Flow path member, liquid ejection device, and recording device

Abstract

A plurality of nozzle groups each include a plurality of nozzles which are open to an ejection surface. A plurality of supply sub-common flow paths are provided such that at least one supply sub-common flow path corresponds to each nozzle group. Through at least one supply sub-common flow path, a liquid is supplied to the plurality of nozzles that are included in a corresponding nozzle group. In at least one first supply flow path corresponding to each nozzle group, when a part which is located on a first end side in a first direction of the nozzle group and through which the liquid is supplied to the nozzle that is located on the first end side and a part which is located on a second end side in the first direction of the nozzle group and through which the liquid is supplied to the nozzle that is located on the second end side are compared to each other, one has a relatively lower pressure and the other has a relatively higher pressure. In at least one portion in which the nozzle groups are adjacent to each other, the lower pressure part corresponding to one of the adjacent nozzle groups and the higher pressure part corresponding to the other are adjacent to each other.

Description

Flow path member, liquid ejection device and recording device

[0001] The present disclosure relates to a flow path member having a plurality of nozzles that eject liquid, a liquid ejection device having the flow path member, and a recording device having the liquid ejection device.

[0002] Recording devices that perform recording (e.g., printing) by ejecting a liquid (e.g., ink) toward a recording medium (e.g., paper) are known (see, for example, Patent Documents 1 and 2 listed below). The liquid is ejected from a plurality of nozzles. The plurality of nozzles are formed, for example, in a flow path member. In addition to the plurality of nozzles, the flow path member also has, for example, a common supply flow path that is connected in common to the plurality of nozzles and supplies liquid to the plurality of nozzles. Patent Documents 1 and 2 show specific examples of the common supply flow path.

[0003] JP 2009-143168 A International Publication No. 2016 / 190413

[0004] A flow path member according to one aspect of the present disclosure includes an ejection surface, a plurality of nozzle groups, and a plurality of first supply flow paths. The ejection surface extends in a first direction and a second direction perpendicular to the first direction. The plurality of nozzle groups each include a plurality of nozzles opening onto the ejection surface. One or more of the plurality of first supply flow paths are provided corresponding to each of the nozzle groups, and each supplies liquid to the plurality of nozzles in the corresponding nozzle group. When viewed in the second direction, the plurality of nozzles are arranged at an interval corresponding to a predetermined resolution in at least a central region of each of the nozzle groups. The plurality of nozzle groups are spaced apart from each other in the first direction by a distance longer than the interval. In one or more of the first supply flow paths corresponding to each of the nozzle groups, a portion located on a first end side of the corresponding nozzle group in the first direction and supplying the liquid to the nozzles on the first end side and a portion located on a second end side of the corresponding nozzle group in the first direction and supplying the liquid to the nozzles on the second end side are, when compared with each other, a relatively low-pressure portion and a relatively high-pressure portion. At any one or more locations where the nozzle groups are adjacent to each other, the low portion corresponding to one of the adjacent nozzle groups is adjacent to the low portion corresponding to the other of the adjacent nozzle groups.

[0005] A liquid ejection device according to one aspect of the present disclosure includes the flow path member, and an actuator that applies pressure to the liquid in the flow path member to eject the liquid from the nozzle.

[0006] A liquid ejection device according to one aspect of the present disclosure includes a plurality of flow path members. Each of the plurality of flow path members has an ejection surface that extends in a first direction and a second direction perpendicular to the first direction. The plurality of flow path members are positioned differently in the first direction, and their ends in the first direction overlap when viewed in the second direction. Each of the flow path members includes one or more nozzle groups and one or more first supply flow paths. Each of the one or more nozzle groups has a plurality of nozzles that open to the ejection surface. The one or more first supply flow paths are provided in numbers of one or more corresponding to each of the nozzle groups, and each supplies liquid to the plurality of nozzles in the corresponding nozzle group. When viewed in the second direction, the plurality of nozzles are arranged at an interval corresponding to a predetermined resolution in at least a central region of each nozzle group. In each of the flow path members, on either side of each nozzle group in the first direction, there is no other nozzle group, or the other nozzle groups are located at a distance in the first direction that is longer than the interval. In one or more of the first supply flow paths corresponding to each of the nozzle groups, a portion that is located on a first end side in the first direction of the corresponding nozzle group and that supplies the liquid to the nozzles on the first end side, and a portion that is located on a second end side in the first direction of the corresponding nozzle group and that supplies the liquid to the nozzles on the second end side, are, when compared with each other, a portion where the pressure is relatively low and a portion where the pressure is relatively high. At any of one or more locations where the ends of the flow path members overlap each other, the low portion of one of the overlapping flow path members and the low portion of the other of the overlapping flow path members are adjacent to or overlap each other as viewed in the second direction.

[0007] A recording apparatus according to one aspect of the present disclosure includes the liquid ejection device and a transport device that moves the liquid ejection device and the recording medium relative to each other in the second direction.

[0008] 1 is a schematic perspective view showing a recording device according to an embodiment. A top view of a plurality of flow path members included in the recording device of FIG. 1. A planar perspective view of one of the plurality of flow path members of FIG. 2. A planar perspective view showing an enlarged view of region IV of FIG. 3. A cross-sectional view of the head taken along line V-V of FIG. 4. A cross-sectional view of the flow path member taken along line VI-VI of FIG. 3. A planar perspective view showing a flow path member according to another example (first example). A planar perspective view showing a flow path member according to yet another example (second example). A planar perspective view showing a flow path member according to yet another example (third example). A planar perspective view showing the configuration of the periphery of an inlet according to another example.

[0009] For aspects that are described relatively later among multiple aspects relating to various devices or components, only differences from the previously described aspects will be described. Matters not specifically mentioned may be considered to be the same as or inferred from the previously described aspects. Furthermore, for the sake of convenience, the same reference numerals may be used to refer to corresponding configurations in multiple aspects, even if there are differences.

[0010] The drawings used in the following description are schematic. Therefore, for example, certain shapes and / or dimensions may be exaggerated or details may be omitted. Furthermore, the dimensional proportions of the same components in the drawings do not necessarily match. However, this does not deny that shape and / or dimensional features may be extracted from the drawings.

[0011] For convenience, the drawings may be illustrated with a Cartesian coordinate system D1D2D3, and terms such as D1 direction, D2 direction, and D3 direction may be used. The recording device according to the embodiment may be used in any orientation. However, for convenience, an example in which the +D3 side is upward may be used without any particular specification, and expressions based on this example may be used.

[0012] 1 is a schematic perspective view of a printer 1 (an example of a recording device) according to an embodiment. The printer 1 is configured as an inkjet printer that prints on a medium 101 (an example of a recording medium) such as paper. More specifically, in the illustrated example, the medium 101 is roll paper, and is transported in the direction indicated by the outline arrow (or the opposite direction). Ink is then ejected from an ejection system 3 toward the medium 101, thereby performing printing.

[0013] The ejection system 3 has, for example, a plurality of (four in the illustrated example) ejection units 5. The plurality of ejection units 5 eject, for example, ink of different colors (for example, four colors). Each ejection unit 5 has, for example, a plurality of (three in the illustrated example) heads 7 arranged in a direction (direction D1) that intersects (for example, is perpendicular to) the transport direction of the medium 101. The ejection system 3, ejection units 5, and heads 7 are each an example of a liquid ejection device.

[0014] 2 is a top view showing the portion of one ejection unit 5 on the media 101 side (more specifically, the flow path member 9 described below). In this figure, however, the nozzle region NA located on the lower surface of the flow path member 9 (ejection surface 9a shown in FIG. 5) is also shown by a two-dot chain line. The nozzle region NA is the region where the nozzles 11 (see FIGS. 4 and 5) that eject ink are arranged.

[0015] One or more (four in the illustrated example) inlets 15S and one or more (four in the illustrated example) outlets 15C are opened on the back surface 9b of each flow path member 9. The inlets 15S receive liquid to be supplied to the nozzles 11 from outside the flow path member 9. The outlets 15C allow liquid that is not ejected from the nozzles 11 to flow out of the flow path member 9.

[0016] Fig. 3 is a plan perspective view of one flow path member 9. Fig. 4 is an enlarged view of region IV in Fig. 3. However, in Figs. 3 and 4, for convenience of illustration, selected components are shown in perspective. More specifically, Fig. 3 shows, for example, the inlet 15S and outlet 15C already described. Fig. 4 shows, for example, the nozzle 11 in addition to the above components.

[0017] 2, 3, and 4, the multiple nozzles 11 are arranged in a matrix within a parallelogram-shaped nozzle region NA. The multiple nozzles 11 included in each nozzle region NA are sometimes collectively referred to as a nozzle group 27. As shown in Fig. 4, in each nozzle group 27, the multiple nozzles 11 are arranged in a direction intersecting direction D2 (direction D4 in the illustrated example) to form multiple (n) nozzle rows 29.

[0018] When viewed in the D2 direction (the transport direction of the medium 101), the nozzles 11 in the multiple (n) nozzle rows 29 are positioned in different directions in the D1 direction. In other words, when viewed in the D2 direction, between adjacent nozzles 11 in one nozzle row 29, nozzles 11 in one or more other nozzle rows 29 are located. This makes it possible to form dots on the medium 101 that are aligned in the D1 direction at a distance (d1 / n) that is shorter than the distance in the D1 direction between adjacent nozzles 11 in one nozzle row 29 (distance d1 in FIG. 4 ). In other words, higher resolution is achieved compared to an embodiment in which only one nozzle row 29 is provided.

[0019] As shown in FIG. 2 , each nozzle region NA has a main region NAm that does not overlap with adjacent nozzle regions NA when viewed in the D2 direction, and a sub-region NAs that does overlap. In the main region NAm, a desired resolution (resolution corresponding to d1 / n) is achieved by only one nozzle region NA (one nozzle group 27). In the sub-region NAs, a desired resolution is achieved by two nozzle regions NA (two sub-regions NAs, two nozzle groups 27) that overlap with each other. From another perspective, the separation of the two nozzle regions NA ensures, for example, space between them that can be used for appropriate purposes (e.g., the arrangement of the main common supply flow path 17S shown in FIGS. 3 and 4 ). The distance L1 ( FIG. 4 ) between adjacent nozzle regions NA is longer than the distance d1.

[0020] 3, the flow path member 9 has one or more (two in the illustrated example) main common supply flow paths 17S extending from an inlet 15S, and a plurality (24 in the illustrated example) of sub-common supply flow paths 19S branching off from each main common supply flow path 17S, in order to supply liquid to the nozzles 11. The liquid flows sequentially through the inlet 15S, the main common supply flow path 17S, and the sub-common supply flow path 19S, and is supplied to the nozzles 11. One or more (a plurality (12) in the illustrated example) sub-common supply flow paths 19S are provided corresponding to each nozzle group 27. The sub-common supply flow paths 19S supply liquid to the plurality of nozzles 11 included in the corresponding nozzle group 27.

[0021] The supply sub-common flow path 19S extends, for example, so as to cross the corresponding nozzle group 27 in the D1 direction (strictly speaking, the D4 direction). The positions of its upstream end and downstream end roughly coincide with the positions of both ends in the D1 direction of the corresponding nozzle group 27. Therefore, when focusing on the locations where the multiple nozzle groups 27 are adjacent to each other, the multiple supply sub-common flow paths 19S corresponding to one of the adjacent nozzle groups 27 and the multiple supply sub-common flow paths 19S corresponding to the other of the adjacent nozzle groups 27 have their ends facing each other in the D1 direction.

[0022] Basically, the pressure in the supply sub-common flow path 19S decreases toward the downstream side (the farther away from the supply main common flow path 17S). That is, as indicated by the reference numerals in Fig. 3, the regions on both ends of the supply sub-common flow path 19S are, when compared with each other, a high region HP where the pressure is relatively high and a low region LP where the pressure is relatively low.

[0023] 3, the symbols of the high region HP and the low region LP refer to regions in the entire plurality of supply sub-common channels 19S corresponding to each nozzle group 27. However, the high region HP and the low region LP may refer to regions in each supply sub-common channel 19S. In the description of the embodiment, the terms high region HP and low region LP may be interpreted in either way unless a contradiction arises.

[0024] 4, the plurality of nozzles 11 are arranged along the plurality of common supply sub-channels 19S, and liquid is supplied to each nozzle from the nearest common supply sub-channel 19S. Basically, the more downstream the nozzles 11 are positioned relative to the common supply sub-channel 19S (the opposite side to the common supply main channel 17S), the more liquid is supplied to each nozzle from the downstream side of the common supply sub-channel 19S. In other words, the nozzles 11 positioned at the ends of the nozzle group 27 in the D1 direction are supplied with liquid from the high region HP or the low region LP.

[0025] When focusing on the pressure in the supply sub-common flow path 19S at the location where multiple nozzle groups 27 are adjacent to one another, the low regions LP are adjacent to one another, or the high regions HP are adjacent to one another, as shown in Figure 3. Note that the expression "adjacent" here refers to the arrangement in the D1 direction of the low regions LP and high regions HP corresponding to each nozzle group 27 (in the illustrated example, the arrangement is LP, HP, HP, LP, LP, HP, HP, HP, LP, in order from the -D1 side). Therefore, for example, when it is said that low regions LP are adjacent to one another, it does not matter if another flow path is located between them.

[0026] Because the low regions LP (or the high regions HP) are adjacent to each other, the plurality of nozzles 11 (the plurality of individual flow paths 20) located at adjacent ends of different nozzle groups 27 are all supplied with liquid from the low regions LP. Therefore, compared to when the low regions LP and the high regions HP are adjacent to each other, the difference in pressure applied to each individual flow path 20 from the supply sub-common flow path 19S among the plurality of individual flow paths 20 is reduced. Consequently, the likelihood of unintended variations in the pressure for ejecting droplets from the nozzles 11 due to the above-mentioned pressure difference is reduced. As a result, the likelihood of image quality being improved is increased.

[0027] In the illustrated example, the low regions LP or the high regions HP are adjacent to each other at all locations between the multiple nozzle groups 27. However, the above-described adjacent relationship may be established for at least one location. Also, there may be only locations where the low regions LP are adjacent to each other, or conversely, there may be only locations where the high regions HP are adjacent to each other. In addition to or instead of adjacent nozzle groups 27 within one flow path member 9, a positional relationship may be established in which the low regions LP or the high regions HP are adjacent to each other in adjacent flow path members 9. In addition to or instead of the low regions LP (or high regions HP) being adjacent to each other, the low regions LP may be considered to overlap when viewed in the D2 direction.

[0028] From the present disclosure, technical matters from a different perspective than the above technical matters may be extracted. In this case, for example, the low portions LP or the high portions HP do not have to be adjacent to each other. Also, for example, the nozzle groups 27 do not have to be adjacent to each other.

[0029] The above is an overview of the printer 1 according to the embodiment. The following will be described in the following order: 1. Printer 1 in general (FIG. 1) 2. Ejection system 3 (FIG. 1) 3. Ejection unit 5 (FIGS. 1 and 2) 4. Head 7 (FIGS. 3 to 6) 4.1. Head 7 in general 4.2. Flow path member 9 4.2.1. Flow path member in general 4.2.2. Flow path shape in general 4.2.3. Common flow path 4.2.3.1. Inlet and outlet 4.2.3.2. Manifold stack structure 4.2.3.3. Main common flow path and sub-common flow path 4.2.4. Individual flow paths 4.2.5. Nozzle arrangement 4.2.6. Bypass flow path (FIG. 6) 4.3. Actuator 5. Other examples 5.1. Flow path member according to first example (FIG. 7) 5.2. Flow path member according to second example (FIG. 8) 5.3. 5.3. Flow path member according to the third example (FIG. 9) 5.4. Connection portion of main common flow path according to another example (FIG. 10) 5.5. Combination of various examples 6. Summary of embodiments

[0030] 1 includes, for example, the above-described ejection system 3 and a transport device 31 that transports the medium 101. Although not specifically shown, the printer 1 may also include, for example, a drying device that dries ink that has landed on the medium 101, or a controller that controls each part of the printer 1 (such as the ejection system 3 and the transport device 31).

[0031] The printer 1 prints on, for example, roll paper as the medium 101. However, the medium 101 may also be sheet paper. The size of the medium 101 is also arbitrary. For example, the size of the medium 101 may be small, like a receipt, the size of paper commonly used in offices, or large, like a poster. From another perspective, the size of the printer 1 is arbitrary.

[0032] The transport device 31 may have any configuration. FIG. 1 illustrates a configuration in which a roller in contact with the media 101 is rotated. Other configurations include a configuration in which a belt that adsorbs the media 101 is transported, or a configuration in which a drum around which the media 101 is wound is rotated. The transport path for the media 101 may also be any configuration. For example, the transport path may extend generally straight (including a path that curves gradually so that part or all of the path does not make a U-turn) (as in the illustrated example), or it may extend in a U-turn.

[0033] 1 is configured for use in a so-called line printer. That is, the ejection system 3 (or, from another perspective, the ejection unit 5) spans almost the entire width (direction D1) of the medium 101. Then, as the medium 101 is transported, printing is performed in a band-shaped area extending in the direction D1, thereby forming a two-dimensional image.

[0034] Unlike the illustrated example, one head 7 may span substantially the entire width of the medium 101. The ejection system 3 may also be for a serial printer. In this case, the operation of printing while moving the head 7 (or the ejection unit 5 or the ejection system 3) in the direction D1 and the transport of the medium 101 are performed alternately. For convenience, in explaining the embodiments, a line printer in which two or more heads 7 (three in FIG. 1) span the width of the medium 101 may be used as an example unless otherwise specified.

[0035] The ejection system 3 has at least one head 7 (12 in the illustrated example). In the example of FIG. 1, as described above, four ejection units 5 are arranged in the D2 direction (the transport direction of the medium 101) corresponding to four colors. In other words, the multiple (three) heads 7 in each ejection unit 5 correspond to ink of the same color. The four colors are, for example, magenta (M), yellow (Y), cyan (C), and black (K). This allows the printer 1 to function as a color printer.

[0036] Contrary to the above description, the printer 1 may be one that prints in a single color, or conversely, one that prints in more than four colors. In other words, the number of colors is arbitrary. Also, contrary to the above description, two or more ejection units 5 may correspond to one color. This may more than double the resolution of one color. Conversely, one head 7 may correspond to two or more colors. As can be understood from the above, the number of ejection units 5 (heads 7) that the ejection system 3 has is arbitrary.

[0037] The discharge system 3 may hold the discharge unit 5 using an appropriate member. In FIG. 1 , a plate-shaped (frame-shaped) unit holding member 33 is shown as an example. The unit holding member 33 has an opening (not shown) that exposes the discharge surface 9 a ( FIG. 5 ) of the head 7 where the nozzles 11 are open. The discharge unit 5 (for example, a head holding member 35 described later) abuts against the periphery of the opening of the unit holding member 33 from the +D3 side, and is fixed to the unit holding member 33 with screws (not shown) or the like.

[0038] (3. Discharge Unit) Each discharge unit 5 has multiple heads 7 (three in the illustrated example) that are positioned at different positions in the D1 direction. The multiple heads 7 may, for example, have the same configuration as each other, or may have different configurations as each other. In the description of the embodiment, the former form may be taken as an example unless otherwise specified.

[0039] The number of heads 7 included in the discharge unit 5 is arbitrary. For example, unlike the illustrated example, the number of heads 7 may be two, or may be four or more. Also, unlike the description of the embodiment, only one head 7 may be provided. In other words, the discharge unit 5 may not be conceptualized.

[0040] In each ejection unit 5, the multiple heads 7 are arranged, for example, linearly in the D1 direction (or, from another perspective, in a row). That is, the positions of the multiple heads 7 in the D2 direction are the same. In this regard, the multiple heads 7 may be arranged so that each of them has a configuration that is rotationally symmetrical by 180 degrees with respect to an axis of symmetry parallel to the D3 axis, or the multiple heads 7 may be arranged so that each of them has a configuration that is rotationally asymmetrical by 180 degrees with respect to an axis of symmetry parallel to the D3 axis, in the same direction or in opposite directions. Whether the positions in the D2 direction are the same or different may be determined, for example, based on the position of the nozzle 11.

[0041] As shown in FIG. 2 , the sub-regions NAs of adjacent heads 7 are adjacent to each other. As with two adjacent sub-regions NAs within a single head 7, the desired resolution is achieved by both nozzles 11. In the explanation of the outline of the embodiment, it was stated that the sub-regions NAs contribute to ensuring an area for arranging the main common supply flow channel 17S. In addition to or instead of ensuring such an area, the sub-regions NAs can contribute to ensuring the distance between adjacent heads 7 (however, in the example of FIG. 2 , the distance between the two is zero) and / or ensuring the distance from the sub-regions NAs of each head 7 to the outer edge of the head 7 in the portion where the heads 7 are adjacent to each other.

[0042] Unlike the illustrated example, the positions of adjacent heads 7 in the D2 direction may be offset from each other by a distance shorter than the length of the heads 7 in the D2 direction. In other words, in such a positional relationship, the shapes of the sub-regions NAs and the positions of the sub-regions NAs relative to the heads 7 may be set so that the desired resolution is achieved by the adjacent sub-regions NAs of the adjacent heads 7. Furthermore, the multiple heads 7 may be arranged in a staggered pattern. In other words, the multiple heads 7 may be arranged in the D1 direction with their positions in the D2 direction alternately differing, so that the ends of the heads 7 overlap each other when viewed in the D2 direction.

[0043] In each ejection unit 5, the multiple heads 7 may be fixed to one another by an appropriate member. FIG. 1 illustrates a plate-shaped (frame-shaped) head holding member 35. The head holding member 35 has, for example, an opening (not shown) that exposes the ejection surface 9a (FIG. 5) of the head 7 on which the nozzles 11 are open. The head 7 abuts against the periphery of the opening of the head holding member 35 from the +D3 side and is fixed to the head holding member 35 by screws (not shown) or the like. Note that, unlike the illustrated example, the multiple heads 7 may be fixed directly to the unit holding member 33 (the head holding member 35 may not be provided).

[0044] (4. Head) (4.1. Head in General) Any driving method may be used for ejecting ink from the head 7. For example, the head 7 may be a piezoelectric type that applies pressure to the ink by deforming a piezoelectric body, or a thermal type that applies pressure to the ink by heating the ink to generate bubbles. In the description of the embodiments, the piezoelectric type may be used as an example unless otherwise specified.

[0045] Figure 5 is a cross-sectional view of the head 7 (at least the portion on the -D3 side) taken along line VV in Figure 4. As shown in this figure, the head 7 has, for example, the flow path member 9 described above and an actuator substrate 37 that applies pressure to the ink in the flow path member 9 to eject ink droplets. The actuator substrate 37 has a plurality of actuators 39 that respectively correspond to the plurality of nozzles 11.

[0046] Although not specifically shown, the head 7 may have other components than those described above. For example, although not specifically shown, the head 7 may have the following components: A plate-like or tubular member that supplies (and / or recovers) ink to the flow path member 9; A flexible substrate that inputs a drive signal to the actuator 39; A rigid circuit board that is connected to the flexible substrate; and A housing that houses these components. Regardless of the presence or absence of these components, only the flow path member 9, or only the combination of the flow path member 9 and the actuator substrate 37, may be considered to be the head.

[0047] One head 7 (one flow path member 9 from another perspective) has, for example, multiple (four in the example of FIG. 2) nozzle regions NA (nozzle groups 27). However, one head 7 may only have one nozzle group 27. In other words, the sub-regions NAs may contribute solely to achieving the desired resolution between adjacent heads 7. However, in the description of the embodiment, unless otherwise specified, the description may be made on the premise that one head 7 has multiple nozzle regions NA.

[0048] The head 7 may simply be supplied with ink from a tank (not shown), or may be supplied with ink from a tank (not shown) and collect the ink in the tank. In other words, the ejection system 3 may not circulate ink, or may circulate ink. In the description of the embodiments, a configuration in which ink circulates will basically be taken as an example.

[0049] (4.2. Flow Path Member) (4.2.1. Flow Path Member in General) The flow path member 9 is, for example, a substantially flat member. However, the ejection surface 9a and / or the back surface 9b do not have to be flat. The planar shape of the flow path member 9 is, for example, a parallelogram, as shown in FIGS. 2 and 3 . Note that, in this case, the corners may be chamfered with straight or curved lines, and the sides may have relatively small recesses or protrusions. The same applies to other members and / or other shapes. This parallelogram has, for example, a first pair of sides parallel to the D1 direction and a second pair of sides inclined with respect to the D2 direction. The second pair of sides are, for example, along opposite sides of the nozzle region NA in the D1 direction (for example, parallel). In other words, the inclination angles of both sides are approximately the same (for example, the difference between the two is 3° or less or 1° or less).

[0050] Unlike the illustrated example, the shape of the flow path member 9 does not have to be a parallelogram. For example, it is clear that the shape and orientation, etc., of the opposing sides facing each other in the D2 direction are arbitrary. It is also clear that the shape and orientation, etc., of the opposing sides facing each other in the D1 direction are arbitrary as long as they are not adjacent to other heads 7. As will be understood from the above explanation that the multiple heads 7 do not have to be arranged in a straight line and the below explanation that the nozzle area NA does not have to be a parallelogram, the shape and orientation, etc., of the opposing sides located between two heads 7 are also arbitrary. A shape for aligning the two heads 7 may be formed on the opposing sides located between the two heads 7. Only a portion of the flow path member 9 on the ejection surface 9a side may be parallelogram-shaped.

[0051] The dimensions of the flow path member 9 are arbitrary. Take an example where the printer 1 is a line printer that prints on a relatively wide medium 101. The maximum length of the flow path member 9 in the D1 direction (the length parallel to the D1 direction from the lower left corner to the upper right corner in FIG. 3 ) may be, for example, 50 mm or more and 300 mm or less. The maximum length of the flow path member 9 in the D2 direction may be, for example, 20 mm or more and 100 mm or less. The maximum length in the D1 direction may be longer than the maximum length in the D2 direction. For example, the former may be 1.5 times or more and 5 times or less than the latter. The thickness of the flow path member 9 may be 0.5 mm or more and 2 mm or less.

[0052] 5, the flow path member 9 is configured, for example, by stacking a plurality of flow path parts 41 in the D3 direction. The flow path parts 41 are generally flat plate-shaped members, and overlapping parts are fixed together with an adhesive (not shown) interposed between them. Holes formed in the plurality of flow path parts 41 are connected to each other to form the flow path 13. The holes that form the flow path 13 are, for example, through-holes that penetrate the flow path part 41 in the thickness direction (D3 direction), or recesses formed on the surface of the flow path part 41 on the +D3 side or the −D3 side.

[0053] The shape, dimensions, number of layers, material, etc. of the flow path parts 41 are arbitrary. For example, the shape and size of the outer edge of each flow path part 41 may be the same as the shape and size (as described above) of the outer edge of the flow path member 9. The thickness of the flow path part 41 may be, for example, 10 μm or more and 300 μm or less. The material of the flow path parts 41 may be, for example, metal, resin, or ceramic.

[0054] The flow path member 9 may be realized in a manner different from the illustrated example. For example, all or a part (e.g., the part on the +D3 side) of the flow path member 9 (flow path 13) may be configured by stacking flow path parts 41 in a direction perpendicular to the D3 direction, rather than by stacking flow path parts 41 in the D3 direction. Furthermore, at least a part of the flow path parts may have a shape that cannot be considered as a plate shape.

[0055] The flow path member 9 may have components other than the flow path, such as a damper (not shown) that attenuates pressure fluctuations of the ink.

[0056] (4.2.2. General Flow Path Shape) The flow paths 13 included in the flow path member 9 may have various configurations. In the illustrated example, the flow paths 13 are configured to be able to circulate ink. More specifically, for example, the flow paths 13 have a supply flow path that leads from the outside of the flow path member 9 to the nozzles 11, and a recovery flow path that leads from any position in the supply flow path to the outside of the flow path member 9. The supply flow path, for example, gradually branches from the outside side of the flow path member 9 and reaches the multiple nozzles 11. The recovery flow path, for example, gradually merges from the side of the multiple nozzles 11 and reaches the outside of the flow path member 9.

[0057] More specifically, for example, as described in the description of the outline of the embodiment, the supply flow path has an inlet 15S (FIGS. 2 to 4), a main common supply flow path 17S (FIGS. 3 and 4), a sub-common supply flow path 19S (FIGS. 3 to 5), and individual flow paths 20. Note that a part of the individual flow path 20 also constitutes a recovery flow path.

[0058] The recovery flow path has the following parts in order of ink flow, for example: - Common recovery sub-path 19C (Fig. 5): At least one (multiple (large number) in the illustrated example) is provided, where multiple individual paths 20 converge. - Common recovery main path 17C (Figs. 3 and 4): At least one (two in the illustrated example) is provided, and extends from the common recovery sub-path 19C (where, for example, multiple common recovery sub-paths 19C converge). - Outlet 15C (Figs. 2 to 4): At least one (four in the illustrated example) is provided, where the common recovery main path 17C is connected, and where ink flows out of the flow path member 9.

[0059] As described above, ink that is not ejected from the nozzles 11 is discharged from the individual flow paths 20 to the outside of the flow path member 9 via the recovery sub-common flow path 19C, the recovery main common flow path 17C, and the outlet 15C in this order.

[0060] One inlet 15S, one supply main common flow path 17S, and one supply sub-common flow path 19S are each connected to multiple nozzles 11 (common to multiple nozzles 11). A combination of two or more of these may be considered as one type of common flow path. The same can be said for one outlet 15C, one recovery main common flow path 17C, and one recovery sub-common flow path 19C. Each of the multiple individual flow paths 20 includes a nozzle 11, and basically, the number of the individual flow paths 20 is the same as the number of the nozzles 11.

[0061] In the following description, a combination of one supply main common channel 17S and multiple supply sub-common channels 19S extending from the single supply main common channel 17S may be referred to as a supply manifold 16S (reference numeral in FIG. 3). Similarly, a combination of one recovery main common channel 17C and multiple recovery sub-common channels 19C extending from the single recovery main common channel 17C may be referred to as a recovery manifold 16C (reference numeral in FIG. 3).

[0062] In addition to the above, the flow path 13 may have a bypass flow path 26 (see FIG. 6 described later) that connects the supply sub-common flow path 19S and the recovery sub-common flow path 19C. The bypass flow path 26 bypasses the individual flow paths 20. The bypass flow path 26 contributes to, for example, circulation of the liquid. Of course, the bypass flow path 26 does not have to be provided.

[0063] In the illustrated example, the flow paths including two nozzle groups 27 on the -D1 side (15S, 17S, 19S, and 20, etc.) and the flow paths including two nozzle groups 27 on the +D1 side are separated from each other (not connected to each other) within the flow path member 9. In other words, a plurality of flow paths (two in the illustrated example) that are independent from each other are arranged in the D1 direction. The configurations of the plurality of independent flow paths are, for example, identical to each other. Each of the independent flow paths is configured, for example, with 180° rotational symmetry with respect to an axis of symmetry parallel to the D3 axis.

[0064] (4.2.3. Common Flow Path) (4.2.3.1. Inlets and Outlets) The number of inlets 15S is arbitrary. In the examples of FIGS. 2 to 4, the number of inlets 15S (in one flow path member 9) is four. Unlike the illustrated example, for example, the number of inlets 15S may be one or more and three or less, or five or more. Also, in the illustrated example, as will be understood from the description below, the two inlets 15S correspond to two nozzle groups 27 together, rather than separately. Unlike the illustrated example, for example, one inlet 15S may correspond to a nozzle group 27 separately from the other inlet 15S, and / or may correspond to only one nozzle group 27, or may correspond to three or more nozzle groups 27.

[0065] The position of the inlet 15S is also arbitrary. In the examples of FIGS. 2 to 4 , the inlet 15S opens in a region of the upper surface of the flow path member 9 that is outside the nozzle region NA in a planar perspective view. Specifically, the inlet 15S is located in a space between the outer edge of the flow path member 9 and opposite sides of the nozzle region NA that face each other in the direction D2, which are inclined with respect to the direction D1. This allows the flow path member 9 to be made smaller. Furthermore, the inlet 15S is selectively located in some of the multiple spaces described above. Unlike the illustrated example, for example, the inlet 15S may be located outside the spaces described above, or may be located in all of the spaces.

[0066] Fig. 6 is a cross-sectional view of the flow path member 9 taken along line VI-VI in Fig. 3. However, the laminated structure of the flow path parts 41 is not shown.

[0067] The shape and dimensions of the inlet 15S are also arbitrary. In the examples shown in FIGS. 2 to 6, the inlet 15S has a generally circular cross section, extends in the D3 direction, and reaches the upper surface of the supply main common flow path 17S. Its diameter is, for example, generally the same as the width of the supply main common flow path 17S. Note that, unlike the above description, only the opening located on the back surface 9b of the flow path member 9 may be considered as the inlet 15S, and the portion extending in the D3 direction may be considered as part of the supply main common flow path 17S.

[0068] The above description of the number, position, shape, dimensions, etc. of the inlet 15S may be applied to the outlet 15C, but in the illustrated example, the outlet 15C is shifted to the opposite side of the main supply common flow path 17S with respect to the inlet 15S.

[0069] (4.2.3.2. Stacked Structure of Manifolds) In the illustrated example, the supply manifold 16S and the recovery manifold 16C are configured to generally overlap in a plan view. That is, as illustrated in FIGS. 5 and 6, they are arranged one above the other. More specifically, for example, in a plan view, the recovery manifold 16C has a configuration similar to that of the supply manifold 16S, in which the supply main common flow path 17S is extended outward from the position of the inlet 15S. The portions (most portions) other than the extended portion are basically the same, except for, for example, manufacturing errors. Therefore, in FIGS. 3 and 4, the shape of the supply manifold 16S may be considered to represent the shape (most portions) of the recovery manifold 16C.

[0070] Unlike the illustrated example, the supply manifold 16S and the recovery manifold 16C may have different shapes apart from the above-described extension portions. Furthermore, regardless of whether they are manifold-shaped or not, the common supply flow path (17S and / or 19S) and the common recovery flow path (17C and / or 19C) may have portions that are located at different positions in a plan view and may have different shapes. For example, they may extend partially or entirely parallel to each other in a plan view.

[0071] In the illustrated example, the common supply flow path (17S and / or 19S) is located above (on the +D3 side of) the common recovery flow path (17C and / or 19C). This allows, for example, the supply sub-common flow path 19S to be closer to the pressure chamber 23 described below, and the recovery sub-common flow path 19C to be closer to the nozzle 11, thereby improving space efficiency. However, the up-down relationship can also be reversed from the illustrated example.

[0072] In the illustrated example, the height (size in the D3 direction) of each of the common supply flow paths (17S and / or 19S) and the common recovery flow paths (17C and / or 19C) is less than half the thickness (in the D3 direction) of the flow path member 9. However, even in a configuration in which the two overlap, it is possible for one of them to be more than half the thickness of the flow path member 9. Furthermore, in an embodiment in which the two do not overlap, or in an embodiment in which a recovery flow path is not provided, it is clear that the height of the common supply flow path may be more than half the thickness of the flow path member 9 (of course, it may also be less than half). The specific height of each common flow path is arbitrary.

[0073] (4.2.3.3. Main common flow path and sub-common flow path) The number and position (in plan view) of the supply main common flow paths 17S are arbitrary. In the example of Fig. 3, one supply main common flow path 17S is provided to connect two inlets 15S, and a total of two supply main common flow paths 17S are provided corresponding to the four inlets 15S. Ink flows from both sides of each supply main common flow path 17S toward the center.

[0074] In the illustrated example, each main common supply channel 17S extends between two adjacent nozzle regions NA (nozzle groups 27) and generally along the opposing ends (sides of a parallelogram) of the two nozzle groups 27. Each main common supply channel 17S supplies ink to the two nozzle groups 27 located on either side of it via sub-common supply channels 19S.

[0075] Furthermore, in the illustrated example, of the three regions located between the four nozzle groups 27, the central region does not have a supply main common channel 17S. In other words, the supply main common channel 17S is provided in every other region located between the multiple nozzle groups 27. From another perspective, the supply main common channel 17S is provided on only one side of each nozzle group 27. Each nozzle group 27 is supplied with ink from only one side.

[0076] Unlike the illustrated example, for example, one supply main common channel 17S may be provided for one inlet 15S. Ink may flow from one end of the supply main common channel 17S to the other. A supply main common channel 17S may be provided between the central nozzle groups 27. Depending on how the heads 7 are arranged, a supply main common channel 17S may be provided on the -D1 side and / or +D1 side of all of the multiple nozzle groups 27 of each head 7. The number of supply main common channels 17S may be the same as the number of spaces between the multiple nozzle groups 27, or it may be greater than that.

[0077] In various aspects different from the illustrated example as described above, each supply main common channel 17S may supply ink only to the nozzle group 27 located on one side thereof, or may supply ink to the nozzle groups 27 located on both sides thereof. From another perspective, one nozzle group 27 may be supplied with ink only from the supply main common channel 17S located on one side thereof, or may be supplied with ink from the supply main common channel 17S located on both sides thereof.

[0078] The shape of the supply main common flow path 17S is also arbitrary. In the illustrated example, the supply main common flow path 17S has a main portion 17a extending along (e.g., parallel to) opposite sides of the nozzle group 27 in the D1 direction, and a connection portion 17b extending from the main portion 17a to the inlet 15S (the same reference numerals may be used for the recovery main common flow path 17C). The direction in which the connection portion 17b extends is arbitrary. In the illustrated example, the connection portion 17b extends along (e.g., parallel to) opposite sides of the nozzle group 27 in the D2 direction. The supply main common flow path 17S (main portion 17a and / or connection portion 17b) extends with, for example, a constant cross section (constant shape and dimensions). The cross-sectional shape is, for example, rectangular.

[0079] As shown in FIG. 3 , the main portion 17a can be considered to have, in its longitudinal direction, an end region RE (first region), a central region RC (second region), and an end region RE (third region). From the end region RE on the +D2 side, a sub-common supply flow path 19S extends toward the nozzle group 27 on the −D1 side (an example of a first nozzle group), but a sub-common supply flow path 19S toward the nozzle group 27 on the +D1 side (an example of a second nozzle group) does not extend. The opposite is true for the end region on the −D2 side. From the central region RC, both the sub-common supply flow path 19S toward the nozzle group 27 on the −D1 side and the sub-common supply flow path 19S toward the nozzle group 27 on the +D1 side extend.

[0080] The connection portion 17b extends, for example, from the end region RE to the opposite side of the supply sub-common channel 19S extending from the end region RE. Consequently, the inlet 15S is located on the opposite side of the end region RE from the supply sub-common channel 19S connected to the end region RE. The connection portion 17b may be connected to any position in the longitudinal direction of the end region RE. In the illustrated example, the connection portion 17b extends from a position away from the end of the main portion 17a. In other words, the main portion 17a has an opening 17c, through which the liquid is supplied, at a position away from the end face (reference numeral omitted) of the main portion 17a. The distance away is arbitrary. In the illustrated example, one or more (one in the illustrated example) openings of the supply sub-common channel 19S to the main portion 17a are located between the opening 17c and the end face of the main portion 17a in the extension direction of the main portion 17a (but on the opposite side of the opening 17c in the width direction of the main portion 17a).

[0081] Each supply sub-common channel 19S extends, for example, between two adjacent nozzle rows 29 and along (for example, parallel to) those two nozzle rows 29. Each supply sub-common channel 19S supplies ink to the nozzles 11 included in the two nozzle rows 29 on either side. Therefore, one channel member 9 has a total of half the number of nozzle rows 29 (24 × 4 ÷ 2 = 48 in the illustrated example). Unlike the illustrated example, for example, one supply sub-common channel 19S may be provided for one nozzle row 29, or one supply sub-common channel 19S may be provided for four nozzle rows 29. The shape and dimensions of the supply sub-common channel 19S are arbitrary. For example, the supply sub-common channel 19S extends linearly with a constant cross section (constant shape and dimensions). The cross-sectional shape is, for example, rectangular (see FIG. 5 ).

[0082] In the description of the outline of the embodiment, it was stated that the supply sub-common flow path 19S has a low region LP and a high region HP. The pressure difference between the two regions is arbitrary. Furthermore, if liquid is flowing, a pressure difference exists, and the low region LP and the high region HP can be identified. Note that the pressure distribution in the supply sub-common flow path 19S may change temporarily and locally depending on the droplet ejection status from the multiple nozzles 11. For example, in the supply sub-common flow path 19S, the pressure decreases with increasing distance from the supply main common flow path 17S. However, once the position where the most distant individual flow path 20 is connected to the supply main common flow path 17S is reached, the pressure may increase. When identifying the low region LP and the high region HP, such temporary and / or microscopic pressure distributions may be ignored. That is, the low region LP and the high region HP may be identified rationally based on steady (or average) and / or macroscopic pressure distributions. This also applies to the low region and the high region in other flow paths.

[0083] From another perspective, the low region LP and the high region HP can be compared with each other as a region with a relatively long flow path length from the inlet 15S and a region with a relatively short flow path length. The flow path length is the distance along the flow path (e.g., its center line). For convenience, a short or long flow path length from a predetermined position may be expressed as being close or far from the predetermined position.

[0084] In the illustrated example, the low portion LP can be referred to as the portion on the other end side or the other end (strictly speaking, it does not have to be the end; the same applies hereinafter in this paragraph) of the supply sub-common flow path 19S, one end of which is directly or indirectly connected to the inlet 15S, and the high portion HP can be referred to as the portion on the one end side or the one end. Furthermore, in the illustrated example, the low portion LP can be referred to as the portion on the other end side or the other end of the supply sub-common flow path 19S, one end of which is connected to the supply main common flow path 17S, and the high portion HP can be referred to as the portion on the one end side or the one end.

[0085] The above-mentioned explanations regarding the number, position, shape, dimensions, etc. of the common supply flow paths (17S and 19S) may be applied to the common recovery flow paths (17C and 19C) unless there is a contradiction, etc. This applies not only to the case where the common recovery flow path overlaps the common supply flow path as in the illustrated example, but also to the case where the two do not overlap.

[0086] 6, when comparing the regions at both ends of the recovery sub-common flow path 19C, one is a high region HPc where the pressure is relatively high, and the other is a low region LPc where the pressure is relatively low. However, unlike the supply sub-common flow path 19S, the region with a short flow path length from the outlet 15C is the low region LPc, and the region with a long flow path length is the high region HPc. In the illustrated example, the low region LP of the supply sub-common flow path 19S and the high region HPc of the recovery sub-common flow path 19C are located on the same side in the extension direction of the sub-common flow paths (19S and 19C). The pressure in the low region LP is higher than the pressure in the high region HPc.

[0087] (4.2.4. Individual Flow Paths) As shown in Fig. 4, the multiple individual flow paths 20 are arranged, for example, along each common supply sub-flow path 19S. From another perspective, the multiple nozzles 11 are arranged along the common supply sub-flow path 19S. In the example shown, this arrangement constitutes a nozzle row 29. In addition, in the examples shown in Figs. 4 and 5, the multiple nozzles 11 connected to each common supply sub-flow path 19S are arranged in two rows, one row on each side of each common supply sub-flow path 19S. The two individual flow paths 20 leading to the nozzles 11 on both sides are, for example, oriented opposite to each other in a direction intersecting the common supply sub-flow path 19S (direction D2 in the example shown).

[0088] 5, each individual flow path 20 has, for example, a supply connection portion 21S, a pressure chamber 23, and a descender 25, in that order from the supply sub-common flow path 19S to the nozzle 11. Furthermore, each individual flow path 20 has a recovery connection portion 21C that connects the descender 25 to the recovery sub-common flow path 19C. Note that in FIG. 4, with regard to the individual flow path 20, only the portion of the supply connection portion 21S that extends from the supply sub-common flow path 19S to the +D3 side, the pressure chamber 23, the descender 25, and the nozzle 11 are shown.

[0089] When the volume of the pressure chamber 23 changes and pressure is applied to the ink, liquid is sent from the pressure chamber 23 to the descender 25, and eventually ink droplets (droplets) are ejected from the nozzle 11. Furthermore, liquid is replenished into the pressure chamber 23 from the supply sub-common flow path 19S via the supply connection portion 21S. Ink that is not ejected from the nozzle 11 is recovered into the recovery sub-common flow path 19C via the recovery connection portion 21C.

[0090] The shapes and dimensions of each part of the individual flow paths 20 are arbitrary. In the illustrated example, they are as follows: The supply connection portion 21S extends upward from the upper surface of the supply sub-common flow path 19S, then extends horizontally, then extends upward again, and is connected to one end of the lower surface of the pressure chamber 23. The pressure chamber 23 opens, for example, to the upper surface of the flow path member 9 and is closed by an actuator substrate 37. The descender 25 extends from one end of the lower surface of the pressure chamber 23 (the side opposite the supply connection portion 21S) toward the ejection surface 9a. The nozzle 11 opens to a part of the bottom surface of the descender 25 (the surface opposite the pressure chamber 23). One end of the recovery connection portion 21C opens, for example, to a region of the side surface of the descender 25 that is closest to the ejection surface 9a. The other end opens, for example, to the lower surface of the recovery sub-common flow path 19C.

[0091] The configuration of the individual flow paths 20 may be different from the illustrated example. For example, the pressure chamber 23 may be blocked by a relatively thin flow path part 41. Depending on the type of actuator 39 (whether it is piezoelectric or not, and the specific structure if it is piezoelectric, etc.), the pressure chamber 23 may be located to the side or below the other flow paths (for example, a common flow path). Also, for example, the descender 25 may not be provided, and the nozzle 11 may open directly to the bottom surface of the pressure chamber 23. However, the pressure chamber 23 and the descender 25 as a whole may be considered to be the pressure chamber, and even in the illustrated example, the nozzle 11 may be considered to open to the bottom surface of the pressure chamber.

[0092] (4.2.5. Nozzle Arrangement) The correspondence between the arrangement pattern of the nozzles 11 in the nozzle group 27 (or, from another perspective, the orientation of the parallelogram presented by the nozzle area NA) and the transport direction of the medium 101 is arbitrary. From another perspective, assuming that the Cartesian coordinate system D1D2D3 is defined fixedly with respect to the transport device 31, in the description of the embodiment, the terms -D1 and +D1 may be interchangeable, and / or the terms -D2 and +D2 may be interchangeable. Furthermore, the arrangement pattern of the nozzles 11 in the nozzle group 27 may or may not be 180° rotationally symmetric with respect to an axis of symmetry parallel to the D3 direction.

[0093] In the main region NAm, the desired resolution is achieved by only one nozzle group 27. Specifically, for example, as shown in FIG. 4 , a plurality of nozzles 11 are arranged at regular intervals in each nozzle row 29. The distance of this interval in the direction D1 is d1. Consider a band-shaped region BA that extends parallel to the direction D2 and has the same width as the distance d1. In the main region NAm of one nozzle group 27, n nozzles 11 that are included in different nozzle rows 29 and are positioned at different positions in the direction D1 are located in the band-shaped region BA. This achieves a resolution that allows dots arranged in the direction D1 at intervals of d1 / n on the medium 101.

[0094] In the sub-region NAs, the desired resolution is achieved by two adjacent nozzle groups 27. Specifically, in the sub-region NAs of each nozzle group 27, for example, less than n nozzles 11 included in different nozzle rows 29 are located in the band-shaped region BA. However, in two sub-regions NAs where the positions in the D1 direction of two adjacent nozzle groups 27 overlap, a total of n nozzles 11 are located in the band-shaped region BA. The n nozzles 11 are located at different positions in the D1 direction. This achieves a resolution of d1 / n.

[0095] In each nozzle group 27, the positions of the multiple nozzle rows 29 are shifted in the D1 direction by a distance of d1 or more, so that, for example, the nozzles on the +D2 side are positioned closer to the +D1 side. This ensures that the number of nozzles 11 (or, from another perspective, nozzle rows 29) included in the strip-shaped area BA in each sub-area NAs is less than n. Furthermore, the inclination angle of opposing sides of the nozzle group 27 in the D1 direction is adjusted by, for example, determining the number of strip-shaped areas BA to be shifted for each row, or the number of rows to be shifted for each strip-shaped area BA. The amount of shift does not have to be constant across the entire side.

[0096] In each nozzle group 27, for example, multiple nozzle rows 29 extend in the D4 direction, which is inclined at an angle θ with respect to the D1 direction. That is, each nozzle row 29 has multiple nozzles 11 arranged in the D4 direction. By inclining the nozzle rows 29, for example, the spacing between the nozzles 11 when each nozzle row 29 is viewed in the D2 direction (spacing in the D1 direction) can be made shorter than the spacing in the D4 direction, thereby improving resolution. The magnitude of the inclination angle θ is arbitrary and may be, for example, between 10° and 50°. However, the nozzle rows 29 may also be parallel to the D1 direction (see FIGS. 8 and 9, described below).

[0097] When the multiple nozzle rows 29 are numbered from the -D2 side to the +D2 side, such as first row, second row, third row, ..., nth row, in each band-shaped region BA, the relationship between the row number of the nozzle row 29 to which each nozzle 11 belongs and the relative positions in the D1 direction of the n nozzles 11 (i.e., the arrangement pattern of the nozzles 11 within the band-shaped region BA) is arbitrary. For example, in each band-shaped region BA, the n nozzles 11 may be arranged so that the nozzles 11 on the +D2 side are located closer to the +D1 side, but they do not have to be arranged in this manner.

[0098] In the above description, the nozzles 11 in each nozzle row 29 are arranged at regular intervals. From another perspective, the arrangement pattern of the n nozzles 11 within a strip area BA is the same across multiple strip areas BA. However, the arrangement pattern does not have to be regular. Alternatively, an integer multiple of n nozzles 11 may be arranged in a regular pattern, and this pattern may be repeated. The nozzles 11 may be intentionally positioned slightly offset from their original positions as long as the principle of achieving a resolution of d1 / n is not violated. Of course, unintentional offsets due to manufacturing errors may also exist.

[0099] (4.2.6. Bypass flow path) The position and number of bypass flow paths 26 ( FIG. 6 ) are arbitrary. In the example shown, the bypass flow path 26 connects the end of the supply sub-common flow path 19S opposite the supply main common flow path 17S to the end of the recovery sub-common flow path 19C opposite the recovery main common flow path 17C. From another perspective, the former end is the low part LP of the supply sub-common flow path 19S. The latter end is the high part HPc of the recovery sub-common flow path 19C. Only one bypass flow path 26 is provided for one supply sub-common flow path 19S and one recovery sub-common flow path 19C that overlap each other in the D3 direction.

[0100] When the bypass flow path 26 is said to be connected to the end of the sub-common flow path (19S and 19C), the opening (reference numeral omitted) connecting the two may or may not be in contact with the end face of the sub-common flow path (as in the illustrated example). The former mode includes a mode in which the opening and the end face are separated due to manufacturing errors. The former mode also includes a mode in which some or all of the openings are open to some or all of the end face. Furthermore, at least some of the openings may be located closer to the end face than the opening connecting the sub-common flow path to the individual flow path 20 located closest to the end face.

[0101] The bypass flow path 26 may have any shape. For example, the bypass flow path 26 may have a constant cross-sectional area and extend parallel to the D3 direction (as in the illustrated example), or the cross-sectional area may vary or the bypass flow path 26 may have a portion that is not parallel to the D3 direction. The cross-sectional shape of the bypass flow path 26 may be any appropriate shape, such as a quadrilateral (e.g., a parallelogram or a rectangle), a circle, or an ellipse.

[0102] The dimensions of the bypass flow path 26 are also arbitrary. For example, as shown in the enlarged view in the upper left of FIG. 3 , the bypass flow path 26 may extend across the entire width of the sub-common flow paths (19S and 19C). The cross-sectional area of ​​the bypass flow path 26 may be smaller than the cross-sectional area of ​​the sub-common flow paths (19S and 19C). Furthermore, the cross-sectional area of ​​the bypass flow path 26 may be smaller than, equal to, or larger than the minimum cross-sectional area of ​​the individual flow paths 20 excluding the nozzle 11. The specific value of the difference in cross-sectional area is arbitrary.

[0103] The shape and dimensions (flow path resistance, from another perspective) of the bypass flow path 26 may be the same for the plurality of sub-common flow paths (19S and 19C) or may be different from one another. In the illustrated example, as shown in the enlarged view in the upper left of Figure 3, the shape and dimensions of the bypass flow path 26 differ depending on the sub-common flow path (19S and 19C).

[0104] Specifically, the shorter the flow path length from the inlet 15S of the multiple supply sub-common flow paths 19S, the higher the pressure. The higher the pressure of the supply sub-common flow path 19S, the greater the flow path resistance of the bypass flow path 26. In other words, the supply main common flow path 17S has, in its extension direction, high regions HPm with relatively high pressure and low regions LPm with relatively low pressure, when compared with each other. The flow path resistance of the bypass flow path 26 for the supply sub-common flow paths 19S connected to the high regions HPm is greater than the flow path resistance of the bypass flow path 26 for the supply sub-common flow paths 19S connected to the low regions LPm.

[0105] The flow path resistance may be increased, for example, by reducing the cross-sectional area (as in the illustrated example) and / or by increasing the length. The specific value of the difference in flow path resistance is arbitrary. Note that for the supply sub-common flow path 19S where the pressure is high, the bypass flow path 26 may be eliminated rather than increasing the flow path resistance of the bypass flow path 26.

[0106] The pressure of the plurality of recovery sub-common channels 19C decreases as the channel approaches the outlet 15C. In the illustrated example, the pressure of a recovery sub-common channel 19C combined with a supply sub-common channel 19S having a higher pressure decreases. Therefore, for the plurality of recovery sub-common channels 19C, the channel resistance of the bypass channel 26 increases as the pressure decreases. From another perspective, the channel resistance of the bypass channel 26 increases as the pressure difference between the supply sub-common channel 19S and the recovery sub-common channel 19C increases. The channel resistance may be set from these perspectives instead of or in addition to the perspective of the pressure of the supply sub-common channel 19S.

[0107] (4.3. Actuator) The actuator substrate 37 is, for example, generally plate-shaped and has an area that covers the plurality of pressure chambers 23. Its planar shape is arbitrary, and it may be provided for each nozzle group 27, or may be provided in common for the plurality of nozzle groups 27. The actuator 39 exemplified in Fig. 5 is configured by a so-called unimorph type piezoelectric actuator. However, the actuator 39 may also be configured by another type of piezoelectric actuator, such as a bimorph type.

[0108] The actuator 39 (actuator substrate 37) has, for example, in this order from the flow path member 9 side, a vibration plate 43, a common electrode 45, a piezoelectric layer 47, and an individual electrode 49. The vibration plate 43, the common electrode 45, and the piezoelectric layer 47 extend across the multiple pressure chambers 23 in a plan view, for example. That is, these are provided in common to the multiple pressure chambers 23. The individual electrode 49 is provided for each pressure chamber 23 and faces the pressure chamber 23.

[0109] The portion of the piezoelectric layer 47 sandwiched between the individual electrode 49 and the common electrode 45 is polarized in the thickness direction. Therefore, for example, when an electric field (voltage) is applied in the polarization direction of the piezoelectric layer 47 by the individual electrode 49 and the common electrode 45, the piezoelectric layer 47 contracts in a direction along the layer. This contraction is regulated by the vibration plate 43. As a result, the actuator 39 is flexibly deformed so as to become convex toward the pressure chamber 23. Consequently, the volume of the pressure chamber 23 is reduced, and pressure is applied to the liquid in the pressure chamber 23. Conversely, when an electric field (voltage) is applied in the opposite direction to the polarization direction, the actuator 39 is flexibly deformed so as to become concave relative to the pressure chamber 23. Using this convex and / or concave deformation, the actuator 39 applies pressure to the pressure chamber 23.

[0110] (5. Other Examples of Flow Path Members) (5.1. Flow Path Member According to First Example) FIG. 7 is a planar perspective view showing a flow path member 9A according to a first example. This figure corresponds to FIG. 3. In short, the flow path member 9A has the arrangement positions of the low portions LP and the high portions HP reversed from those of the flow path member 9. However, in this example, similar to the flow path member 9, at locations where nozzle groups 27 are adjacent, the low portions LP or the high portions HP are adjacent to each other. Note that the flow path member 9A is also an example in which one supply main common flow path 17S (and one recovery main common flow path 17C) corresponds to one nozzle group 27, and an example in which liquid flows from one end to the other in the supply main common flow path 17S.

[0111] (5.2. Flow path member according to the second example) Figure 8 is a plan perspective view showing a flow path member 9B according to the second example. This figure corresponds to Figure 3, and shows common supply flow paths (15S, 17S, and 19S) and common recovery flow paths (15C and 17C; 19C coincides with 19S). This figure also shows the nozzle area NA.

[0112] Although not specifically shown, in the flow path member 9B, the multiple nozzles 11 are arranged in a trapezoidal shape. Specifically, the nozzle rows 29 are parallel to the D1 direction, and the nozzle rows 29 closer to the +D2 side have shorter lengths in the D1 direction (the number of nozzles 11 is reduced on both sides in the D1 direction). Consequently, the nozzle region NA has a trapezoidal shape. The multiple nozzle regions NA are arranged in the D1 direction with their orientations in the D2 direction alternately reversed. This ensures that the multiple nozzle groups 27 are spaced apart in the D1 direction by a distance greater than the distance d1, while achieving a resolution of d1 / n.

[0113] In the flow path member 9B, as in the flow path member 9, the main supply common flow paths 17S are arranged alternately between the plurality of nozzle groups 27. Furthermore, a plurality of sub-common supply flow paths 19S extend from each main supply common flow path 17S to both sides in the direction D1. Liquid is then supplied to the two nozzle groups 27 on both sides of each main supply common flow path 17S. Therefore, in the flow path member 9B as well, where the nozzle groups 27 are adjacent to each other, the low regions LP or the high regions HP are adjacent to each other.

[0114] However, in the supply main common flow path 17S of the flow path member 9B, liquid flows from one end to the other. Specifically, the supply main common flow path 17S of the flow path member 9B is configured by dividing the supply main common flow path 17S of the flow path member 9 in the length direction. Each supply main common flow path 17S supplies ink to either the +D2 side or the −D2 side half of the two nozzle groups 27 on either side.

[0115] (5.3. Flow path member according to a third example) Fig. 9 is a plan perspective view showing two flow path members 9C according to yet another example. However, the individual flow paths 20 are shown schematically. Also, the number of nozzles 11 is shown as being small for the sake of convenience. The relative relationship between the spacing between the nozzle rows 29 and the distance d1, etc., is also set from the viewpoint of ease of illustration.

[0116] Each flow path member 9C has only one nozzle group 27. The nozzle group 27 is arranged in a parallelogram shape. However, in the examples described above, the positions of the multiple nozzle rows 29 in the D1 direction are (basically) shifted from one another by a distance of d1 or more, causing the opposite sides on the -D1 side and the +D1 side to be inclined. In the flow path member 9C, the arrangement pattern of the n nozzles 11 (four in the illustrated example) in the band-shaped area BA is set so that the nozzles 11 are positioned closer to the +D2 side as they approach the +D1 side, causing the opposite sides on the -D1 side and the +D1 side to be inclined. However, the opposite sides do not have to be inclined with respect to the D2 direction.

[0117] The two flow path members 9C are arranged at different positions in the D2 direction. Furthermore, when viewed in the D2 direction, the ends of the two flow path members 9C in the D1 direction overlap. When viewed in the D2 direction, the distance between the nozzle 11 located furthest to the +D1 side of the -D1 side flow path member 9C and the nozzle 11 located furthest to the -D1 side of the +D1 side flow path member 9C is d1 / n. This achieves a resolution equivalent to d1 / n between the two flow path members 9C (or, from another perspective, two nozzle groups 27). When three or more flow path members 9C (heads) are arranged, they are arranged in a staggered pattern.

[0118] The supply sub-common flow path 19S and the recovery sub-common flow path 19C extend in a direction intersecting the nozzle row 29. In addition, the two extend parallel to each other in a planar perspective view. The individual flow paths 20 connect adjacent supply sub-common flow paths 19S and recovery sub-common flow paths 19C.

[0119] The plurality of common supply sub-channels 19S and the plurality of common recovery sub-channels 19C are arranged alternately in the D1 direction. In the illustrated example, the number of common supply sub-channels 19S and the number of common recovery sub-channels 19C are the same. Unlike the illustrated example, the number of common supply sub-channels 19S may be one more than the number of common recovery sub-channels 19C, and the common supply sub-channels 19S may be located at both ends in the D1 direction. Conversely, the common recovery sub-channels 19C may be located at both ends in the D1 direction.

[0120] One end of the +D2 side of the common supply sub-channel 19S is connected to the inlet 15S. In other words, the common supply main channel 17S is not provided. As indicated by the arrows in the common supply sub-channel 19S located in the center, liquid flows from the +D2 side to the -D2 side in this channel.

[0121] One end of the recovery sub-common channel 19C on the -D2 side is connected to the outlet 15C. In other words, the recovery main common channel 17C is not provided. As indicated by the arrows on the recovery sub-common channel 19C located in the center, liquid flows from the +D2 side to the -D2 side in this channel. In other words, the liquid flows in the same direction as the flow direction in the supply sub-common channel 19S.

[0122] Unlike the illustrated example, inlets 15S may be provided at both ends of the supply sub-common channel 19S, and outlets 15C may be provided at both ends of the recovery sub-common channel 19C. That is, liquid may flow from both ends to the center in the supply sub-common channel 19S. Liquid may also flow from the center to both ends in the recovery sub-common channel 19C.

[0123] Although not specifically shown, a head including the flow path member 9C may have, for example, another flow path member that is overlaid on the flow path member 9C. This other flow path member extends along the multiple inlets 15S and has a supply flow path that leads to the multiple inlets 15S. In this supply flow path, for example, liquid flows in the direction of the arrow shown at the top of the figure relative to each flow path member 9C. That is, in the flow path member 9C on the -D1 side, liquid flows toward the +D1 side. In the flow path member 9C on the +D1 side, liquid flows opposite to the above, toward the -D1 side.

[0124] Therefore, among the multiple supply sub-common channels 19S of the flow path member 9C on the -D1 side, the pressure is lower as the supply sub-common channel 19S is closer to the +D1 side. As a result, among the multiple supply sub-common channels 19S, the supply sub-common channel 19S located at the end on the -D1 side is a high region HP where the pressure is relatively high, and the supply sub-common channel 19S located at the end on the +D1 side is a low region LP where the pressure is relatively low. In the flow path member 9C on the +D1 side, the low region LP is located on the -D1 side, and the high region HP is located on the +D1 side, conversely to the above.

[0125] As a result, in this example as well, when viewed in the D2 direction, the low portions LP are adjacent to each other or overlap each other (illustrated example). Whether the low portions LP are adjacent to each other or overlap each other when viewed in the D2 direction is determined by whether or not a supply sub-common flow path 19S located at an end closer to the nozzle group 27 is provided, as well as the width and inclination of the supply sub-common flow path 19S. As can be seen from the illustrated example, the recovery sub-common flow path 19C may or may not be present closer to the end of the flow path member 9C than the supply sub-common flow paths 19S that are adjacent to each other or overlap each other.

[0126] Unlike the illustrated example, the high portions HP may overlap each other (or may be adjacent to each other) when viewed in the D2 direction. Also, although not specifically illustrated, when three or more flow path members 9C are arranged, at multiple locations where the ends of the flow path members 9C overlap each other when viewed in the D2 direction, for example, locations where the low portions LP overlap each other and locations where the high portions HP overlap each other may be arranged alternately. It is also acceptable for the low portions LP and the high portions HP to overlap at some of the multiple locations.

[0127] In cases where technical matters different from those described in the summary of the embodiment are extracted, unlike the illustrated example, in the other flow path members overlaid on flow path member 9C, the liquid flows from the center to both ends in the D1 direction, so that low regions LP are located at both ends of nozzle group 27 (in this case, the central portion may be identified as the high region HP where the pressure is relatively high), and only the portions where the low regions LP overlap may be lined up. Conversely, the liquid flows from both ends in the D1 direction to the center, so that high regions HP are located at both ends of nozzle group 27 (in this case, the central portion may be identified as the low region LP where the pressure is relatively low), and only the portions where the high regions HP overlap may be lined up.

[0128] In the illustrated example, the same can be said for the recovery sub-common flow path 19C as for the supply sub-common flow path 19S. However, in the recovery flow paths of other flow path members (not shown) that recover liquid from multiple outlets 15C, the liquid flows in the opposite direction to the supply flow paths of the other flow path members, as shown by the arrows at the bottom of the figure for each flow path member 9C. Furthermore, the high portions HPc are adjacent to or overlap each other. Note that, unlike the illustrated example, in other flow path members (not shown), the flow directions of the supply flow paths and the recovery flow paths may be the same.

[0129] 10 is a diagram showing another example of the connection portion 17b of the supply main common flow path 17S. The upper and lower parts of this figure each correspond to a part of FIG. 3.

[0130] As shown in the upper diagram, the connecting portion 17b may be connected to the end of the main portion 17a of the supply main common flow path 17S. In other words, the opening 17c connecting the two may be in contact with the end face (reference numeral omitted) of the main portion 17a. In this regard, the opening 17c may be, for example, perceived as opening only on the side face of the main portion 17a, or as extending over both the side face and end face of the main portion 17a. Furthermore, the opening 17c and the end face may be slightly spaced apart due to manufacturing errors. In the example shown in the upper diagram, the extending direction of the connecting portion 17b is arbitrary. For example, the connecting portion 17b may be parallel to the D1 direction (as shown in the example), parallel to the supply sub-common flow path 19S (see FIG. 3), or perpendicular to the main portion 17a.

[0131] As shown in the lower diagram, the direction in which the connecting portion 17b extends may be different from the direction in which the supply sub-common flow path 19S extends. The upper diagram is also an example of an embodiment in which the directions are different. In the lower diagram, the connecting portion 17b is inclined with respect to the supply sub-common flow path 19S in a direction that approaches the center of the main portion 17a as it approaches the main portion 17a. From another perspective, the inclination angle of the connecting portion 17b with respect to the main portion 17a is smaller than the inclination angle of the supply sub-common flow path 19S with respect to the main portion 17a. The connection position (position of the opening 17c) of the connecting portion 17b with respect to the main portion 17a, which extends in a direction different from the extension direction of the supply sub-common flow path 19S, is arbitrary. For example, in the lower diagram, the opening 17c is spaced apart from the end face of the main portion 17a. However, the connecting portion 17b oriented as shown in the lower diagram may be connected to the end of the main portion 17a (the opening 17c may be in contact with the end face of the main portion 17a).

[0132] Although not specifically shown, the connecting portion 17b may not be provided. For example, the inlet 15S may be provided directly above the main portion 17a and directly communicate with the opening 17c of the main portion 17a. In this case, the opening 17c may be connected to a position away from the end face of the main portion 17a, as in the example of Fig. 3 and the example in the lower part of Fig. 10, or may be in contact with the end face of the main portion 17a, as in the example in the upper part of Fig. 10.

[0133] (5.5. Combinations of Various Examples) The configurations of the flow path members 9 and 9A to 9C may be combined as appropriate. For example, a configuration in which the main common flow path (17S and 17C) is divided in the longitudinal direction, as in the flow path member 9B, may be applied to a flow path member 9 having a parallelogram-shaped nozzle region NA. Conversely, an undivided main common flow path may be applied to a flow path member 9B having a trapezoidal nozzle region NA.

[0134] Furthermore, for example, a configuration in which a main common flow path (17S and 17C) is not provided, such as flow path member 9C, may be applied to a configuration in which a sub-common flow path (19S and 19C) extends along nozzle row 29, or may be applied to a configuration in which supply sub-common flow path 19S and recovery sub-common flow path 19C are stacked, or may be applied to a configuration in which inlet 15S and outlet 15C are adjacent to each other (a configuration in which the flow directions are opposite between supply sub-common flow path 19S and recovery sub-common flow path 19C).

[0135] The bypass flow path 26 may be applied to an embodiment in which the supply sub-common flow path 19S and the recovery sub-common flow path 19C extend parallel to each other in a plan view, as in the flow path member 9C. The bypass flow path 26 may also be applied to an embodiment in which the end of the supply sub-common flow path 19S farther from the inlet 15S and the end of the recovery sub-common flow path 19C farther from the outlet 15C are not located on the same side in the direction in which the sub-common flow paths (19S and 19C) extend.

[0136] For example, it is possible to consider a configuration in which the main common flow path (17S or 17C) is connected to both ends of each of the sub-common flow paths (19S and 19C), or the inlet 15S or outlet 15C is directly connected to each other. In these configurations, the central portion of the sub-common flow path is the portion far from the inlet 15S or outlet 15C. In other words, the central portion of the supply sub-common flow path 19S is a portion of the flow path where the pressure is relatively low. The central portion of the recovery sub-common flow path 19C is a portion of the flow path where the pressure is relatively high. The central portions may then be connected to each other by a bypass flow path 26.

[0137] Also, for example, an embodiment (see FIG. 9 ) is conceivable in which the end of the supply sub-common flow path 19S farther from the inlet 15S and the end of the recovery sub-common flow path 19C farther from the outlet 15C are located on opposite sides of the extension direction of the sub-common flow paths (19S and 19C). In this embodiment, the far end of the supply sub-common flow path 19S may be connected to an appropriate position of the recovery sub-common flow path 19C. And / or the far end of the recovery sub-common flow path 19C may be connected to an appropriate position of the supply sub-common flow path 19S. The likelihood of unintended backflow may be reduced by, for example, increasing the flow path resistance of the bypass flow path 26.

[0138] (6. Summary of the embodiment) In the following, the reference numeral of the flow path member 9 may be used to represent the flow path members 9 and 9A to 9C. However, unless a contradiction arises, the same applies to the flow path members 9A to 9C. In addition, various configurations and their effects will be described below. However, the effects are merely examples, and various configurations may not necessarily achieve the effects corresponding to the various configurations.

[0139] The flow path member 9 has an ejection surface 9a, multiple nozzle groups 27, and multiple first supply flow paths (supply sub-common flow paths 19S). The ejection surface 9a extends in a first direction (D1 direction) and a second direction (D2 direction) perpendicular to the D1 direction. Each of the multiple nozzle groups 27 includes multiple nozzles 11 opening onto the ejection surface 9a. One or more multiple supply sub-common flow paths 19S are provided corresponding to each nozzle group 27, and each supplies liquid to the multiple nozzles 11 of the corresponding nozzle group 27. When viewed in the D2 direction, the multiple nozzles 11 are arranged at an interval (d1 / n) corresponding to a predetermined resolution in at least the central region (main region NAm) of each nozzle group 27 (i.e., the resolution direction is the D1 direction). The multiple nozzle groups 27 are positioned apart from each other in the D1 direction by a distance L1 longer than the interval (d1 / n). In one or more of the one or more common supply sub-flow paths 19S corresponding to each nozzle group 27, a portion located on one end side of the nozzle group 27 in the D1 direction (for example, the -D1 side) that supplies liquid to the nozzles 11 on that end side, and a portion located on the other end side of the nozzle group 27 in the D1 direction (for example, the +D1 side) that supplies liquid to the nozzles 11 on that end side, when compared with each other, one is a portion where the pressure is relatively low (low portion LP) and the other is a portion where the pressure is relatively high (high portion HP). At one or more locations (three locations in the example of FIG. 3 ) where the nozzle groups 27 are adjacent to each other (the central location in the example of FIG. 3 ), the low portion LP corresponding to one of the adjacent nozzle groups 27 is adjacent to the low portion LP corresponding to the other of the adjacent nozzle groups 27.

[0140] From another perspective, in one or more supply sub-common channels 19S corresponding to each nozzle group 27, when a portion located on one end side of the nozzle group 27 in the D1 direction and supplying liquid to the nozzles 11 on the one end side is compared with a portion located on the other end side of the nozzle group 27 in the D1 direction and supplying liquid to the nozzles 11 on the other end side of the nozzle group 27, one is a portion where the flow path length is relatively long (low portion LP), and the other is a portion where the flow path length is relatively short (high portion HP). At any of one or more locations where a plurality of nozzle groups 27 are adjacent to each other, the long portion corresponding to one of the adjacent nozzle groups 27 is adjacent to the long portion corresponding to the other of the adjacent nozzle groups 27.

[0141] Therefore, for example, as described in the description of the overview of the embodiment, the likelihood of unintended variations in the pressure applied to the liquid in the nozzles 11 at locations where nozzle groups 27 are adjacent to each other is reduced, thereby making it easier to improve image quality.

[0142] The number of the plurality of nozzle groups 27 may be three or more. At the plurality of locations where the nozzle groups 27 are adjacent to one another, locations where the low portions LP are adjacent to one another and locations where the high portions HP are adjacent to one another may be arranged alternately in the D1 direction.

[0143] In this case, the same effect can be obtained at the locations where the high portions HP are adjacent to each other as at the locations where the low portions LP are adjacent to each other. In addition, the likelihood of unintended variations in the pressure applied to the liquid in the nozzle 11 is reduced at any of the multiple locations, which improves the effect of facilitating image quality improvement.

[0144] In a planar perspective view, each of the supply sub-common channels 19S may extend from one end in the D1 direction of the corresponding nozzle group 27 to the other end in the D1 direction of the corresponding nozzle group 27. The portions on both sides of the extending direction may be a low portion LP and a high portion HP.

[0145] In this case, for example, it is not necessary to provide the main common supply flow path 17S between the low regions LP, thereby improving the strength of the flow path member 9. Also, for example, the sub-common supply flow path 19S can be formed between the nozzle rows 29. In theory, the spacing between the nozzle rows 29 is arbitrary regardless of the resolution, so the width of the sub-common supply flow path 19S can be increased to reduce the pressure difference between the low regions LP and the high regions HP.

[0146] The flow path member 9 may have a second supply flow path (main common supply flow path 17S) that supplies liquid to the plurality of sub-common supply flow paths 19S. The main common supply flow path 17S may have a portion (main portion 17a) that extends so as to connect the high points HP of the plurality of sub-common supply flow paths 19S corresponding to each nozzle group 27. Liquid may be supplied to the main common supply flow path 17S from both end sides.

[0147] In this case, the pressure difference between the plurality of supply sub-common channels 19S corresponding to each nozzle group 27 is reduced compared to the case where liquid is supplied from one end side. As a result, the effect of arranging the low regions LP (and / or the high regions HP) adjacent to each other is improved. Note that when liquid is supplied from both ends, it is not necessarily required that liquid be supplied to both ends, as in the example of Figure 3. For example, it is sufficient if liquid is supplied from both sides to the central position (or the central range divided into three equal parts).

[0148] The flow path member 9 may further have a plurality of individual flow paths 20 and a plurality of first recovery flow paths (recovery sub-common flow paths 19C). The plurality of individual flow paths 20 may have a plurality of nozzles 11, and liquid may be supplied from the supply sub-common flow path 19S. One or more recovery sub-common flow paths 19C may be provided corresponding to each nozzle group 27, and may recover liquid from the plurality of individual flow paths 20 to which the plurality of nozzles 11 of the corresponding nozzle group 27 belong. The recovery sub-common flow path 19C may extend in parallel to the supply sub-common flow path 19S. When compared with each other, the regions on both sides of the extension direction may be a region with relatively low pressure (low region LPc) and a region with relatively high pressure (high region HPc). In the supply sub-common flow path 19S and the recovery sub-common flow path 19C that are parallel to each other, the low portion LP of the supply sub-common flow path 19S and the high portion HPc of the recovery sub-common flow path 19C may be located on the same side in the D1 direction (in other words, the high portion HP of the supply sub-common flow path 19S and the low portion LPc of the recovery sub-common flow path 19C may be located on the same side in the D1 direction).

[0149] In this case, for example, the pressure in the recovery sub-common channel 19C is lower in the individual channel 20 connected to the high region HP than in the individual channel 20 connected to the low region LP, so it is easier to release the pressure from the supply sub-common channel 19S. As a result, it is easier to reduce the difference in pressure applied to the liquid in the nozzle 11, which is caused by the pressure difference between the high region HP and the low region LP.

[0150] The flow path member 9 may have a bypass flow path 26. The bypass flow path 26 may be open to the low portion LP of the supply sub-common flow path 19S and also to the high portion HPc of the recovery sub-common flow path 19C, and may connect the two without passing through the multiple individual flow paths 20.

[0151] In this case, for example, the probability that liquid will accumulate in the low portion LP can be reduced. Since the low portion LP is connected to the high portion HPc, the probability that backflow will occur in the recovery sub-common channel 19C can be reduced. Consequently, the probability that liquid will accumulate in the high portion HPc of the recovery sub-common channel 19C can also be reduced.

[0152] The main common supply flow path 17S may have, in its extension direction, a relatively high-pressure region (high region HPm) and a relatively low-pressure region (low region LPm) when compared with each other. The flow path resistance of the bypass flow path 26 for the sub-common supply flow path 19S connected to the high region HPm may be made larger than the flow path resistance of the bypass flow path 26 for the sub-common supply flow path 19S connected to the low region LPm.

[0153] In this case, for example, it is possible to reduce the pressure difference between the plurality of common supply sub-channels 19S. This reduces the possibility of unintended variations in the pressure applied to the liquid between the plurality of nozzles 11, which may occur due to the nozzles 11 communicating with different common supply sub-channels 19S in each nozzle group 27. As a result, the effect of arranging the low portions LP adjacent to each other is improved.

[0154] The main common supply channel 17S may have a main portion 17a. The main portion 17a may extend so as to connect the high points HP of the plurality of sub-common supply channels 19S corresponding to each nozzle group 27. The main portion 17a may have an opening 17c, through which liquid is supplied, located away from the end face of the main portion 17a (see, for example, FIG. 3 ).

[0155] In this case, for example, compared to the embodiment in which the opening 17c is in contact with the end face of the main portion 17a (upper part of Figure 10), it is easier to make the flow path resistance of the path from the opening 17c via the supply main common flow path 17S to the supply sub-common flow path 19S closer to each other among the supply sub-common flow paths 19S. From another perspective, the pressure difference between the high region HPm and the low region LPm in the supply main common flow path 17S can be reduced. As a result, it is possible to reduce the likelihood of unintended variations in the pressure applied to the liquid among the multiple nozzles 11 due to the nozzles communicating with different supply sub-common flow paths 19S. This improves the effect of arranging the low regions LP next to each other.

[0156] Unlike the above, the main portion 17a may have an opening 17c through which the liquid is supplied, at a position adjacent to the end face of the main portion 17a (upper part of FIG. 10).

[0157] In this case, for example, the likelihood of liquid accumulating at the end of the main portion 17a is reduced, which in turn reduces the likelihood of various problems occurring due to the liquid solidifying.

[0158] The main common supply flow path 17S may have a connecting portion 17b in addition to the main portion 17a. The connecting portion 17b may extend from the inlet 15S, to which the liquid is supplied, to the main portion 17a. In a planar perspective view, the extending direction of the connecting portion 17b may be different from the extending direction of the sub-common supply flow path 19S (FIG. 10).

[0159] In this case, for example, compared to an embodiment in which the connecting portion 17b and the supply sub-common flow path 19S extend in the same direction, it is easier to make the flow path resistance of the path from the opening 17c to the supply sub-common flow path 19S via the supply main common flow path 17S closer to each other among the supply sub-common flow paths 19S. For example, in the example of FIG. 3, liquid easily flows from the connecting portion 17b to the supply sub-common flow path 19S that is positioned in series with the connecting portion 17b and the supply main common flow path 17S sandwiched between the connecting portion 17b and the supply sub-common flow path 19S. As a result, the difference in flow path resistance from the opening 17c between the supply sub-common flow path 19S and the other supply sub-common flow paths 19S tends to be large. However, the embodiment of FIG. 10 can reduce the difference in flow path resistance.

[0160] The flow path member 9 may have a main common supply flow path 17S. The main common supply flow path 17S may extend in a direction intersecting the D1 direction between adjacent first and second nozzle groups 27. The main common supply flow path 17S may supply liquid to a plurality of sub-common supply flow paths 19S corresponding to the first and second nozzle groups. The main common supply flow path 17S may have, in that order along its extension, a first range (e.g., an end range RE on the +D2 side), a second range (a central range RC), and a third range (e.g., an end range RE on the −D2 side). A sub-common supply flow path 19S corresponding to the first nozzle group (e.g., the nozzle group 27 on the −D1 side) may extend from the first range, but a sub-common supply flow path 19S corresponding to the second nozzle group (e.g., the nozzle group 27 on the +D1 side) may not extend. The common sub-supply flow path 19S corresponding to the first nozzle group and the common sub-supply flow path 19S corresponding to the second nozzle group may extend from the second range. The common sub-supply flow path 19S corresponding to the first nozzle group does not have to extend from the third range, but the common sub-supply flow path 19S corresponding to the second nozzle group may extend.

[0161] Here, the end range RE and the flow paths (19S and 20) connected to the end range RE are more likely to approach the opposing sides (i.e., the outer edges of the flow path member 9) in the D2 direction of the flow path member 9 than the central range RC and the flow paths (19S and 20) connected to the central range RC. As a result, for example, the former are more likely to experience a decrease in the temperature of the liquid than the latter. When the temperature of the liquid decreases, for example, the viscosity of the liquid increases and the fluidity decreases. By extending the supply sub-common flow path 19S extending from the end range RE to only one side, for example, it is possible to reduce the pressure drop in the end range RE and alleviate the decrease in fluidity.

[0162] The flow path member 9 may have an inlet 15S that opens to the outer surface of the flow path member 9 and communicates (directly or indirectly) with the main supply common flow path 17S. In a planar perspective view of the ejection surface 9a, the inlet 15S may be located on the opposite side (+D1 side) from the first nozzle group (e.g., the nozzle group 27 on the −D1 side) with respect to the first range (e.g., the end range RE on the +D2 side).

[0163] In this case, for example, the dead space created by extending the supply sub-common flow path 19S from the end range RE to only one side can be utilized as the location of the inlet 15S. Also, for example, when the inlet 15S is connected to the end range RE, the pressure in the end range RE tends to be higher than the pressure in the central range RC. Consequently, the above-mentioned effect (mitigation of the decrease in fluidity in the flow path related to the end range RE) is improved.

[0164] The flow path member 9 may have multiple manifolds (supply manifolds 16S) arranged in the D1 direction. The supply manifold 16S may supply liquid to multiple nozzle groups 27. The outer edge of the flow path member 9 may be a parallelogram having a pair of first opposite sides (reference numeral omitted) parallel to the D1 direction and a pair of second opposite sides inclined with respect to the D2 direction perpendicular to the D1 direction. On the outer edge, a pair of diagonals (reference numeral omitted) may be located on a first side in the D1 direction (e.g., the −D1 side) and a third side in the D2 direction (e.g., the −D2 side), and a second side (e.g., the +D1 side) opposite the first side and a fourth side (e.g., the +D2 side) opposite the third side. Each supply manifold 16S may have a main common supply flow path 17S and multiple sub-common supply flow paths 19S in a planar perspective view of the ejection surface 9a. The main common supply flow channel 17S may extend parallel to the second opposite side between adjacent nozzle groups 27. The multiple sub-common supply flow channels 19S may extend parallel to each other from the main common supply flow channel 17S toward the -D1 side and the -D2 side. The other multiple sub-common supply flow channels 19S may extend parallel to each other from the main common supply flow channel 17S toward the +D1 side and the +D2 side. Each supply manifold 16S may be configured with 180° rotational symmetry.

[0165] In this case, for example, by inclining the multiple supply sub-common channels 19S in the D1 direction, the length within a predetermined range in the D1 direction can be increased compared to when the multiple supply sub-common channels 19S are parallel to the D1 direction. By configuring a channel group by extending multiple supply sub-common channels 19S in parallel and arranging multiple channel groups in the D1 direction, the overall volume of the multiple supply sub-common channels 19S is increased. Meanwhile, since the multiple supply sub-common channels 19S are not entirely connected but are separated into multiple supply manifolds 16S, pressure loss across the multiple supply sub-common channels 19S as a whole is reduced. Furthermore, the pressure and flow rate distribution can be made smooth. This ultimately reduces variation in ink ejection characteristics. As a result, for example, the likelihood of insufficient ejection occurring in some nozzles 11 can be reduced.

[0166] The liquid ejection device (head 7, ejection unit 5 or ejection system 3) according to the embodiment includes the flow path member 9 according to the above embodiment and an actuator 39. The actuator 39 applies pressure to the liquid in the flow path member 9 to eject the liquid from the nozzles 11. Since the head 7 includes the flow path member 9, it is possible to enjoy the various effects that the flow path member 9 provides.

[0167] The head 7 may have a plurality of flow path members 9. The plurality of flow path members 9 may be located at different positions in the D1 direction, and their ends in the D1 direction may overlap when viewed in the D2 direction. At one or more locations where the ends overlap, a low portion LP of one of the overlapping flow path members 9 may be adjacent to or overlap a low portion LP of the other of the overlapping flow path members 9 when viewed in the D2 direction.

[0168] In this case, for example, at a location where flow path members 9 are adjacent to each other, an effect is achieved by the low portions LP being adjacent to each other (or overlapping) in the same way as at a location where nozzle groups 27 are adjacent to each other within one flow path member 9. Note that the above configuration may also be achieved between flow path members 9 each having only one nozzle group 27, as exemplified in FIG.

[0169] The technology according to the present disclosure is not limited to the above-described embodiments and may be implemented in various forms.

[0170] For example, the recording device is not limited to those generally classified as printers. For example, the recording device may be a plotter. Furthermore, for example, the recording device may be a device in which a liquid ejection device is moved by a robot to print on a stationary recording medium, or a handheld printer in which a liquid ejection device is moved by hand to print on a stationary recording medium. As can be understood from the above, the transport device is not limited to one that moves the recording medium, but may also be one that moves the liquid ejection device, or one that moves both the liquid ejection device and the recording medium.

[0171] Furthermore, for example, the liquid is not limited to ink, but may be paint or a conductive material for patterning a circuit board (however, either can be considered as a type of ink). Furthermore, for example, the liquid may be one that exhibits the properties of a Newtonian fluid, or one that exhibits the properties of a non-Newtonian fluid (e.g., pseudoplasticity).

[0172] Furthermore, for example, the media is not limited to paper, but may be, for example, resin, cloth, wood, metal, or ceramic. Furthermore, the media is not limited to paper (film)-like objects, but may be, for example, plate-like objects, car bodies, or buildings.

[0173] The nozzle plate and the liquid ejection device may be used for purposes other than recording. For example, the nozzle plate may be used for ejecting a chemical substance from a nozzle toward another chemical substance to cause a chemical reaction.

[0174] 1...printer (recording device), 3...ejection system (liquid ejection device), 5...ejection unit (liquid ejection device), 7...head (liquid ejection device), 9...flow path member, 9a...ejection surface, 11...nozzle, 19S...supply sub-common flow path (first supply flow path), 27...nozzle group, LP...low region (region with low pressure), HP...high region (region with high pressure), NAm...main region (central region).

Claims

1. A liquid ejection device comprising: an ejection surface extending in a first direction and a second direction perpendicular to the first direction; a plurality of nozzle groups each including a plurality of nozzles opening onto the ejection surface; and a plurality of first supply flow paths, one or more of which are provided corresponding to each of the nozzle groups and each supplying liquid to the plurality of nozzles in the corresponding nozzle group, wherein when viewed in the second direction, the plurality of nozzles are lined up at intervals corresponding to a predetermined resolution in at least a central region of each of the nozzle groups, and the plurality of nozzle groups are positioned apart from each other in the first direction by a distance longer than the intervals, and in the one or more first supply flow paths corresponding to each of the nozzle groups, a portion located on the first end side of the corresponding nozzle group in the first direction and supplying liquid to the nozzles on the first end side, and a portion located on the second end side of the corresponding nozzle group in the first direction and supplying liquid to the nozzles on the second end side, are positioned such that, when compared with each other, one is a portion with a relatively low pressure and the other is a portion with a relatively high pressure, A flow path member in which, at one or more locations where the nozzle groups are adjacent to each other, the low portion corresponding to one of the adjacent nozzle groups is adjacent to the low portion corresponding to the other of the adjacent nozzle groups.

2. A flow path member as described in claim 1, wherein the number of the plurality of nozzle groups is three or more, and at a plurality of locations where the nozzle groups are adjacent to one another, locations where the low portions are adjacent to one another and locations where the high portions are adjacent to one another are arranged alternately in the first direction.

3. A flow path member as described in claim 1 or 2, wherein each of the first supply flow paths extends from the first end side of the corresponding nozzle group toward the second end side of the corresponding nozzle group in a planar perspective view of the ejection surface, and the portions on both sides of the direction of extension are the low portion and the high portion.

4. A flow path member according to claim 3, further comprising a second supply flow path which has a portion extending so as to connect the higher portions of the plurality of first supply flow paths corresponding to each of the nozzle groups and supplies the liquid to the plurality of first supply flow paths, and the second supply flow path is supplied with the liquid from both end sides.

5. A flow path member according to claim 3 or 4, further comprising: a plurality of individual flow paths each having a plurality of the nozzles and to which the liquid is supplied from the first supply flow path; and a plurality of first recovery flow paths, one or more in number corresponding to each of the nozzle groups, which recover the liquid from the plurality of individual flow paths to which the plurality of nozzles of the corresponding nozzle group belong; wherein the first recovery flow path extends in parallel to the first supply flow path, and portions on both sides of the direction of extension are portions with relatively low and high pressures when compared with each other; and wherein the first supply flow path and first recovery flow path are parallel to each other, and the low portion of the first supply flow path and the high portion of the first recovery flow path are located on the same side in the first direction.

6. A flow path member as described in claim 5, having a bypass flow path that opens to the lower portion of the first supply flow path and also opens to the higher portion of the first recovery flow path, connecting the two without going through multiple individual flow paths.

7. A flow path member according to any one of claims 1 to 6, further comprising: a second supply flow path having an extending portion connecting the high portions of the plurality of first supply flow paths corresponding to each of the nozzle groups, and supplying the liquid to the plurality of first supply flow paths; a plurality of individual flow paths having a plurality of the nozzles, and to which the liquid is supplied from the first supply flow paths; a plurality of first recovery flow paths, the number of which is one or more, provided corresponding to each of the nozzle groups, and recovering the liquid from the plurality of individual flow paths to which the plurality of nozzles of the corresponding nozzle group belong; and a plurality of bypass flow paths connecting the plurality of first supply flow paths and the plurality of first recovery flow paths without passing through the plurality of individual flow paths, wherein the second supply flow paths have, in their extending direction, portions of relatively high pressure and portions of relatively low pressure when compared with each other, and the flow path member according to any one of claims 1 to 6, further comprising: a second supply flow path having an extending portion connecting the high portions of the plurality of first supply flow paths, and supplying the liquid to the plurality of first supply flow paths 8. A flow path member as set forth in claim 3 and any one of claims 4 to 7 which directly or indirectly cite claim 3, comprising a second supply flow path which supplies the liquid to a plurality of first supply flow paths corresponding to each of the nozzle groups, wherein the second supply flow path has a main portion which extends so as to connect the higher portions of the plurality of first supply flow paths corresponding to each of the nozzle groups, and the main portion has an opening through which the liquid is supplied at a position away from an end face of the main portion.

9. A flow path member as set forth in claim 3 and any one of claims 4 to 7 which directly or indirectly cite claim 3, comprising a second supply flow path which supplies the liquid to a plurality of first supply flow paths corresponding to each of the nozzle groups, wherein the second supply flow path has a main portion which extends so as to connect the higher portions of the plurality of first supply flow paths corresponding to each of the nozzle groups, and the main portion has an opening through which the liquid is supplied, located in contact with an end face of the main portion.

10. A flow path member as set forth in claim 3 and any one of claims 4 to 9 which directly or indirectly cite claim 3, comprising a second supply flow path which supplies the liquid to a plurality of the first supply flow paths corresponding to each of the nozzle groups, wherein the second supply flow path has a main portion which extends so as to connect the higher portions of the plurality of first supply flow paths corresponding to each of the nozzle groups, and a connecting portion which extends from an inlet to which the liquid is supplied to the main portion, wherein, in a planar perspective view of the ejection surface, the extending direction of the connecting portion and the extending direction of the first supply flow path are different from each other.

11. A flow path member according to claim 3 and any one of claims 4 to 10 which directly or indirectly cite claim 3, comprising second supply flow paths extending in a direction intersecting the first direction between adjacent first and second nozzle groups among said plurality of nozzle groups, and supplying the liquid to a plurality of first supply flow paths corresponding to said first and second nozzle groups, wherein said second supply flow paths have a first range, a second range, and a third range in that order in the direction in which they extend, wherein said first supply flow paths corresponding to said first nozzle group extend from said first range, but said first supply flow paths corresponding to said second nozzle group do not extend, wherein said first supply flow paths corresponding to said first nozzle group and said first supply flow paths corresponding to said second nozzle group extend from said second range, wherein said first supply flow paths corresponding to said first nozzle group do not extend from said third range, but said first supply flow paths corresponding to said second nozzle group extend.

12. A flow path member as described in claim 11, wherein the flow path member has an inlet that opens to the outer surface of the flow path member and communicates with the second supply flow path, and when viewed from above in a perspective view of the ejection surface, the inlet is located on the opposite side of the first range from the first nozzle group.

13. A flow path member according to claim 3 and any one of claims 4 to 12 which directly or indirectly cite claim 3, comprising a plurality of manifolds which are arranged in the first direction and supply the liquid to the plurality of nozzle groups, wherein an outer edge of the flow path member is a parallelogram having a pair of first opposite sides parallel to the first direction and a pair of second opposite sides inclined with respect to the second direction, and a pair of acute diagonal angles which are located on a first side in the first direction and a third side in the second direction, and on a second side opposite the first side and a fourth side opposite the third side, wherein each of the manifolds, in a planar perspective view of the ejection surface, has: a second supply flow path extending parallel to the second opposite sides between adjacent nozzle groups; a plurality of first supply flow paths extending parallel to each other from the second supply flow path to the first side and the third side; and a plurality of first supply flow paths extending parallel to each other from the second supply flow path to the second side and the fourth side, and which is configured with 180° rotational symmetry.

14. A liquid ejection device comprising: an ejection surface extending in a first direction and a second direction perpendicular to the first direction; a plurality of nozzle groups each including a plurality of nozzles opening on the ejection surface; a plurality of first supply flow paths, one or more of which are provided corresponding to each of the nozzle groups and each supply liquid to the plurality of nozzles of the corresponding nozzle group; and one or more inlets which are connected to the plurality of nozzle groups via the plurality of first supply flow paths and are capable of receiving liquid from the outside; when viewed in the second direction, the plurality of nozzles are arranged at intervals corresponding to a predetermined resolution in at least a central region of each of the nozzle groups; and the plurality of nozzle groups are positioned apart in the first direction by a distance longer than the intervals, In one or more of the first supply flow paths corresponding to each of the nozzle groups, a portion located on a first end side of the nozzle group in the first direction and supplying the liquid to the nozzles on the first end side, and a portion located on a second end side of the nozzle group in the first direction and supplying the liquid to the nozzles on the second end side, when comparing the flow path lengths from the nearest inlet for each portion, one is a portion where the flow path length is relatively long and the other is a portion where the flow path length is relatively short, and at any of one or more locations where the multiple nozzle groups are adjacent to each other, the long portion corresponding to one of the adjacent nozzle groups and the long portion corresponding to the other of the adjacent nozzle groups are adjacent to each other.

15. A liquid ejection device comprising: a flow path member according to any one of claims 1 to 14; and an actuator that applies pressure to the liquid in the flow path member to eject the liquid from the nozzle.

16. A liquid ejection device as described in claim 15, which has a plurality of flow path members whose positions in the first direction are different from each other and whose ends in the first direction overlap when viewed in the second direction, and at any one or more locations where the ends overlap, when viewed in the second direction, the low portion of one of the overlapping flow path members and the low portion of the other of the overlapping flow path members are adjacent to or overlap each other.

17. A liquid ejection device comprising a plurality of flow path members each having an ejection surface extending in a first direction and a second direction perpendicular to the first direction, wherein the plurality of flow path members are positioned differently in the first direction and have ends in the first direction overlapping each other when viewed in the second direction, wherein each of the flow path members comprises one or more nozzle groups each having a plurality of nozzles opening onto the ejection surface, and one or more first supply flow paths, each of which is provided in a number of one or more corresponding to each of the nozzle groups and supplies liquid to the plurality of nozzles of the corresponding nozzle group, wherein when viewed in the second direction, the plurality of nozzles are arranged at an interval corresponding to a predetermined resolution in at least a central region of each of the nozzle groups, and in each of the flow path members, on either side of each of the nozzle groups in the first direction, there are no other nozzle groups or the other nozzle groups are positioned at a distance in the first direction longer than the interval, In one or more of the first supply flow paths corresponding to each of the nozzle groups, a portion located on the first end side of the corresponding nozzle group in the first direction and supplying the liquid to the nozzles on the first end side, and a portion located on the second end side of the corresponding nozzle group in the first direction and supplying the liquid to the nozzles on the second end side, when compared with each other, one is a portion with relatively low pressure and the other is a portion with relatively high pressure, and at any of one or more locations where the ends of the flow path members overlap each other, the low portion of one of the overlapping flow path members and the low portion of the other of the overlapping flow path members are adjacent to or overlap each other when viewed in the second direction.

18. A recording device comprising: a liquid ejection device according to any one of claims 15 to 17; and a transport device that moves the liquid ejection device and a recording medium relatively in the second direction.

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