Liquid discharge device

Abstract

To provide a liquid discharge device which can discharge two types of liquids from one liquid discharge head while inhibiting increase in size of the liquid discharge head in a second direction.SOLUTION: A liquid discharge device includes: a plurality of first pressure chambers respectively communicating with a plurality of first nozzles; a first common passage having a plurality of branch passages respectively communicating with the first pressure chambers and a first main passage communicating with the first branch passages; a plurality of second pressure chambers respectively communicating with second nozzles which is located at one side relative to the first nozzles in a second direction intersecting with a first direction in which the first nozzles are lined up; and a second common passage having a plurality of second branch passages respectively communicating with the second pressure chambers and a second main passage communicating with the second branch passages. The first main passage and the second main passage are disposed between the first nozzles and the second nozzles in the second direction. The first main passage and the second main passage respectively overlap with at least parts of the first common passage and the second common passage in a third direction intersecting with the first direction and the second direction.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device that ejects liquid. [Background technology]

[0002] A known example of a conventional liquid ejection device is the liquid ejection device disclosed in Patent Document 1. The liquid ejection head of this device includes a plurality of nozzles and a liquid flow path that communicates with the nozzles. The liquid flow path includes a plurality of pressure chambers, a plurality of common supply flow path branches and a plurality of common recovery flow path branches that communicate with the pressure chambers, a common supply flow path main that communicates with the plurality of common supply flow path branches, and a common recovery flow path main that communicates with the plurality of common recovery flow path branches. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-155683 Summary of the Invention [Problem to be solved by the invention]

[0004] In the liquid ejection head described above, liquid flows through a common supply channel main, a common supply channel tributary, and a pressure chamber and is supplied to the nozzle. A portion of the liquid is ejected from the nozzle, and the remaining liquid that is not ejected flows through a common recovery channel tributary and a common recovery channel main, and is then recovered. A liquid ejection head in which liquid is circulated by supply and recovery in this manner is provided with a channel that supplies the liquid to the nozzle, as well as a channel that recovers the liquid that is not ejected from the nozzle. When ejecting two types of liquid from such a liquid ejection head, arranging the same number of liquid channels as the types of liquid in the liquid ejection head poses the problem of increasing the size of the liquid ejection head in the direction of arrangement.

[0005] In view of the above, the present invention aims to provide a liquid ejection device that can eject two types of liquid from one head while suppressing an increase in the size of the head in the direction in which the liquid flow paths are arranged. [Means for solving the problem]

[0006] A liquid ejection device according to the present disclosure comprises a plurality of first nozzles that eject a first liquid, a plurality of first pressure chambers each communicating with the first nozzles, a plurality of first branch channels each communicating with the first pressure chambers, and a first common channel having a first main channel communicating with the first branch channels, a plurality of second nozzles that are arranged on one side of the first nozzles in a second direction intersecting a first direction in which the first nozzles are lined up in a row, and eject a second liquid that is different from the first liquid, a plurality of second pressure chambers each communicating with the second nozzles, a plurality of second branch channels each communicating with the second pressure chambers, and a second main channel communicating with the second branch channels, wherein the first main channel and the second main channel are arranged between the first nozzles and the second nozzles in the second direction, and wherein the first main channel and the second main channel overlap at least a portion of the first common channel and the second common channel in a third direction intersecting the first direction and the second direction. [Effects of the Invention]

[0007] According to the present disclosure, the first main path of the first common path and the second main path of the second common path overlap at least a portion of the first common path and the second common path. Furthermore, a first liquid is ejected from a first nozzle communicating with a first branch path of the first common path, and a second liquid is ejected from a second nozzle communicating with a second branch path of the second common path. This makes it possible to eject two types of liquid from a single head while preventing the head from becoming too large in the direction in which the first and second common paths are aligned. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of a liquid ejection device according to the present disclosure, viewed from above; [Figure 2] FIG. [Figure 3] FIG. 10 is a top view of a portion of an individual plate in which first individual paths and second individual paths are formed. [Figure 4] 10 is a top view of a first common plate in which a first common path is formed and a second common plate in which a second common path is formed. FIG. [Figure 5] 5 is a top view of the second common plate in which the second common path of FIG. 4 is formed. FIG. [Figure 6] FIG. [Figure 7] Fig. 7A is a cross-sectional view of the common plate and the damper plate taken along line VIIA-VIIA in Fig. 6. Fig. 7B is a cross-sectional view of the common plate and the damper plate taken along line VIIB-VIIB in Fig. 6. Fig. 7C is a cross-sectional view of the common plate and the damper plate taken along line VIIC-VIIC in Fig. 6. [Figure 8] Fig. 8A is a cross-sectional view of a common plate and a damper plate cut at a first recovery port in a liquid ejection device according to Modification 1. Fig. 8B is a cross-sectional view of the common plate and the damper plate cut along the first and second supply branch paths in Fig. 8A. Fig. 8C is a cross-sectional view of the common plate and the damper plate cut at a second recovery port in Fig. 8A. [Figure 9] 10 is a diagram showing a first common plate on which a first common path is formed and a second common plate on which a second common path is formed in a liquid ejection device according to Modification 2, as viewed from above. FIG. [Figure 10] 10 is a top view of the second common plate in which the second common path of FIG. 9 is formed. FIG. [Figure 11] Fig. 11A is a cross-sectional view of the common plate and damper plate cut at the second recovery port in Fig. 9. Fig. 11B is a cross-sectional view of the common plate and damper plate cut at the second recovery port when an extension portion is provided in the second main recovery path of Modification 1. [Figure 12] FIG. 10 is a top view of a support member of a common plate of a liquid ejection device according to a second embodiment. [Figure 13] 13 is a top view of the main path member 24d4 of the common plate in FIG. 12. FIG. [Figure 14] FIG. 13 is a top view of the damper plate of FIG. 12. [Figure 15] Fig. 15A is a cross-sectional view of the common plate and the damper plate taken along XVA-XVA in Fig. 13. Fig. 15B is a cross-sectional view of the common plate and the damper plate taken along XVB-XVB in Fig. 13. DETAILED DESCRIPTION OF THE INVENTION

[0009] <First Embodiment> <Liquid discharge device> 1, a liquid ejection device 10 according to a first embodiment of the present disclosure is a device that ejects liquid, and is, for example, a printing device such as an inkjet printer. In the following, a case where a serial head type inkjet printer is used as the liquid ejection device 10 will be described, but the liquid ejection device 10 is not limited to this, and for example, a line head type inkjet printer or the like may also be used as the liquid ejection device 10.

[0010] Furthermore, the liquid ejection device 10 includes one or more liquid ejection heads (hereinafter referred to as heads) 20 that eject liquid. The head 20 has a plurality of first nozzles 21a that eject a first liquid and a plurality of second nozzles 22a that eject a second liquid. The second liquid is a different type of liquid from the first liquid. Therefore, the head 20 ejects the first liquid and the second liquid, which are different from each other. The head 20 will be described later.

[0011] The liquid ejection device 10 may also have multiple (for example, two) heads 20. In this case, the first head 20 may eject black ink as the first liquid and cyan ink as the second liquid. The second head 20 may eject magenta ink as the first liquid and yellow ink as the second liquid. In this way, the liquid ejection device 10 may eject four types of ink using the two heads 20.

[0012] The multiple first nozzles 21a are lined up along the first direction to form a first nozzle row. The multiple second nozzles 22a are lined up along the first direction to form a second nozzle row. The multiple first nozzle rows are lined up in a second direction that intersects (e.g., perpendicular to) the first direction. The multiple second nozzle rows are lined up in the second direction. The second nozzle row is arranged on one side of the first nozzle row in the second direction. Note that, hereinafter, the first direction will be referred to as the front-to-rear direction, and the second direction will be referred to as the left-to-right direction. One side of this second direction will be referred to as the left. Furthermore, a third direction that intersects (e.g., perpendicular to) the first and second directions will be referred to as the up-down direction. However, the directions related to the head 20 are not limited to these.

[0013] Furthermore, the liquid ejection device 10 includes a first cartridge 11 that stores the first liquid, and a second cartridge 12 that stores the second liquid. The first cartridge 11 and the second cartridge 12 are detachably attached to the housing of the liquid ejection device 10. The first cartridge 11 supplies the first liquid to the first nozzles 21a, and the second cartridge 12 supplies the second liquid to the second nozzles 22a.

[0014] The liquid ejection device 10 further includes a transport device 13 that transports the ejection receiving medium A, and a moving device 14 that moves the head 20. The transport device 13 has a roller 13a with a central axis that extends in the left-right direction. The roller 13a rotates around the central axis, thereby transporting the ejection receiving medium A in the front-to-rear direction. The moving device 14 also has a guide rail 14a that extends in the left-to-right direction, and an endless belt 14b connected to the head 20. As the endless belt 14b runs, the head 20 is supported by the guide rail 14a and moves in the left-to-right direction. In the printing process of this liquid ejection device 10, the head 20 ejects liquid onto the ejection receiving medium A while moving in the left-to-right direction, and an image is printed on the ejection receiving medium A by transporting the ejection receiving medium A in the front-to-rear direction.

[0015] <head> 2A and 2B, the head 20 has a liquid flow path 23 and a chip 24 in which the liquid flow path 23 is formed. The chip 24 has, for example, a plurality of plates stacked in the vertical direction. The plurality of plates includes a nozzle plate 24a, individual plates 24b, a vibration plate 24c, a common plate 24d, and a damper plate 24e. The liquid flow path 23 is formed in the chip 24 by through holes and recesses formed in each of the plates.

[0016] The liquid flow path 23 includes a first liquid flow path 23 through which a first liquid flows and a second liquid flow path 23 through which a second liquid flows. The first liquid flow path 23 has a plurality of first nozzles 21a, a plurality of first individual paths 21b connected to the plurality of first nozzles 21a respectively, and a first common path 30 connected to the plurality of first individual paths 21b. The second liquid flow path 23 has a plurality of second nozzles 22a, a plurality of second individual paths 22b connected to the plurality of second nozzles 22a respectively, and a second common path 40 connected to the plurality of second individual paths 22b.

[0017] The nozzle plate 24a is formed with a plurality of first nozzles 21a and a plurality of second nozzles 22a. Each of the first nozzles 21a and the second nozzles 22a extends in the vertical direction, penetrates the nozzle plate 24a, and opens on the lower surface of the nozzle plate 24a. As a result, the first liquid is ejected from the opening of the first nozzle 21a, and the second liquid is ejected from the opening of the second nozzle 22a.

[0018] The individual plate 24b is stacked on the nozzle plate 24a, and a plurality of first individual paths 21b and a plurality of second individual paths 22b are formed in the individual plate 24b. The first individual paths 21b are provided for each first nozzle 21a and have a first pressure chamber 21b1 connected to the first nozzle 21a. Note that a descender extending in the vertical direction may be provided between the first pressure chamber 21b1 and the first nozzle 21a. In this way, the first pressure chamber 21b1 is connected to the first nozzle 21a directly or via a descender, and the plurality of first pressure chambers 21b1 are connected to the plurality of first nozzles 21a, respectively.

[0019] Furthermore, the second individual passage 22b is provided for each second nozzle 22a and has a second pressure chamber 22b1 connected to the second nozzle 22a. Note that a descender extending in the vertical direction may be provided between the second pressure chamber 22b1 and the second nozzle 22a. In this manner, the second pressure chamber 22b1 communicates with the second nozzle 22a directly or via the descender, and the multiple second pressure chambers 22b1 are respectively communicated with the multiple second nozzles 22a.

[0020] 2A and 3, the first individual channel 21b has a first supply communication channel 21b2, a first supply individual channel 21b3, a first recovery communication channel 21b4, and a first recovery individual channel 21b5. The first supply communication channel 21b2 is connected to the first pressure chamber 21b1 and the first supply individual channel 21b3, and the first recovery communication channel 21b4 is connected to the first pressure chamber 21b1 and the first recovery individual channel 21b5. As a result, the first liquid is supplied to the first nozzle 21a via the first supply individual channel 21b3, the first supply communication channel 21b2, and the first pressure chamber 21b1. Then, the first liquid that is not ejected from the first nozzle 21a is recovered from the first pressure chamber 21b1 via the first recovery communication channel 21b4 and the first recovery individual channel 21b5.

[0021] 2B and 3, the second individual channel 22b has a second supply communicating channel 22b2, a second supply individual channel 22b3, a second recovery communicating channel 22b4, and a second recovery individual channel 22b5. The second supply communicating channel 22b2 is connected to the second pressure chamber 22b1 and the second supply individual channel 22b3, and the second recovery communicating channel 22b4 is connected to the second pressure chamber 22b1 and the second recovery individual channel 22b5. As a result, the second liquid is supplied to the second nozzle 22a via the second supply individual channel 22b3, the second supply communicating channel 22b2, and the second pressure chamber 22b1. The second liquid that is not ejected from the second nozzle 22a is recovered from the second pressure chamber 22b1 via the second recovery communicating channel 22b4 and the second recovery individual channel 22b5.

[0022] 2A and 2B, the vibration plate 24c is laminated on the individual plate 24b and covers the first pressure chamber 21b1 and the second pressure chamber 22b1 of the individual plate 24b. Piezoelectric elements 25 are provided on the vibration plate 24c at positions corresponding to the first pressure chamber 21b1 and the second pressure chamber 22b1, respectively. When the piezoelectric elements 25 are driven, the vibration plate 24c deforms, applying pressure to the liquid in the first pressure chamber 21b1 and the second pressure chamber 22b1, respectively. As a result, the first liquid is ejected from the first nozzle 21a connected to the first pressure chamber 21b1, and the second liquid is ejected from the second nozzle 22a connected to the second pressure chamber 22b1.

[0023] Furthermore, of the first individual paths 21b, the first supply communication path 21b2 (FIG. 3) and the first return communication path 21b4 (FIG. 3) are covered by the vibrating plate 24c, and the first supply individual path 21b3 and the first return individual path 21b5 penetrate the vibrating plate 24c in the vertical direction. Furthermore, of the second individual paths 22b, the second supply communication path 22b2 (FIG. 3) and the second return communication path 22b4 (FIG. 3) are covered by the vibrating plate 24c, and the second supply individual path 22b3 and the second return individual path 22b5 penetrate the vibrating plate 24c in the vertical direction.

[0024] The common plate 24d is laminated on the diaphragm 24c. A first common path 30 and a second common path 40 are formed on the common plate 24d. The first common path 30 has a first supply common path 31 and a first recovery common path 34, and the second common path 40 has a second supply common path 41 and a second recovery common path 44. The first common path 30 and the second common path 40 will be described later.

[0025] Furthermore, the common plate 24d is provided with a first supply individual channel 21b3 and a first recovery individual channel 21b5. The first supply individual channel 21b3 is connected to the first supply common channel 31, and the first recovery individual channel 21b5 is connected to the first recovery common channel 34. As a result, the first supply common channel 31 communicates with the first pressure chamber 21b1 via the first supply individual channel 21b3 and the first supply communicating channel 21b2 (FIG. 3), and the first recovery common channel 34 communicates with the first pressure chamber 21b1 via the first recovery individual channel 21b5 and the first recovery communicating channel 21b4 (FIG. 3).

[0026] The first common supply path 31 and the first common recovery path 34 are connected to a first tank 26. The first tank 26 is mounted on, for example, the head 20, and is connected to the first cartridge 11 (FIG. 1) by a pipe or the like, and stores the first liquid supplied from the first cartridge 11. The first tank 26 is connected to the first common supply path 31 by a first supply path 26a, and is also connected to the first common recovery path 34 by a first recovery path 26b. A first supply pump 26a1 is provided in the first supply path 26a, and a first recovery pump 26b1 is provided in the first recovery path 26b.

[0027] The first tank 26, first supply path 26a, first supply common path 31, first supply individual path 21b3, first supply communication path 21b2 (FIG. 3), first pressure chamber 21b1, first recovery communication path 21b4 (FIG. 3), first recovery individual path 21b5, first recovery common path 34, first recovery path 26b, and first tank 26 are connected in this order to form a circulation path for the first liquid. When first supply pump 26a1 and first recovery pump 26b1 are driven, the first liquid flows through this circulation path.

[0028] Furthermore, the common plate 24d is provided with a second supply individual channel 22b3 and a second recovery individual channel 22b5. The second supply individual channel 22b3 is connected to the second supply common channel 41, and the second recovery individual channel 22b5 is connected to the second recovery common channel 44. As a result, the second supply common channel 41 communicates with the second pressure chamber 22b1 via the second supply individual channel 22b3 and the second supply communicating channel 22b2 (FIG. 3), and the second recovery common channel 44 communicates with the second pressure chamber 22b1 via the second recovery individual channel 22b5 and the second recovery communicating channel 22b4 (FIG. 3).

[0029] The second common supply path 41 and the second common recovery path 44 are connected to the second tank 27. The second tank 27 is mounted on, for example, the head 20, and is connected to the second cartridge 12 (FIG. 1) by a pipe or the like, and stores the second liquid supplied from the second cartridge 12. The second tank 27 is connected to the second common supply path 41 by a second supply path 27a, and is also connected to the second common recovery path 44 by a second recovery path 27b. A second supply pump 27a1 is provided in the second supply path 27a, and a second recovery pump 27b1 is provided in the second recovery path 27b.

[0030] The second tank 27, second supply path 27a, second supply common path 41, second supply individual path 22b3, second supply communication path 22b2 (FIG. 3), second pressure chamber 22b1, second recovery communication path 22b4 (FIG. 3), second recovery individual path 22b5, second recovery common path 44, second recovery path 27b, and second tank 27 are connected in this order to form a circulation path for the second liquid. When second supply pump 27a1 and second recovery pump 27b1 are driven, the second liquid flows through this circulation path.

[0031] The damper plate 24e is laminated on the common plate 24d. The damper plate 24e has a through-hole formed therein, and a damper 28 is provided to cover the through-hole. The damper 28 is made of a thin metal or inorganic film that is elastic and resistant to organic solvents, and has a thickness of, for example, 10 μm or less. The damper 28 covers the first supply common channel 31, the first recovery common channel 34, the second supply common channel 41, and the second recovery common channel 44. The damper 28 flexes to absorb pressure applied to the first liquid flowing through the first supply common channel 31 and the first recovery common channel 34. The damper 28 flexes to absorb pressure applied to the second liquid flowing through the second supply common channel 41 and the second recovery common channel 44.

[0032] <1st common road> As shown in FIGS. 3 and 4, as described above, the first common channel 30 includes a first supply common channel 31 and a first recovery common channel 34. The first supply common channel 31 includes a plurality of first branch channels, i.e., first supply branch channels 32, and a first main channel, i.e., a first main channel 33. The first supply common channel 31 is comb-shaped, and the first main channel 33 branches into a plurality of first supply branch channels 32. The plurality of first supply branch channels 32 are arranged parallel to one another and spaced apart in the front-rear direction. The first supply branch channel 32 extends, for example, from the first main channel 33 at an angle obliquely rearward and leftward, and is connected to the first individual supply channels 21b3 of the plurality of first individual channels 21b. As a result, the first supply branch channel 32 communicates with the first pressure chambers 21b1 (FIG. 2A) of the plurality of first individual channels 21b. Note that in FIG. 4, for simplicity, the first supply branch channels 32 are depicted as extending in the left-right direction.

[0033] The first supply main channel 33 extends in the direction in which the multiple first nozzles 21a (FIG. 3) are lined up, for example, in the front-to-rear direction. The first supply main channel 33 is disposed to the right of the multiple first supply branch channels 32 and is connected to the right ends of each of the multiple first supply branch channels 32. The rearmost portion of the first supply main channel 33 is connected to the rearmost first supply branch channel 32 among the multiple first supply branch channels 32 lined up in the front-to-rear direction, and the frontmost portion of the first supply main channel 33 is connected to the frontmost first supply branch channel 32 among the multiple first supply branch channels 32 lined up in the front-to-rear direction. As a result, the first liquid is diverted into the multiple first supply branch channels 32 as it flows forward through the first supply main channel 33. Then, as the first liquid flows leftward through the first supply branch channel 32, it is diverted into the multiple first individual channels 21b. The first liquid is then supplied to the first nozzles 21a (FIG. 2A) that are respectively connected to the multiple first individual channels 21b.

[0034] The first common recovery channel 34 has a plurality of first branch channels, i.e., first recovery branch channels 35, and a first main channel, i.e., first recovery main channel 36. The first common recovery channel 34 is comb-shaped, with a plurality of first branch channels 35 branching off from the first main recovery channel 36. The plurality of first branch channels 35 are arranged parallel to one another and spaced apart in the front-to-rear direction. The first branch channel 35 extends, for example, from the first main recovery channel 36 at an angle diagonally forward and right, and is connected to the first individual recovery channels 21b5 of the plurality of first individual channels 21b. As a result, the first branch channel 35 communicates with the first pressure chambers 21b1 (FIG. 2A) of the plurality of first individual channels 21b. For simplicity, in FIG. 4, the first branch channel 35 is depicted as extending in the left-to-right direction.

[0035] The first recovery main channel 36 extends in the direction in which the multiple first nozzles 21a (FIG. 3) are lined up, for example, in the front-to-rear direction, and is disposed to the left of the multiple first recovery branch channels 35 and connected to the left ends of each of the multiple first recovery branch channels 35. The rearmost portion of the first recovery main channel 36 is connected to the rearmost first recovery branch channel 35 of the multiple first recovery branch channels 35 lined up in the front-to-rear direction, and the frontmost portion of the first recovery main channel 36 is connected to the frontmost first recovery branch channel 35 of the multiple first recovery branch channels 35 lined up in the front-to-rear direction. As a result, the first liquid is recovered, for example, from the multiple first individual channels 21b into the first recovery branch channel 35 and flows to the left through the first recovery branch channel 35. The first liquid then merges with the first recovery main channel 36 from the multiple first individual channels 21b and flows forward through the first recovery main channel 36.

[0036] The first recovery main channel 36 is disposed to the left of the first supply main channel 33. A plurality of first supply branch channels 32 and a plurality of first recovery branch channels 35 are arranged in the front-to-rear direction between the first supply main channel 33 and the first recovery main channel 36. The first supply branch channels 32 and first recovery branch channels 35 are parallel to each other and arranged alternately in the front-to-rear direction.

[0037] <Second common road> As shown in FIGS. 3 to 5, the second common path 40 has a second supply common path 41 and a second recovery common path 44, as described above. The second common path 40 is bilaterally symmetrical to the first common path 30 and has the same configuration as the first common path 30, except that a portion of the second common path 40 overlaps a portion of the first common path 30 in the front-to-rear direction. Therefore, the second supply common path 41 has a plurality of second branch paths, i.e., second supply branch paths 42, and a second main path, i.e., second main path 43. The second supply common path 41 has a comb shape, with a plurality of second branch paths 42 branching off from the second main path 43. Note that, for simplification, in FIGS. 4 and 5, the second branch paths 42 are shown extending in the left-to-right direction.

[0038] The second supply branch passage 42 extends, for example, from the second main supply passage 43 at an angle diagonally forward and to the right, and is connected to the second individual supply passages 22b3 of the plurality of second individual passages 22b. As a result, the second supply branch passage 42 communicates with the second pressure chambers 22b1 (FIG. 2B) of the plurality of second individual passages 22b, respectively. The second main supply passage 43 extends in the direction in which the plurality of second nozzles 22a (FIG. 3) are lined up, for example, in the front-to-rear direction, and is disposed to the left of the plurality of second supply branch passages 42 and is connected to the left ends of the plurality of second supply branch passages 42.

[0039] The second common recovery channel 44 has a plurality of second branch channels, i.e., second recovery branch channels 45, and a second main channel, i.e., second recovery main channel 46. The second common recovery channel 44 is comb-shaped, with the plurality of second branch channels 45 branching off from the second main recovery channel 46. The second branch channel 45 extends, for example, from the second main recovery channel 46 at an obliquely rearward left angle, and is connected to the second individual recovery channels 22b5 of the plurality of second individual channels 22b. As a result, the second branch channel 45 communicates with the second pressure chambers 22b1 (FIG. 2B) of the plurality of second individual channels 22b. The second main recovery channel 46 extends in the direction in which the plurality of second nozzles 22a (FIG. 3) are lined up, for example, in the front-rear direction, and is disposed to the right of the plurality of second branch channels 45, and is connected to the right ends of each of the plurality of second branch channels 45. 4 and 5, for the sake of simplicity, the second recovery branch 45 is shown extending in the left-right direction.

[0040] The second recovery main channel 46 is disposed to the right of the second supply main channel 43. A plurality of second supply branch channels 42 and a plurality of second recovery branch channels 45 are arranged in the front-to-rear direction between the second recovery main channel 46 and the second supply main channel 43. The second supply branch channels 42 and second recovery branch channels 45 are parallel to each other and arranged alternately in the front-to-rear direction.

[0041] In addition, in the left-right direction, the first recovery main channel 36 and the second recovery main channel 46 are disposed between the first recovery branch channel 35 and the second recovery branch channel 45. Furthermore, the first recovery main channel 36 and the second recovery main channel 46 are disposed between the plurality of first nozzles 21 a communicating with the first recovery branch channel 35 and the plurality of second nozzles 22 a communicating with the second recovery branch channel 45.

[0042] 7A, the first main recovery path 36 overlaps the second main recovery path 46 in the vertical direction. As a result, the first main recovery path 36 overlaps the second main recovery path 46, which is part of the second common path 40, and the second main recovery path 46 overlaps the first main recovery path 36, which is part of the first common path 30. When viewed from above, the first common path 30 and the second common path 40 are arranged symmetrically with respect to the center line of this overlapping portion in the horizontal direction.

[0043] In this case, the common plate 24d has a first common plate 24d1 on which the first common path 30 is formed, and a second common plate 24d2 on which the second common path 40 is formed. The first common plate 24d1 is disposed on the second common plate 24d2 so as to overlap the second main recovery path 46 without overlapping the second branch recovery path 45 of the second common path 40. Also, as shown in FIG. 7B , the first common plate 24d1 is disposed on the second common plate 24d2 so as to overlap the second main recovery path 46 without overlapping the second branch supply path 42 of the second common path 40.

[0044] <Damper plate> 6 and 7A, as described above, the damper plate 24e is laminated on the common plate 24d. This damper plate 24e has a first damper plate 24e1 laminated on the first common plate 24d1 and a second damper plate 24e2 laminated on the second common plate 24d2. As shown in FIGS. 7A and 7B, the damper 28 provided on the first damper plate 24e1 covers the first supply branch path 32 and the first return branch path 35 of the first common path 30. The damper 28 provided on the second damper plate 24e2 covers the second supply branch path 42 and the second return branch path 45 of the second common path 40. Note that, for simplification, FIG. 6 illustrates the damper 28 as extending in the left-right direction, but the damper 28 is provided on the damper plate 24e so as to cover the branch paths 32, 35, 42, and 45 in accordance with their shapes.

[0045] Furthermore, the first damper plate 24e1 and the second damper plate 24e2 have through holes, and filters 29 are provided to cover the through holes. The filters 29 cover the first supply main path 33 and the second supply main path 43, respectively. The first liquid is supplied from the first tank 26 to the first supply main path 33 through the filter 29. Impurities in the first liquid are removed by the filter 29. The second liquid is supplied from the second tank 27 (FIG. 7C) to the second supply main path 43 through the filter 29. Impurities in the second liquid are removed by the filter 29.

[0046] 6, the damper plate 24e is provided with a first recovery port 37 and a second recovery port 47a. The first recovery port 37 and the second recovery port 47a are arranged on the first main recovery channel 36 (FIG. 4) and the second main recovery channel 46 (FIG. 5). The first recovery port 37 is arranged downstream of the first liquid flowing through the first main recovery channel 36, and the second recovery port 47a is arranged downstream of the second liquid flowing through the second main recovery channel 46. In the example of FIG. 6, the first recovery port 37 is arranged on the front part of the first main recovery channel 36, and the second recovery port 47a is arranged on the rear part of the first main recovery channel 36.

[0047] 7A, the first recovery port 37 passes through the first damper plate 24e1 in the vertical direction, and is connected to the first tank 26 by the first recovery path 26b. As a result, the first liquid flows in this order through the first recovery branch path 35, the first main recovery path 36, the first recovery port 37, and the first recovery path 26b, and then flows out into the first tank 26. In this way, the first recovery port 37 constitutes a first communication path that communicates with the first tank 26 and the first main recovery path 36.

[0048] 7C, the second recovery port 47a penetrates the first damper plate 24e1 in the vertical direction and is connected to the second tank 27 by the second recovery path 27b. Furthermore, the second damper plate 24e2 is provided with a second recovery port 47b. The second recovery port 47a overlaps the second recovery port 47a when viewed from above. The second recovery port 47a and the second recovery port 47b are connected to a conduit 47c. The conduit 47c penetrates the first common plate 24d1 and the first main recovery path 36 in the vertical direction, with its upper end opening connected to the second recovery port 47a and its lower end opening connected to the second recovery port 47b. This causes the second liquid to flow sequentially through the second recovery branch path 45, the second main recovery path 46, the second recovery port 47b, the conduit 47c, the second recovery port 47a, and the second recovery path 27b, before flowing out into the second tank 27. In this way, the second recovery port 47a, the pipe line 47c and the second recovery port 47b form a second communication passage that is connected to the second tank 27 and the second recovery main line 46, and extends vertically from the second recovery main line 46 and penetrates the first recovery main line 36.

[0049] In addition, since the dimension of conduit 47c in the left-right direction is smaller than the dimension of first recovery main channel 36, the first liquid can pass outside conduit 47c and flow through first recovery main channel 36. Furthermore, conduit 47c passes through first recovery main channel 36 in the up-down direction, but does not open into first recovery main channel 36. For this reason, the second liquid does not flow out from conduit 47c into first recovery main channel 36, and is prevented from mixing with the first liquid flowing through first recovery main channel 36.

[0050] <Actions and Effects> In this way, the first main recovery channel 36 and the second main recovery channel 46 are disposed between the first nozzle 21a and the second nozzle 22a in the left-right direction. Furthermore, in the up-down direction, the first main recovery channel 36 and the second main recovery channel 46 overlap at least a portion of the first common channel 30 and the second common channel 40, respectively. By overlapping the first common channel 30 and the second common channel 40 in the up-down direction in this way, the size of the head 20 including the first common channel 30 and the second common channel 40 in the left-right direction is reduced compared to when the first common channel 30 and the second common channel 40 do not overlap. Furthermore, the first liquid is ejected from the first nozzle 21a communicating with the first common channel 30, and the second liquid is ejected from the second nozzle 22a communicating with the second common channel 40. Therefore, two types of liquids can be ejected from one head 20 while preventing the head 20 from becoming larger in the left-right direction.

[0051] Furthermore, the first recovery main channel 36 and the second recovery main channel 46 each extend in the direction in which the first nozzles 21a are lined up in a row, and overlap each other in the vertical direction. This allows the first liquid to be ejected from the multiple first nozzles 21a connected to the first recovery main channel 36 via the first recovery branch channel 35, and the second liquid to be ejected from the multiple second nozzles 22a connected to the second recovery main channel 46 via the second recovery branch channel 45. The overlap between the first recovery main channel 36 and the second recovery main channel 46 in the vertical direction makes it possible to eject two types of liquid from a single head 20 while preventing the head 20 from becoming larger in the left-right direction.

[0052] Furthermore, the damper 28 covers the first supply branch channel 32 and the second supply branch channel 42. This allows the damper 28 to absorb fluctuations in the supply pressure of the first liquid from the first supply branch channel 32 to the first nozzle 21a, and fluctuations in the supply pressure of the second liquid from the second supply branch channel 42 to the second nozzle 22a. This makes it possible to suppress fluctuations in the ejection rate of the first liquid from the first nozzle 21a, and fluctuations in the ejection rate of the second liquid from the second nozzle 22a.

[0053] Furthermore, the damper 28 covers the first supply branch channel 32 and the first recovery branch channel 35, and also covers the second supply branch channel 42 and the second recovery branch channel 45. For example, when a discharge pressure is applied to the first nozzle 21a, even if pressure waves of the discharge pressure propagate to the first supply branch channel 32 and the first recovery branch channel 35, they are absorbed by the damper 28. This makes it possible to suppress crosstalk, which would inhibit the discharge of other first nozzles 21a due to pressure waves propagating to other first individual channels 21b. Furthermore, crosstalk is suppressed for the second nozzle 22a as with the first nozzle 21a.

[0054] Furthermore, the first recovery main channel 36 is disposed on the second recovery main channel 46. The first communication channel (for example, the first recovery port 37) communicates with the first tank 26 and the first recovery main channel 36. This allows the first liquid to be recovered from the first recovery main channel 36 to the first tank 26 via the first communication channel. Furthermore, the second communication channel (for example, the second recovery port 47a, the pipe line 47c, and the second recovery port 47b) communicates with the second tank 27 and the second recovery main channel 46, and extends in the vertical direction from the second recovery main channel 46 to penetrate the first recovery main channel 36. By having this second communication channel penetrate the first recovery main channel 36, the second liquid can be recovered from the second recovery main channel 46 to the second tank 27 via the second communication channel without increasing the size of the head 20 in the front-to-rear direction.

[0055] The first recovery main channel 36 and the second recovery main channel 46 are disposed between the first supply main channel 33 and the second supply main channel 43 in the left-right direction. Because the first recovery main channel 36 and the second recovery main channel 46 overlap each other in the up-down direction, for example, the first communication channel connected to the first recovery main channel 36 and the second communication channel connected to the second recovery main channel 46 have different shapes. In contrast, the first supply main channel 33 and the second supply main channel 43 do not overlap the first common channel 30 and the second common channel 40, respectively. Therefore, the first supply main channel 33 and the flow path connected thereto, and the second supply main channel 43 and the flow path connected thereto have the same shape, etc. This allows the supply pressure of the first liquid from the first supply main channel 33 to the first nozzle 21a and the supply pressure of the second liquid from the second supply main channel 43 to the second nozzle 22a to be equal to each other.

[0056] <Variation 1> In the liquid ejection device 10 according to the first modification, the first branch path has a larger vertical dimension than the first main path in the above embodiment, and the second branch path has a larger vertical dimension than the second main path.

[0057] 8A, the first main recovery channel 36 and the second main recovery channel 46 overlap each other in the up-down direction. Furthermore, the first nozzle 21a is connected to the first main recovery channel 36 via the first branch recovery channel 35, and the second nozzle 22a is connected to the second main recovery channel 46 via the second branch recovery channel 45. Therefore, two types of liquid can be ejected from one head 20 while preventing the head 20 from becoming larger in the left-right direction.

[0058] 8A and 8B, in the vertical direction, the dimension B36 of the first recovery main path 36 of this first common path 30 is smaller than the dimension B35 of the first recovery branch path 35, the dimension B33 of the first supply main path 33, and the dimension B32 of the first supply branch path 32, and is, for example, less than half of these dimensions. In the vertical direction, the dimension B46 of the second recovery main path 46 of this second common path 40 is smaller than the dimension B45 of the second recovery branch path 45, the dimension B43 of the second supply main path 43, and the dimension B42 of the second supply branch path 42, and is, for example, less than half of these dimensions. For example, the dimension B36 of the first recovery main line 36 and the dimension B46 of the second recovery main line 46 are equal to each other, and the dimension B35 of the first recovery branch line 35, the dimension B35 of the first supply main line 33, the dimension B32 of the first supply branch line 32, the dimension B44 of the second recovery branch line 45, the dimension B43 of the second supply main line 43 and the dimension B42 of the second supply branch line 42 are equal to each other.

[0059] In this way, in the first common path 30 and the second common path 40, the dimension B36 of the first recovery main path 36 and the dimension B46 of the second recovery main path 46 are smaller than the other dimensions, and the first recovery main path 36 and the second recovery main path 46 overlap each other. As a result, for example, both the damper 28 covering the first supply branch path 32 and the first recovery branch path 35, and the damper 28 covering the second supply branch path 42 and the second recovery branch path 45 may be provided on a single damper plate 24e. In this case, the structure of the tip 24 in the head 20 can be simplified.

[0060] Furthermore, the dimension B36 of the first main recovery channel 36 and the dimension B46 of the second main recovery channel 46 are smaller than the other dimensions, so that the first main recovery channel 36 and the second main recovery channel 46 overlap each other. This allows the first individual channel 21b connected to the first common channel 30 and the first nozzle 21a, and the second individual channel 22b connected to the second common channel 40 and the second nozzle 22a, to be unified in length. This allows the supply pressure of the first liquid supplied from the first common channel 30 to the first nozzle 21a and the supply pressure of the second liquid supplied from the second common channel 40 to the second nozzle 22a to be unified.

[0061] Furthermore, in the first common path 30 and the second common path 40, the other dimensions are larger than the dimension B36 of the first recovery main path 36 and the dimension B46 of the second recovery main path 46. In this case, the sizes of the first common path 30 and the second common path 40 can be increased without increasing the size of the tip 24 in the up-down direction compared to when the dimension B36 of the first recovery main path 36 and the dimension B46 of the second recovery main path 46 are the same as the other dimensions.

[0062] 6, 8A, and 8C, damper plate 24e is provided with first recovery port 37 and second recovery port 47a. Furthermore, common plate 24d has a partition wall separating first main recovery path 36 and second main recovery path 46, with second recovery port 47b provided in the partition wall. Second recovery port 47b passes through the partition wall in the vertical direction and is connected to conduit 47c. Conduit 47c is connected to second recovery port 47a, so the second liquid flows through second branch recovery path 45, second main recovery path 46, second recovery port 47b, conduit 47c, second recovery port 47a, and second recovery path 27b in this order before flowing out into second tank 27.

[0063] In this way, the second recovery port 47a, the conduit 47c, and the second recovery port 47b constitute a second communication passage that communicates with the second tank 27 and the second main recovery passage 46, and that extends in the vertical direction from the second main recovery passage 46 and penetrates the first main recovery passage 36. This allows the second liquid to be recovered from the second main recovery passage 46 to the second tank 27 via the second communication passage without increasing the size of the head 20 in the front-to-rear direction.

[0064] <Variation 2> In the liquid ejection device 10 according to the second modification, the first main path is disposed on the second main path in the first embodiment and the first modification, and the second main path has an extension 46b that extends further than the first main path in one direction in the front-to-rear direction. The liquid ejection device 10 includes a first communication path that communicates with the first tank 26 and the first main path, and a second communication path that communicates with the second tank 27 and the extension 46b of the second main path and that extends vertically from the second main path in one direction in the front-to-rear direction than the first main path.

[0065] Specifically, as shown in the examples of Figures 9 and 10, the second main recovery path 46 of the second common path 40 has a connection portion 46a and an extension portion 46b. The connection portion 46a extends in the front-rear direction and is connected to the right ends of each of the multiple second branch recovery paths 45. A dimension C46a of the connection portion 46a in the front-rear direction is equal to the dimension C36 of the first main recovery path 36. In the up-down direction, the first main recovery path 36 overlaps the connection portion 46a. For simplification, in Figures 9 and 10, the branch paths 32, 35, 42, and 45 are shown extending in the left-right direction.

[0066] The extension portion 46b extends rearward beyond the rear end of the connecting portion 46a. The dimension C46b of the extension portion 46b in the front-rear direction is shorter than the dimension C46a of the connecting portion 46a, and the dimensions of the extension portion 46b in the left-right and up-down directions are equal to the dimensions of the connecting portion 46a. The extension portion 46b does not overlap with the first main recovery path 36, but extends rearward from the rear end of the first main recovery path 36. As shown in FIG. 11A, the first common plate 24d1 is provided with a portion overlapping with the extension portion 46b. The first damper plate 24e1 stacked on this first common plate 24d1 is provided with a second recovery port 47a at a portion overlapping with the conduit 47c. The conduit 47c penetrates the first common plate 24d1 in the up-down direction.

[0067] A second damper plate 24e2 is laminated on the second common plate 24d2, on which the connection portion 46a and the extension portion 46b are formed. A second recovery port 47b is provided in the second damper plate 24e2 at a portion overlapping the extension portion 46b. The second recovery port 47b is connected to a conduit 47c, and the conduit 47c is connected to the second recovery port 47a. The second recovery port 47a, the conduit 47c, and the second recovery port 47b form a second communication passage that communicates with the second tank 27 and the second main recovery passage 46. As a result, the second liquid flows through the second branch recovery passage 45, the connection portion 46a, the extension portion 46b, the second recovery port 47b, the conduit 47c, the second recovery port 47a, and the second recovery passage 27b in this order, before flowing out into the second tank 27.

[0068] In this way, the second communication passage (for example, second recovery port 47a, conduit 47c, and second recovery port 47b) extends upward from the second main recovery passage 46 behind the first main recovery passage 36. In this case, the structure of the tip 24 in the head 20 can be simplified compared to when the second communication passage passes through the first main recovery passage 36. Furthermore, even if leakage of the second liquid occurs in the second communication passage, because the second communication passage is located behind the first main recovery passage 36, it is possible to prevent the leaked second liquid from mixing with the first liquid in the first main recovery passage 36.

[0069] 11B, the second recovery main channel 46 may also have a connection portion 46a and an extension portion 46b. In this case, a conduit 47c is provided on the extension portion 46b of the common plate 24d, and a second recovery port 47a is provided on the damper plate 24e at a position corresponding to the conduit 47c. The extension portion 46b is connected to the conduit 47c, and the conduit 47c is connected to the second recovery port 47a. The second recovery port 47a and the conduit 47c form a second communication passage that communicates with the second tank 27 and the second recovery main channel 46. As a result, the second liquid flows sequentially through the second recovery branch channel 45, the connection portion 46a, the extension portion 46b, the conduit 47c, the second recovery port 47a, and the second recovery channel 27b, before flowing out into the second tank 27.

[0070] <Embodiment 2> 15B, in the liquid ejection device 10 according to the second embodiment, the common plate 24d has a branch path member 24d3 and a main path member 24d4. The branch path member 24d3 and the main path member 24d4 are each flat. The main path member 24d4 is stacked on the damper plate 24e, which is stacked on the branch path member 24d3. The first supply main path 33 has a first supply main path 33a formed in the branch path member 24d3 and a first supply main path 33b formed in the main path member 24d4.

[0071] As shown in FIGS. 12 and 15A, the branch path member 24d3 is provided with a first supply main path 33a, multiple first supply branch paths 32, and multiple first individual supply paths 21b3. The first supply main path 33a and the first supply branch paths 32 are formed by recesses recessed downward from the upper surface of the branch path member 24d3. The first individual supply path 21b3 extends vertically downward from the first supply branch path 32 of the branch path member 24d3. The first supply main path 33a is disposed to the right of the first supply branch path 32 and is connected to the right ends of the multiple first supply branch paths 32. Multiple first individual supply paths 21b3 are connected to each of the multiple first supply branch paths 32, and the first nozzle 21a is connected to the first individual supply path 21b3. Note that in FIG. 12, for simplicity, the branch paths 32, 35, 42, and 45 are depicted as extending in the left-right direction.

[0072] Furthermore, the branch path member 24d3 is provided with a second supply main path 43a, multiple second supply branch paths 42, and multiple second individual supply paths 22b3. The second supply main path 43a and the second supply branch paths 42 are formed by recesses recessed downward from the upper surface of the branch path member 24d3. The second individual supply path 22b3 penetrates downward from the second supply branch path 42 of the branch path member 24d3 in the vertical direction. The second supply main path 43a is disposed to the left of the multiple second supply branch paths 42 and is connected to the left ends of the multiple second supply branch paths 42. Multiple second individual supply paths 22b3 are connected to each of the multiple second supply branch paths 42, and the second nozzle 22a is connected to the second individual supply path 22b3. In the left-right direction, the first supply main path 33, the first supply branch path 32, the second supply branch path 42, and the second supply main path 43a are arranged in this order.

[0073] 12 and 15B, branch path member 24d3 is further provided with a plurality of first recovery branch paths 35 and a plurality of first individual recovery paths 21b5. The first recovery branch paths 35 are formed by recesses recessed downward from the upper surface of branch path member 24d3, and first individual recovery paths 21b5 extend vertically through branch path member 24d3 below first recovery branch path 35. A plurality of first individual recovery paths 21b5 are connected to each of the plurality of first recovery branch paths 35, and first nozzle 21a is connected to first individual recovery paths 21b5.

[0074] Furthermore, branch path member 24d3 is provided with a plurality of second recovery branch paths 45 and a plurality of second individual recovery paths 22b5. Second recovery branch paths 45 are formed by recesses recessed downward from the upper surface of branch path member 24d3, and second individual recovery paths 22b5 extend vertically through branch path member 24d3 below second recovery branch path 45. A plurality of second individual recovery paths 22b5 are connected to each of the plurality of second recovery branch paths 45, and second nozzle 22a is connected to second individual recovery paths 22b5.

[0075] As shown in FIG. 12, a plurality of first recovery branch channels 35, a plurality of first supply branch channels 32, a plurality of second recovery branch channels 45, and a plurality of second supply branch channels 42 are arranged between the first supply main channel 33a and the second supply main channel 43a in the left-right direction. The first supply main channel 33a and the second supply main channel 43a extend in a direction in which the plurality of first nozzles 21a (FIG. 3) are arranged in rows, for example, in the front-rear direction. In the front-rear direction, the first supply branch channels 32 and the first recovery branch channels 35 are alternately arranged in a row, and the second supply branch channels 42 and the second recovery branch channels 45 are alternately arranged in a row. In the left-right direction, a partition wall 24d3a is provided between the first supply branch channel 32 and the second supply branch channel 42, and a partition wall 24d3a is also provided between the first recovery branch channel 35 and the second recovery branch channel 45. The partition wall 24d3a is a flat plate that extends linearly in the front-rear direction. The first common path 30 and the second common path 40 are arranged line-symmetrically with respect to the partition wall 24d3a.

[0076] 13, 15A, and 15B, the main path member 24d4 is provided with a first supply main path 33b and a first return main path 36. The first supply main path 33b passes through the main path member 24d4 in the vertical direction, and the first return main path 36 is formed by a recess recessed upward from the lower surface of the main path member 24d4. The first supply main path 33b is disposed on the first supply main path 33a, and the first return main path 36 is disposed on the first supply branch path 32 and the first return branch path 35.

[0077] Further, the main path member 24d4 is provided with a second supply main path 43b and a second recovery main path 46. The second supply main path 43b passes through the main path member 24d4 in the vertical direction, and the second recovery main path 46 is formed by a recess recessed upward from the lower surface of the main path member 24d4. The second supply main path 43b is disposed on the second supply main path 43a, and the second recovery main path 46 is disposed on the second supply branch path 42 and the second recovery branch path 45.

[0078] In the left-right direction, the first supply main channel 33b, the first recovery main channel 36, the second recovery main channel 46, and the second supply main channel 43b are arranged in this order, and extend in the direction in which the multiple first nozzles 21a (FIG. 3) are arranged in a row, for example, in the front-rear direction.

[0079] As shown in FIGS. 14, 15A, and 15B, the damper plate 24e is an intermediate member stacked on the branch path member 24d3. The damper plate 24e is provided with a filter 29, a damper 28, a first connection path 38, and a second connection path 48. The filter 29 covers each of the first supply main path 33a and the second supply main path 43a, and is provided between the first supply main path 33a and the first supply main path 33b, and between the second supply main path 43a and the second supply main path 43b. The first liquid passes through the filter 29 from the first supply main path 33b and flows into the first supply main path 33a, and the second liquid passes through the filter 29 from the second supply main path 43b and flows into the second supply main path 43a. The filter 29 removes impurities from the liquid.

[0080] The damper 28 covers the first supply branch passage 32, the first return branch passage 35, the second supply branch passage 42, and the second return branch passage 45. The damper 28 covering the first supply branch passage 32 has a dimension equal to the dimension of the first supply branch passage 32 in the left-right direction and is disposed between the first supply branch passage 32 and the first return main passage 36 in the up-down direction. Because the first liquid does not pass through the damper 28, the first liquids flowing through the first supply branch passage 32 and the first return main passage 36 do not mix. Furthermore, the damper 28 covering the second supply branch passage 42 has a dimension equal to the dimension of the second supply branch passage 42 in the left-right direction and is disposed between the second supply branch passage 42 and the second return main passage 46 in the up-down direction. Because the second liquid does not pass through the damper 28, the second liquids flowing through the second supply branch passage 42 and the second return main passage 46 do not mix. In FIG. 14, for the sake of simplicity, the damper 28 is shown extending in the left-right direction, but the damper 28 is provided on the damper plate 24e so as to cover the branch passages 32, 35, 42, and 45 in accordance with their shapes.

[0081] Furthermore, the dimension of damper 28 covering first recovery branch passage 35 is shorter than the dimension of first recovery branch passage 35 in the left-right direction, and is disposed between first recovery branch passage 35 and first main recovery passage 36 in the up-down direction. A first connection passage 38 is provided between first recovery branch passage 35 and first main recovery passage 36 to the left of damper 28. First connection passage 38 is formed by a through-hole that penetrates in the up-down direction, and is connected to first recovery branch passage 35 and first main recovery passage 36. This allows the first liquid to flow from first recovery branch passage 35 through first connection passage 38 to first main recovery passage 36.

[0082] Furthermore, the dimension of damper 28 covering second recovery branch passage 45 is shorter than the dimension of second recovery branch passage 45 in the left-right direction, and is disposed between second recovery branch passage 45 and second main recovery passage 46 in the up-down direction. A second connection passage 48 is provided between second recovery branch passage 45 and second main recovery passage 46 to the left of damper 28. Second connection passage 48 is formed by a through-hole that penetrates in the up-down direction, and is connected to second recovery branch passage 45 and second main recovery passage 46. This allows the second liquid to flow from second recovery branch passage 45 through second connection passage 48 to second main recovery passage 46.

[0083] In the left-right direction, the first connection path 38 and the second connection path 48 are disposed between the first nozzle 21a connected to the first recovery branch path 35 via the first individual recovery path 21b5 and the second nozzle 22a connected to the second individual recovery path 22b5 via the second individual recovery path 22b5. This makes it possible to suppress the effect of a change in the flow direction of the first liquid from the first recovery branch path 35 to the first connection path 38 on the discharge of the first liquid from the first nozzle 21a, and to suppress the effect of a change in the flow direction of the second liquid from the second recovery branch path 45 to the second connection path 48 on the discharge of the second liquid from the second nozzle 22a.

[0084] In such a liquid ejection device 10, in the vertical direction, the first recovery main channel 36 overlaps with the first supply branch channel 32 and the first recovery branch channel 35, and the second recovery main channel 46 overlaps with the second supply branch channel 42 and the second recovery branch channel 45. The first liquid is ejected from the first nozzle 21a communicating with this first recovery main channel 36, and the second liquid is ejected from the second nozzle 22a communicating with the second recovery main channel 46. This makes it possible to eject two types of liquid from one head 20 while preventing the head 20 from becoming too large in the left-right direction.

[0085] Furthermore, the first common channel 30 and the second common channel 40 are arranged line-symmetrically with respect to the partition wall 24d3a. The flow path resistance of the first liquid flowing through the first common channel 30 and the flow path resistance of the first liquid flowing through the second common channel 40 are equal to each other. This makes it possible to equalize the supply pressure of the first liquid from the first supply common channel 31 of the first common channel 30 to the first nozzle 21a and the supply pressure of the second liquid from the second supply common channel 41 of the second common channel 40 to the second nozzle 22a.

[0086] The damper 28 also covers the first supply branch channel 32 and the second supply branch channel 42. This allows the damper 28 to absorb fluctuations in the supply pressure of the first liquid from the first supply branch channel 32 to the first nozzle 21a and fluctuations in the supply pressure of the second liquid from the second supply branch channel 42 to the second nozzle 22a. The damper 28 also covers the first supply branch channel 32, the first return branch channel 35, the second supply branch channel 42, and the second return branch channel 45. This allows pressure waves of the discharge pressure of the first nozzle 21a and the second nozzle 22a to be absorbed by the damper 28 even if they are propagated to the first supply branch channel 32, the first return branch channel 35, the second supply branch channel 42, or the second return branch channel 45. This allows crosstalk between the first nozzle 21a and the second nozzle 22a to be suppressed.

[0087] Furthermore, in the left-right direction, the first recovery main channel 36 and the second recovery main channel 46 are disposed between the first supply main channel 33 and the second supply main channel 43. This provides a first connection channel 38 connecting the first recovery main channel 36 and the first recovery branch channel 35, and a second connection channel 48 connecting the second recovery main channel 46 and the second recovery branch channel 45. The first connection channel 38 and the second connection channel 48 allow the size of the dampers 28 covering the first supply branch channel 32 and the second supply branch channel 42 to be larger than the size of the dampers 28 covering the first recovery branch channel 35 and the second recovery branch channel 45, respectively. This allows the dampers 28 to absorb fluctuations in the supply pressure of the first liquid from the first supply branch channel 32 to the first nozzle 21a and fluctuations in the supply pressure of the second liquid from the second supply branch channel 42 to the second nozzle 22a.

[0088] <Other variations> In all of the above-described embodiments and modifications, the first main recovery channel 36 overlaps with the second main recovery channel 46 or the first branch recovery channel 35, and the second main recovery channel 46 overlaps with the first main recovery channel 36 or the second branch recovery channel 45 in the vertical direction. However, it is sufficient that the first main channel and the second main channel overlap with at least a portion of the first common channel 30 and the second common channel 40, respectively. For example, the first supply main channel 33 may overlap with at least a portion of the first common channel 30 and the second common channel 40, and the second supply main channel 43 may overlap with at least a portion of the first common channel 30 and the second common channel 40 in the vertical direction.

[0089] It should be noted that many modifications and other embodiments of the present disclosure will be apparent to those skilled in the art from the above description. Therefore, the above description should be construed as merely illustrative and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present disclosure. [Explanation of symbols]

[0090] 10:Liquid discharge device 20: Liquid ejection head 21a: First nozzle 21b1: First pressure chamber 22a: Second nozzle 22b1: Second pressure chamber 24d3: Branch member 24d4: Main road members 24e: Damper plate (intermediate part) 26: First Tank 27: Second Tank 28: Damper 30: 1st common road 31: 1st supply common route 32:1st supply branch (1st branch) 33: 1st supply main road (1st main road) 33a: 1st supply main road (1st main road) 33b: 1st supply main road 34: First common collection route 35: First Collection Branch (First Branch) 36: First Collection Route (First Route) 37: First collection port (first connecting passage) 38: First connecting road 40:Second common road 41: 2nd supply common route 42:Second supply branch (second branch) 43:Second supply main road (second main road) 43a: 2nd supply main road (2nd main road) 43b: 2nd supply main road (2nd main road) 44: Second common collection route 45: Second Collection Branch (Second Branch) 46: 2nd Recovery Route (2nd Route) 46a: Connection part 46b: Extension part 47a: Second collection port (second connecting passage) 47b: Second collection port (second connecting passage) 47c: Pipeline (second communication path) 48: Second connecting road

Claims

1. a plurality of first nozzles that eject a first liquid; a plurality of first pressure chambers respectively communicating with the plurality of first nozzles; a first common path having a plurality of first branch paths respectively communicating with the plurality of first pressure chambers, and a first main path communicating with the plurality of first branch paths; a plurality of second nozzles that are arranged on one side of the first nozzles in a second direction that intersects with a first direction in which the plurality of first nozzles are arranged in a row, and that eject a second liquid that is different from the first liquid; a plurality of second pressure chambers respectively communicating with the plurality of second nozzles; a second common path having a plurality of second branch paths respectively communicating with the plurality of second pressure chambers, and a second main path communicating with the plurality of second branch paths, the first main path and the second main path are disposed between the first nozzle and the second nozzle in the second direction; In a third direction intersecting the first direction and the second direction, the first main path and the second main path overlap at least a part of the first common path and the second common path, respectively. Liquid discharge device.

2. The first main path and the second main path each extend along the first direction and overlap each other in the third direction. The liquid ejection device according to claim 1 .

3. In the third direction, a dimension of the first branch path is larger than a dimension of the first main path; In the third direction, the dimension of the second branch path is larger than the dimension of the second main path. The liquid ejection device according to claim 2 .

4. a damper covering the first branch path of the first common path and the second branch path of the second common path; The liquid ejection device according to claim 1 .

5. a first tank that stores the first liquid; a second tank that stores the second liquid; the first main road is disposed on the second main road; a first communication passage communicating with the first tank and the first main passage; a second communication passage communicating with the second tank and the second main passage, extending from the second main passage in the third direction and penetrating the first main passage; Equipped with The liquid ejection device according to claim 1 .

6. a first tank that stores the first liquid; a second tank that stores the second liquid; the first main road is disposed on the second main road; the second main path has an extension portion that extends further than the first main path in one direction of the first direction, a first communication passage communicating with the first tank and the first main passage; a second communication passage communicating with the second tank and the extended portion of the second main passage, and extending from the second main passage in the third direction at a position further in the first direction than the first main passage; Equipped with The liquid ejection device according to claim 1 .

7. the first common channel includes a first supply common channel that supplies the first liquid to the first nozzles, and a first recovery common channel that recovers the first liquid that has not been ejected from the first nozzles, the second common channel includes a second supply common channel that supplies the second liquid to the second nozzles, and a second recovery common channel that recovers the second liquid that has not been ejected from the second nozzles, the first main path of the first common recovery path and the second main path of the second common recovery path overlap each other in the third direction, In the second direction, the first main path of the first common recovery path and the second main path of the second common recovery path are disposed between the first main path of the first common supply path and the second main path of the second common supply path. The liquid ejection device according to claim 1 .

8. a branch path member in which the first branch path and the second branch path are formed; an intermediate member stacked on the support member in the third direction; a main path member that is stacked on the intermediate member in the third direction and has the first main path and the second main path formed thereon; a first connection path connecting the first branch path and the first main path; a second connection path connecting the second branch path and the second main path; Equipped with the first main path overlaps the first branch path in the third direction; the second main path overlaps the second branch path in the third direction; The liquid ejection device according to claim 1 .

9. a damper provided on the intermediate member and covering the first branch path of the first common path and the second branch path of the second common path; The liquid ejection device according to claim 8 .

10. each of the first connection path and the second connection path is formed by a through hole penetrating the intermediate member; The liquid ejection device according to claim 8 .

11. the through hole is disposed between the first nozzle and the second nozzle in the second direction. The liquid ejection device according to claim 10.

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