Liquid jet head and liquid jet apparatus

Abstract

To provide a filter unit which can sufficiently discharge bubbles through a distance outflow path from an inflow path, a liquid jet head, and a liquid jet device.SOLUTION: The filter unit comprises: a filter F through which liquid passes; a filter chamber 100 partitioned by the filter F into an upstream chamber 101 and a downstream chamber 102; an inflow path 103 through which liquid is flown into the upstream chamber 101; a first outflow path 104 through which liquid is flown out from the downstream chamber 102; and a second outflow path 105 through which liquid is flown out from the downstream chamber 102. A distance from the inflow path 103 to the first outflow path 104 is shorter than a distance from the inflow path 103 to the second outflow path 105, and flow path resistance of the second outflow path 105 is smaller than flow path resistance of the first outflow path 104.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a filter unit, a liquid ejection head, and a liquid ejection apparatus, and more particularly to a filter unit through which ink flows as a liquid, an ink jet recording head that ejects ink, and a liquid ejection apparatus. [Background technology]

[0002] Liquid ejection devices, such as inkjet printers and plotters, have nozzles that can eject droplets of a liquid, such as ink, stored in a liquid storage unit, such as a cartridge or tank. A filter unit is provided between the liquid storage unit and the nozzle, and has a flow path that includes a filter chamber in which a filter is disposed.

[0003] In a filter unit, the filter chamber is divided into an upstream chamber and a downstream chamber by a filter, and foreign matter such as air bubbles and dust contained in the liquid in the upstream chamber is removed by the filter and allowed to flow into the downstream chamber. Such a filter unit is provided with an inlet path for allowing the liquid to flow into the upstream chamber of the filter chamber and an outlet path for allowing the liquid to flow out of the downstream chamber of the filter chamber.

[0004] For example, there is a filter in which one outlet path is provided at one end of a first space, which is an upstream chamber of the filter chamber, and two outlet paths are provided in a second space, which is a downstream chamber of the filter chamber (see, for example, Patent Document 1). By using such a configuration, it is possible to prevent bubbles contained in the liquid from remaining. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2020-32677 Summary of the Invention [Problem to be solved by the invention]

[0006] In a configuration in which the distances from the inlet channel to each of the multiple outlet channels are different, stagnation of the ink flow occurs in the area of ​​the upstream chamber far from the inlet channel, and air bubbles tend to accumulate. For this reason, when performing various cleaning operations such as suction cleaning and pressure cleaning, air bubbles that have accumulated in the area of ​​the upstream chamber far from the inlet channel tend to flow into the outlet channel far from the inlet channel. When air bubbles flow into the outlet channel far from the inlet channel, they temporarily create resistance, making it difficult for the ink to be discharged.

[0007] As a result, ink in the filter chamber is actively discharged from the outlet channel closer to the inlet channel, and air bubbles may not be sufficiently discharged through the outlet channel farther from the inlet channel. Also, it may take a long time to discharge the air bubbles, which may increase the amount of waste ink.

[0008] It should be noted that such problems are not limited to filter units through which ink flows, inkjet recording heads that eject ink, and inkjet recording devices, but also exist in filter units through which liquids other than ink flow, and liquid ejection heads and liquid ejection devices that eject liquids. [Means for solving the problem]

[0009] An aspect of the present invention that solves the above problem is a filter unit comprising: a filter through which liquid passes; a filter chamber partitioned by the filter into an upstream chamber and a downstream chamber; an inlet channel for allowing liquid to flow into the upstream chamber; a first outlet channel for allowing liquid to flow out of the downstream chamber; and a second outlet channel for allowing liquid to flow out of the downstream chamber, wherein the distance from the inlet channel to the first outlet channel is shorter than the distance from the inlet channel to the second outlet channel, and the flow resistance of the second outlet channel is smaller than the flow resistance of the first outlet channel.

[0010] Another aspect of the present invention is a filter unit comprising: a filter through which liquid passes; a filter chamber divided by the filter into an upstream chamber and a downstream chamber; an inlet channel for introducing liquid into the upstream chamber; a first outlet channel for discharging liquid from the downstream chamber; and a second outlet channel for discharging liquid from the downstream chamber, wherein the distance from the inlet channel to the first outlet channel is shorter than the distance from the inlet channel to the second outlet channel, and the area of ​​the opening formed in the downstream chamber of the second outlet channel is larger than the area of ​​the opening formed in the downstream chamber of the first outlet channel.

[0011] Another aspect of the present invention is a liquid jet head comprising: the filter unit according to the above aspect; and a plurality of nozzles that jet the liquid supplied from the filter unit.

[0012] Another aspect of the present invention is a liquid ejecting apparatus comprising the above-described liquid ejecting head and a liquid reservoir for supplying liquid to the filter unit. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing a schematic configuration of an ink jet recording apparatus according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing a schematic configuration of a recording head according to a first embodiment. [Figure 3] FIG. 1 is a plan view of a filter unit according to a first embodiment. [Figure 4] FIG. 1 is a cross-sectional view of a filter unit according to a first embodiment. [Figure 5] 2 is a cross-sectional view of a liquid ejecting unit according to the first embodiment. FIG. [Figure 6] FIG. 10 is a cross-sectional view of a filter unit according to a second embodiment. [Figure 7] FIG. 10 is a plan view of a filter unit according to a third embodiment. [Figure 8] FIG. 10 is a cross-sectional view of a filter unit according to a third embodiment. [Figure 9]FIG. 10 is a plan view of a filter unit according to a fourth embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a filter unit according to a fourth embodiment. [Figure 11] FIG. 2 is a diagram illustrating an example of a flow path for circulating ink in a print head. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below based on embodiments. However, the following description is of one aspect of the present invention, and the configuration of the present invention can be modified as desired within the scope of the invention.

[0015] In each figure, X, Y, and Z represent three spatial axes that are orthogonal to one another. In this specification, the directions along these axes are referred to as the X direction, Y direction, and Z direction. In each figure, the direction indicated by the arrow is the positive (+) direction, and the direction opposite the arrow is the negative (-) direction. In addition, the three spatial axes X, Y, and Z, which are not limited to positive and negative directions, are referred to as the X axis, Y axis, and Z axis. The Z axis indicates the vertical direction (also known as the direction of gravity), with the +Z direction pointing vertically downward and the -Z direction pointing vertically upward.

[0016] (Embodiment 1) Fig. 1 is a diagram showing a schematic configuration of an ink jet recording apparatus 1 according to a first embodiment of the present invention. Fig. 2 is a diagram showing a schematic configuration of an ink jet recording head 2, and is a side view seen in the X-axis direction.

[0017] First, the overall configuration of an ink jet recording apparatus 1 according to this embodiment will be described. 1, an inkjet recording apparatus 1, which is an example of a "liquid ejection apparatus" of this embodiment, is a printing apparatus that ejects ink, which is a type of liquid, as ink droplets onto a medium S, such as printing paper, and prints an image or the like by forming an arrangement of dots on the medium S. The medium S can be made of any material, such as a resin film or cloth, in addition to recording paper.

[0018] The inkjet recording device 1 includes an inkjet recording head 2 (hereinafter also simply referred to as the recording head 2), a cartridge 3, a transport mechanism 4 that feeds out the medium S, a control unit 5 that is a control section, and a movement mechanism 6.

[0019] The recording head 2 is an example of a "liquid ejection head," and has an ejection surface 12 with nozzles 11 provided on a surface facing the +Z direction, as shown in Fig. 2. The recording head 2 is also arranged so that the ejection surface 12 is oriented along a horizontal plane perpendicular to the Z axis, which is the vertical direction, i.e., along the XY plane defined by the X axis and Y axis.

[0020] As shown in FIG. 1, the moving mechanism 6 is controlled by the control unit 5 to move the recording head 2 back and forth in the +X direction and the -X direction along the X axis, and the +X direction and the -X direction in which the recording head 2 is moved back and forth by the moving mechanism 6 intersect with the -Y direction or the +Y direction in which the medium S is transported.

[0021] The movement mechanism 6 of this embodiment includes a conveyor 6a and a conveyor belt 6b. The conveyor 6a is a generally box-shaped structure, a so-called carriage, that houses the recording head 2, and is fixed to the conveyor belt 6b. The conveyor belt 6b is an endless belt that is stretched along the X-axis. The conveyor belt 6b rotates under the control of the control unit 5, causing the recording head 2 to move back and forth in the X-axis direction together with the conveyor 6a.

[0022] The cartridge 3 is an example of a "liquid storage section" that stores ink, which is the "liquid" to be supplied to the nozzles 11, and stores multiple types of ink (e.g., multiple colors) separately to be ejected from the recording head 2. The cartridge 3 is mounted on the conveying body 6a of the moving mechanism 6 together with the recording head 2, and the cartridge 3 is detachable from the recording head 2.

[0023] The "liquid storage unit" is not limited to the cartridge 3, and may be, for example, a bag-shaped ink pack made of a flexible film, an ink tank that can be refilled with ink, etc. The "liquid storage unit" is not limited to one that is mounted on the conveying body 6a, and may be one that is not mounted on the conveying body 6a but is fixed to the device main body and connected to the recording head 2 via a flow path such as a tube. In this embodiment, a plurality of cartridges 3 are provided corresponding to a plurality of different colors and types of ink, but in Figures 1 and 2, the plurality of cartridges 3 are illustrated as one.

[0024] The transport mechanism 4 is an example of a "transport unit" that is controlled by the control unit 5 and transports the medium S in the Y-axis direction, and includes, for example, a transport roller 4a. Note that the transport mechanism 4 that transports the medium S is not limited to the transport roller 4a, and may transport the medium S using a belt or a drum.

[0025] The control unit 5 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 unit 5 comprehensively controls each element of the inkjet recording device 1, i.e., the transport mechanism 4, the movement mechanism 6, the recording head 2, etc., by the control device executing a program stored in the storage device.

[0026] In this inkjet recording device 1, the recording head 2 performs a recording operation of ejecting ink supplied from the cartridge 3 as liquid ink droplets onto the medium S under the control of the control unit 5. As described above, ink droplets are ejected in the +Z direction from this recording head 2. Then, when the medium S is transported in the Y-axis direction by the transport mechanism 4 and the recording head 2 is transported in the X-axis direction by the movement mechanism 6, the recording head 2 ejects ink droplets onto the medium S, thereby forming a desired image on the XY plane of the medium S.

[0027] Furthermore, a wiper 7 is disposed on one side in the X-axis direction, which is the movement direction of the recording head 2, that is, on the +X direction side in this embodiment, as a wiping member that wipes the ejection surface 12 of the recording head 2. The wiper 7 is made of an elastic and flexible material such as rubber or elastomer. In the wiping operation, the tip of the wiper 7 contacts the ejection surface 12 and the two move relative to each other, thereby wiping the ejection surface 12 with the wiper 7 wiping the ejection surface 12. Note that various well-known configurations can be used as a mechanism for wiping the ejection surface 12, such as a configuration in which a sheet-like wiper made of nonwoven fabric or the like is used for wiping.

[0028] Furthermore, a cap 8 is disposed adjacent to the wiper 7 on the +X direction side, which is the standby position (also known as the home position) of the recording head 2. As shown in Fig. 5, the cap 8 is formed in the shape of a tray that can come into contact with the ejection surface 12 of the recording head 2. The cap 8 is configured so that it can be brought into close contact with the ejection surface 12 with the multiple nozzles 11 of the recording head 2 facing into its internal space.

[0029] More specifically, when the cap 8 abuts against the ejection surface 12, it forms a closed space CL into which a plurality of nozzles 11 constituting a first nozzle row 15A (described later) and a plurality of nozzles 11 constituting a second nozzle row 15B (described later) are open. That is, the internal space within the cap 8 functions as a sealed space. A tube 9 is connected to the cap 8, which connects a waste liquid tank (not shown) with a discharge hole 8a formed in the bottom wall of the cap 8. A pump P1 is provided midway along the tube 9.

[0030] In the recording device 1, for example, suction cleaning is performed at a predetermined timing with the cap 8 in close contact with the ejection surface 12 of the recording head 2. In suction cleaning, the pump P1 connected to the cap 8 is driven to create a negative pressure inside the cap 8, thereby sucking ink from inside the recording head 2 and discharging the ink from each nozzle 11 into the cap 8.

[0031] Furthermore, in the recording device 1, for example, pressurized cleaning can be performed with the cap 8 in close contact with or facing the ejection surface 12 of the recording head 2. In pressurized cleaning, ink is discharged from each nozzle 11 into the cap 8 by pressurizing the ink in the recording head 2 using a liquid pressurizing mechanism such as a diaphragm pump or a tube pump (not shown) that is arranged upstream of a filter chamber 100 (described later).

[0032] As shown in FIG. 2, the recording head 2 of this embodiment includes a liquid ejecting section 10 that ejects liquid, and a filter unit 20.

[0033] A plurality of filter units 20 are provided corresponding to the number of cartridges 3, i.e., the plurality of types of ink with different colors and types. In Figure 2, a plurality of filter units 20 are illustrated as one unit. Of course, two or more filter units 20 may be provided for the same type of ink by branching the same type of ink.

[0034] The liquid ejection unit 10 has an ejection surface 12, on the surface facing the medium S, i.e., the surface facing the +Z direction, where a nozzle 11 that ejects liquid ink as ink droplets is opened. The liquid ejection unit 10 also includes a flow path connected to the nozzle 11 and a pressure generating unit that generates a pressure change in the ink in the flow path. For example, a piezoelectric actuator having a piezoelectric material with electromechanical transduction function can be used as the pressure generating unit. This piezoelectric actuator changes the volume of the liquid flow path by deforming the piezoelectric actuator, thereby generating a pressure change in the ink in the flow path and ejecting ink droplets from the nozzle 11. For example, a pressure generating unit can be used that includes a heating element disposed in the flow path and generates bubbles by heating the heating element to eject ink droplets from the nozzle 11. For example, a so-called electrostatic actuator can be used as the pressure generating unit. This pressure generating unit generates electrostatic force between a vibration plate and an electrode, which deforms the vibration plate and ejects ink droplets from the nozzle 11.

[0035] The filter unit 20 is provided with a flow path through which ink, which is a "liquid," is supplied from the cartridge 3. The ink in the cartridge 3 is supplied to the liquid ejecting unit 10 via the flow path of the filter unit 20.

[0036] Fig. 3 is a plan view of the filter unit 20 according to embodiment 1 as viewed in the +Z direction. Fig. 4 is a cross-sectional view taken along line AA' in Fig. 3. Note that the solid arrows in Fig. 4 indicate the flow of ink in the upstream chamber, and the dashed arrows indicate the flow of air bubbles when various cleaning operations and the like are performed.

[0037] 3 and 4, the filter unit 20 includes a first flow path member 30 and a second flow path member 40. The first flow path member 30 and the second flow path member 40 are stacked together along the Z axis, with the first flow path member 30 disposed in the −Z direction relative to the second flow path member 40.

[0038] A filter chamber 100 is defined between the first flow path member 30 and the second flow path member 40. The filter chamber 100 is formed by aligning the openings of a first recess 31, which is provided in the first flow path member 30 and opens on a surface facing the +Z direction, and a second recess 41, which is provided in the second flow path member 40 and opens on a surface facing the -Z direction. In other words, the filter chamber 100 is defined by the first recess 31 and the second recess 41.

[0039] A filter F is fixed to the opening of the second recess 41 of the second flow path member 40. The filter F is arranged so that the in-plane direction of the main surface on which the filter F extends is perpendicular to the +Z direction, which is the stacking direction of the first flow path member 30 and the second flow path member 40, that is, the direction along the XY plane, which is a horizontal plane. In other words, the extension direction of the filter F is preferably approximately parallel to the horizontal plane. Note that "approximately parallel to the horizontal plane" here means including a plane within ±10° of a plane parallel to the horizontal plane.

[0040] The filter F captures foreign matter such as air bubbles and dust contained in the ink, and may be, for example, a sheet-like filter with multiple microscopic holes formed by finely weaving metal, resin, or other fibers. Alternatively, the filter F may be a plate-like member made of metal, resin, or other material with multiple microscopic through-holes. The filter F may also be made of nonwoven fabric or the like, and the material is not particularly limited. The method for fixing the filter F to the second flow path member 40 is not particularly limited, and examples include adhesion with an adhesive, heat welding, and the like.

[0041] The filter chamber 100 is divided by the filter F into an upstream chamber 101 upstream of the filter F and a downstream chamber 102 downstream of the filter F. As shown in FIG. 3, when viewed from the +Z direction, the filter chamber 100 and the filter F are basically rectangular in shape with the X axis as the longitudinal direction, with both longitudinal ends being semicircular, forming a so-called rounded rectangular shape (also known as a track shape).

[0042] That is, filter chamber 100 and filter F have an elongated shape with the direction along the X-axis being the longitudinal direction and the direction along the Y-axis being the lateral direction. Of course, the shape of filter chamber 100 and filter F when viewed in the +Z direction is not particularly limited, and may be, for example, a square, rectangle, parallelogram, polygon, sector, circle, or oblong hole shape. Incidentally, an oblong hole shape refers to an ellipse or a shape similar to an ellipse, such as a rounded rectangle, egg shape, or oval shape.

[0043] The filter unit 20 is also provided with an inflow channel 103 , a first outflow channel 104 , and a second outflow channel 105 that communicate with the filter chamber 100 .

[0044] The inflow channel 103 communicates with the upstream chamber 101 of the filter chamber 100 and supplies ink from the cartridge 3 to the upstream chamber 101. The inflow channel 103 penetrates the first flow path member 30 along the Z axis, with one end opening at the tip of a connection portion 32 that protrudes from the surface of the first flow path member 30 facing the -Z direction. The other end of the inflow channel 103 opens at the ceiling surface 31a of the first recess 31 that defines the upstream chamber 101 of the first flow path member 30. The inflow port 103a, which is the opening of the inflow channel 103 on the upstream chamber 101 side, is positioned in the +X direction relative to the center of the filter chamber 100 in the X-axis direction in a plan view of the filter chamber 100 seen in the +Z direction.

[0045] The connecting part 32 is a so-called supply needle having an inflow channel 103 provided therein and a sharpened needle-like tip, and is inserted into the cartridge 3. Of course, the connecting part 32 is not limited to a supply needle, and may be a supply pipe to which a tube is connected. Also, instead of providing the connecting part 32 protruding from the first flow path member 30, an inflow port 103a may be provided as the inflow channel 103 that penetrates the ceiling surface 31a of the first flow path member 30.

[0046] On the other hand, the first outflow path 104 and the second outflow path 105 are flow paths that communicate with the downstream chamber 102 of the filter chamber 100 and supply the ink in the filter chamber 100 to the outside, in this embodiment, to the liquid ejecting unit 10.

[0047] The first outlet path 104 and the second outlet path 105 are arranged to penetrate the second flow path member 40 along the Z axis, with one end opening to a surface of the second flow path member 40 facing the +Z direction and the other end opening to the bottom surface of the second recess 41 of the second flow path member 40, i.e., the surface of the second recess 41 facing the -Z direction.

[0048] First outlet 104a, which is the opening of first outlet channel 104 on the downstream chamber 102 side, is positioned in the +X direction from the center of filter chamber 100 in the direction along the X axis in a plan view of filter chamber 100 seen in the +Z direction. In other words, first outlet 104a is positioned between the center of filter F in the X axis direction and inlet 103a in the X axis direction.

[0049] Second outlet 105a, which is the opening of second outlet channel 105 on the downstream chamber 102 side, is located in the -X direction from the center of filter chamber 100 in the direction along the X axis in a plan view of filter chamber 100 looking in the +Z direction. In other words, second outlet 105a is located on the opposite side of inlet 103a from the center of filter F in the X axis direction in the X axis direction.

[0050] The flow of ink in the upstream chamber 101 occurs mainly along the −X direction from the inlet 103a toward the second outlet 105a. In FIG. 4, the flow of ink from the inlet 103a toward the first outlet 104a and the flow of ink from the inlet 103a toward the second outlet 105a are indicated by solid arrows. In this embodiment, the “flow direction,” which is the direction in which ink flows in the upstream chamber 101, is the direction from the inlet 103a toward the second outlet 105a on a line connecting the center of the opening of the inlet 103a and the center of the opening of the second outlet 105a, which is the −X direction. In reality, the flow of ink from the inlet 103a toward the second outlet 105a occurs not only on the line connecting the inlet 103a and the second outlet 105a, but also along flow lines that bulge in the +Y and −Y directions from this line. Therefore, the flow of ink in the upstream chamber 101 occurs over substantially the entire main surface of the filter F in the XY plane.

[0051] Therefore, in the filter unit 20 of this embodiment, the first outlet channel 104 is disposed between the inlet channel 103 and the second outlet channel 105 in the flow direction in which ink flows from the inlet channel 103 to the second outlet channel 105. In other words, the first outlet port 104a is disposed between the inlet port 103a and the second outlet port 105a in the −X direction, which is the flow direction, when viewed in the Z axis direction, which is the stacking direction of the first flow path member 30 and the second flow path member 40 that constitute the filter unit 20.

[0052] Here, "the first outlet 104a is located between the inlet 103a and the second outlet 105a in the -X direction" includes a case where the X-axis coordinate of the first outlet 104a is the same as the X-axis coordinate of the inlet 103a in the XY plane viewed from the +Z direction, and refers to a case where the X-axis coordinate of the first outlet 104a is located in the -X direction relative to the X-axis coordinate of the inlet 103a. Furthermore, the first outlet 104a may be located at a position shifted in the +Y direction or the -Y direction relative to the inlet 103a and the second outlet 105a. In this embodiment, the position of the inlet 103a refers to the center of the opening of the inlet 103a, the position of the first outlet 104a refers to the center of the opening of the first outlet 105a, and the position of the second outlet 105a refers to the center of the opening of the second outlet 105a.

[0053] Furthermore, in order to improve the discharge of air bubbles from the downstream chamber 102, the second recess 41 is provided with an inclined bottom surface such that the depth in the +Z direction gradually increases from the outer periphery of the filter F and between the first outlet 104a and the second outlet 105a toward each of the first outlet 104a and the second outlet 105a. Furthermore, in this embodiment, the bottom surface of the second recess 41 between the first outlet 104a and the second outlet 105a is formed with a slight gap from the surface of the filter F in the +Z direction, but it may be formed so as to be in contact with the filter F.

[0054] As described above, in the filter unit 20, the first outlet channel 104 is provided between the inlet channel 103 and the second outlet channel 105 in the flow direction. Therefore, the distance from the inlet channel 103 to the first outlet channel 104 is different from the distance from the inlet channel 103 to the second outlet channel 105. For example, as shown in FIG. 3 , the distance D1 from the inlet channel 103 to the first outlet channel 104 is shorter than the distance D2 from the inlet channel 103 to the second outlet channel 105.

[0055] In this embodiment, the length L1 of the first outlet path 104 is the same as the length L2 of the second outlet path 105. That is, the first outlet path 104 and the second outlet path 105 are formed to have approximately the same length.

[0056] The flow path resistance of the second outlet path 105, which is provided at a position farther from the inlet path 103 than the first outlet path 104, is smaller than the flow path resistance of the first outlet path 104. In particular, it is preferable that the flow path resistance of the second outlet path 105 near the second outlet port 105a is smaller than the flow path resistance of the first outlet path 104. Furthermore, it is preferable that the overall flow path resistance of the second outlet path 105 is smaller than the overall flow path resistance of the first outlet path 104.

[0057] In this embodiment, the area of ​​the opening of the second outlet channel 105 formed in the downstream chamber 102, i.e., the area of ​​the second outlet 105a, is larger than the area of ​​the opening of the first outlet channel 104 formed in the downstream chamber 102, i.e., the area of ​​the first outlet 104a. The depth of the portion of the second outlet 105a where the area is larger than that of the first outlet 104a is preferably at least equal to or greater than the diameter of the second outlet 105a, more preferably at least twice as large. In this embodiment, the first outlet channel 104 and the second outlet channel 105 are each formed with approximately the same inner diameter along their length, and the depth of the portion of the second outlet 105a where the area is larger than that of the first outlet 104a is approximately twice as large as that of the second outlet 105a. As a result, the flow path resistance of the second outlet channel 105 is smaller than the flow path resistance of the first outlet channel 104.

[0058] Here, the first outflow path 104 and the second outflow path 105 are basically flow paths formed in the member in which the downstream chamber 102 of the filter unit 20 is formed, which in this embodiment is the second flow path member 40, but they may also include flow paths formed in a member joined to the second flow path member 40. Furthermore, the second flow path member 40 does not necessarily have to be a single component, and may, for example, be an integrated member of multiple components. Furthermore, the first outflow path 104 and the second outflow path 105 refer to flow paths formed by inner circumferential surfaces extending in a direction approximately perpendicular to the surface of the filter F. Note that, as used herein, "approximately perpendicular to the surface of the filter F" means that a range of approximately ±3° is allowed with respect to the direction perpendicular to the surface of the filter F.

[0059] In this way, the flow path resistance of the second outlet path 105 is smaller than the flow path resistance of the first outlet path 104, so that when performing various cleaning operations such as suction cleaning and pressure cleaning, it is possible to prevent the bubbles Bb in the upstream chamber 101 from being unable to be sufficiently discharged via the second outlet path 105. This point will be described in detail with reference to FIG.

[0060] As indicated by the solid arrows in Figure 4, during a recording operation, ink supplied from the cartridge 3 to the filter unit 20 flows from the inflow channel 103 to the first outflow channel 104, or from the inflow channel 103 to the second outflow channel 105. Therefore, air bubbles Bb that have flowed into the upstream chamber 101 tend to move in the -X direction due to the flow of ink from the inflow channel 103 to the second outflow channel 105. Furthermore, because buoyancy acts on the air bubbles Bb in the -Z direction, they tend to move to a corner C1 on the -X and -Z sides of the upstream chamber 101. Furthermore, at the corner C1, ink is less likely to flow from the inflow channel 103 to the second outflow channel 105, which tends to cause stagnation and cause the air bubbles Bb to accumulate. Incidentally, at corner C2 on the +X direction side and the -Z direction side of the upstream chamber 101, ink is less likely to flow from the inflow channel 103 to the first outflow channel 104, so air bubbles Bb accumulate due to buoyancy. However, because corner C1 is more susceptible to stagnation than corner C2, the amount of air bubbles Bb that accumulate near corner C2 is smaller than the amount of air bubbles Bb that accumulate near corner C1.

[0061] In this way, bubbles Bb tend to accumulate in the upstream chamber 101 near the second outlet path 105 on the side farther from the inlet path 103, and when various cleaning operations are performed in such a state, the accumulated bubbles Bb tend to flow into the second outlet path 105. In other words, a large amount of bubbles Bb that have accumulated in the corner C1 are mainly discharged from the second outlet path 105.

[0062] Now, consider a comparative example in which the flow path resistance of the first outlet channel 104 and the flow path resistance of the second outlet channel 105 are the same. In this comparative example, the time required to discharge the air bubbles Bb retained in the corner C2 from the first outlet channel 104 is shorter than the time required to discharge a large amount of air bubbles Bb retained in the corner C1 from the second outlet channel 105. In other words, the cleaning time required to discharge the air bubbles Bb in the upstream chamber 101 via the first outlet channel 104 is shorter than the cleaning time required to discharge the air bubbles Bb in the upstream chamber 101 via the second outlet channel 105. Therefore, after the cleaning time required to discharge the air bubbles Bb in the upstream chamber 101 via the first outlet channel 104 has elapsed since the start of the cleaning operation, while ink containing a large amount of air bubbles Bb is being discharged from the second outlet channel 105, mainly ink continues to be discharged from the first outlet channel 104, resulting in an increase in the amount of waste ink.

[0063] On the other hand, in this embodiment, the flow path resistance of the second outlet path 105 is smaller than the flow path resistance of the first outlet path 104, so the flow rate of ink flowing through the second outlet path 105 is greater than the flow rate of ink flowing through the first outlet path 104. Therefore, compared to the comparative example, a large amount of air bubbles Bb that have accumulated near the corner C1 can be more easily discharged to the outside from the nozzle 11 of the liquid ejection unit 10 via the second outlet path 105, thereby reducing the risk of air bubbles Bb remaining in the upstream chamber 101 after various cleaning operations are performed. Furthermore, compared to the comparative example, the time required to discharge a large amount of air bubbles Bb that have accumulated near the corner C1 to the outside from the nozzle 11 of the liquid ejection unit 10 via the second outlet path 105 can be shortened, thereby shortening the cleaning time. As a result, the amount of ink discharged from the first outlet path 104, through which ink mainly flows more easily than from the second outlet path 105, can be reduced, thereby reducing the amount of waste ink.

[0064] Furthermore, as described above, air bubbles Bb near the corner C1 are more likely to flow into the second outlet 105a than into the first outlet 104a. Therefore, if the area of ​​the second outlet 105a is the same as the area of ​​the first outlet 104a, the second outlet 105a is more likely to be temporarily blocked by the air bubbles Bb, and the air bubbles Bb create flow path resistance in the second outlet path 105. As a result, the ink in the filter chamber 100 actively flows through the first outlet path 104, which has the first outlet 104a, which is less likely to be blocked by the air bubbles Bb. In particular, when the first nozzle row 15A communicating with the first outlet path 104 and the second nozzle row 15B communicating with the second outlet path 105 face the same closed space CL, the negative pressure generated in the closed space CL by the pump P1 acts more easily on the first outlet path 104 than on the second outlet path 105, making this effect more pronounced.

[0065] On the other hand, in this embodiment, the area of ​​the second outlet 105a is larger than the area of ​​the first outlet 104a. This makes it less likely that air bubbles Bb near the corner C1 will clog the second outlet 105a, which reduces the difficulty in discharging ink containing air bubbles Bb from the filter chamber 100 via the second outlet path 105, prevents air bubbles Bb from remaining in the filter chamber 100, and further reduces cleaning time and the amount of waste ink.

[0066] Here, the diameters of the first outlet 104a and the second outlet 105a may be set so that the flow path resistance of the second outlet 105 is lower than the flow path resistance of the first outlet 104, and are, for example, 1 mm or more and 2 mm or less, and it is preferable that the diameter of the first outlet 104a is 0.5 mm or more and less than 1 mm.

[0067] The configuration of the liquid ejecting unit 10 having the flow path to which ink is supplied from the filter unit 20 is not particularly limited, and any existing configuration may be adopted, but an example will be briefly described here. Figure 5 is a cross-sectional view showing a part of the liquid ejecting unit 10 according to this embodiment in the X-axis direction.

[0068] The liquid ejection unit 10 comprises a head body 110 having a plurality of nozzles 11, and a holding member 150 to which the head body 110 is fixed and which has a flow path formed therein connecting the head body 110 and the filter unit 20.

[0069] The head main body 110 comprises a plurality of components such as a flow path forming substrate 111, a communicating plate 112, a nozzle plate 113 in which the nozzles 11 are formed, a protective substrate 114, and a case member 115, and these components are joined together using adhesive or the like.

[0070] Pressure chambers 116 communicating with the nozzles 11 are formed in the flow path forming substrate 111. Although not shown in the figure, a plurality of pressure chambers 116 are arranged in a row along the Y axis direction. That is, a plurality of pressure chambers 116 are provided corresponding to the nozzles 11 arranged in a row. Furthermore, the flow path forming substrate 111 is provided with a plurality of rows of pressure chambers 116 arranged in a row in the Y axis direction along the X axis direction (two rows in this embodiment).

[0071] A communication plate 112 and a nozzle plate 113 are bonded to the surface of the flow path forming substrate 111 facing the +Z direction. Nozzle communication passages 117 that communicate between the pressure chambers 116 and the nozzles 11 are formed in the communication plate 112. A first manifold section 118 and a second manifold section 119 are also formed in the communication plate 112, and supply communication passages 121 that connect the first manifold section 118 or the second manifold section 119 to each of the pressure chambers 116 arranged side by side are also formed. The first manifold section 118 and the second manifold section 119, together with a third manifold section (described later) defined by the case member 115, constitute a manifold 120 for storing ink to be supplied to the multiple pressure chambers 116.

[0072] The nozzle plate 113 has a plurality of nozzles 11 arranged in a row along the Y-axis direction, and two nozzle rows 15, each having a plurality of nozzles 11 arranged in a row along the Y-axis direction, are provided in accordance with the rows of the pressure chambers 116. That is, the nozzle plate 113 has a first nozzle row 15A and a second nozzle row 15B formed therein, which correspond to the two rows of the pressure chambers 116.

[0073] A compliance substrate 123 is joined to the surface of the communicating plate 112 where the first manifold portion 118 and the second manifold portion 119 open. The compliance substrate 123 seals the openings of the first manifold portion 118 and the second manifold portion 119 on the ejection surface 12 side.

[0074] A vibration plate 124 is provided on the surface of the flow channel forming substrate 111 opposite the communication plate 112. A piezoelectric actuator 125 is also provided on the vibration plate 124. The piezoelectric actuator 125 is an example of the pressure generating device described above, and is configured, for example, by a piezoelectric element provided corresponding to each pressure chamber 116 and two electrodes provided on either side of the piezoelectric element. A potential difference generated between these two electrodes displaces the piezoelectric element, and the vibration plate also displaces in response to the displacement of the piezoelectric element. This causes a pressure change in the ink in the pressure chamber 116, causing ink to be ejected from the nozzle 11. A protective substrate 114 having approximately the same size as the flow channel forming substrate 111 is bonded to the surface of the flow channel forming substrate 111 facing the piezoelectric actuator 125. The protective substrate 114 has a holding portion 126, which is a space for protecting and accommodating the piezoelectric actuator 125. The protective substrate 114 also has a through-hole 127 penetrating in the Z-axis direction. The wiring of the piezoelectric actuator 125 is electrically connected within this through hole 127 to a wiring member 128 on which a drive circuit such as a drive IC is mounted.

[0075] A case member 115 is fixed to the surface of the protective substrate 114 opposite to the flow path forming substrate 111. The case member 115 is joined to the protective substrate 114 and the communication plate 112. As a result, a third manifold portion 129 is defined by the case member 115 on the outer periphery of the flow path forming substrate 111. The manifold 120 is composed of the first manifold portion 118 or the second manifold portion 119 provided on the communication plate 112 and the third manifold portion 129. In this embodiment, two manifolds 120 (120A, 120B) are provided corresponding to the first nozzle row 15A and the second nozzle row 15B, respectively.

[0076] The case member 115 is provided with introduction paths 130 that communicate with the manifolds 120 and supply ink to each manifold 120. In this embodiment, one head main body 110 is provided with two independent manifolds 120, and therefore a total of two introduction paths 130 are provided for each manifold 120. The case member 115 is also provided with a connection port 131 that communicates with the through-hole 127 of the protection substrate 114 and through which the wiring member 128 is inserted.

[0077] The head main body 110 configured as described above is fixed to the holding member 150. That is, the head main body 110 is fixed to the +Z direction side of the holding member 150, and the filter unit 20 is fixed to the -Z direction side of the holding member 150.

[0078] 5 shows only one head body 110, but in reality, multiple head bodies 110 are fixed to the holding member 150. However, multiple head bodies 110 do not necessarily have to be fixed to the holding member 150, and of course, only one head body 110 may be fixed to the holding member 150.

[0079] The holding member 150 is provided on its +Z direction side with a concave head body holding portion 151 that houses and holds the head body 110. The head body 110 housed in the head body holding portion 151 has a surface opposite to the ejection surface 12 fixed to the bottom surface of the head body holding portion 151.

[0080] A cover head 160 that covers the opening of the head body holding part 151 is provided on the surface of the holding member 150 on the head body holding part 151 side. The cover head 160 is made of a plate-like member having an exposure opening 161 that exposes the ejection surface 12 of the head body 110.

[0081] A wiring board 170 is housed on the −Z direction side of the holding member 150, i.e., on the filter unit 20 side. The holding member 150 is also provided with a wiring member insertion hole 152 for inserting the wiring member 128. The wiring member 128 is connected to the wiring board 170 in a state where it is inserted through the wiring member insertion hole 152.

[0082] The holding member 150 is also provided with a connection flow path 154 for supplying ink supplied from the filter unit 20 to the head main body 110. A connection flow path 154 is provided for each introduction path 130 of the head main body 110. In this embodiment, one head main body 110 is provided with two introduction paths 130 (130A, 130B), and therefore the holding member 150 is also provided with two connection flow paths 154 (154A, 154B).

[0083] Specifically, an introduction channel 130A connected to the first nozzle row 15A and an introduction channel 130B connected to the second nozzle row 15B are formed in the head main body 110. The holding member 150 is provided with a connection flow channel 154A that connects the first outlet channel 104 of the filter unit 20 to the introduction channel 130A, and a connection flow channel 154B that connects the second outlet channel 105 to the introduction channel 130B.

[0084] One end of each of the connection channels 154A and 154B opens to an end face of a first protrusion 155 that protrudes from the surface of the holding member 150. The other ends of the connection channels 154A and 154B open to the bottom surface of the head body holding portion 151. One end that opens to the end face of the first protrusion 155 is connected to the filter unit 20, and the other end that opens to the bottom surface of the head body holding portion 151 is connected to the introduction channel 130 of the head body 110. As a result, ink from the filter unit 20 is supplied to the head body 110 via the connection channels 154A and 154B. Specifically, ink flowing out from the first outlet channel 104 of the filter unit 20 is supplied to the introduction channel 130A of the head body 110 via the connection channel 154A, and ink flowing out from the second outlet channel 105 of the filter unit 20 is supplied to the introduction channel 130B of the head body 110 via the connection channel 154B.

[0085] As described above, according to the configuration of the recording head of this embodiment, when various cleaning operations are performed, air bubbles can be moved from each of the first outlet path 104 and the second outlet path 105 of the filter unit 20 toward the liquid ejection section 10, and the air bubbles can be discharged from each of the multiple nozzles 11.

[0086] The filter unit 20 of the present invention comprises a filter F through which liquid passes, a filter chamber 100 divided by the filter F into an upstream chamber 101 and a downstream chamber 102, an inlet channel 103 for allowing liquid to flow into the upstream chamber 101, a first outlet channel 104 for allowing liquid to flow out of the downstream chamber 102, and a second outlet channel 105 for allowing liquid to flow out of the downstream chamber 102, wherein the distance from the inlet channel 103 to the first outlet channel 104 is shorter than the distance from the inlet channel 103 to the second outlet channel 105, and the flow resistance of the second outlet channel 105 is smaller than the flow resistance of the first outlet channel 104.

[0087] Furthermore, the recording head 2, which is a liquid ejection head according to the present invention, includes a filter unit 20 and a plurality of nozzles 11 that eject liquid supplied from the filter unit 20. More specifically, the recording head 2 includes a liquid ejection section 10 having a first nozzle row 15A configured from a portion of the plurality of nozzles 11 and a second nozzle row 15B configured from a portion of the plurality of nozzles 11 different from the first nozzle row 15A, and the first nozzle row 15A is supplied with liquid from a downstream chamber 102 via a first outlet channel 104, and the second nozzle row 15B is supplied with liquid from the downstream chamber 102 via a second outlet channel 105.

[0088] The recording apparatus 1 according to the present invention also includes a recording head 2, which is a liquid ejection head, and a liquid storage section 3 for supplying liquid to the filter unit 20. Furthermore, it is preferable that the extension direction of the filter F in the recording apparatus 1 is approximately parallel to a horizontal plane.

[0089] In any of these configurations, the flow path resistance of the second outflow path 105 in the filter unit 20 is reduced, which increases the ink flow rate in the second outflow path 105 and makes it easier to expel air bubbles from the second outflow path 105. Furthermore, since it is easier to expel air bubbles, it is possible to shorten cleaning time and reduce the amount of waste ink.

[0090] Furthermore, the area of ​​the opening formed in the downstream chamber 102 of the second outlet channel 105 is preferably larger than the area of ​​the opening formed in the downstream chamber 102 of the first outlet channel 104. This makes it difficult for air bubbles to clog the second outlet channel 105, allowing air bubbles to be efficiently discharged from the second outlet channel 105.

[0091] It is also preferable that the diameter of the opening of the second outflow channel 105 is 1 mm or more and 2 mm or less, and the diameter of the opening of the first outflow channel 104 is 0.5 mm or more and less than 1 mm. By optimizing the size of the opening of the second outflow channel 105 according to the size of the air bubbles, it is possible to improve the gas discharge performance.

[0092] Furthermore, the first outlet channel 104 is preferably disposed between the inlet channel 103 and the second outlet channel 105 in the flow direction of the liquid flowing from the inlet channel 103 to the second outlet channel 105. Since bubbles Bb tend to accumulate in the upstream chamber 101 near the second outlet channel 105, such a configuration provides a more significant effect.

[0093] (Embodiment 2) 6 is a cross-sectional view of a filter unit according to embodiment 2 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.

[0094] As shown in FIG. 6, the filter unit 20 according to this embodiment is further provided with a third outlet channel 106 in addition to a first outlet channel 104 and a second outlet channel 105 that communicate with the downstream chamber 102.

[0095] The third outlet path 106 is disposed in the −X direction relative to the second outlet path 105, which is the flow direction of ink flowing through the upstream chamber 101. In other words, the third outlet 106a, which is the opening of the third outlet path 106 to the downstream chamber 102, is disposed in the −X direction relative to the second outlet 105a.

[0096] Here, "third outlet 106a being positioned in the -X direction relative to second outlet 105a" means that, in the XY plane viewed from the +Z direction, the X-axis coordinate of third outlet 106a is positioned in the -X direction relative to the X-axis coordinate of second outlet 105a. In other words, this includes third outlet 106a being positioned at a position shifted in the +Y direction or the -Y direction relative to second outlet 105a. Note that the position of third outlet 106a refers to the center of the opening of third outlet 106a, and the position of second outlet 105a refers to the center of the opening of second outlet 105a.

[0097] Similarly to the first embodiment, the flow path resistance of the second outlet path 105, which is provided farther from the inlet path 103 than the first outlet path 104, is smaller than the flow path resistance of the first outlet path 104. Furthermore, the flow path resistance of the third outlet path 106, which is provided farther from the inlet path 103 than the second outlet path 105, is smaller than the flow path resistance of the second outlet path 105. In particular, it is preferable that the flow path resistance of the third outlet path 106 near the third outlet port 106a is smaller than the flow path resistance of the second outlet path 105. Furthermore, it is preferable that the overall flow path resistance of the third outlet path 106 is smaller than the overall flow path resistance of the second outlet path 105.

[0098] In this embodiment, the area of ​​the opening of the third outlet channel 106 formed in the downstream chamber 102, i.e., the area of ​​the third outlet 106a, is larger than the area of ​​the opening of the second outlet channel 105 formed in the downstream chamber 102, i.e., the area of ​​the second outlet 105a. The depth of the portion of the third outlet 106a where the area is larger than that of the second outlet 105a is preferably at least equal to or greater than the diameter of the third outlet 106a, more preferably at least twice as large. In this embodiment, the first outlet channel 104, the second outlet channel 105, and the third outlet channel 106 are each formed with approximately the same inner diameter along their length, and the depth of the portion of the third outlet 106a where the area is larger than that of the second outlet 105a is approximately twice as large as that of the third outlet 106a. As a result, the flow path resistance of the third outlet channel 106 is smaller than the flow path resistance of the second outlet channel 105.

[0099] As described above, this embodiment further includes the third outlet path 106 for discharging liquid from the downstream chamber 102, the distance from the inflow path 103 to the second outlet path 105 is shorter than the distance from the inflow path 103 to the third outlet path 106, and the size of the opening of the third outlet path 106 formed in the downstream chamber 102 is larger than the size of the opening of the second outlet path 105. Furthermore, the size of the opening of the second outlet path 105 is larger than the size of the opening of the first outlet path 104.

[0100] Furthermore, this embodiment further includes a third outlet path 106 for discharging liquid from the downstream chamber 102, and the distance from the inlet path 103 to the second outlet path 105 is shorter than the distance from the inlet path 103 to the third outlet path 106, and the flow path resistance of the third outlet path 106 is smaller than the flow path resistance of the second outlet path 105. Furthermore, the flow path resistance of the second outlet path 105 is smaller than the flow path resistance of the first outlet path 104.

[0101] When various cleaning operations are performed, a large amount of bubbles Bb remaining near the corner C1 tends to flow into each outlet channel in the order of the third outlet channel 106, the second outlet channel 105, and the first outlet channel 104. However, the flow channel resistance decreases in the order of the third outlet channel 106, the second outlet channel 105, and the first outlet channel 104, so the same effect as in the first embodiment can be obtained. In addition, the opening area increases in the order of the third outlet 106a, the second outlet 105a, and the first outlet 104a, so the same effect as in the first embodiment can be obtained.

[0102] In this embodiment, the flow path resistance of the second outlet path 105 is lower than the flow path resistance of the first outlet path 104, but the flow path resistance of the second outlet path 105 may be the same as the flow path resistance of the first outlet path 104. In other words, only the flow path resistance of the third outlet path 106 may be lower than the flow path resistance of the other outlet paths.

[0103] In addition, in this embodiment, a configuration in which the filter unit 20 includes a first outlet channel 104, a second outlet channel 105, and a third outlet channel 106 has been exemplified, but the configuration of the filter unit 20 is not particularly limited, and for example, the filter unit 20 may be configured to further include a fourth outlet channel arranged in the -X direction of the third outlet channel 106.

[0104] Even in this case, the same effect as in this embodiment can be obtained by making the size of the opening formed in the downstream chamber 102 of the fourth outlet path larger than the size of the opening of the third outlet path 106, and further making the flow path resistance of the fourth outlet path smaller than the flow path resistance of the third outlet path 106.

[0105] (Embodiment 3) Fig. 7 is a plan view of a filter unit according to a third embodiment of the present invention as seen in the +Z direction, and Fig. 8 is a cross-sectional view taken along line BB' in Fig. 7. Note that the same members as those in the above-described embodiments are given the same reference numerals, and redundant explanations will be omitted.

[0106] This embodiment is a modified example of the second outlet channel 105, and the other configurations are similar to those of the first embodiment. Specifically, as shown in FIGS. 7 and 8, the number of second outlets 105a, which are openings formed in the downstream chamber 102 of the second outlet channel 105A provided in the filter unit 20, is greater than the number of first outlets 104a, which are openings formed in the downstream chamber 102 of the first outlet channel 104. Specifically, the second outlet channel 105A is composed of two branch channels 107A and 107B opening into the downstream chamber 102, and a junction channel 108 where the branch channels 107A and 107B join together. That is, the filter unit 20 of this embodiment is provided with one first outlet 104a and two second outlets 105a.

[0107] Also in this configuration, the flow path resistance of the second outlet path 105A is smaller than the flow path resistance of the first outlet path 104. The total area of ​​each second outlet 105a is larger than the area of ​​the first outlet 104a.

[0108] As described above, in this embodiment, the number of openings formed in the downstream chamber 102 of the second outlet channel 105A is greater than the number of openings formed in the downstream chamber 102 of the first outlet channel 104. The distance from the inlet channel 103 to each opening of the second outlet channel 105A is the same. Furthermore, the second outlet channel 105A has a plurality of branch channels 107A, 107B that open into the downstream chamber 102, and a junction channel 108 where the branch channels 107A, 107B join together.

[0109] Even with this configuration, as in the above-described embodiment, the ink flow rate in the second outlet channel 105A increases, making it easier to expel air bubbles from the second outlet channel 105A. Furthermore, by making it easier to expel air bubbles, it is possible to shorten cleaning time and reduce the amount of waste ink.

[0110] Furthermore, the distance D3 from the inlet channel 103 to the second outlet 105a of the branch channel 107A is set to be the same as the distance D4 from the inlet channel 103 to the second outlet 105a of the branch channel 107B. This arrangement reduces variations in the ease of discharging the bubbles Bb from the second outlet 105a of the branch channel 107A and the ease of discharging the bubbles Bb from the second outlet 105a of the branch channel 107B. Furthermore, when the distances D3 and D4 are the same, it is preferable that the flow path resistance of the branch channel 107A and the flow path resistance of the branch channel 107B are the same. Furthermore, when the distances D3 and D4 are the same, it is preferable that the opening area of ​​the second outlet 105a of the branch channel 107A and the opening area of ​​the second outlet 105a of the branch channel 107B are the same.

[0111] The size of the opening of each second outlet 105a is not particularly limited, but is preferably the same as or larger than the first outlet 104a, which allows the ink flow rate in the second outlet channel 105A to be more appropriately increased.

[0112] (Embodiment 4) Fig. 9 is a plan view of a filter unit according to a fourth embodiment of the present invention as seen in the +Z direction, and Fig. 10 is a cross-sectional view taken along line CC' in Fig. 9. Note that the same components as those in the above-described embodiments are given the same reference numerals, and redundant explanations will be omitted. In Fig. 10, solid arrows indicate the flow of ink in the upstream chamber 101, and dashed arrows indicate the flow of air bubbles when various cleaning operations are performed.

[0113] The filter unit 20 according to this embodiment has the same configuration as that of the first embodiment, except that the arrangements of the inlet channel 103, the first outlet channel 104, and the second outlet channel 105 are changed. Specifically, as shown in Figures 9 and 10 , in a plan view of the filter chamber 100 seen in the +Z direction, the inlet 103a of the inlet channel 103 is positioned in the +X direction relative to the center of the X-axis direction of the filter chamber 100, but is positioned in the -X direction relative to the first outlet 104a of the first outlet channel 104. In other words, in a plan view of the filter chamber 100 seen in the +Z direction, the first outlet 104a of the first outlet channel 104 is positioned in the +X direction relative to the inlet 103a.

[0114] In a plan view of the filter chamber 100 looking in the +Z direction, the second outlet 105a of the second outlet path 105 is disposed in the -X direction from the center of the filter chamber 100 in the direction along the X axis. In addition, the distance D5 from the inlet path 103 to the first outlet path 104 is shorter than the distance D6 from the inlet path 103 to the second outlet path 105.

[0115] In the filter unit 20 according to this embodiment, similarly to the above-described embodiments, the flow path resistance of the second outlet path 105 is smaller than the flow path resistance of the first outlet path 104. This makes it possible to prevent the air bubbles Bb in the upstream chamber 101 from being unable to be sufficiently discharged via the second outlet path 105 when various cleaning operations are performed.

[0116] 10, during a recording operation, ink supplied from the cartridge 3 to the filter unit 20 flows in the +X direction from the inflow channel 103 toward the first outflow channel 104, and also flows in the -X direction toward the second outflow channel 105. Therefore, the air bubble Bb that has flowed into the upstream chamber 101 moves in the +X direction due to the flow from the inflow channel 103 toward the first outflow channel 104, and also moves in the -X direction due to the flow from the inflow channel 103 toward the second outflow channel 105. For this reason, the air bubble Bb stagnates at each of the corners C1 and C2.

[0117] However, as described in the first embodiment, in the upstream chamber 101 near the second outlet channel 105 on the side farther from the inflow channel 103, particularly near the corner C1, ink is less likely to flow from the inflow channel 103 toward the second outlet channel 105, and stagnation is more likely to occur there than at the corner C2. Therefore, air bubbles Bb are more likely to accumulate at the corner C1 than at the corner C2.

[0118] When various cleaning operations and the like are performed, air bubbles Bb that have accumulated near the corner C1 are mainly discharged from the second outlet channel 105. In this embodiment, the flow path resistance of the second outlet channel 105 is smaller than the flow path resistance of the first outlet channel 104, so the flow rate of ink flowing through the second outlet channel 105 is greater than the flow rate of ink flowing through the first outlet channel 104. Therefore, a large amount of air bubbles Bb that have accumulated near the corner C1 can be easily discharged to the outside from the nozzle 11 of the liquid ejecting unit 10 via the second outlet channel 105, thereby reducing the risk of air bubbles Bb remaining in the upstream chamber 101 after various cleaning operations are performed. Furthermore, because air bubbles can be easily discharged, cleaning time can be shortened and the amount of waste ink can be reduced.

[0119] (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.

[0120] Furthermore, for example, in the above-described embodiment, an example was described in which the flow resistance of the second outflow path in the filter unit was smaller than the flow resistance of the first outflow path, but the filter unit of the present invention is not limited to this configuration. For example, in the filter unit of the present invention, the flow resistance of the second outflow path does not necessarily have to be smaller than the flow resistance of the first outflow path, as long as the area of ​​the opening formed in the second flow path is larger than the area of ​​the opening formed in the downstream chamber of the first outflow path. By setting the area of ​​the opening formed in the second outflow path to a size that sufficiently increases the flow rate of the liquid flowing through the second outflow path, it is possible to obtain the same effects as in the above-described embodiment, even if the flow resistance of the second outflow path is larger than the flow resistance of the first outflow path.

[0121] Furthermore, in each of the above-described embodiments, a configuration in which the filter unit 20 is provided so that the ink flows in the X-axis direction has been exemplified, but there are no particular limitations on the arrangement of the filter unit 20. For example, the filter unit 20 may be arranged so that the ink flows in the Y-axis direction.

[0122] In the above embodiment, the filter F was arranged so that its extension direction was approximately parallel to the horizontal plane, but the filter F may be arranged so that it intersects the horizontal plane as long as the first outlet 104a is not positioned higher than the second outlet 105a in the direction of gravity.

[0123] In the above-described first embodiment, the first nozzle row 15A communicating with the first outlet channel 104 and the second nozzle row 15B communicating with the second outlet channel 105 are provided in the same head body 110, but the first nozzle row 15A and the second nozzle row 15B do not necessarily have to be provided in the same head body 110. For example, the liquid ejecting unit 10 may have a configuration in which the first nozzle row 15A is provided in one of two different head bodies 110, and the second nozzle row 15B is provided in the other head body 110.

[0124] In the above-described embodiment, a recording head 2 that performs cleaning operations such as suction cleaning and pressure cleaning has been exemplified, but the recording head 2 may also be one that performs so-called circulation cleaning, in which ink is circulated between a flow path within the recording head 2 and a flow path outside the recording head 2 to remove impurities and air bubbles from the ink.

[0125] Here, an example of a flow path for circulating ink in the recording head 2 on which circulation cleaning is performed will be described. Fig. 11 is a diagram for explaining the flow path for circulating ink in the recording head 2, and is a simplified diagram of the recording head.

[0126] 11, the inflow channel 103 of the filter unit 20 is connected to an ink tank 3A, which is a liquid storage section, by a supply tube 201. The filter chamber 100, which is connected to the inflow channel 103, is connected to the manifold 120A via the first outflow channel 104, the connecting channel 154A, and the introduction channel 130A, as in the above-described embodiment. The filter chamber 100 is also connected to the manifold 120B via the second outflow channel 105, the connecting channel 154B, and the introduction channel 130B.

[0127] The filter unit 20 is also provided with a first discharge communicating passage 202 and a second discharge communicating passage 203 for discharging ink from the head main body 110. When the recording head 2 includes a plurality of head main bodies 110, the first discharge communicating passage 202 and the second discharge communicating passage 203 are provided corresponding to each head main body 110. The case member 115 and the holding member 150 that constitute the liquid ejecting unit 10 are also provided with a first outlet passage 204 that connects the manifold 120A and the first discharge communicating passage 202, and a second outlet passage 205 that connects the manifold 120B and the second discharge communicating passage 203.

[0128] Here, the first discharge communication passage 202 communicates with the outside at a connection port 202a without passing through the filter chamber 100. The second discharge communication passage 203 also communicates with the outside at a connection port 203a without passing through the filter chamber 100. A first discharge tube 206 leading to the ink tank 3A is connected to the connection port 202a of the first discharge communication passage 202. In other words, the first discharge communication passage 202 is connected to the ink tank 3A via the first discharge tube 206. A second discharge tube 207 is connected to the connection port 203a of the second discharge communication passage 203, and this second discharge tube 207 merges with the first discharge tube 206 midway. A pump P2, which serves as a power source for circulating the ink, is provided upstream of the junction of the first discharge tube 206 and the second discharge tube 207.

[0129] 11, when circulation cleaning is performed on the recording head 2, ink is supplied from the ink tank 3A to the manifold 120A via the filter chamber 100, and is returned to the ink tank 3A by the pump P2 via the first outlet path 204, the first discharge communicating path 202, and the first discharge tube 206 without passing through the filter chamber 100. Similarly, ink is supplied from the ink tank 3A to the manifold 120B via the filter chamber 100, and is returned to the ink tank 3A by the pump P2 via the second outlet path 205, the second discharge communicating path 203, the second discharge tube 207, and the first discharge tube 206 without passing through the filter chamber 100, and is thus circulated.

[0130] Even when such circulation cleaning is performed, the present invention allows air bubbles inside the filter chamber 100 to be properly discharged. In other words, air bubbles inside the filter chamber 100 can be discharged downstream of the filter chamber 100 and moved to the ink tank 3A via the manifolds 120A and 120B. Another advantageous effect is that the cleaning time can be shortened.

[0131] 11, the first discharge tube 206 and the second discharge tube 207 are joined together, but instead, the first discharge communication passage 202 and the second discharge communication passage 203 may be joined together inside the filter unit 20. In this case, the second discharge tube 207 is not necessary. Alternatively, the first outlet passage 204 and the second outlet passage 205 may be joined together inside the head main body 110. In this case, the second discharge communication passage 203 and the second discharge tube 207 are not necessary.

[0132] Furthermore, in this example, the ink is circulated by being supplied from the ink tank 3A to the manifold 120A via the filter chamber 100 and then returned to the ink tank 3A via the first outlet path 204, the first discharge communication path 202, and the first discharge tube 206 without passing through the filter chamber 100, but the configuration of the ink circulation flow path is not limited to this. The ink circulation flow path may be configured, for example, so that the ink supplied to the manifold 120A is returned to the ink tank 3A via the pressure chamber 116.

[0133] Furthermore, in the above-described inkjet recording device 1, the recording head 2 is mounted on a transport body 6a and moves in the main scanning direction, but the configuration of the recording device 1 is not limited to this. For example, the recording device 1 may be one in which the recording head 2 is fixed and printing is performed simply by moving the medium S in the sub-scanning direction. In other words, the present invention can also be applied to so-called line-type recording devices.

[0134] Furthermore, the present invention is broadly intended for liquid jet heads in general, and can be applied to, for example, recording heads such as various ink jet recording heads used in image recording devices such as printers, as well as color material jetting heads used in the manufacture of color filters for liquid crystal displays and the like, electrode material jetting heads used in the formation of electrodes for organic EL displays, FEDs (field emission displays), and the like, and bioorganic material jetting heads used in the manufacture of biochips.

[0135] The present invention can also be applied to liquid ejection apparatuses equipped with other liquid ejection heads such as those described above.The present invention also targets filter units in general, and can be applied to filter units used in devices other than liquid ejection apparatuses and liquid ejection heads. [Explanation of symbols]

[0136] 1...inkjet recording device (recording device), 2...inkjet recording head (recording head), 3...cartridge (liquid storage section), 3A...ink tank (liquid storage section), 4...conveying mechanism, 4a...conveying roller, 5...control unit, 6...moving mechanism, 6a...conveying body, 6b...conveying belt, 7...wiper, 8...cap, 8a...discharge hole, 9...tube, 10...liquid ejecting section, 11...nozzle, 12...ejecting surface, 15...nozzle row, 20...filter unit, 3 0...first flow path member, 31...first recess, 31a...ceiling surface, 32...connecting portion, 40...second flow path member, 41...second recess, 100...filter chamber, 101...upstream chamber, 102...downstream chamber, 103...inlet, 103a...inlet, 104...first outlet, 104a...first outlet, 105, 105A...second outlet, 105a...second outlet, 106...third outlet, 106a...third outlet, 107A, 107B...branching path, 108...merging path, 110...head main body, 111...flow path Forming substrate, 112...communication plate, 113...nozzle plate, 114...protection substrate, 115...case member, 116...pressure chamber, 117...nozzle communication passage, 118...first manifold portion, 119...second manifold portion, 120...manifold, 121...supply communication passage, 123...compliance substrate, 124...vibration plate, 125...piezoelectric actuator, 126...holding portion, 127...through hole, 128...wiring member, 129...third manifold portion, 130...introduction passage, 13 1...connection port, 150...holding member, 151...head body holding portion, 152...wiring member insertion hole, 154...connection flow path, 155...first protrusion, 160...cover head, 161...exposure opening, 170...wiring board, 201...supply tube, 202...first discharge communication path, 202a...connection port, 203...second discharge communication path, 203a...connection port, 204...first outlet path, 205...second outlet path, 206...first discharge tube, 207...second discharge tube, F...filter, S...medium

Claims

1. A filter through which a liquid passes, and a chamber separated by the filter into an upstream chamber and a downstream chamber. a filter chamber, an inlet channel for introducing liquid into the upstream chamber, and a filter chamber for introducing liquid from the downstream chamber. a first outlet passage for allowing liquid to flow out of the downstream chamber; and a second outlet passage for allowing liquid to flow out of the downstream chamber. a filter unit comprising: A nozzle for spraying the liquid supplied from the filter unit a first nozzle array formed by a part of the plurality of nozzles different from the first nozzle array; a liquid ejecting unit having a second nozzle row configured as Equipped with the first nozzle row is supplied with liquid from the downstream chamber via the first outlet channel; the second nozzle row is supplied with liquid from the downstream chamber via the second outlet channel; The distance from the inlet channel to the first outlet channel is the distance from the inlet channel to the second outlet channel. shorter than the distance The flow resistance of the second outlet path is smaller than the flow resistance of the first outlet path. A liquid jet head characterized by:

2. The area of ​​the opening formed in the downstream chamber of the second outlet passage is the area of ​​the opening formed in The liquid jet head according to claim 1 .

3. A filter through which a liquid passes, and a chamber separated by the filter into an upstream chamber and a downstream chamber. a filter chamber, an inlet passage for introducing liquid into the upstream chamber, and a filter passage for introducing liquid from the downstream chamber. a first outlet passage for discharging liquid from the downstream chamber; and a second outlet passage for discharging liquid from the downstream chamber. a filter unit comprising: A nozzle for spraying the liquid supplied from the filter unit a first nozzle array formed by a part of the plurality of nozzles different from the first nozzle array; a liquid ejecting unit having a second nozzle row configured as Equipped with the first nozzle row is supplied with liquid from the downstream chamber via the first outlet channel; the second nozzle row is supplied with liquid from the downstream chamber via the second outlet channel; The distance from the inlet channel to the first outlet channel is the distance from the inlet channel to the second outlet channel. shorter than the distance The area of ​​the opening formed in the downstream chamber of the second outlet passage is the area of ​​the opening formed in A liquid jet head characterized by:

4. The diameter of the opening of the second outflow channel is equal to or greater than 1 mm and equal to or less than 2 mm, The diameter of the opening of the first outflow channel is equal to or greater than 0.5 mm and less than 1 mm.

4. The liquid jet head according to claim 2, wherein the first and second electrodes are arranged parallel to each other.

5. The length of the first outlet path and the length of the second outlet path are the same.

5. The liquid jet head according to claim 2, wherein the liquid jet head is a liquid jet head.

6. a third outlet passage for discharging liquid from the downstream chamber; The distance from the inlet channel to the second outlet channel is the distance from the inlet channel to the third outlet channel. shorter than the distance The size of the opening formed in the downstream chamber of the third outlet passage is equal to the size of the opening of the second outlet passage. is larger than the size of 6. The liquid jet head according to claim 2, wherein the liquid jet head is a liquid jet head.

7. The number of openings formed in the downstream chamber of the second outlet passage is equal to the number of openings formed in the downstream chamber of the first outlet passage. more than the number of openings formed, 7. The liquid jet head according to claim 1, wherein the liquid jet head is a liquid jet head.

8. The distance from the inlet channel to each opening of the second outlet channel is the same. The liquid jet head according to claim 7 .

9. The second outlet passage includes a plurality of branch passages that open into the downstream chamber and a passage where the plurality of branch passages join together. and a merging path through which the 9. The liquid jet head according to claim 7, wherein the first and second electrodes are arranged parallel to each other.

10. In a flow direction in which liquid flows from the inlet channel to the second outlet channel, disposed between the inlet channel and the second outlet channel; 10. The liquid jet head according to claim 1, wherein the liquid jet head is a liquid jet head.

11. A method for discharging liquid from the downstream chamber in a direction opposite to the flow direction of the inlet passage. The outflow tract is not located, The liquid jet head according to claim 10 .

12. a third outlet passage for discharging liquid from the downstream chamber; The distance from the inlet channel to the second outlet channel is the distance from the inlet channel to the third outlet channel. shorter than the distance The flow resistance of the third outlet path is smaller than the flow resistance of the second outlet path.

12. The liquid jet head according to claim 1, wherein the liquid jet head is a liquid jet head.

13. A jetting surface of the liquid jet head on which the plurality of nozzles are provided and an extension direction of the filter The direction is approximately parallel.

13. The liquid jet head according to claim 1, wherein the liquid jet head is a liquid jet head.

14. A liquid jet head according to any one of claims 1 to 13; a liquid reservoir for supplying liquid to the filter unit; Equipped with A liquid ejection device characterized by:

15. The extension direction of the filter is approximately parallel to a horizontal plane. The liquid ejection apparatus according to claim 14 .

16. When the nozzles of the liquid injection head are brought into contact with an injection surface on which the plurality of nozzles are provided, the first The plurality of nozzles constituting the nozzle row and the plurality of nozzles constituting the second nozzle row a cap capable of forming a closed space in which the tube opens; a pump that is driven to create a negative pressure in the closed space; The liquid ejection apparatus according to claim 14 or 15, further comprising:

Images