example of the "second direction," and the -Y direction is an example of the "third direction."

[0082] Furthermore, in this embodiment, the second direction is a direction perpendicular to the first direction, but is not limited to this and may be any direction intersecting the first direction. In other words, the second direction may be a direction inclined at an angle of less than 90 degrees with respect to the +Y direction, which is perpendicular to the +Z direction, which is the first direction. Of course, the second direction is not limited to the +Y direction or a direction inclined relative to it, and may be either one of the directions in the X-axis direction or a direction inclined relative to it.

[0083] (Other embodiments) Although the embodiments of the present invention have been described above, the basic configuration of the present invention is not limited to those described above.

[0084] For example, in each of the above-described embodiments, the filter chamber 30 is provided in the filter unit 2, but the present invention is not particularly limited to this. For example, the filter chamber may be provided in the liquid jet head H. By moving the liquid jet head H between the first position and the second position, it is possible to improve the ability to discharge air bubbles.

[0085] Furthermore, in each of the above-described embodiments, the first flow path connecting portion 12 and the fourth flow path connecting portion 24 are exemplified as being cylindrical, but this is not particularly limited to this, and either or both of the first flow path connecting portion 12 and the fourth flow path connecting portion 24 may be needle-shaped with a pointed tip.

[0086] Furthermore, in each of the above-described embodiments, the liquid ejection head H is positioned to eject ink in the +Z direction, but this is not particularly limited to this, and as long as the filter unit is in the position of each of the above-described embodiments, the direction in which the liquid ejection head H ejects ink is not limited to the +Z direction.

[0087] (Addendum) From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0088] A preferred embodiment of a filter unit according to Aspect 1 is a filter unit used in an orientation where the direction of gravity intersects with an imaginary plane extending along the filter. The filter unit includes the filter, a filter chamber having an upstream chamber and a downstream chamber partitioned by the filter, an inlet for introducing liquid from outside the filter unit, and an outlet for discharging liquid from the filter chamber to the outside of the filter unit via the downstream chamber. The inlet opens in a second direction intersecting a first direction perpendicular to the imaginary plane extending along the filter, and the outlet opens in a third direction opposite the second direction. The inlet overlaps with the outlet when viewed in the third direction. This allows the filter unit to rotate around the portions where the inlet and the outlet are provided as rotation axes. This allows the orientation of the filter unit to be changed between printing and maintenance, preventing poor liquid supply and unnecessary liquid consumption during printing and improving air bubble discharge during maintenance.

[0089] In Aspect 2, which is a specific example of Aspect 1, a virtual center line that passes through the center of the inlet and extends in the third direction passes through the center of the outlet, which makes it easy to rotate the filter unit around the portion where the inlet and outlet are provided as a rotation axis.

[0090] In Aspect 3, which is a specific example of Aspect 1, the inlet overlaps with the filter chamber when viewed in the third direction. This allows the filter unit to be made smaller in size in the first direction than when the inlet does not overlap with the filter chamber, thereby reducing the space required to rotate the filter unit.

[0091] In Aspect 4, which is a specific example of Aspect 3, the inlet overlaps with the upstream chamber when viewed in the third direction. Accordingly, by arranging the inlet at a position overlapping with the upstream chamber, which has a larger volume than the downstream chamber in order to retain more air bubbles, the inlet can be formed in the same member, and leakage of liquid can be suppressed compared to when the inlet is formed with two members.

[0092] In Aspect 5, which is a specific example of Aspect 1, an outlet for discharging liquid from the downstream chamber is provided, and the outlet opens in the first direction. This makes it easy to discharge air bubbles from the outlet during maintenance.

[0093] In Aspect 6, which is a specific example of Aspect 1, the inlet is disposed in the center of the filter unit in a direction perpendicular to the second direction, thereby reducing the space required to rotate the filter unit.

[0094] A preferred embodiment of a liquid ejection device according to aspect 7 includes a liquid ejection head that ejects liquid, a liquid storage unit that stores the liquid to be supplied to the liquid ejection head, and the filter unit according to aspect 1 that is disposed midway along a supply flow path for supplying liquid from the liquid storage unit to the liquid ejection head. This allows the position of the filter unit to be changed between during printing and during maintenance, thereby preventing poor liquid supply and unnecessary liquid consumption during printing and improving air bubble discharge during maintenance.

[0095] In Aspect 8, which is a specific example of Aspect 7, the second direction is a direction that intersects with the direction of gravity.

[0096] A preferred embodiment of a ninth aspect of the maintenance method for a liquid jet head is a maintenance method for a liquid jet head having a plurality of nozzles that eject liquid supplied from a filter chamber having an upstream chamber and a downstream chamber partitioned by a filter, the method comprising: performing a printing operation in which the liquid jet head ejects liquid onto a medium with the filter chamber in a first position such that the underside of the filter that defines the downstream chamber faces the direction of gravity; and performing maintenance in which the liquid is discharged from the plurality of nozzles via the filter chamber to the outside with the filter chamber in a second position such that the underside faces the direction opposite to the direction of gravity. This allows the filter chamber to be positioned differently between printing and maintenance, thereby preventing poor liquid supply and unnecessary liquid consumption during printing and improving bubble discharge performance during maintenance. [Explanation of symbols]

[0097] C...rotating shaft, F...filter, Fa...main surface (upper surface), Fb...lower surface, H...liquid jet head, N...nozzle, S...medium, T, T1, T2...supply tube, 1...liquid jet device, 2...filter unit, 3...liquid storage section, 4...control device, 5...transport mechanism, 6...movement mechanism, 7...pump, 10...first flow path member, 11...first recess, 12...first flow path connecting section, 13...cap, 14...waste liquid tube, 20...second flow path member, 21...second recess, 22...second flow path connecting section, 23...third flow path connecting section, 24...fourth flow path connecting section, 26...ball, 27...projection, 30...filter chamber, 31...upstream chamber, 32...downstream chamber, 33...inflow channel, 33a...inlet, 34...first outflow channel, 34a...outlet, 34b...small diameter section , 34c...large diameter portion, 35...second outflow path, 35a...outlet, 36...first portion, 37...second portion, 38...discharge path, 38a...discharge port, 39...bypass flow path, 40...communicating pipe, 41, 42...communicating passage, 43...valve, 50...first connecting pipe, 51...second connecting pipe, 60...rotary joint, 61...first flow path, 62...first main body, 63...second flow path, 64...second main body , 65...slide bearing portion, 66...ball bearing, 67...first sealing member, 68...second sealing member, 70...rotation mechanism, 71...bearing, 72...gear, 73...electric motor, 73a...pinion gear, 80...third flow path member, 100...control unit, 101...memory unit, 102...external I / F, 103...internal I / F, 110...external device, 200...bubbles.

Claims

1. A filter unit used in a position where the direction of gravity intersects with a virtual plane along the filter, the filter; a filter chamber having an upstream chamber and a downstream chamber separated by the filter; an inlet for introducing a liquid from the outside of the filter unit; an outlet for discharging the liquid in the filter chamber to the outside of the filter unit through the downstream chamber; Equipped with the inlet is open in a second direction intersecting a first direction perpendicular to an imaginary plane along the filter, the outlet opens toward a third direction opposite to the second direction, The inlet overlaps with the outlet when viewed in the third direction. A filter unit characterized by:

2. a virtual center line that passes through a center of the inlet and extends in the third direction passes through a center of the outlet; 2. The filter unit according to claim 1.

3. The inlet overlaps with the filter chamber when viewed in the third direction.

2. The filter unit according to claim 1.

4. The inlet overlaps with the upstream chamber when viewed in the third direction.

4. The filter unit according to claim 3.

5. an outlet for discharging liquid from the downstream chamber; The outlet opens in the first direction.

2. The filter unit according to claim 1.

6. The inlet is disposed at a center of the filter unit in a direction perpendicular to the second direction.

2. The filter unit according to claim 1.

7. a liquid ejection head that ejects liquid; a liquid storage section that stores the liquid to be supplied to the liquid jet head; the filter unit according to claim 1 , which is disposed midway along a supply flow path for supplying liquid from the liquid storage portion to the liquid jet head; Equipped with A liquid ejection device characterized by:

8. The second direction is a direction intersecting the direction of gravity. The liquid ejection apparatus according to claim 7 .

9. A maintenance method for a liquid ejection head having a plurality of nozzles that eject liquid supplied from a filter chamber having an upstream chamber and a downstream chamber partitioned by a filter, comprising: performing a printing operation in which the liquid ejection head ejects liquid onto a medium in a first attitude of the filter chamber such that a lower surface of the filter that defines the downstream chamber faces a gravity direction; performing maintenance in which liquid is discharged to the outside from the plurality of nozzles through the filter chamber in a second orientation of the filter chamber in which the lower surface faces the direction opposite to the direction of gravity; A maintenance method for a liquid jet head, comprising:

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