Liquid ejection head and printing apparatus

Abstract

The purpose of the present disclosure is to provide a liquid ejecting head that is thinner than a liquid ejecting head in the prior art even in a case where a plurality of flow channels are arranged. In a state in which the liquid ejecting head is used, the first upstream flow channel has a first region which is vertically positioned above the first downstream flow channel, and in which a cross-sectional area of the first upstream flow channel becomes smaller and smaller vertically downward. The second upstream flow channel has a second region vertically above the second downstream flow channel, and in the second region, a cross-sectional area of the second upstream flow channel becomes smaller and smaller vertically downward. In a view viewed in the first direction, the first downstream flow channel and the second downstream flow channel do not overlap each other, while the first region and the second region overlap each other. The invention further relates to a printing device.

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head and a printing apparatus. Background Art

[0002] Some printing apparatuses that perform printing by ejecting liquid to a printing medium use a liquid ejection head that has a liquid storage chamber and a liquid ejection unit that are integrated with each other and that is attachable to and detachable from the printing apparatus.

[0003] Japanese Patent Laid-Open No. 2008-260199 discloses an inkjet print cartridge (also referred to as a liquid ejection head), which includes a plurality of storage chambers (storage chambers) storing liquids and an inkjet print head (ejection unit) configured to perform printing by ejecting the liquids. Japanese Patent Laid-Open No. 2008-260199 also discloses that a plurality of supply channels (flow channels) for supplying liquids from the storage chambers are configured between the corresponding storage chambers and the ejection unit and are all connected to the ejection unit.

[0004] However, for a liquid ejection head having a plurality of densely arranged flow channels as described in Japanese Patent Laid-Open No. 2008-260199, it is difficult to thin the width of the main body of the liquid ejection head while reducing bubble generation. Summary of the invention

[0005] An object of the present disclosure is to provide a liquid ejection head in which bubbles are generated less and thinner than in a related art liquid ejection head even when a plurality of flow channels are provided.

[0006] In one aspect of the present disclosure, a liquid ejection head is provided, comprising: a first ejection port array and a second ejection port array arranged side by side, each ejection port array being formed by a plurality of ejection ports arranged in a first direction for ejecting liquid; a first filter, the first filter being configured to filter liquid to be supplied to the first ejection port array; a second filter, the second filter being configured to filter liquid to be supplied to the second ejection port array; a first flow channel, the first flow channel being configured to supply liquid from the first filter to the first ejection port array; and a second flow channel, the second flow channel being configured to supply liquid from the second filter to the second ejection port array, wherein the first flow channel comprises a first downstream flow channel communicating with the first ejection port array and a first upstream flow channel communicating with the first filter and the first downstream flow channel, and the second flow channel comprises A second downstream flow channel connected to the second injection port array and a second upstream flow channel connected to the second filter and the second downstream flow channel, wherein, when the liquid injection head is used, the first upstream flow channel has a first area, the first area is located above the first downstream flow channel in the vertical direction, and in the first area, the cross-sectional area of ​​the first upstream flow channel becomes smaller and smaller from the upper side to the lower side in the vertical direction, and the second upstream flow channel has a second area, the second area is located above the second downstream flow channel in the vertical direction, and in the second area, the cross-sectional area of ​​the second upstream flow channel becomes smaller and smaller from the upper side to the lower side in the vertical direction, and in a view observed along the first direction, the first downstream flow channel and the second downstream flow channel do not overlap with each other, while the first area and the second area overlap with each other.

[0007] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram showing an example of a printing device of an embodiment;

[0009] Figure 2 is a perspective view showing an example of a cartridge of one embodiment;

[0010] Figure 3 is an exploded perspective view showing an example of a cartridge of one embodiment;

[0011] Figure 4 is a perspective view showing an example of a flow channel unit of one embodiment;

[0012] Figure 5A is a top view of a flow channel unit of an embodiment;

[0013] Figure 5B is a side view of a flow channel unit of one embodiment;

[0014] Figure 5C is a front view of a flow channel unit of an embodiment;

[0015] Fig. 6A is a top view of a flow channel of an embodiment;

[0016] Figure 6B is a side view of a flow channel of one embodiment;

[0017] Figure 6C is a front view of a flow channel of one embodiment;

[0018] Fig. 7A is a top view of a flow channel of an embodiment;

[0019] Figure 7B is a side view of a flow channel of one embodiment;

[0020] Figure 7C is a front view of a flow channel of one embodiment;

[0021] Fig. 8A is a top view of a flow channel of an embodiment;

[0022] Figure 8B is a side view of a flow channel of one embodiment;

[0023] Figure 8C is a front view of a flow channel of one embodiment;

[0024] Fig.8D is a cross-sectional view of a flow channel of an embodiment;

[0025] Fig. 9A is a schematic top view of the first retaining portion;

[0026] Fig. 9B is a schematic front view of a first retaining portion;

[0027] Fig. 10A is a top view of a housing of an embodiment;

[0028] Fig. 10B It is along Fig. 10A A cross-sectional view taken along line XB-XB in FIG.

[0029] Fig.11 is a plan view showing an example of a storage room of one embodiment;

[0030] Fig.12is a plan view showing an example of an injection port array of one embodiment;

[0031] Fig.13 is a diagram showing an example of a flow channel of one embodiment;

[0032] Fig.14A is a top view of a conventional flow channel unit;

[0033] Fig. 14B yes Fig.14A A side view of the flow channel unit shown;

[0034] Fig. 14C yes Fig.14A A rear view of the flow channel unit is shown;

[0035] Fig.15 is a graph showing oscillating pressure of one embodiment;

[0036] Figures 16A to 16D is a conceptual diagram of the interior of a mold used to make a box of one embodiment;

[0037] Fig.17A is a schematic transparent top view of a cartridge of one embodiment;

[0038] Fig. 17B is a schematic transparent side view of a cartridge of one embodiment;

[0039] Fig. 17C is a schematic transparent front view of a cartridge of one embodiment;

[0040] Fig.18 is a perspective view showing an example of a flow channel unit of one embodiment;

[0041] Fig.19A is a top view of a flow channel unit of an embodiment;

[0042] Fig.19B is a side view of a flow channel unit of one embodiment; and

[0043] Fig.19C is a front view of a flow channel unit according to one embodiment. DETAILED DESCRIPTION

[0044] [First embodiment]

[0045] The present embodiment will be described below with reference to the drawings.

[0046] Figure 1 1 is a schematic diagram showing an inkjet printing apparatus (hereinafter also simply referred to as a printing apparatus) 102 to which the present embodiment can be applied.

[0047] In the drawings, the X direction indicates the scanning direction of the carriage, the Y direction indicates the conveying direction of the printing medium, and the Z direction indicates the vertical upward direction. Note that in the drawings showing only the cartridge (showing only the liquid ejecting head), the drawings showing the same as the liquid ejecting head are based on the case where the cartridge (hereinafter also referred to as the liquid ejecting head) is attached to the printing device. Figure 1 The same X-axis, Y-axis and Z-axis are used in the printing apparatus. It should be noted that, in a state where the box is attached to the printing apparatus, the direction along the long side of the box (depth direction) is the Y direction. The direction along the short side of the box (width direction) is the X direction. The vertical direction (height direction) of the box is the Z direction.

[0048] The printing device 102 is configured so that the box 100 can be mounted on the carriage 101, and printing is performed by ejecting liquid (hereinafter also referred to as ink) to the print medium 103 while the box 100 mounted on the carriage 101 moves relative to the print medium 103. In other words, the printing device 102 is a printing device including a serial type liquid ejection head. In the ejection, the liquid is ejected from the box 100 while the carriage 101 reciprocates in the X direction. As the liquid is ejected from the box 100, the print medium 103 is conveyed in a predetermined amount each time in a direction (Y direction) that intersects (orthogonally in this example) the direction of the reciprocating motion of the carriage 101, and an image is formed on the print medium 103.

[0049] Figure 2 is a perspective view showing the exterior of the box 100, and Figure 3 2 is an exploded perspective view of the cartridge 100. The cartridge 100 includes a printing element substrate 303 for ejecting liquid, a housing 200 in which a storage chamber 302 for storing liquid is formed, and a cover 201. Each storage chamber 302 accommodates a filter 301 and an absorber 300 for holding the stored liquid. The liquid held by the absorber 300 is discharged through a flow channel unit ( Figure 2 and Figure 3 304 (not shown) is supplied to the ejection openings on the printing element substrate 303. Although the absorber 300 is inserted into the storage chamber 302 as a negative pressure generating unit for holding liquid in the present embodiment, a mode using a negative pressure generating unit such as a pressure control unit or a circulation unit can be similarly used to hold liquid.

[0050] The storage chamber 302 of the present embodiment includes a first storage chamber 302A capable of storing a first type of liquid, a second storage chamber 302B capable of storing a second type of liquid different from the first type, and a third storage chamber 302C capable of storing a third type of liquid different from the first type or the second type. The first storage chamber 302A, the second storage chamber 302B, and the third storage chamber 302C are arranged adjacent to each other along a straight line in the depth direction (Y direction) of the box 100.

[0051] The filter 301A, the filter 301B and the filter 301C for intercepting foreign matter are respectively arranged in the first storage chamber 302A, the second storage chamber 302B and the third storage chamber 302C. As will be described in detail later, in the present embodiment, a first jet port array for ejecting a first type of liquid, a second jet port array for ejecting a second type of liquid, and a third jet port array for ejecting a third type of liquid are formed. The filter 301A is configured to be able to filter the liquid to be supplied to the first jet port array. The filter 301B is configured to be able to filter the liquid to be supplied to the second jet port array. The filter 301C is configured to be able to filter the liquid to be supplied to the third jet port array.

[0052] The liquid stored in the storage chamber 302 is usually a color ink, and cyan, magenta, and yellow inks are stored in the corresponding storage chambers. Although the box 100 has three storage chambers 302 in the example described in the present embodiment, the present disclosure is not limited to such a configuration, and the present embodiment can be applied to a mode with less than two or more than four storage chambers 302. For example, the same concept is applicable to an integrated box with four colors: in addition to the above three colors of ink, there is also black ink.

[0053] Figure 3 Three absorbers 300A, 300B, 300C for cyan, magenta and yellow are shown. Considering the convenience of liquid supply, the absorber 300 is ideally close to a rectangular parallelepiped in shape. It should be noted that, in the case of changing the size of the absorber 300 in consideration of the capacity of storing liquid, it is preferred that the absorber 300 extends in the direction of gravity (Z direction). Increasing the size of the absorber 300 in the scanning direction (X direction) will make the box 100 wider, thus causing an increase in the overall size of the device. In addition, increasing the size of the absorber 300 in the direction (Y direction) where the ejection ports are arranged will make the flow channel extending from the absorber 300 to the printing element substrate 303 longer, which increases the flow resistance in the liquid supply, and is therefore not preferred.

[0054] The absorber 300 is formed of a fiber body, a porous body, etc., and can retain ink therein by the action of capillary force. The absorber 300 is accommodated in a storage chamber 302 of the housing 200 and abuts against the filter 301 at the same time, and the liquid in the absorber 300 is supplied to the printing element substrate 303 via the filter 301 and the flow channel unit.

[0055] The printing element substrate 303 is an ejection unit configured to eject ink and is arranged on the bottom surface of the housing 200 located at a lower position in the direction of gravity. The printing element substrate 303 is arranged near the lower part of the absorber 300A and the absorber 300B and is positioned away from the absorber 300C. The housing 200 has a box portion 307 forming a storage chamber 302 and a flow channel forming portion 306 protruding from the box portion 307 along the -Z direction, and the printing element substrate 303 is attached to the -Z direction side of the flow channel forming portion 306. Specifically, the printing element substrate 303 includes an element (for example, a heater or a piezoelectric element) for applying energy required for liquid ejection to the liquid. The printing element substrate 303 is attached to a printing element setting portion formed in a component forming the flow channel forming portion 306. Specifically, the printing element substrate 303 is arranged at the bottom surface of the box 100 as a whole and is close to the print medium 103 when ejecting liquid.

[0056] The cover 201 is provided to close the opening of the housing 200 and partition the storage chamber 302 accommodating the absorber 300. The cover 201 has an atmosphere communication port (not shown) so that air can be sucked from the outside corresponding to the amount of liquid in the absorber 300 consumed by spraying.

[0057] Figure 4 4 is a perspective view of a flow channel unit 400 which is a model of a liquid flow channel space extracted from a housing. Figure 5A is a top view of the flow channel unit 400, Figure 5B is a side view of the flow channel unit 400, and Figure 5C is a front view of the flow channel unit 400. It should be noted that the following description will be Figure 5A Horizontal portion 708 and horizontal portion 808 are shown. The flow channel unit 400 is a model of the extracted ink flow channel, and includes flow channels (400A, 400B, 400C) for three colors. The flow channels are independent of each other, and specifically arranged in the order of flow channel 400A, flow channel 400B and flow channel 400C in the Y direction, as shown in FIG. Figure 5A In this manner, the flow channel unit 400 is configured to be able to store the storage chamber 302 (see Figure 3 ) is supplied to the printing element substrate 303 (see Figure 3 ).

[0058] like Figure 4 and Figure 5BAs shown, in the view of the box observed along the depth direction, the tapered portions formed at the corresponding connecting flow channels arranged along the width direction of the box face opposite directions alternately. In the flow channel unit 400, the terminal portions of the corresponding connecting flow channels adjacent to each other along the width direction of the box are arranged to face opposite directions alternately in the depth direction of the box (the terminal portions are the portions with the smallest height (length in the Z direction)). It should be noted that the connecting flow channels and tapered portions of the flow channel unit 400 will be described below.

[0059] Fig. 6A is a top view of the flow channel 400A, Figure 6B is a side view of flow channel 400A, and Figure 6C is a front view of flow channel 400A. Fig. 7A is a top view of flow channel 400B, Figure 7B is a side view of flow channel 400B, and Figure 7C is a front view of flow channel 400B. Fig. 8A is a top view of flow channel 400C, Figure 8B is a side view of flow channel 400C, Figure 8C is a front view of flow channel 400C, and Fig.8D It is along Fig. 8A A cross-sectional view taken along line VIIID-VIIID in FIG.

[0060] like FIG. 6A to FIG. 6C As shown, the flow channel 400A includes a filter 301A (see Figure 3 ) and the first opening portion 600 and the first holding portion 601 covered. The flow channel 400A includes a second holding portion 602, a second opening portion 609 connecting the first holding portion 601 and the second holding portion 602 to each other, and a connecting flow channel 607 connected to the printed element substrate 303 (see Figure 3 ). In a state where the liquid ejecting head (cartridge) is used, a second opening portion 609 communicating with the second holding portion 602 is formed at the uppermost portion of the first holding portion 601 .

[0061] In the present embodiment, when the cartridge is viewed along the extending direction in which the horizontal portion (to be described later) extends, a space that can retain air bubbles and has a greater width than a connecting portion (e.g., connecting flow channel 607, 707, or 807) is referred to as a "retaining portion." For example, the first retaining portion 601 and the second retaining portion 602 are wider than other regions, and allow air bubbles generated by jetting or the like to be retained above the liquid surface.

[0062] In the state where the cartridge is attached to the printing apparatus, the first holding portion 601 has a tapered portion 604 whose opening 633 at the vertical upper end is larger than the opening 634 at the vertical lower end. In the state where the cartridge is attached to the printing apparatus, the second holding portion 602 is provided to extend vertically.

[0063] In a state where the cartridge is attached to the printing apparatus, the second holding portion 602 has a tapered portion (a first tapered portion 605 and a second tapered portion 606) such that the first opening portion 600 at the vertical upper end is larger than the second opening portion 609 at the vertical lower end. The first holding portion 601 is provided between the connecting flow passage 607 and the second holding portion 602. The second holding portion 602 is provided between the first holding portion 601 and the first storage chamber 302A (see Figure 3 ).

[0064] The first opening portion 600 is an opening for receiving the liquid that has passed through the filter 301A, and is located in the storage chamber 302 (see Figure 3 ). The first holding portion 601 and the second holding portion 602 are configured to have a space that becomes larger and larger upward in the vertical direction. Specifically, the first holding portion 601 is provided with a tapered portion 604 to have a space that becomes larger and larger upward in the vertical direction, and the second holding portion 602 is provided with a first tapered portion 605 and a second tapered portion 606. This configuration enables bubbles generated inside the flow channel to be collected using their buoyancy so that they do not approach the ejection portion.

[0065] In the present embodiment, the second holding part 602 is provided with a plurality of partition walls 603. The plurality of partition walls 603 separate the interior of the second holding part 602 into a plurality of spaces that are combined with each other. Two adjacent partition walls 603 are ideally arranged to be more than 1 mm away from each other. It is also ideal to separate the interior of the second holding part 602 into two or more spaces. The more spaces formed in the interior of the second holding part 602, the better.

[0066] Dividing the interior of the second holding portion 602 into a plurality of spaces helps prevent bubbles from moving to different separated spaces. Since the interior of the second holding portion 602 is divided into a plurality of spaces, if one of these spaces is blocked for some reason, the flow channel is ensured through the other spaces. Therefore, this helps prevent poor liquid supply when liquid is supplied downstream (vertically downward).

[0067] Two tapered portions (i.e., a first tapered portion 605 and a second tapered portion 606) are formed at the second retaining portion 602 so that bubbles can move toward the filter in a narrow space. The angle of the first tapered portion 605 relative to the horizontal direction (X direction) is preferably not less than 10 degrees and not more than 80 degrees, more preferably not less than 20 degrees and not more than 60 degrees, or further more preferably not less than 30 degrees and not more than 50 degrees, so that bubbles can move upward without forming a meniscus. In addition, in the second retaining portion 602, it is necessary to shorten the distance from the space in the second retaining portion 602 to the filter 301A to increase the flow rate of the ink flow in the case of a recovery operation such as suction. Therefore, the angle of the second tapered portion 606 relative to the horizontal direction is preferably not more than 45 degrees, more preferably not more than 30 degrees, or further more preferably not more than 20 degrees.

[0068] The first holding portion 601 is connected to the connecting flow channel 607, and the opening 635 formed at the lower end of the connecting flow channel 607 is connected to the printing element substrate 303 (see Figure 3 ) at the injection port array.

[0069] In the present embodiment, the second holding portion 602 includes an opening 631 located at the upper end of the first tapered portion 605 and an opening 632 located at the lower end of the first tapered portion 605. The area of ​​the opening 631 is larger than the area of ​​the opening 632. For example, it is preferable that the area of ​​the opening 631 is 1.5 times or more the area of ​​the opening 632 so as to retain the generated bubbles without flowing into the ejection port array.

[0070] The first holding portion 601 includes an opening 633 at an upper end portion of the first holding portion 601 and an opening 634 at a lower end portion of the first holding portion 601. The area of ​​the opening 633 is larger than the area of ​​the opening 634. For example, it is preferable that the area of ​​the opening 633 is 1.2 times or more the area of ​​the opening 634 so that the generated bubbles are retained without flowing into the ejection port array.

[0071] The third tapered portion 621 and the wall surface 622 are formed at the connecting flow channel 607 so that bubbles in the liquid in the connecting flow channel 607 can be easily discharged from the opening 635 in the case of a recovery operation. The wall surface 622 extends perpendicularly to the base from the end of the base of the connecting flow channel 607 and is connected to the first retaining portion 601.

[0072] The third tapered portion 621 is formed at the connecting flow channel 607 so that the length "L61" of the connecting flow channel 607 in the depth direction (Y direction) at the portion connected to the first retaining portion 601 is smaller than the length "L62" of the connecting flow channel 607 in the depth direction (Y direction) at the portion connected to the printing element substrate 303. The opening 634 is formed vertically (just) below the second opening portion 609. This makes it easier for bubbles to move vertically upward. In order to make the bubbles move vertically upward in a narrow space, it is preferred to form two-stage inclined surfaces with different angles relative to the opening 635 at the third tapered portion 621.

[0073] In the present embodiment, the third tapered portion 621 includes a first inclined portion and a second inclined portion. The first inclined portion is formed to extend from one end of the connecting flow channel 607 in the depth direction toward the first retaining portion 601 and is inclined at a first angle relative to the opening 635. The second inclined portion is formed to extend from an end of the first inclined portion toward the first retaining portion 601, the end being opposite to the one end of the connecting flow channel 607 in the depth direction. The second inclined portion is inclined at a second angle less than the first angle relative to the opening 635.

[0074] The first holding portion 601 is preferably formed as large as possible so as to be able to retain more bubbles. Therefore, the first holding portion 601 is formed to become larger from the opening 634 to the opening 633. In addition, the relationship between the length "L61" along the depth direction (Y direction) at the second opening portion 609 and the length "L62" along the depth direction (Y direction) at the opening 635 can be expressed as follows:

[0075] L62>L61×2…(Formula 1)

[0076] Specifically, the length “ L62 ” in the depth direction at the opening 635 connecting the connecting flow channel 607 to the printing element substrate is more than twice the length “ L61 ” in the depth direction at the opening 634 connecting the connecting flow channel 607 to the first holding portion 601 .

[0077] like 7A to 7C As shown, the flow channel 400B includes a first opening portion 700 provided with a filter 301B, a first retaining portion 701, a second retaining portion 702, a second opening portion 709 connecting the first retaining portion 701 and the second retaining portion 702 to each other, and a connecting flow channel 707. The first retaining portion 701 having a tapered portion 704 is provided at a position lower than the horizontal portion 708.

[0078] The second holding part 702 is provided with a plurality of partition walls 703. The plurality of partition walls 703 divide the interior of the second holding part 702 into a plurality of spaces that are combined with each other. Two adjacent partition walls 703 are ideally arranged to be more than 1 mm away from each other. It is also ideal to divide the interior of the second holding part 702 into two or more spaces. The more spaces formed inside the second holding part 702, the better.

[0079] Dividing the interior of the second holding portion 702 into a plurality of spaces helps prevent bubbles from moving to different separated spaces. Since the interior of the second holding portion 702 is divided into a plurality of spaces, if one of these spaces is blocked for some reason, the flow channel is ensured through the other spaces. Therefore, this helps prevent poor liquid supply when liquid is supplied downstream (vertically downward).

[0080] The first opening portion 700 is used to receive the liquid that has passed through the filter 301B (see Figure 3 ) of the liquid, and is located in the storage chamber 302 (see Figure 3 ). The first holding portion 701 disposed near the nozzle array and the second holding portion 702 disposed near the storage chamber are connected to each other via the second opening portion 709 and the horizontal portion 708 extending in the Y direction. In addition, the first holding portion 701 and the second holding portion 702 are configured to have a space that becomes larger and larger upward in the vertical direction. The first holding portion 701 is provided with a tapered portion 704 to have a space that becomes larger and larger upward in the vertical direction, and the second holding portion 702 is provided with a first tapered portion 705 and a second tapered portion 706. This configuration enables bubbles generated inside the flow channel to be collected using their buoyancy so that they do not approach the ejection portion.

[0081] In order to make the bubbles move toward the filter in a narrow space, it is preferred to form a two-stage tapered portion at the second holding portion 702, namely, a first tapered portion 705 and a second tapered portion 706. The angle of the first tapered portion 705 relative to the horizontal direction (X direction) is preferably not less than 10 degrees and not more than 80 degrees, more preferably not less than 20 degrees and not more than 60 degrees, or further more preferably not less than 30 degrees and not more than 50 degrees, so that the bubbles can move upward without forming a meniscus. In addition, in the second holding portion 702, it is necessary to shorten the distance from the space in the second holding portion 702 to the filter 301B to increase the flow rate of the ink flow in the case of a recovery operation such as suction. Therefore, the angle of the second tapered portion 706 relative to the horizontal direction is preferably not more than 45 degrees, more preferably not more than 30 degrees, or further more preferably not more than 20 degrees.

[0082] The first holding portion 701 is connected to the connecting flow channel 707 , and an opening 735 formed at the lower end of the connecting flow channel 707 is connected to the ejection port array at the printing element substrate 303 .

[0083] The second holding portion 702 includes an opening 731 located at the upper end of the first tapered portion 705 and an opening 732 located at the lower end of the first tapered portion 705. The area of ​​the opening 731 is larger than the area of ​​the opening 732. For example, it is preferable that the area of ​​the opening 731 is 1.5 times or more the area of ​​the opening 732 so that the generated bubbles are retained without flowing into the ejection port array.

[0084] The first holding portion 701 includes an opening 733 at an upper end portion of the first holding portion 701 and an opening 734 at a lower end portion of the first holding portion 701. The area of ​​the opening 733 is larger than the area of ​​the opening 734. For example, it is preferable that the area of ​​the opening 733 is 1.2 times or more the area of ​​the opening 734 so that the generated bubbles are retained without flowing into the ejection port array.

[0085] The third tapered portion 721 and the wall surface 722 are formed at the connecting flow channel 707 so that bubbles in the liquid in the connecting flow channel 707 can be easily discharged from the opening 735 in the case of a recovery operation. The wall surface 722 extends perpendicularly to the base from the end of the base of the connecting flow channel 707 and is connected to the first retaining portion 701.

[0086] The third tapered portion 721 is formed at the connecting flow channel 707 so that the length "L71" of the connecting flow channel 707 in the depth direction (Y direction) at the portion connected to the first holding portion 701 is smaller than the length "L72" of the connecting flow channel 707 in the depth direction (Y direction) at the portion connected to the printing element substrate 303. The plurality of openings 734 are arranged at positions closer to the opening 733 along the Y direction. It is preferable to form two-stage inclined surfaces having different angles with respect to the opening 735 at the third tapered portion 721.

[0087] In this embodiment, the third tapered portion 721 includes a first inclined portion and a second inclined portion. The first inclined portion is inclined at a first angle relative to the opening 735. The second inclined portion is inclined at a second angle less than the first angle relative to the opening 735.

[0088] The first holding portion 701 is preferably formed as large as possible so as to be able to retain more bubbles. Therefore, the first holding portion 701 is formed to become larger from the opening 734 to the opening 733. In addition, the relationship between the length "L71" along the depth direction (Y direction) at the second opening 709 and the length "L72" along the depth direction (Y direction) at the opening 735 can be expressed as follows:

[0089] L72>L71×2…(Formula 2)

[0090] Specifically, the length “ L72 ” in the depth direction at the opening 735 connecting the connecting flow channel 707 to the printing element substrate is more than twice the length “ L71 ” in the depth direction at the opening 734 connecting the connecting flow channel 707 to the first holding portion 701 .

[0091] like Figures 8A to 8D As shown, the flow channel 400C has a filter 301C (see Figure 3 ), a first opening portion 800, a first retaining portion 801, a second retaining portion 802, a second opening portion 809 connecting the first retaining portion 801 and the second retaining portion 802 to each other, and a connecting flow channel 807.

[0092] The second holding part 802 is provided with a plurality of partition walls 803. The plurality of partition walls 803 separate the interior of the second holding part 802 into a plurality of spaces that are combined with each other. Two adjacent partition walls 803 are ideally arranged to be more than 1 mm away from each other. It is also ideal to separate the interior of the second holding part 802 into two or more spaces. The more spaces formed in the interior of the second holding part 802, the better.

[0093] Dividing the interior of the second holding portion 802 into a plurality of spaces helps prevent bubbles from moving to different separated spaces. Since the interior of the second holding portion 802 is divided into a plurality of spaces, if one of these spaces is blocked for some reason, the flow channel is ensured through the other spaces. Therefore, this helps prevent poor liquid supply when liquid is supplied downstream (vertically downward).

[0094] The first opening portion 800 is an opening for receiving the liquid that has passed through the filter 301C, and is located at the bottom surface of the storage chamber 302 that accommodates the absorbent 300C. The first holding portion 801 disposed near the nozzle array and the second holding portion 802 disposed near the storage chamber are connected to each other via the second opening portion 809 and the horizontal portion 808 extending in the Y direction. In addition, the first holding portion 801 and the second holding portion 802 are configured to have a space that becomes larger and larger upward along the vertical direction. The first holding portion 801 is provided with a tapered portion 804 to have a space that becomes larger and larger upward along the vertical direction, and the second holding portion 802 is provided with a first tapered portion 805 and a second tapered portion 806. This configuration enables bubbles generated inside the flow channel to be collected using their buoyancy so that they do not approach the ejection portion.

[0095] In order to make the air bubble move toward the filter in a narrow space, it is preferable to form a two-stage tapered portion at the second holding portion 802, namely, a first tapered portion 805 and a second tapered portion 806. The angle of the first tapered portion 805 relative to the horizontal direction is preferably not less than 10 degrees and not more than 80 degrees, more preferably not less than 20 degrees and not more than 60 degrees, or further more preferably not less than 30 degrees and not more than 50 degrees, so that the air bubble can move upward without forming a meniscus. In addition, in the second holding portion 802, it is necessary to shorten the distance from the space in the second holding portion 802 to the filter 301C in order to increase the flow rate of the ink flow in the case of a recovery operation such as suction. Therefore, the angle of the second tapered portion 806 relative to the horizontal direction is ideally not more than 45 degrees, more ideally not more than 30 degrees, or further more ideally not more than 20 degrees.

[0096] Horizontal portion 808 is arranged at a position lower than second opening portion 809. The first holding portion 801 with tapered portion 804 is arranged at a position lower than horizontal portion 808. Horizontal portion 808 extends in the depth direction (Y direction) of box. The terminal portion of horizontal portion 808 is connected to the third opening portion 810C. The third opening portion 810C is connected to the ejection port array at the printing element substrate via the first holding portion 801 and the connecting flow channel 807. Compared with the prior art, the configuration of arranging this horizontal portion 808 improves the flexibility of layout in the storage chamber 302.

[0097] The second holding portion 802 includes an opening 831 located at the upper end of the first tapered portion 805 and an opening 832 located at the lower end of the first tapered portion 805. The area of ​​the opening 831 is larger than the area of ​​the opening 832. For example, it is preferable that the area of ​​the opening 831 is 1.5 times or more the area of ​​the opening 832 so that the generated bubbles are retained without flowing into the ejection port array.

[0098] The first holding portion 801 includes an opening 833 at the upper end portion of the first holding portion 801 and an opening 834 at the lower end portion of the first holding portion 801. The area of ​​the opening 833 is larger than the area of ​​the opening 834. For example, it is preferable that the area of ​​the opening 833 is 1.2 times or more the area of ​​the opening 834 so that the generated bubbles are retained without flowing into the ejection port array.

[0099] The third tapered portion 821 and the wall surface 822 are formed at the connecting flow channel 807 so that bubbles in the liquid in the connecting flow channel 807 can be easily discharged from the opening 835 in the case of a recovery operation. The wall surface 822 extends perpendicularly to the base from the end of the base of the connecting flow channel 807 and is connected to the first retaining portion 801.

[0100] The third tapered portion 821 is formed at the connecting flow channel 807 so that the length "L81" of the connecting flow channel 807 in the depth direction (Y direction) at the portion connected to the first holding portion 801 is smaller than the length "L82" of the connecting flow channel 807 in the depth direction (Y direction) at the portion connected to the printing element substrate 303. The plurality of openings 834 are provided at positions closer to the openings 833 along the Y direction. It is preferable to form two-stage inclined surfaces having different angles with respect to the openings 835 at the third tapered portion 821 so as to move the bubbles upward in the vertical direction in a narrow space.

[0101] In this embodiment, the third tapered portion 821 includes a first inclined portion and a second inclined portion. The first inclined portion is inclined at a first angle relative to the opening 835. The second inclined portion is inclined at a second angle less than the first angle relative to the opening 835.

[0102] The first holding portion 801 is preferably formed as large as possible so as to be able to retain more bubbles. Therefore, the first holding portion 801 is formed to become larger from the opening 834 to the opening 833. In addition, the relationship between the length "L81" along the depth direction (Y direction) at the second opening portion 809 and the length "L82" along the depth direction (Y direction) at the opening 835 can be expressed as follows:

[0103] L82>L81×2…(Formula 3)

[0104] Specifically, the length “ L82 ” in the depth direction at the opening 835 connecting the connecting flow channel 807 to the printing element substrate is more than twice the length “ L81 ” in the depth direction at the opening 834 connecting the connecting flow channel 807 to the first holding portion 801 .

[0105] The first holding portion 801 is connected to a connecting flow channel 807 , and the connecting flow channel 807 is connected to the ejection port array at the printing element substrate 303 .

[0106] like Fig.8DAs shown, the corner portion 808c is arranged at the bottom of the horizontal portion 808. Due to the capillary force at the corner portion 808c, when bubbles are generated, the bubbles can be trapped at the corner portion 808c, and the liquid can be supplied to the third opening portion 810C. Bubbles have a tendency to accumulate at the upper part of the flow channel. Due to this tendency, the corner portion 808c is ideally located below the vertical direction. As long as bubbles can be trapped, at least one corner portion 808c is sufficient. However, the more corner portions 808c, the better. The width "w" of the horizontal portion 808 is greater than the height "h" of the horizontal portion 808. This makes it possible to reduce the overall height of the box and ensure the fluidity of the liquid when bubbles are generated. In other words, since the width "w" of the horizontal portion 808 is greater than its height "h", the convenience of supplying liquid to the printing element substrate can be ensured. For example, the ratio of the height "h" of the horizontal portion 808 to the width "w" of the horizontal portion 808 is ideally 1 to not less than 1.5.

[0107] Fig. 9A is a schematic top view of the first holding portion 601 , the first holding portion 701 , and the first holding portion 801 . Fig. 9B is a schematic front view of the first holding portion 601 , the first holding portion 701 , and the first holding portion 801 .

[0108] like Fig. 9A As shown, the first holding portion 701 and the first holding portion 801 adjacent in the box width direction (X direction) are arranged at positions that do not overlap with the first holding portion 601 in the depth direction (Y direction). In other words, the first holding portion 701 and the first holding portion 801 are arranged at positions that do not overlap with the first holding portion 601 when viewed in the X direction and the Z direction.

[0109] like Fig. 9B As shown, in the view of observing the box along the predetermined direction, one of the holding portions in the corresponding flow channel overlaps with at least one other holding portion. In this example, in the view of the first holding portion 601, the first holding portion 701 and the first holding portion 801 observed along the depth direction (Y direction) of the box, the first holding portion 701 and the first holding portion 801 have an overlapping portion 90 overlapping with a portion of the first holding portion 601.

[0110] In this way, in this embodiment, the first flow channel (flow channel 400A (see Figure 4 )) has the same configuration as the first ejection port array (ejection port array 1101A (see Fig.12 )) communicates with the first downstream flow channel (connecting flow channel 607 (see Figures 6A to 6C )). The first flow channel has a first filter (filter 301A (see Figure 3 ))A first upstream flow channel (a portion of the flow channel 400A outside the connecting flow channel 607) that communicates with the first downstream flow channel.

[0111] The second flow channel (flow channel 400B (see Figure 4 )) has the same configuration as the second ejection port array (ejection port array 1101B (see Fig.12 )) communicates with the second downstream flow channel (connecting flow channel 707 (see Figures 7A to 7C )). The second flow channel has a second filter (filter 301B (see Figure 3 ))A second upstream flow channel (a portion of the flow channel 400B outside the connecting flow channel 707) that communicates with the second downstream flow channel.

[0112] In a state where the liquid ejection head is used, the first upstream flow channel includes a first region (e.g., the first holding portion 601) located above the first downstream flow channel in the vertical direction (Z direction), and in which the cross-sectional area of ​​the first upstream flow channel becomes smaller from the upper side to the lower side in the vertical direction. The second upstream flow channel includes a second region (e.g., the first holding portion 701) located above the second downstream flow channel in the vertical direction (Z direction), and in which the cross-sectional area of ​​the second upstream flow channel becomes smaller from the upper side to the lower side in the vertical direction.

[0113] In the view of the liquid ejection head observed from the front along the first direction, the first downstream flow channel and the second downstream flow channel do not overlap each other, and the first portion communicating with the first filter and the second portion communicating with the second filter overlap each other. For example, in the view of the liquid ejection head observed from the front along the Y direction, the connecting flow channel 607 and the connecting flow channel 707 do not overlap each other, and the second retaining portion 602 communicating with the filter 301A and the second retaining portion 702 communicating with the filter 301B overlap each other.

[0114] By this arrangement of the holding part, each of the three holding parts can have a sufficient size, and the size of the liquid ejection head (box) in the width direction (X direction) does not have to increase too much. Although it is assumed that flow channel 400B is used as the second flow channel in the case described in this embodiment, flow channel 400C can be used as the second flow channel. This configuration can also provide a favorable effect similar to the case of using flow channel 400B.

[0115] Fig. 10A900A, 900B, and 900C are arranged on the same straight line extending in the Y direction. The opening 900A is connected to the first opening portion 600 (see FIG. Figures 6A to 6C ). The opening 900B is connected to the first opening portion 700 (see Figures 7A to 7C ). The opening 900C is connected to the first opening portion 800 (see Figures 8A to 8C The openings 900A, 900B, and 900C are arranged closer to the -Y direction side ( Fig. 10A ), so that flow channels 400A, 400B and 400C (see Figure 4 ) can be shorter in the Y direction. In addition, ribs 901 are provided in each storage chamber 302 so as to provide atmospheric communication even when an absorbent body is inserted therein. Rib 901A is provided in the storage chamber 302 corresponding to opening 900A, rib 901B is provided in the storage chamber 302 corresponding to opening 900B, and rib 901C is provided in the storage chamber 302 corresponding to opening 900C.

[0116] The rib 901 is provided near the openings 900A, 900B, 900C in the storage chamber 302. This helps prevent liquid from leaking from the cover 201 even when the air in the flow channel unit 400 or the air in the gap between the absorber 300 and the storage chamber 302 expands due to environmental changes such as temperature or atmospheric pressure.

[0117] The second opening portion 609 of the flow channel 400A is disposed on the X-direction center line C of the housing 200. In addition, the second opening portion 709 of the flow channel 400B is disposed at a position deviated from the center line C in the -X direction, and the rib 901B is disposed closer to the second opening portion 709 ( Fig. 10A In addition, the second opening portion 809 of the flow channel 400C is provided at a position deviated from the center line C in the +X direction, and the rib 901C is provided closer to the second opening portion 809 ( Fig. 10A on the right side of the image).

[0118] The deviation of the second opening portion 709 and the second opening portion 809 relative to the center line C is in the range of preferably not less than 5% to not more than 30% of the width of the filter 301 in the X direction, more preferably not less than 10% to not more than 25% of the width, or further more preferably not less than 15% to not more than 20% of the width. In the present embodiment, the second opening portion 709 and the second opening portion 809 both deviate by ±1mm (8.3%) in the X direction relative to a filter having a width of 12mm. It is not ideal to deviate the second opening portion 609 too much because it will produce a situation where it is difficult to supply liquid from the side opposite to the direction in which the second opening portion 609 deviates. Therefore, it is ideal to set the second opening portions 609, 709, 809 at a position close to the center line C, as in the present embodiment. Although the shape of the second opening portions 609, 709, 809 is an oblong slit in the present embodiment, they may have other shapes. For example, the shape of the second opening portion 609 , 709 , 809 may be circular, oval, or the like.

[0119] In the present embodiment, the second opening portion 609 has a slit shape, and it has two long sides extending parallel to the depth direction (Y direction) of the box. The second opening portion 609 has a corner portion 902A at the four corners of the opening. In other words, the cross-sectional shape of the second opening portion 609 at least partially includes the corner portion 902A. Therefore, the second opening portion 609 with a slit shape helps to prevent relatively large bubbles from entering the flow channel and allows the flow channel to have enough area at the same time. In other words, the second opening portion 609 with a slit shape enables liquid to be more stably supplied to the ejection port.

[0120] In the present embodiment, the second opening portion 709 has a slit shape, and it has two long sides extending parallel to the depth direction (Y direction) of the box. The second opening portion 709 has a corner portion 902B at the four corners of the opening. In other words, the cross-sectional shape of the second opening portion 709 at least partially includes the corner portion 902B. Therefore, the second opening portion 709 with a slit shape helps to prevent relatively large bubbles from entering the flow channel and allows the flow channel to have enough area at the same time. In other words, the second opening portion 709 with a slit shape enables liquid to be more stably supplied to the ejection port.

[0121] In the present embodiment, the second opening portion 809 has a slit shape, and it has two long sides extending parallel to the depth direction (Y direction) of the box. The second opening portion 809 has a corner portion 902C at the four corners of the opening. In other words, the cross-sectional shape of the second opening portion 809 at least partially includes the corner portion 902C. Therefore, the second opening portion 809 with a slit shape helps to prevent relatively large bubbles from entering the flow channel and allows the flow channel to have enough area at the same time. In other words, the second opening portion 809 with a slit shape enables liquid to be more stably supplied to the ejection port.

[0122] Fig. 10B It is along Fig. 10A Horizontal portion 708 and horizontal portion 808 are formed by aligning a recess formed in a first component and a recess formed in a second component with each other to join a first component forming flow channel forming portion 306 and a second component forming box portion 307. Specifically, resin 920 is poured into a space formed by recesses between flow channel forming portion 306 and box portion 307 (excluding recesses forming horizontal portion 708 and horizontal portion 808). Thus, horizontal portion 708 and horizontal portion 808 are formed, and flow channel forming portion 306 and box portion 307 are fixed to each other.

[0123] With such a joining method, a flow channel including horizontal portion 708 is formed in the first member forming flow channel forming portion 306 and the second member forming box portion 307, and a flow channel including horizontal portion 808 is formed in the first member forming flow channel forming portion 306 and the second member forming box portion 307. Horizontal portion 708 and horizontal portion 808 include a joining portion between the first member forming flow channel forming portion 306 and the second member forming box portion 307. Therefore, joining flow channel forming portion 306 and box portion 307 to each other enables the flow channel to be formed without forming welding burrs or adhesive overflow portions on the inner wall of horizontal portion 708.

[0124] Fig.11 301 is a top view of the housing 200 in which the filter 301 is welded. In the housing 200, three filters 301 are welded to cover the three first opening portions described above so as to reduce foreign matter intruding into the second opening portions 609, 709, 809. It is to be noted that an adhesive or the like may be used instead of welding to fix the filter 301 to the housing 200. Alternatively, the housing 200 and the filter 301 may be formed integrally.

[0125] Fig.12300 is a top view of the housing 200 in which the absorber 300 is inserted. The absorber 300 is inserted into the storage chamber 302 in the housing 200, and liquid can be held by the absorber 300. The liquid held by the absorber 300 is supplied to the printing element substrate 303 through the flow channel unit. Fig.12 The printing element substrate 303 and the ejection opening array 1101 are shown by dotted lines.

[0126] The liquid held in the absorbent body 300A flows through the flow channel 400A (see Figure 4 ) is supplied to the ejection port array 1101A of the printing element substrate 303. The liquid held in the absorbent body 300B ... Figure 4 ) is supplied to the ejection port array 1101B of the printing element substrate 303. The liquid held in the absorbent body 300C ... Figure 4 ) is supplied to the ejection port array 1101C of the printing element substrate 303.

[0127] In the box of the present embodiment, the inside of the housing 200 is divided into three sections to form three storage chambers 302, so that absorbers 300A, 300B, 300C can be arranged along the X-direction center line C (Y-direction). When the box is mounted on the carriage for scanning, the box moves in the +X or -X direction. The ejection port array 1101 arranged at the printing element substrate 303 all has an ejection port array arranged in the Y direction. In other words, absorbers 300A, 300B, 300C are arranged along the direction identical with the direction of the ejection port arrangement, and are arranged along the direction intersecting with the scanning direction (in the present embodiment, orthogonal to the scanning direction).

[0128] The housing 200 is formed by resin molding. The housing 200 is formed by separately molding the flow channel forming portion and the box portion (primary molding) and then performing secondary molding to join the flow channel forming portion and the box portion. It should be noted that the method for secondary molding may be a method of pouring resin into the space created between the box portion and the flow channel forming portion abutting against each other or other methods such as bonding. By separately molding the flow channel forming portion and the box portion as described above and then joining the flow channel forming portion and the box portion to each other, a flow channel can be formed in the housing 200. Although the storage chambers 302 are arranged at equal intervals in the present embodiment, the intervals do not have to be equal.

[0129] The width of the box (length in the X direction) is ideally 25 mm or less. In the present embodiment, the three storage chambers 302 are arranged in a straight line in the Y direction, which allows the box 100 to have a smaller width than a conventional box. However, considering the convenience of ink supply and the convenience of ink injection, it is ideal that the absorber 300 has a width of more than 5 mm. It is also ideal that the storage chamber 302 also has a width of more than 5 mm in the X direction.

[0130] It should be noted that the width of the box 100 is 10mm to 25mm, more preferably 13mm to 23mm, or further more preferably 15mm to 21mm. When the ratio between the width of the housing 200 along the X direction and the length of the housing 200 along the Y direction makes the cross section of the absorber 300 intercepted along the XY plane close to a square, the convenience of ink supply is better. Therefore, when three storage chambers are formed as in the present embodiment, it is preferred that the ratio of the width along the X direction to the length along the Y direction is about 2:5 to 2:7. The width of the box 100 of the present embodiment along the X direction is 20mm, and the depth length along the Y direction is 70mm.

[0131] As mentioned above, it is desirable that the cross section of the absorbent 300 taken along the XY plane is close to a square, and one side of the absorbent 300 is ideally 5mm to 25mm, more ideally 10mm to 23mm, or further more ideally 15mm to 21mm. Considering the liquid retention capacity, the height of the absorbent 300 in the Z direction should be greater than its length in the X and Y directions so that the liquid can be used up more thoroughly. However, extending the length of the absorbent 300 in the Z direction increases the size of the box, and correspondingly increases the overall size of the device. Therefore, the height of the absorbent 300 in the Z direction is ideally no more than four times of its width in the X direction or its length in the Y direction, more ideally no more than three times, or further more ideally no more than two times. The width of the absorbent 300 in the X direction of the present embodiment is 17mm, the depth in the Y direction is 21mm, and the height in the Z direction is 33mm.

[0132] Fig.13 is a top view of flow channel 400B and flow channel 400C, that is, Figure 5AThe flow channel unit 400 shown in the figure is a figure after the flow channel 400A is removed. The second opening portion 709 of the flow channel 400B and the second opening portion 809 of the flow channel 400C are both set at a position deviated from the X-direction center of the housing 200. Specifically, the second opening portion 709 of the flow channel 400B is set at a position deviated from the X-direction center of the housing 200 in the -X direction, and the second opening portion 809 of the flow channel 400C is set at a position deviated from the X-direction center of the housing 200 in the +X direction. Setting the second opening portion 709 at such a deviated position can shorten the length of the horizontal portion 708 of the flow channel 400B extending to the injection port array in the Y direction, and also allow the horizontal portion 808 of the flow channel 400C to be wider in the X direction. In addition, setting the second opening portion 809 at a position deviated from the center in the direction opposite to the second opening portion 709 can shorten the length of the horizontal portion 808 of the flow channel 400C.

[0133] The absorbent body 300 is accommodated in the corresponding storage chamber 302, and the filter 301 is provided between the absorbent body 300 and the flow channel unit 400 (see Fig.11 and Fig.12 ). In order to obtain lower flow resistance, the size of the filter 301 is as large as possible. The size of the filter 301 is ideally equal to or greater than half of the cross-sectional area of ​​the absorbent body 300 taken along the XY plane, and it is more ideal that the shape of the filter 301 is close to a square. This allows the absorbent body 300 and the filter 301 to abut against each other to a greater extent, which enables the liquid to be used up more thoroughly. Specifically, the size of the filter 301 is ideally 30% to 90% or less of the cross-sectional area of ​​the absorbent body 300 taken along the XY plane, more ideally 40% to 80%, or further more ideally 50% to 70%. In the present embodiment, the size of the filter 301 is 12 mm in width in the X direction and 12 mm in depth in the Y direction (40% of the cross-sectional area of ​​the absorbent body taken along the XY plane).

[0134] Flow channel 400A (see Figure 4 ) is formed below the filter 301A, the flow channel 400B is formed below the filter 301B, and the flow channel 400C is formed below the filter 301C (see Fig. 10A , 10B and Fig.11 ). Although the following description is about flow channel 400B, this also applies to flow channel 400A and flow channel 400C.

[0135] Return to reference 7A to 7C, the liquid having passed through the filter 301B passes through the first opening portion 700 of the flow channel 400B and enters the second opening portion 709. The second opening portion 709 is ideally provided near the X-direction center portion of the filter 301 so that the liquid is less likely to remain in the space below the filter 301B.

[0136] The space from the first opening portion 700 to the second opening portion 709 is the second holding portion 702 for retaining bubbles. In the second holding portion 702, in order to make it easier for bubbles to move upward, the second opening portion 709 has a small width in the X direction, or specifically, the width of the second opening portion 709 in the X direction is smaller than the width of the first opening portion 700 in the X direction. However, in the case where the width of the second opening portion 709 along the X direction is too small, the flow resistance increases. Therefore, the width of the second opening portion 709 along the X direction is ideally 10% to 60% of the width of the filter 301B along the X direction, more ideally 10% to 40%, or further more ideally 10% to 20%. In the present embodiment, the width of the second opening portion 709 along the X direction is 1.3 mm (10.8% of the width of the filter along the X direction).

[0137] It should be noted that the width reduction portion 1301B with a reduced flow channel width can be arranged at a portion of the horizontal portion 708. The width reduction portion 1301C can be arranged at a portion of the horizontal portion 808. Reducing the width of the flow channel provides resistance, which can reduce the oscillation pressure described later. Reducing the width of the width reduction portion 1301 too much will increase the flow resistance during ink supply. Therefore, for a flow channel having a length of about 50mm, the width is ideally more than 1mm, more ideally more than 1.5mm, or further more ideally more than 2mm. At the same time, making the flow channel width too thick at the width reduction portion 1301 will increase the width of the box. Therefore, it is preferred that the width of the width reduction portion 1301 is at most less than 3mm.

[0138] Furthermore, the longer the path from the absorber to the ejection port array is, the greater the influence that the oscillating pressure will have. Therefore, the width reduction portion 1301C may be provided only at the flow channel 400C further away from the printing element substrate. In this way, the Figure 4 The changes in oscillating pressure in the flow channels 400A, 400B, 400C are shown so as to achieve stable ejection and suppress degradation of print quality.

[0139] Fig.14A 1 is a top view of a flow channel unit 140 which is an extracted model of a flow channel space formed between a conventional absorber and an ejection port array. Fig. 14B yes Fig.14AA side view of the flow channel unit 140 is shown. Fig. 14C yes Fig.14A A rear view of the flow channel unit 140 is shown.

[0140] The liquid held by the conventional absorber is supplied to the ejection opening array at the printing element substrate via the flow channel unit 140. The flow channel unit 140 includes three flow channels.

[0141] exist Fig. 14C In the example, the flow channel 140B connecting the absorber to the jet array is arranged at the far right, the flow channel 140C connecting the absorber to the jet array is arranged at the far left, and the flow channel 140A connecting the absorber to the jet array is arranged in such a manner as to be sandwiched by the flow channels 140B and 140C. Therefore, in this example, the storage chamber and the absorber for supplying liquid to the flow channels 140A, 140B, 140C are arranged directly above the flow channels 140A, 140B, 140C (directly above in the Z direction), respectively.

[0142] Here, the situation that the conventional box mounted to the carriage scans along the +X direction is discussed. In this case, once the carriage is accelerated, the inertial force acts on the liquid held by the absorber in the direction opposite to the scanning direction (-X direction). Then, once the carriage is decelerated, the inertial force acts on the liquid held by the absorber in the direction opposite to the above direction (+X direction). In addition, in the case where the carriage scans along the -X direction, the inertial force acts in the direction opposite to the above direction when accelerating and decelerating, respectively. In other words, whenever the carriage scans, the force in the +X direction and the force in the -X direction act on the absorber alternately, so that the liquid held by the absorber oscillates in the +X direction and the -X direction each time. As a result, the pressure fluctuation of the liquid supplied to the flow channel 140B and the flow channel 140C affects the ejection state of the ejection port arrays 131B and 131C. The greater the deviation between the center of gravity of the absorber and the ejection port array along the scanning direction (X direction), the greater the pressure change.

[0143] In addition, when the force in the +X direction acts on the box, the ejection port array 131B is in a pressurized state, and the ejection port array 131C is in a decompressed state. When the force in the -X direction acts on the box, the ejection port array 131B is in a decompressed state, and the ejection port array 131C is in a pressurized state. Since the states of pressure increase and pressure reduction are different between the colors of the ink, respectively, there is a possibility that the quality of the image presented on the print medium is degraded. The pressure received by the liquid in the flow channel from the liquid held by the absorber is hereinafter referred to as an oscillation pressure.

[0144] Fig.154 is a plan view of the flow channel 400B, the flow channel 400C, the absorber 300B corresponding to the flow channel 400B, and the absorber 300C corresponding to the flow channel 400C in the cartridge 100 of the present embodiment. Fig.15 Extension lines of the ejection port array 1101B and the ejection port array 1101C (neither of which is shown) are also indicated by dotted lines.

[0145] The following describes an example of how a force acts on the box 100 along the +X direction when the carriage moves. The jet array 1101B that ejects the liquid supplied from the flow channel 400B is set at a position deviated along the -X direction from the center of gravity 160B of the absorber 300B that holds the liquid to be supplied to the flow channel 400B. The liquid is supplied from the absorber 300B to the jet array 1101B via the flow channel 400B. Although the center of gravity 160B and the jet array 1101B deviate from each other in the X direction, the deviation is small compared to the conventional example described above (i.e., the configuration in which the center of gravity of the absorber is not arranged along a straight line in a direction orthogonal to the scanning direction).

[0146] In addition, the ejection port array 1101C that ejects the liquid supplied from the flow channel 400C is disposed at a position deviated in the +X direction from the center of gravity 160C of the absorber 300C that holds the liquid to be supplied to the flow channel 400C. The liquid is supplied from the absorber 300C to the ejection port array 1101C via the flow channel 400C. Although the center of gravity 160C and the ejection port array 1101C deviate from each other in the X direction, the amount of deviation is small compared to the conventional example described above (i.e., a configuration in which the center of gravity of the absorber is not arranged in a straight line in a direction orthogonal to the scanning direction).

[0147] When the box 100 receives a force in the X direction, such as Fig.15 As shown, the oscillating pressure 161B acts on the jet array 1101B in the direction toward the center of gravity 160B of the absorbent body 300B. Therefore, the jet array 1101B enters a decompressed state. At the same time, the oscillating pressure 161C acts on the jet array 1101C in the direction from the center of gravity 130C of the absorbent body 300C. Therefore, the jet array 1101C enters a pressurized state.

[0148] It should be noted that in this embodiment, the absorbent bodies 300A, 300B, 300C (see Figure 3 ) are arranged in a straight line in the Y direction. The linear arrangement of the absorber can make the ejection port arrays 1101B and 1101C (see Fig.12 ) The deviation amount of the center of gravity of the absorber 300B, 300C in the X direction is smaller than that in the prior art. This can reduce the oscillation pressure applied to the ejection port array, which helps to achieve less unstable ejection and suppress the decline in print quality.

[0149] In this way, in the box, the positions of the centers of gravity of the plurality of absorbers are arranged in a straight line in the arrangement direction of the ejection ports of the ejection port array. Therefore, the provided box and printing device can suppress the increase in the size of the device. In addition, less unstable ejection is achieved and the decline in print quality is suppressed.

[0150] FIG. 16A to FIG. 16D 920 is a conceptual diagram showing the inside of a mold for manufacturing a box of this embodiment. In-mold molding technology is used as a method for pouring resin 920 (see Fig. 10B ). The in-mold forming technology is described step by step.

[0151] In the present embodiment, a first mold 1601 having a mold for forming the flow channel forming portion 306 and a second mold 1602 having a mold for forming the box portion 307 are used. The first mold 1601 is a mold on the fixed side, and the second mold 1602 is a mold on the movable side.

[0152] First, if Fig.16A As shown, the first mold 1601 on the fixed side and the second mold 1602 on the movable side are joined, and the mold formed by the first mold and the second mold is filled with resin poured from a first gate provided at the first mold 1601. Then, the first component forming the flow channel forming portion 306 and the second component forming the box portion 307 are formed.

[0153] Next, if Fig. 16B Then, the first component forming the flow channel forming portion 306 is left in the first mold 1601 , and the second component forming the box portion 307 is left in the second mold 1602 .

[0154] Next, if Fig. 16C As shown, the second mold 1602 is moved to position the second component forming the box portion 307 above the first component forming the flow channel forming portion 306 remaining in the first mold 1601 .

[0155] Next, if Fig.16D As shown, the second mold 1602 is lowered with the position of the flow channel forming portion 306 and the position of the box portion 307 aligned with each other to close the first mold 1601 and the second mold 1602. As a result of the closing of the first mold 1601 and the second mold 1602, the first member forming the flow channel forming portion 306 remaining in the first mold 1601 and the box portion 307 remaining in the second mold 1602 are arranged in the mold in combination with each other.

[0156] Next, molten resin 920 is poured from a second gate provided at the first member forming the flow channel forming portion 306 (see Fig. 10B ), thereby joining the flow channel forming portion 306 and the box portion 307 to each other. Finally, the mold is opened again, and the component having the flow channel forming portion 306 and the box portion 307 joined to each other is taken out from the mold.

[0157] Using such in-mold molding technology, the flow channel forming portion 306 and the box portion 307 are molded and joined inside the mold, so the first member forming the flow channel forming portion 306 and the second member forming the box portion 307 can be joined to each other inexpensively and accurately.

[0158] As described above, according to the box of the present embodiment, in the view of the box observed in the depth direction, the one located in the center of the three first holding parts is arranged to overlap with each of the two first holding parts located on the left and right sides of the first holding part. More specifically, in each of the three flow channels, a first holding part having a function of retaining bubbles and having a width greater than other areas is arranged at a position upstream of the connecting flow channel. Then, in the view of the box observed in the direction of the ejection port array (Y direction), the one located in the center of the three first holding parts is arranged to partially overlap with the other two first holding parts. The three flow channels are formed to satisfy such a condition to allow the overall width of the flow channel unit to be reduced compared to the prior art.

[0159] Therefore, according to the cartridge of the present embodiment, even in the case where a plurality of flow channels are provided, fewer bubbles are generated, and the cartridge according to the present embodiment is thinner than that of the related art.

[0160] In addition, according to the box of the present embodiment, when bubbles are generated in the liquid in the flow channel, the bubbles are retained in the first holding part, the second holding part, or both. Then, before the printing operation, the bubbles retained in the first holding part, the second holding part, or both are discharged after a considerable amount of bubbles accumulate. Therefore, according to the box of the present embodiment, bubbles can be removed without frequent recovery operations.

[0161] Although the present embodiment describes a cartridge type (detachable type) liquid ejection head having a liquid storage chamber, the technology of the present disclosure is not limited thereto and can be applied to a permanent type liquid ejection head having no liquid storage chamber. In the case of a permanent type liquid ejection head, the liquid supplied to the liquid ejection head can be supplied from a tank in the main body of the printing device, or can be supplied from a liquid cartridge mounted to the liquid ejection head.

[0162] [Second embodiment]

[0163] The second embodiment of the technology of the present disclosure is described below with reference to the accompanying drawings. The box of this embodiment differs from the box of the first embodiment in the arrangement of the storage chambers. In the first embodiment, the three storage chambers are arranged in a straight line. In contrast, in the present embodiment, the three storage chambers are arranged in the shape of the letter T. The following description focuses mainly on the difference, and the same reference numerals as used in the first embodiment are used to represent the same or corresponding configurations as in the first embodiment and their descriptions are omitted.

[0164] Fig.17A 17 is a schematic transparent top view of the box 1700 of this embodiment. Fig. 17B is a schematic transparent side view of the box 1700 of this embodiment. Fig. 17C is a schematic transparent front view of the box 1700 of this embodiment.

[0165] like Fig.17A As shown, in the present embodiment, the interior of the box 1700 is divided into a letter T shape so that three storage chambers can be adjacent to each other. In the sections thus divided, a first storage chamber 1701A, a second storage chamber 1701B, and a third storage chamber 1701C are provided. An absorbent body is contained in the first storage chamber 1701A, the second storage chamber 1701B, and the third storage chamber 1701C to hold liquids of different types. The second storage chamber 1701B and the third storage chamber 1701C are arranged side by side in the width direction (X direction) of the box 1700. The first storage chamber 1701A is arranged at the rear side ( Fig.17A ).

[0166] like Fig. 17B and 17C As shown, the first storage chamber 1701A is connected to the first opening portion 1702A. A first flow channel is formed that extends continuously from the first opening portion 1702A to the printing element substrate. The second storage chamber 1701B is connected to the first opening portion 1702B. A second flow channel is formed that extends continuously from the first opening portion 1702B to the printing element substrate. The third storage chamber 1701C is connected to the first opening portion 1702C. A third flow channel is formed that extends continuously from the first opening portion 1702C to the printing element substrate.

[0167] Fig.18 18 is a perspective view of a flow channel unit 1800 which is a model of a liquid flow channel space extracted from a housing in the present embodiment. The flow channel unit 1800 is an extracted model of an ink flow channel.

[0168] like Fig.18As shown, the flow channel unit 1800 includes a first flow channel 1800A having a first opening portion 1702A, a second flow channel 1800B having a first opening portion 1702B, and a third flow channel 1800C having a first opening portion 1702C.

[0169] The first flow channel 1800A is formed to be able to independently supply the first type of liquid from the first storage chamber to the printing element substrate. The second flow channel 1800B is formed to be able to independently supply the second type of liquid from the second storage chamber to the printing element substrate. The third flow channel 1800C is formed to be able to independently supply the third type of liquid from the third storage chamber to the printing element substrate.

[0170] Fig.19A is a top view of the flow channel unit 1800, Fig.19B is a side view of the flow channel unit 1800, and Fig.19C is a front view of the flow channel unit 1800.

[0171] like Figures 19A to 19C As shown, the first flow channel 1800A has a first retaining portion 1901A which is wider than other regions and can retain bubbles generated during ejection, etc. The second flow channel 1800B has a first retaining portion 1901B which is wider than other regions and can retain bubbles generated during ejection, etc. The third flow channel 1800C has a first retaining portion 1901C which is wider than other regions and can retain bubbles generated during ejection, etc.

[0172] In such Fig.19C In the view of the first retaining portion 1901A, the first retaining portion 1901B, and the first retaining portion 1901C as viewed in the depth direction of the box, the first retaining portion 1901B and the first retaining portion 1901C have an overlapping portion 1900 that partially overlaps with the first retaining portion 1901A.

[0173] In this manner, also, the cartridge according to the present embodiment generates fewer bubbles even in the case where a plurality of flow channels are arranged, and the cartridge according to the present embodiment is thinner than the related art.

[0174] [Other embodiments]

[0175] exist Fig. 9BIn the example, the left side and right side of the first holding part 601 are inclined relative to the vertical direction (Z direction). However, one of the left side and right side of the first holding part 601 can extend in the vertical direction. In addition, although the left side and right side of the first holding part 701 are inclined relative to the vertical direction (Z direction), one of the left side and right side of the first holding part 701 can extend in the vertical direction. In addition, although the left side and right side of the first holding part 801 are inclined relative to the vertical direction (Z direction), one of the left side and right side of the first holding part 801 can extend in the vertical direction. Through such a configuration, the width of the main body of the box can also be made thinner.

[0176] In the first embodiment, the first retaining portion 601 is used as the first region of the first upstream flow channel, wherein the cross-sectional area of ​​the first upstream flow channel becomes smaller and smaller from the upper side to the lower side in the vertical direction. Alternatively, the second retaining portion 602 may be used as the first region. By utilizing the configuration of reducing the cross-sectional area of ​​the first upstream flow channel by the first tapered portion 605 and the second tapered portion 606 of the second retaining portion 602, it is also possible to provide an advantageous effect similar to that of the first embodiment.

[0177] Furthermore, in the first embodiment, the first retaining portion 701 is used as the second region of the second upstream flow channel, wherein the cross-sectional area of ​​the second upstream flow channel becomes smaller and smaller from the upper side to the lower side in the vertical direction. Alternatively, the second retaining portion 702 may be used as the second region. By utilizing the configuration of reducing the cross-sectional area of ​​the first upstream flow channel by the first tapered portion 705 and the second tapered portion 706 of the second retaining portion 702, it is also possible to provide an advantageous effect similar to that of the first embodiment.

[0178] In addition, the second holding portion 802 can be used as the second region. The cross-sectional area of ​​the third upstream flow channel (the portion of the flow channel 400C outside the connecting flow channel 807) can be reduced by the first tapered portion 805 and the second tapered portion 806 of the second holding portion 802. With such a configuration, similar advantageous effects as those of the first embodiment can also be provided.

[0179] The liquid ejection head according to the present disclosure generates fewer bubbles even when a plurality of flow channels are arranged, and the liquid ejection head according to the present disclosure is thinner than the related art.

[0180] Although the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A liquid ejection head, comprising: a first ejection port array and a second ejection port array arranged side by side, each ejection port array being formed by a plurality of ejection ports arranged in a first direction for ejecting liquid; a first filter configured to filter liquid to be supplied to the first injection port array; a second filter configured to filter liquid to be supplied to the second injection port array; a first flow channel configured to supply liquid from the first filter to the first injection port array; as well as a second flow channel configured to supply liquid from the second filter to the second injection port array, wherein The first flow channel includes a first downstream flow channel communicating with the first injection port array and a first upstream flow channel communicating with the first filter and the first downstream flow channel. The second flow passage includes a second downstream flow passage communicating with the second injection port array and a second upstream flow passage communicating with the second filter and the second downstream flow passage, In a state where the liquid ejecting head is used, The first upstream flow channel has a first region located above the first downstream flow channel in the vertical direction, in which a cross-sectional area of ​​the first upstream flow channel becomes smaller from the upper side to the lower side in the vertical direction, and The second upstream flow channel has a second region located above the second downstream flow channel in the vertical direction, in which a cross-sectional area of ​​the second upstream flow channel becomes smaller from the upper side to the lower side in the vertical direction, and In a view viewed along the first direction, the first downstream flow channel and the second downstream flow channel do not overlap with each other, whereas the first region and the second region overlap with each other.

2. The liquid ejecting head according to claim 1, comprising: a first storage chamber in communication with the first upstream flow channel and configured to store a liquid; as well as a second storage chamber, the second storage chamber being in communication with the second upstream flow channel and configured to store liquid, wherein The first filter is disposed in the first storage chamber, and The second filter is disposed in the second storage chamber.

3. The liquid ejecting head according to claim 2, wherein In a state in which the liquid ejection head is used, the first reservoir chamber and the second reservoir chamber do not overlap each other in a view viewed along a second direction intersecting the vertical direction and the first direction.

4. The liquid ejecting head according to claim 3, wherein: The first downstream flow channel has: a first opening in communication with the first array of injection ports, and a second opening communicating with the first upstream flow passage, and A length of the first opening in the first direction is greater than a length of the second opening in the second direction.

5. The liquid ejecting head according to claim 4, wherein The first downstream flow passage has a first tapered portion extending in the first direction and inclined relative to the first opening.

6. The liquid ejecting head according to claim 5, wherein: The first tapered portion comprises: a first inclined portion formed from one end in the first direction toward the first upstream flow passage, and a second inclined portion formed continuously from the other end portion of the first inclined portion in the first direction, and The first inclined portion and the second inclined portion are inclined at angles different from each other with respect to the first opening.

7. The liquid ejecting head according to claim 5 or 6, wherein The second downstream flow passage has a second tapered portion extending in the first direction and inclined relative to the first opening, and In a view viewed along the first direction, the first tapered portions and the second tapered portions arranged in the second direction are disposed to alternately face in opposite directions along the first direction.

8. The liquid ejecting head according to claim 1 or 2, wherein The first downstream flow path has a wall surface extending along the vertical direction in a state in which the liquid ejection head is used.

9. The liquid ejection head according to claim 2, wherein Different types of liquids are stored in the first storage chamber and the second storage chamber.

10. The liquid ejection head according to claim 1, wherein The first upstream flow passage includes a first portion in communication with the first filter and a second portion in communication with the first portion and the first downstream flow passage, The first portion and the second portion respectively include regions where cross-sectional areas of the first portion and the second portion become smaller from the upper side to the lower side in the vertical direction in a state where the liquid ejecting head is used, and The second portion includes the first region.

11. The liquid ejection head according to claim 10, wherein An opening communicating with the first portion is formed on the uppermost portion of the second portion when the liquid ejecting head is in use.

12. The liquid ejection head according to claim 10, wherein An opening communicating with the first downstream flow path is formed at the lowermost portion of the second portion in a state in which the liquid ejecting head is used.

13. The liquid ejection head according to claim 10, wherein The second upstream flow passage includes a third portion communicating with the second filter and a fourth portion communicating with the third portion and the second downstream flow passage, The third portion and the fourth portion respectively include regions whose cross-sectional areas become smaller from the upper side to the lower side in the vertical direction in a state where the liquid ejecting head is used, and The fourth portion includes the second region.

14. A printing device, comprising: A liquid ejection head, the liquid ejection head comprising: a first ejection port array and a second ejection port array arranged side by side, each ejection port array being formed by a plurality of ejection ports arranged in a first direction for ejecting liquid; a first filter configured to filter liquid to be supplied to the first ejection port array; a second filter configured to filter liquid to be supplied to the second ejection port array; a first flow channel configured to supply liquid from the first filter to the first ejection port array; and a second flow channel configured to supply liquid from the second filter to the second ejection port array, and an attachment unit capable of attaching the liquid ejection head, wherein The first flow channel includes a first downstream flow channel communicating with the first injection port array and a first upstream flow channel communicating with the first filter and the first downstream flow channel. The second flow passage includes a second downstream flow passage communicating with the second injection port array and a second upstream flow passage communicating with the second filter and the second downstream flow passage, In a state where the liquid ejecting head is used, The first upstream flow channel has a first region located above the first downstream flow channel in the vertical direction, in which a cross-sectional area of ​​the first upstream flow channel becomes smaller from the upper side to the lower side in the vertical direction, and The second upstream flow channel has a second region located above the second downstream flow channel in the vertical direction, in which a cross-sectional area of ​​the second upstream flow channel becomes smaller from the upper side to the lower side in the vertical direction, and In a view viewed along the first direction, the first downstream flow channel and the second downstream flow channel do not overlap with each other, whereas the first region and the second region overlap with each other.

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