Head System

Abstract

To provide a head system that can supply liquid by crossflow to a plurality of manifolds in a head, while preventing the head system from enlarging in size.SOLUTION: The head system comprises a head and a flow path member. Four manifolds having common flow paths extended in a first direction and connected to a plurality of nozzles and inflow ports connected to one ends of the common flow paths are arranged in the order of first to fourth. The flow path member has a first member and a second member which have single supply ports. First-fourth supply flow paths respectively extending are formed between the supply ports and the inflow ports of the first-fourth manifolds. In a first manifold group, inflow ports are connected to end parts at one sides in a first direction of the common flow paths. In a second manifold group, the inflow ports are connected to end parts at the other sides in the first direction of the common flow path. The first manifold group includes the first manifold and the third manifold or the first manifold and the fourth manifold. The third supply flow path and the fourth supply flow path are respectively formed in both of the first member and the second member.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a head system. [Background technology]

[0002] A head system is used that includes a head having multiple nozzle rows and multiple manifolds that supply liquid to the multiple nozzle rows, and a flow path member that supplies liquid to the head, and that forms an image on a medium by ejecting liquid from the multiple nozzle rows of the head.

[0003] Patent document 1 discloses a head system having four manifolds and a head having four nozzle rows connected to each of the four manifolds, and a flow path member that supplies liquid to the four manifolds of the head in a manner in which the liquid flows in opposite directions between adjacent manifolds (so-called "cross flow"). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-160345 Summary of the Invention [Problem to be solved by the invention]

[0005] When liquid is supplied to a plurality of manifolds in the head by cross flow, the structure of the flow path member becomes complex, which may lead to an increase in the size of the flow path member and, in turn, an increase in the size of the head system.

[0006] Specifically, as in Patent Document 1, for example, a flow path member having two flow paths separated by a rubber sheet and two supply ports and two discharge ports requires two ink supply pipes and two ink discharge pipes to connect the flow path member to the subtank. Therefore, the connector (joint) for connecting the four pipes (i.e., two ink supply pipes and two ink discharge pipes) to the flow path member has a complex structure, and the head system becomes larger, for example, in the vertical direction (height direction). Furthermore, because two branch flow paths extending from the supply ports to both sides in the medium width direction (the direction in which the nozzle rows extend) are configured inside the flow path member, and two branch flow paths extending from the discharge ports to both sides in the medium width direction are also configured inside the flow path member, the total flow path length inside the flow path member increases, and the flow path member itself also becomes larger.

[0007] An object of the present invention is to provide a head system that can supply liquid to a plurality of manifolds in the head by cross flow while suppressing an increase in the size of the head system. [Means for solving the problem]

[0008] According to a first aspect of the present invention, there is provided a head system including a head that ejects liquid, and a flow path member that is disposed above the head and that supplies the liquid to the head. The head has four manifolds, each of which has a common flow path extending in a first direction and connected to a plurality of nozzles, and an inlet connected to one end of the common flow path, and the four manifolds are arranged in the order of first manifold, second manifold, third manifold, and fourth manifold along a second direction perpendicular to the first direction. The flow path member has a first member having a single supply port and a second member facing the first member in the second direction, and is a flow path member in which a first supply flow path extending between the supply port and the inlet of the first manifold, a second supply flow path extending between the supply port and the inlet of the second manifold, a third supply flow path extending between the supply port and the inlet of the third manifold, and a fourth supply flow path extending between the supply port and the inlet of the fourth manifold are formed. In a first manifold group including two of the first to fourth manifolds, the inlet is connected to an end of the common flow path on one side in the first direction, and in a second manifold group including the remaining two of the first to fourth manifolds, the inlet is connected to an end of the common flow path on the other side in the first direction. The first manifold group includes the first manifold and the third manifold and the second manifold group includes the second manifold and the fourth manifold, or the first manifold group includes the first manifold and the fourth manifold and the second manifold group includes the second manifold and the third manifold. The third supply flow path and the fourth supply flow path are each formed in both the first member and the second member. [Effects of the Invention]

[0009] According to the head system of the present invention, it is possible to supply liquid to a plurality of manifolds in the head by cross flow while suppressing an increase in the size of the head system. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of the printer. [Figure 2] FIG. 2 is a plan view of the head unit. [Figure 3] FIG. 3 is a perspective view of the head system. [Figure 4] FIG. 4 is an exploded perspective view of the flow path member. [Figure 5] 5 is a perspective view of the first flow path member and the second flow path member to explain the flow paths formed inside the first flow path member and the second flow path member, in which the ink guide portion is not shown. [Figure 6] FIG. 6 is a plan view of the rubber sheet. [Figure 7] FIG. 7 is an exploded perspective view of the structure of the head system below the flow path member. [Figure 8] FIG. 8 is a plan view of the head. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 10 is a side view of the head system. [Figure 11] FIG. 11 is an explanatory diagram illustrating the flow paths in the head system of the first embodiment. [Figure 12] FIG. 12 is an explanatory diagram illustrating a flow path in the head system of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment The head unit 100 and head system HS1 according to the first embodiment of the present invention will be described using an example in which the head unit 100 is used in a printer (printing device) 1000.

[0012] [Printer 1000] 1, the printer 1000 mainly comprises four head units 100, a platen 400, a pair of transport rollers 501 and 502, a control unit CONT, and a housing 900 that houses these components. The housing 900 also houses an ink tank 600, four sub-tanks 700, and a cooling mechanism 800.

[0013] In the following description, the direction in which the pair of transport rollers 501, 502 are aligned, i.e., the direction in which the medium PM is transported during image formation, is referred to as the transport direction of the printer 1000. With regard to the transport direction, the upstream side and downstream side of the direction in which the medium PM is transported are referred to as the supply side and discharge side of the transport direction, respectively. The transport direction is an example of the "second direction" in the present invention.

[0014] Additionally, the direction in the horizontal plane perpendicular to the transport direction, i.e., the direction in which the rotation axes of the transport rollers 501 and 502 extend, is referred to as the medium width direction. The left and right sides of the medium width direction when viewed from the discharge side to the supply side in the transport direction are referred to as the left and right sides, respectively, of the medium width direction. The medium width direction is an example of the "first direction" of the present invention. The direction perpendicular to the transport direction and the medium width direction is referred to as the up-down direction.

[0015] Each of the four head units 100 is a so-called line-type head, and is supported by a support 100a at both ends in the medium width direction. In this embodiment, the four head units 100 eject ink of different colors. As an example, the four colors of ink ejected by the four head units 100 are cyan ink, magenta ink, yellow ink, and black ink. The specific structure and function of each of the four head units 100 will be described later.

[0016] The platen 400 is a plate-like member that supports the medium PM from the opposite side (below) of the head unit 100 when ink is ejected from the head unit 100 toward the medium PM. The width of the platen 400 in the medium width direction is larger than the width of the largest medium on which the printer 1000 can record an image.

[0017] The pair of conveying rollers 501, 502 are arranged to sandwich the platen 400 in the conveying direction. When the head unit 100 forms an image on the medium PM, the pair of conveying rollers 501, 502 send the medium PM to the discharge side in the conveying direction in a predetermined manner.

[0018] The ink tank 600 is divided into four sections so that it can contain ink of four colors. The four sub-tanks 700 are provided above the four head units 100, one each.

[0019] The four colors of ink are sent to a reservoir 620 via a conduit 610. The conduit 610 and the reservoir 620 are divided into four sections so that the four colors of ink can flow and be stored. Each color of ink sent to the reservoir 620 is circulated between one of the four sub-tanks 700 and the reservoir 620 via a conduit and a pump (not shown).

[0020] Each of the four sub-tanks 700 supplies ink to the head unit 100 located directly below it, and collects ink from the head unit 100.

[0021] The cooling mechanism 800 is a mechanism that circulates a refrigerant to cool a control board 82 (described later) provided in the head unit 100. The cooling mechanism 800 mainly has a refrigerant tank, a pump, a refrigerant supply pipe, and a refrigerant recovery pipe (none of which are shown). The cooling mechanism 800 circulates the refrigerant between the refrigerant tank and the head unit 100 via the refrigerant supply pipe and the refrigerant recovery pipe.

[0022] The control device CONT controls all the components of the printer 1000 and performs operations such as forming an image on the medium PM. The control device CONT includes an FPGA (Field Programmable Gate Array), an EEPROM (Electrically Eracable Programmable Read-Only Memory), and a RAM (Random Access Memory). The control device CONT may also include a CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit). The control device CONT is connected to an external device (not shown) such as a PC so that data communication is possible, and controls each component of the printer 1000 based on print data sent from the external device.

[0023] [Head Unit 100] Since the four head units 100 have the same configuration, one will be representatively described below.

[0024] As shown in FIG. 2, the head unit 100 includes a holding member HM and ten head systems HS1 integrally supported by the holding member HM.

[0025] The holding member HM is a rectangular plate-like member in a plan view, with its longitudinal direction aligned with the medium width direction and its transverse direction aligned with the transport direction. Both longitudinal ends of the holding member HM are supported portions that are supported by the support body 100a.

[0026] The ten head systems HS1 are each arranged inside a plurality of openings (not shown) of the holding member HM, and are thereby held together by the holding member HM. The ten head systems HS1 are arranged in a staggered (zigzag) pattern along the medium width direction in a plan view.

[0027] [Head System HS1] Since the ten head systems HS1 have the same configuration, the following description will focus on one representative example. The following description will be given assuming that the head system HS1 is installed so that the extension direction of the nozzle row L3 (FIG. 8, described in detail later) coincides with the medium width direction of the printer 1000. However, the installation mode of the head system HS1 is not limited to this.

[0028] 3, the head system HS1 has, from top to bottom, a connector 10, a flow path member 20, an alignment frame 30, a cooling frame 40, a front-end frame 50, and a head 60. As shown in FIGS. 7 and 10, a head heater mechanism 70 and a discharge control unit 80 are provided inside the front-end frame 50.

[0029] The connector 10 is, for example, a thick plate-like member made of resin. The connector 10 has an ink supply pipe connection port ISC, an ink discharge pipe connection port IDC, a refrigerant supply pipe connection port CSC, and a refrigerant discharge pipe connection port CDC that pass through the connector 10 in the vertical direction.

[0030] An ink supply pipe and an ink discharge pipe (neither shown) extending from the sub-tank 700 are connected from above to the ink supply pipe connection port ISC and the ink discharge pipe connection port IDC of the connector 10. A refrigerant supply pipe and a refrigerant discharge pipe (neither shown) of the cooling mechanism 800 are connected from above to the refrigerant supply pipe connection port CSC and the refrigerant discharge pipe connection port CDC of the connector 10, respectively.

[0031] As shown in FIG. 4, the flow path member 20 includes a first flow path member 21, a second flow path member 22, a seal member 23, a first pressing plate 24, and a second pressing plate 25.

[0032] The first flow path member 21 is a block-shaped member formed, for example, from a resin such as POM, and has a rectangular plate-shaped main part MP1, a first base part BP11 that protrudes from the right and lower corner of the main part MP1 in the medium width direction to the discharge side and downward, and a second base part BP12 that protrudes from the left and lower corner of the main part MP1 in the medium width direction to the discharge side and downward.

[0033] An ink circulation port (supply port) CP11 is provided on the upper surface MP1u of the main portion MP1 in the center in the medium width direction of the first flow path member 21. An ink guide portion IG1 is provided extending from the ink circulation port CP11 to the right in the medium width direction and to the supply side in the transport direction. The ink guide portion IG1 has a peripheral wall IG1w that is elliptical in plan view, and a bottom portion IG1b that is surrounded by the peripheral wall IG1w.

[0034] As shown in Figure 5, ink circulation ports CP12 and CP13 are formed side by side in the transport direction on the underside of the first base part BP11. Ink circulation port CP12 is located on the discharge side, and ink circulation port CP13 is located on the supply side. Ink circulation ports CP14 and CP15 are formed side by side in the transport direction on the underside of the second base part BP12. Ink circulation port CP14 is located on the discharge side, and ink circulation port CP15 is located on the supply side.

[0035] A first groove G11 and a second groove G12 are formed on an inner surface MP1i (surface facing the supply side in the conveying direction) of the main portion MP1.

[0036] The first groove G11 has a top G11 tp and extends downward and to the right in the medium width direction to a lower end G11 bt1 The first portion G111 and the top portion G11 tp and extends downward and to the left in the media width direction to a lower end G11 bt2 and a second portion G112 leading to

[0037] Top G11 tp is located at the center of the inner surface MP1i in the medium width direction. bt1 is located near the right end of the inner surface MP1i. bt2 is located to the left of the center of the inner surface MP1i in the width direction of the medium. bt1 is located within the area where the first base part BP11 is provided.

[0038] The extending direction of the first portion G111 and the second portion G112 is inclined at a predetermined angle with respect to the up-down direction (vertical direction). tp From bottom end G11 bt1The ink is bent once on the path leading to the first portion G111. By tilting the extension direction of the flow path relative to the horizontal, it is possible to suppress the pigment from settling on the bottom surface of the flow path, and in turn to prevent blockage of the flow path that may occur when the pigment that has settled on the bottom surface of the flow path flows all at once. In addition, it is possible to suppress the retention of air bubbles mixed in the ink on the upper surface of the flow path, and to more reliably flow them upward. The top G11 of the first portion G111 and the second portion G112 tp The angle of inclination of the flow path relative to the vertical axis extending downward from the flow path can be set to any angle equal to or less than 90°. The length of the flow path can also be adjusted by changing the number of bends in the path.

[0039] The second groove G12 is formed below the first groove G11. tp and extends downward and to the left in the media width direction to a lower end G12 bt The extension direction of the second groove G12 is inclined at a predetermined angle with respect to the up-down direction (vertical direction). tp From bottom end G12 bt There is one bend on the path to

[0040] Top G12 tp is located to the left of the center of the inner surface MP1i in the medium width direction. bt is located near the left end of the inner surface MP1i. When viewed in the conveying direction, the lower end G12 bt is located within the area where the second base part BP12 is provided.

[0041] Top G11 of first groove G11 tp An opening A11 is provided in the first groove G11. bt1 An opening A12 is provided at the bottom end G12 of the second groove G12. bt An opening A14 is provided at the lower left of the opening A12. An opening A13 is provided at the lower left of the opening A12, and an opening A15 is provided at the upper left of the opening A14.

[0042] Inside the main portion MP1, the top G11 of the first groove G11 is tpA flow channel ch11 extending in the vertical direction is formed at a position overlapping with the first groove G11. The lower end of the flow channel ch11 communicates with the first groove G11 via the opening A11, and the upper end of the flow channel ch11 communicates with the ink circulation port CP11.

[0043] The main portion MP1 and the first base portion BP11 have a lower end G11 of the first groove G11. bt1 A flow channel ch12 connecting the opening A13 and the ink circulation port CP12, and a flow channel ch13 connecting the opening A13 and the ink circulation port CP13 are formed.

[0044] The upper end of the flow path ch12 communicates with the first groove G11 via the opening A12. The flow path ch12 extends from the upper end toward the discharge side in the transport direction, then bends downward to reach the ink circulation port CP12. The flow path ch13 extends from the opening A13 toward the discharge side in the transport direction, then bends downward to reach the ink circulation port CP13. As shown in FIG. 5, the flow path length of the region extending horizontally along the transport direction is longer in the flow path ch12 than in the flow path ch13.

[0045] The lower end G12 of the second groove G12 is provided inside the main portion MP1 and the second base portion BP12. bt A flow channel ch14 connecting the opening A15 and the ink circulation port CP14, and a flow channel ch15 connecting the opening A15 and the ink circulation port CP15 are formed.

[0046] The upper end of the flow path ch14 communicates with the second groove G12 via the opening A14. The flow path ch14 extends from the upper end to the discharge side in the transport direction, then bends downward to reach the ink circulation port CP14. The flow path ch15 extends from the opening A15 to the discharge side in the transport direction, then bends downward, passes beside the flow path ch14, and reaches the ink circulation port CP15. As shown in FIG. 5, the flow path length of the region extending horizontally along the transport direction is longer in the flow path ch14 than in the flow path ch15. Furthermore, the flow path lengths of the region extending horizontally along the transport direction are equal in the flow path ch12 and the flow path ch14, and are equal in the flow path ch13 and the flow path ch15.

[0047] The second flow path member 22 faces the first flow path member 21 in the conveying direction. The second flow path member 22 is a block-shaped member made of resin such as POM, for example, and has a rectangular plate-shaped main part MP2, a first base part BP21 that protrudes downward and to the supply side from a corner on the right side and lower side of the main part MP2 in the medium width direction, and a second base part BP22 that protrudes downward and to the supply side from a corner on the left side and lower side of the main part MP2 in the medium width direction.

[0048] An ink circulation port (discharge port) CP21 is provided on the upper surface MP2u of the main portion MP2 in the center in the medium width direction of the second flow path member 22. An ink guide portion IG2 is provided extending from the ink circulation port CP21 to the left in the medium width direction and to the discharge side in the transport direction. The ink guide portion IG2 has a peripheral wall IG2w that is elliptical in plan view, and a bottom portion IG2b that is surrounded by the peripheral wall IG2w.

[0049] Ink circulation ports CP22 and CP23 are formed side by side in the transport direction on the underside of the first base part BP21. Ink circulation port CP22 is located on the supply side, and ink circulation port CP23 is located on the discharge side. Ink circulation ports CP24 and CP25 are formed side by side in the transport direction on the underside of the second base part BP22. Ink circulation port CP24 is located on the supply side, and ink circulation port CP25 is located on the discharge side.

[0050] A first groove G21 and a second groove G22 are formed on an inner surface MP2i (surface facing the discharge side in the conveying direction) of the main portion MP2.

[0051] The first groove G21 is linear, and the top G21 tp and extends downward and to the left in the medium width direction to a lower end G21 bt The extending direction of the first groove G21 is inclined at a predetermined angle with respect to the up-down direction (vertical direction).

[0052] Top G21 tp The lower end G21 is located to the left of the center of the inner surface MP2i in the medium width direction. bt is located near the left end of the inner surface MP2i. btis located within the area where the second base part BP22 is provided.

[0053] The second groove G22 is formed to the right of the first groove G21. tp and extends downward and to the right in the medium width direction to a lower end G22 bt1 The first portion G221 leading to the top G22 tp and extends downward and to the left in the medium width direction to a lower end G22 bt2 The extending direction of the first portion G221 and the second portion G222 is inclined at a predetermined angle with respect to the up-down direction (vertical direction). The first portion G221 is tp From bottom end G22 bt1 It bends twice on the way to the

[0054] Top G22 tp is located at the center of the inner surface MP2i in the medium width direction. bt1 is located near the right end of the inner surface MP2i. bt2 is located to the left of the center of the inner surface MP2i in the width direction of the medium. bt1 is located within the area where the first base part BP21 is provided.

[0055] Lower end G21 of the first groove G21 bt An opening A24 is provided at the top G22 of the second groove G22. tp An opening A21 is provided at the bottom end G22 of the second groove G22. bt1 An opening A22 is provided at the lower right of the opening A24. An opening A25 is provided at the lower right of the opening A24, and an opening A23 is provided at the upper right of the opening A22.

[0056] Inside the main portion MP2, the top G22 of the second groove G22 is tp A channel ch21 extending in the vertical direction is formed at a position overlapping the top G22. tpThe flow path ch21 communicates with the second groove G22 via an opening A21 formed in the upper end thereof, and the upper end of the flow path ch21 communicates with the ink circulation port CP21.

[0057] The lower end G22 of the second groove G22 is provided inside the main portion MP2 and the first base portion BP21. bt1 A flow path ch22 connecting the opening A23 and the ink circulation port CP22, and a flow path ch23 connecting the opening A23 and the ink circulation port CP23 are formed.

[0058] The upper end of the flow path ch22 communicates with the second groove G22 via the opening A22. The flow path ch22 extends from the upper end toward the supply side in the transport direction, then bends downward to reach the ink circulation port CP22. The flow path ch23 extends from the opening A23 toward the supply side in the transport direction, then bends downward, passes beside the flow path ch22, and reaches the ink circulation port CP23. As shown in FIG. 5, the flow path length of the region extending horizontally along the transport direction is longer in the flow path ch22 than in the flow path ch23.

[0059] The lower end G21 of the first groove G21 is provided inside the main portion MP2 and the second base portion BP22. bt A flow path ch24 connecting the opening A25 and the ink circulation port CP24, and a flow path ch25 connecting the opening A25 and the ink circulation port CP25 are formed.

[0060] The upper end of flow path ch24 communicates with first groove G21 via opening A24. Flow path ch24 extends from the upper end toward the supply side in the transport direction, then bends downward to reach ink circulation port CP24. Flow path ch25 extends from opening A25 toward the supply side in the transport direction, then bends downward to reach ink circulation port CP25. As shown in FIG. 5, the flow path length of the region extending horizontally along the transport direction is longer in flow path ch24 than in flow path ch25. Furthermore, the flow path lengths of the region extending horizontally along the transport direction are equal in flow path ch22 and flow path ch24, and are equal in flow path ch23 and flow path ch25.

[0061] The rubber sheet 23 (an example of a "sealing member" of the present invention) is disposed between the first flow path member 21 and the second flow path member 22, and prevents ink leakage from the flow path formed by the first flow path member 21 and the second flow path member 22. The rubber sheet 23 may be an elastic member made of EPDM, silicone, or the like.

[0062] As shown in Fig. 6, the rubber sheet 23 is provided with slits SL1 and SL2 penetrating through it in the thickness direction. The slits SL1 and SL2 each have an upwardly convex shape, with the slit SL2 being provided below the slit SL1. The slit SL1 has a shape that extends over the entire flow path (described in detail below) formed by the first groove G11 of the first flow path member 21 and the first groove G21 of the second flow path member 22. The slit SL2 has a shape that extends over the entire flow path (described in detail below) formed by the second groove G12 of the first flow path member 21 and the second groove G22 of the second flow path member 22.

[0063] The first pressing plate 24 (an example of the "first metal plate" of the present invention) and the second pressing plate 25 (an example of the "second metal plate" of the present invention) are members for holding the first flow path member 21 and the second flow path member 22 in close contact with the rubber sheet 23. The first pressing plate 24 and the second pressing plate 25 are formed from metal (for example, iron such as S45C).

[0064] The first pressure plate 24 has a plate-shaped main portion 240, a plate-shaped first convex portion 241 that protrudes from the upper right corner of the main portion 240 toward the supply side in the conveying direction, and a plate-shaped second convex portion 242 that protrudes from the upper left corner of the main portion 240 toward the supply side in the conveying direction.

[0065] In the flow path member 20, as shown in Fig. 4, the first flow path member 21 and the second flow path member 22 sandwich the rubber sheet 23, and the first presser plate 24 and the second presser plate 25 sandwich the first flow path member 21 and the second flow path member 22, and these are fixed with screws. 21 , five through holes th provided in the second flow path member 22 22 , five through holes th provided in the rubber sheet 2323 , five through holes th provided in the first pressing plate 24 24 , and five through holes th provided in the second pressing plate 25 25 This is done by passing five screws (not shown) through the

[0066] In this state, the first presser plate 24 and the second presser plate 25 are fixed to each other with screws. Furthermore, the first presser plate 24 presses the first flow path member 21 toward the second flow path member 22, and the second presser plate 25 presses the second flow path member 22 toward the first flow path member 21. As a result, the first flow path member 21 and the second flow path member 22 are pressed against the rubber sheet 23.

[0067] In this way, by sandwiching the first flow path member 21 and the second flow path member 22 between the planar first presser plate 24 and second presser plate 25, the inner surface MP1i of the first flow path member 21 and the inner surface MP2i of the second flow path member 22 are pressed uniformly in the in-plane direction against the rubber sheet 23. This makes it possible to more effectively suppress leakage of ink from the flow path member 20. Furthermore, because screws are used for fastening, the first presser plate 24 and the second presser plate 25 can be repeatedly attached and detached.

[0068] The first groove G11 of the first flow path member 21 is closed (capped) by the inner surface MP2i of the main portion MP2 of the second flow path member 22 via the slit SL1 of the rubber sheet 23. The second groove G12 of the first flow path member 21 is closed (capped) by the inner surface MP2i of the main portion MP2 of the second flow path member 22 via the slit SL2 of the rubber sheet 23.

[0069] Similarly, the first groove G21 of the second flow path member 22 is closed (covered) by the inner surface MP1i of the main portion MP1 of the first flow path member 21 via the slit SL1 of the rubber sheet 23. In addition, the second groove G22 of the second flow path member 22 is closed (covered) by the inner surface MP1i of the main portion MP1 of the first flow path member 21 via the slit SL2 of the rubber sheet 23.

[0070] The lower end G11 of the first groove G11 of the first flow path member 21 bt1The lower end G11 of the first groove G11 of the first flow path member 21 overlaps with the opening A23 of the second flow path member 22 when viewed in the conveying direction. bt1 The opening A23 of the second flow path member 22 communicates with the opening A23 of the rubber sheet 23 via the slit SL1.

[0071] The lower end G11 of the first groove G11 of the first flow path member 21 bt2 The top G21 of the first groove G21 of the second flow path member 22 tp That is, the lower end G11 of the first groove G11 of the first flow path member 21 overlaps with the lower end G11 of the first groove G11 of the first flow path member 21 when viewed in the conveying direction. bt2 The slit SL1 of the rubber sheet 23 is connected to the top G21 of the first groove G21 of the second flow path member 22. tp It is connected to.

[0072] Upper end G12 of the second groove G12 of the first flow path member 21 tp The lower end G22 of the second groove G22 of the second flow path member 22 bt2 That is, the upper end G12 of the second groove G12 of the first flow path member 21 overlaps with the upper end G12 of the second groove G12 of the first flow path member 21 when viewed in the conveying direction. tp The lower end G22 of the second groove G22 of the second flow path member 22 is connected to the slit SL2 of the rubber sheet 23. bt2 It is connected to.

[0073] The lower end G12 of the second groove G12 of the first flow path member 21 bt The opening A25 of the second flow path member 22 overlaps with the opening A25 of the second flow path member 22 when viewed in the conveying direction. bt The opening A25 communicates with the opening A25 of the second flow path member 22 via the slit SL2 of the rubber sheet 23.

[0074] The opening A13 of the first flow path member 21 is located at the lower end G22 of the second groove G22 of the second flow path member 22. bt1 That is, the opening A13 of the first flow path member 21 is in contact with the lower end G22 of the second groove G22 of the second flow path member 22 via the slit SL2 of the rubber sheet 23. bt1 It is connected to.

[0075] The opening A15 of the first flow path member 21 is located at the lower end G21 of the first groove G21 of the second flow path member 22 when viewed in the conveying direction. bt That is, the opening A15 of the first flow path member 21 is aligned with the lower end G21 of the first groove G21 of the second flow path member 22 via the slit SL1 of the rubber sheet 23. bt It is connected to.

[0076] The flow path member 20 is fixed to the underside of the connector 10 by screwing the connector 10 to the first protrusion 241 and the second protrusion 242 of the first presser plate 24. The end of the ink guide portion IG1 of the first flow path member 21 opposite the ink circulation port CP11 is located directly below the ink supply tube connection port ISC of the connector 10. The end of the ink guide portion IG2 of the second flow path member 22 opposite the ink circulation port CP21 is located directly below the ink discharge tube connection port IDC of the connector 10.

[0077] The alignment frame 30 is, for example, a flat plate member made of SUS. As shown in FIG. 7, the alignment frame 30 has a central through-hole TH that is rectangular in plan view and penetrates the center from top to bottom. 30 and the central through hole TH 30 Eight circular ink flow paths IC arranged around the 30 It has the following.

[0078] The alignment frame 30 is fixed to the lower surface of the flow path member 20. In this state, the ink flow ports CP12 to CP15 and CP22 to CP25 on the lower surface of the flow path member 20 are aligned with the ink flow paths IC 30 It is connected to.

[0079] The cooling frame 40 may be made of a material with high thermal conductivity, such as aluminum, for example. As shown in Fig. 7, the cooling frame 40 is a thick plate-like member that is rectangular in plan view.

[0080] A refrigerant flow path CC having a generally U-shaped configuration in plan view is formed inside the cooling frame 40. The refrigerant flow path CC is connected to a refrigerant supply port CSP on the top surface of the cooling frame 40. 40 and refrigerant outlet CDP 40The refrigerant flow path CC is surrounded by eight ink flow paths IC, which are circular in plan view. 40 and the central through hole TH 40 and is provided.

[0081] The cooling frame 40 is fixed to the lower surface of the alignment frame 30. In this state, the eight ink flow paths IC 30 Each of the eight ink channels IC of the cooling frame 40 40 It is in communication with each of the above.

[0082] 3, a refrigerant supply pipe CST and a refrigerant discharge pipe CDT are provided between the connector 10 and the cooling frame 40. The upper and lower ends of the refrigerant supply pipe CST are connected to a refrigerant supply pipe connection port CSC of the connector 10 and a refrigerant supply port CSP of the cooling frame 40. 40 The upper and lower ends of the refrigerant discharge pipe CDT are connected to the refrigerant discharge pipe connection port CDC of the connector 10 and the refrigerant discharge port CDP of the cooling frame 40. 40 are connected to the respective

[0083] The front end frame 50 is, for example, a flat plate member made of SUS. The front end frame 50 has a central through-hole TH that is rectangular in plan view and penetrates the center from top to bottom. 50 and the central through hole TH 50 Eight ink flow paths IC, which are roughly rectangular in plan view, are provided around the 50 It has the following.

[0084] The front end frame 50 is fixed to the lower surface of the cooling frame 40. In this state, the eight ink flow paths IC 50 Each of the eight ink channels IC of the cooling frame 40 40 and each of the

[0085] The head 60 includes a flow path unit 61 and a piezoelectric actuator 62 (FIGS. 7, 8, and 9).

[0086] 9, the flow path unit 61 is a laminated structure in which an ink sealing film 61A, plates 61B to 61E, and a nozzle plate 61F are laminated in this order from above. As shown in FIG. 8, a flow path CH is formed inside the flow path unit 61.

[0087] The channels CH include four manifold channels M1, M2, M3, and M4 and 48 individual channels iCH. Each of the four manifold channels M1 to M4 has a linear common channel cCH and ink flow ports IP at both ends of the common channel cCH. 60 (inlet, outlet). Twelve individual flow channels iCH are connected to each of the four manifold flow channels M1 to M4.

[0088] As shown in FIG. 9, each of the individual channels iCH includes a pressure chamber 1, a descender channel 2, and a nozzle 3. The upper surface of the pressure chamber 1 is formed by an ink sealing film 61A. The descender channel 2 extends vertically from the pressure chamber 1 toward the nozzle 3. The nozzle 3 is a minute opening that ejects ink toward the medium PM, and is formed in the nozzle plate 61F. The lower surface of the nozzle plate 61F is the lower surface of the head system HS1, which is the nozzle surface NS. On the nozzle surface NS, a nozzle row L3 (FIG. 8) is formed along the direction in which the manifold channels M1 to M4 extend.

[0089] 9, the piezoelectric actuator 62 is composed of a first piezoelectric layer L1 provided on the upper surface of the flow path unit 61, a second piezoelectric layer L2 above the first piezoelectric layer L1, a common electrode cET sandwiched between the first piezoelectric layer L1 and the second piezoelectric layer L2, and a plurality of individual electrodes iET provided on the upper surface of the second piezoelectric layer L2. The plurality of individual electrodes iET are provided on the upper surface of the second piezoelectric layer L2 so as to be respectively positioned above the pressure chambers 1 of the plurality of individual flow paths iCH. Portions of the second piezoelectric layer L2 sandwiched between the common electrode cET and each of the plurality of individual electrodes iET form active portions AC polarized in the thickness direction.

[0090] The head heater mechanism 70 (an example of a "heater" according to the present invention) applies heat to the head 60 to heat the ink flowing inside the head 60. As shown in FIGS. 7 and 10, the head heater mechanism 70 includes a heat transfer member 71, a film heater 72, and a leaf spring 73.

[0091] The heat transfer member 71 is made of a metal with high thermal conductivity, such as aluminum, and as shown in Fig. 7 (the enclosed diagram in Fig. 7 shows a bottom perspective view of the heat transfer member 71) and Fig. 10, the heat transfer member 71 has a plate portion 71A that is substantially square in plan view, a pair of wall portions 71B that protrude upward from both ends of the top surface of the plate portion 71A, and a frame-shaped protrusion 71C that protrudes downward from the outer edge of the bottom surface of the plate portion 71A.

[0092] The heat transfer member 71 is attached to the upper surface of the head 60 so that the lower end of the frame-shaped protrusion 71C abuts against the flow path unit 61 around (outside) the piezoelectric actuator 62. Note that a flexible printed circuit board 81 of the discharge control unit 80 is partially sandwiched between the frame-shaped protrusion 71C and the flow path unit 61 (described later).

[0093] The film heater 72 is disposed on the heat transfer member 71 so that its heat-generating surface abuts on the upper surface of the plate portion 71A of the heat transfer member 71. The heat generated by the film heater 72 is applied to the flow path unit 61 via the heat transfer member 71.

[0094] The leaf spring 73 is disposed on the upper surface of the film heater 72 .

[0095] 7 and 10, the discharge control unit 80 includes an FPC (Flexible Printed Circuits) 81 and a control board 82 on which a driver IC is mounted. The FPC 81 is not shown in FIG.

[0096] The FPC 81 is strip-shaped, and has a plurality of contacts (not shown) formed in a central portion 81A in the longitudinal direction.

[0097] The control board 82 is disposed above the leaf spring 73 of the head heater mechanism 70 and parallel to the plate portion 71A of the heat transfer member 71. The leaf spring 73 separates the control board 82 from the film heater 72 and brings the control board 82 into contact with the cooling frame 40. The leaf spring 73 also blocks the radiant heat of the film heater 72, thereby suppressing heating of the control board 82.

[0098] 10 , the FPC 81 is disposed on the upper surface of the piezoelectric actuator 62 so that each of the multiple contacts in the central portion 81A is electrically connected to each of the multiple individual electrodes iET of the piezoelectric actuator 62. The portion of the FPC 81 outside the central portion 81A passes between the heat transfer member 71 of the head heater mechanism 70 and the head 60, extends upward along the side surface of the heat transfer member 71, and is connected to the control board 82. This connects each of the multiple individual electrodes iET of the piezoelectric actuator 62 to the control board 82 via the FPC 81.

[0099] The head 60 is fixed to the front end frame 50. In this state, eight ink flow ports IP 60 Each of the eight ink flow path ICs of the front end frame 50 50 The piezoelectric actuator 62, the head heater mechanism 70, and the discharge control section 80 are connected to the central through-hole TH of the front-end frame 50. 50 It is placed inside.

[0100] As an example, the head system HS1 is fixed to a holding member HM via an alignment frame 30. A control board 82 of the ejection control unit 80 is connected to the control unit CONT by wiring (not shown).

[0101] [Flow path configuration within the HS1 head system] The configuration of the flow paths formed inside the head system HS1 will be summarized with reference to Fig. 11. In Fig. 11, the flow paths formed inside the first flow path member 21 are indicated by dashed lines, the flow paths formed inside the second flow path member 22 are indicated by solid lines, and the flow paths formed outside the first flow path member 21 and the second flow path member 22 are indicated by dashed lines.

[0102] The ink circulation port CP11 functions as the only ink supply port that the flow path member 20 has, and is an example of the "single supply port" of the present invention.

[0103] The flow path ch11 and the first groove G11 of the first flow path member 21 and the first groove G21 of the second flow path member 22 form a gap between the ink flow port CP11 and the lower end G11. bt1 , G21 bt The branch flow path is an example of the "main supply flow path" of the present invention. bt1 The flow path between the ink flow port CP11 and the lower end G21 bt and the flow paths therebetween are examples of the "first main supply flow path" and the "second main supply flow path" of the present invention, respectively.

[0104] The ink flow passage CP11 is connected to the lower end G11 of the first flow passage member 21 through the flow passage ch11 and the first portion G111. bt1 The flow path leading to the ink passage includes the opening A12 of the first flow path member 21, the flow path ch12, the ink circulation port CP12, and the ink flow path IC 30 ,I C 40 ,I C 50 through the ink flow port IP 60 a flow path (an example of the "first supply branch flow path" of the present invention) leading to the ink passage IC, a slit SL1 in the rubber sheet 23, an opening A23 in the second flow path member 22, a flow path ch23, an ink circulation port CP23, and an ink flow path IC 30 ,I C 40 ,I C 50 and the third ink flow port IP from the right side in the medium width direction of the head 60 and the discharge side in the transport direction. 60 The flow path branches into a flow path (an example of the "third supply branch flow path" of the present invention) leading to the

[0105] The ink flow passage CP11 is connected to the ink passage ch11, the second portion G112, the first groove G21, and the lower end portion G21 of the second passage member 22. bt The flow path leading to the ink passage is formed by the slit SL1 of the rubber sheet 23, the opening A15 of the first flow path member 21, the flow path ch15, the ink circulation port CP15, and the ink flow path IC30 ,I C 40 ,I C 50 , and then to the left side of the head 60 in the medium width direction and the second ink flow port IP from the discharge side in the conveying direction. 60 the opening A24 of the second flow path member 22, the flow path ch24, the ink flow port CP24, and the ink flow path IC 30 ,I C 40 ,I C 50 The ink flow port IP 60 (an example of the "fourth supply branch flow path" of the present invention).

[0106] Ink flow port CP11 to bottom end G11 bt1 , through the ink circulation port CP12, to the ink circulation port IP 60 The flow path from the ink flow port CP11 to the lower end G11 is an example of the "first supply flow path" of the present invention. bt1 , through the ink circulation port CP23, to the right side in the media width direction and the third ink circulation port IP from the discharge side in the transport direction 60 The flow path from the ink flow port CP11 to the lower end G21 is an example of the "third supply flow path" of the present invention. bt , through the ink circulation port CP15, to the left side in the media width direction and the second ink circulation port IP from the discharge side in the transport direction 60 The flow path from the ink flow port CP11 to the lower end G21 is an example of the "second supply flow path" of the present invention. bt , through the ink circulation port CP24, to the ink circulation port IP 60 The flow path leading to the fourth supply flow path is an example of the "fourth supply flow path" of the present invention.

[0107] The ink flow port CP21 functions as the only ink outlet port that the flow path member 20 has, and is an example of the "single outlet port" of the present invention.

[0108] The flow path ch21 and the second groove G22 of the second flow path member 22 and the second groove G12 of the first flow path member 21 form a gap between the ink flow port CP21 and the lower end G22 bt1 , G12bt This branch flow path is an example of the "main discharge flow path" of the present invention.

[0109] From the ink flow port CP21 through the flow path ch21 and the first portion 221 to the lower end G22 bt1 The flow path leading to the ink passage is the opening A13, the flow path ch13, the ink flow port CP13, the ink flow path IC 30 ,I C 40 ,I C 50 and the second ink flow port IP from the right side in the medium width direction of the head 60 and the discharge side in the transport direction. 60 a flow path (an example of the "second discharge branch flow path" of the present invention) leading to the ink passage IC 30 ,I C 40 ,I C 50 through the ink flow port IP 60 The flow path branches into a flow path (an example of the "fourth discharge branch flow path" of the present invention) leading to the

[0110] Ink flow port CP21 to bottom end G12 bt The flow path leading to the ink passage is the opening A14, the flow path ch14, the ink flow port CP14, the ink flow path IC 30 ,I C 40 ,I C 50 The ink flow port IP 60 a flow path (an example of the "first discharge branch flow path" of the present invention) leading to the ink passage IC25; an opening A25; a flow path ch25; an ink circulation port CP25; 30 ,I C 40 ,I C 50 and the third ink flow port IP from the left side in the medium width direction of the head 60 and the discharge side in the conveying direction. 60 and a flow path (an example of the "third discharge branch flow path" of the present invention) leading to the

[0111] Ink flow port CP21 to bottom end G12 bt , through the ink circulation port CP14, to the ink circulation port IP 60The flow path from the ink flow port CP21 to the lower end G12 is an example of the "first discharge flow path" of the present invention. bt , through the ink circulation port CP25, to the left side in the media width direction and the third ink circulation port IP from the discharge side in the transport direction 60 The flow path from the ink flow port CP21 to the lower end G22 is an example of the "third discharge flow path" of the present invention. bt1 , through the ink circulation port CP13, to the right side in the media width direction and the second ink circulation port IP from the discharge side in the transport direction 60 The flow path from the ink flow port CP21 to the lower end G22 is an example of the "second discharge flow path" of the present invention. bt1 , through the ink circulation port CP22, to the ink circulation port IP 60 The flow path leading to the fourth discharge flow path is an example of the "fourth discharge flow path" of the present invention.

[0112] Although not limited to, the ink circulation port CP11 and the four ink circulation ports IP of the head 60 60 The flow path resistances of the four flow paths (i.e., flow paths which are examples of the "first supply flow path" to the "fourth supply flow path" of the present invention) between the ink flow path CP11 and the ink flow path CP21 may be the same. 60 The ink is evenly distributed to the nozzles 3 of the head 60, thereby suppressing variations in the ejection of the ink from the nozzles 3 of the head 60. In addition, although not limited thereto, the ink flow port CP21 and the four ink flow ports IP 60 The flow path resistances of the four flow paths (i.e., flow paths which are examples of the "first discharge flow path" to the "fourth discharge flow path" of the present invention) between the ink flow path CP11 and the ink flow path CP21 may be the same. 60 This allows for more even distribution, and the variation in ejection from the multiple nozzles 3 of the head 60 is more effectively suppressed.

[0113] In this specification and the present invention, the expression "the flow path resistance of one flow path is the same as the flow path resistance of another flow path" not only means that the flow path resistances of both flow paths are completely the same, but also means that the difference between the flow path resistance of one flow path and the flow path resistance of the other flow path is within ±5% of the value of the other flow path resistance. For example, the flow path resistance increases when the flow path length is longer and when the flow path cross-sectional area is smaller.

[0114] Here, the lower end G11 of the first groove G11 bt1 In the transport direction, the ink circulation port CP12 (and the ink circulation port IP 60 ) and ink circulation port CP23 (and the third ink circulation port IP 60 ) and the bottom end G11 bt1 The length of the flow path from the ink flow port CP12 to the lower end G11 bt1 Therefore, the length of the flow path from the ink circulation port CP11 to the ink circulation port IP23 on the right side in the medium width direction and on the most discharge side in the transport direction can be easily matched. 60 a flow path (an example of the "first supply flow path" of the present invention) leading to the ink flow path CP11, and a third ink flow path IP 60 This makes it easy to match the flow path resistance with the flow path leading to the second supply path (an example of the "third supply flow path" of the present invention).

[0115] In addition, the lower end G21 of the first groove G21 bt In the transport direction, the ink circulation port CP15 (and the ink circulation port IP20 on the left side in the media width direction and the second ink circulation port IP10 from the discharge side in the transport direction) 60 ) and ink circulation port CP24 (and ink circulation port IP 60 ) and the bottom end G21 bt The length of the flow path from the ink flow port CP15 to the lower end G21 bt Therefore, the ink flow path length from the ink flow path CP11 to the ink flow path CP24 can be easily matched. 60a flow path (an example of the "second supply flow path" of the present invention) leading to the ink flow path CP11, and an ink flow path IP 60 This makes it easy to match the flow path resistance with the flow path leading to the second supply path (an example of the "fourth supply flow path" of the present invention).

[0116] In the head system HS1 having the above-described flow path configuration, when ink is supplied from the subtank 700 to the ink circulation port CP11, the ink circulation port IP 60 The ink supplied to the first manifold M1 flows leftward through the first manifold M1 and is distributed to the individual flow channels iCH that are connected to the first manifold M1. The ink that is not distributed to the individual flow channels iCH flows out of the ink flow port IP 60 The ink is returned to the subtank 700 via the ink flow port CP21.

[0117] Ink supplied to the ink circulation port CP11 flows in the same manner to the right through the second manifold M2, to the left through the third manifold M3, and to the right through the fourth manifold M4, and is distributed to the individual flow channels iCH connected to each manifold. Ink that is not distributed to the individual flow channels iCH flows through the ink circulation ports IP at the ends of each manifold. 60 The ink is returned to the subtank 700 via the ink flow port CP21.

[0118] The ink flowing inside the head 60 tends to become cooler and more viscous as it moves downstream of the manifold. Changes in ink viscosity cause changes in the ejection performance from the nozzles, so when an image is formed by ejecting ink from a nozzle row connected to the manifold, density unevenness can occur in the formed image.

[0119] In contrast, by opposing the ink flow direction between two manifolds adjacent to each other in the transport direction (i.e., by flowing the ink in a "cross-flow" manner), density variations are offset (averaged) between the two adjacent manifolds, thereby suppressing deterioration in the quality of the formed image.

[0120] <Image forming method> An image is formed on the medium PM using the printer 1000 and the head unit 100 as follows.

[0121] First, the medium PM in a feed tray (not shown) is sent to the supply side of the transport rollers 501, and is then sent onto the platen 400 by the transport rollers 501. The multiple head systems HS1 of the head unit 100 continuously eject ink droplets onto the medium PM being sent in the transport direction by the transport rollers 501 and 502, forming an image on the medium PM. The medium PM with the image formed on it is sent to the discharge side of the transport rollers 502 and is discharged to a discharge tray (not shown).

[0122] The head system HS1 ejects ink droplets by applying pressure to ink in a specific pressure chamber 1 (referred to as the "target pressure chamber") using a piezoelectric actuator 62. Specifically, first, under the command of the control device CONT, the driver IC on the control board 82 applies a drive potential to the individual electrode iET corresponding to the target pressure chamber via the FPC 81. This generates an electric field parallel to the polarization direction in the active portion AC sandwiched between the individual electrode iET to which the drive potential is applied and the common electrode cET, causing the active portion AC to contract in the horizontal direction perpendicular to the polarization direction. As a result, the ink sealing film 61A above the target pressure chamber vibrates, applying pressure to the ink in the target pressure chamber, and ink droplets are ejected from the nozzle 3 connected to the pressure chamber 1 via the descender flow path 2.

[0123] Ink in the sub-tank 700 is continuously supplied to the pressure chamber 1 via the flow path member 20, the manifolds M1 to M4, etc. Furthermore, of the ink in the manifolds M1 to M4, the ink that has not been supplied to the pressure chamber 1 is sent to the sub-tank 700 via the flow path member 20.

[0124] The effects of the head system HS1 of the first embodiment are summarized below.

[0125] In the head system HS1 of the first embodiment, a cross flow is achieved within the head 60 using the flow path member 20. Generally, in order to achieve a cross flow in a head, in which ink flows in different directions between a certain manifold and a manifold adjacent to that manifold, the flow paths for supplying ink to the head and recovering ink from the head become complicated, making it difficult to miniaturize the head system.

[0126] For example, as in Patent Document 1, a flow path member having two flow paths separated by a rubber sheet and two supply ports and two discharge ports requires two ink supply pipes and two ink discharge pipes to connect the flow path member to the subtank. Therefore, the connector (joint) for connecting the four pipes (i.e., two ink supply pipes and two ink discharge pipes) to the flow path member has a complex structure, and the head system becomes larger, for example, in the vertical direction (height direction). Furthermore, because two branch flow paths extending from the supply ports to both sides in the medium width direction (the direction of the nozzle rows) are configured inside the flow path member, and two branch flow paths extending from the discharge ports to both sides in the medium width direction are also configured inside the flow path member, the total flow path length inside the flow path member increases, and the flow path member itself also becomes larger.

[0127] In contrast, the flow path member 20 of the head system HS1 of the first embodiment is provided with a supply flow path that straddles (crosses) the first flow path member 21 and the second flow path member 22, and thereby ink supplied from a single supply port (ink circulation port CP11) is distributed to four ink circulation ports IP on both sides of the head 60 in the medium width direction using only one branch flow path that branches from the supply port to both sides in the medium width direction. 60 Similarly, the flow path member 20 is provided with a discharge flow path that straddles (crosses) the first flow path member 21 and the second flow path member 22, so that the four ink flow ports IP 60 Ink from a single outlet (ink circulation port CP21) is collected at a single outlet by using only one branch flow path that branches off from the single outlet to both sides in the width direction of the medium. In other words, ink from a single supply port is collected at four ink circulation ports IP 60It is divided into four ink distribution ports IP 60 The ink from the nozzle is collected into a single ink outlet using a two-stage branching flow path.

[0128] Therefore, in the head system HS1 of the first embodiment, it is possible to reduce the size of the connection structure between the flow path member 20 and the ink supply pipe and ink discharge pipe. In addition, the total flow path length within the flow path member 20 is also shortened, and the flow path member 20 itself can be reduced in size.

[0129] Furthermore, when a flow path member has multiple supply ports and multiple recovery ports, the manufacturing costs of the flow path member tend to increase. In contrast, in the head system HS1 of the first embodiment, the flow path member 20 has a single supply port and a single discharge port, which makes it possible to suppress the manufacturing costs.

[0130] Furthermore, in the head system HS1 of the first embodiment, the flow path member 20 has a single supply port and a single discharge port, so the diameters of the supply port and discharge port can be increased, and the O-rings provided at the supply port and discharge port can also be increased in size. This makes it possible to more effectively prevent ink from leaking from the supply port and discharge port. Furthermore, by increasing the diameters of the supply port and discharge port, the flow path resistance of the flow path inside the flow path member 20 can be reduced, making it easier to adjust the pressure of the nozzle 3.

[0131] Second Embodiment A head system HS2 according to a second embodiment of the present invention will be described with reference to Fig. 12. In Fig. 12, the flow paths formed inside the first flow path member are indicated by dashed lines, the flow paths formed inside the second flow path member are indicated by solid lines, and the flow paths formed outside the first and second flow path members are indicated by dashed lines.

[0132] The head system HS2 of the second embodiment is the same as the head system HS1 of the first embodiment except that it has a flow path member 20' instead of the flow path member 20. Description of the same configuration as the head system HS1 of the first embodiment will be omitted.

[0133] As shown in FIG. 12, in the flow path member 20′, the upper end of the flow path ch22 is connected to the lower end G11 of the first groove G11 through the opening A23. bt1 The upper end of the flow channel ch23 is connected to the lower end G22 of the second groove G22 through the opening A22. bt1 In the flow path member 20′, the upper end of the flow path ch24 is connected to the lower end G12 of the second groove G12 through the opening A25. bt The upper end of the flow channel ch25 is connected to the lower end G21 of the first groove G21 through the opening A24. bt The other configurations are the same as those of the flow path member 20 of the first embodiment.

[0134] In the head system HS2 of the second embodiment, the ink flow port CP11 to the lower end G11 bt1 , through the flow path ch12 and the ink circulation port CP12, to the ink supply port IP 60 a flow path (an example of the "first supply flow path" of the present invention) leading to the ink flow port CP11 and a flow path from the ink flow port CP11 to the lower end G11 bt1 , the ink supply port IP22 on the right side in the medium width direction and on the most supply side in the conveying direction through the flow path ch22 and the ink circulation port CP22 60 A flow path (an example of the "fourth supply flow path" of the present invention) is formed from the ink flow port CP11 to the lower end G21. bt , through the flow path ch15 and the ink circulation port CP15, to the left side in the media width direction and the second ink supply port IP from the discharge side in the transport direction. 60 a flow path (an example of the "second supply flow path" of the present invention) from the ink flow port CP11 to the lower end G21 bt , through the flow path ch25 and the ink circulation port CP25, to the left side in the media width direction and the third ink supply port IP from the discharge side in the conveying direction. 60 A flow path (an example of the "third supply flow path" of the present invention) leading to the

[0135] In the head system HS2 of the second embodiment, the ink flow port CP21 to the lower end G12 bt , the ink supply port IP14 on the left side in the medium width direction and on the most discharge side in the conveying direction through the flow path ch14 and the ink circulation port CP14.60 a flow path (an example of the "first discharge flow path" of the present invention) leading to the ink flow port CP21 and ... bt , the ink supply port IP24 on the left side in the medium width direction and on the most supply side in the conveying direction through the flow path ch24 and the ink circulation port CP24. 60 A flow path (an example of the "fourth discharge flow path" of the present invention) is formed from the ink flow port CP21 to the lower end G22. bt1 , through the flow path ch13 and the ink circulation port CP13, to the right side in the media width direction and the second ink supply port IP from the discharge side in the transport direction. 60 a flow path (an example of the "second discharge flow path" of the present invention) leading to the ink flow port CP21 and a flow path from the ink flow port CP21 to the lower end G22 bt1 , through the flow path ch23 and the ink circulation port CP23, to the right side in the width direction of the medium and the third ink supply port IP from the discharge side in the conveying direction. 60 A flow path (an example of the "third discharge flow path" of the present invention) leading to the

[0136] In the head system HS2 of the second embodiment, ink flows leftward in the first manifold M1 and the fourth manifold M4, and ink flows rightward in the second manifold M2 and the third manifold M3. This type of ink flow in the first manifold M1 to the fourth manifold M4 is also one aspect of crossflow.

[0137] <Modification> The following modifications can also be used in the head system HS1 of the first embodiment and the head system HS2 of the second embodiment.

[0138] In the head system HS1 of the first embodiment and the head system HS2 of the second embodiment, the flow path for discharging ink may be omitted. That is, the head system HS1 and the head system HS2 may be configured to only supply ink to the head 60. Also, in the head system HS1 of the first embodiment and the head system HS2 of the second embodiment, the ink circulation port CP21 of the flow path member 20 may be used as an ink supply port, and the ink circulation port CP11 may be used as an ink discharge port.

[0139] In the head system HS1 of the first embodiment and the head system HS2 of the second embodiment, the rubber sheet 23 may be a sheet in which openings are provided only in the portion where a flow path that crosses the first flow path member 21 and the second flow path member 22 is formed, instead of the slits SL1 and SL2. Alternatively, instead of the rubber sheet 23, an annular packing that surrounds the edge of the flow path (the edge of the flow path as seen in the conveying direction) may be used. Also, instead of the rubber sheet 23, a sheet made of a highly rigid material such as a resin film may be used. The annular packing and the highly rigid sheet are also examples of the sealing member of the present invention.

[0140] In the head system HS1 of the first embodiment and the head system HS2 of the second embodiment, the flow path member 20 does not necessarily have to have the rubber sheet 23, and does not necessarily have to have the first pressing plate 24 and the second pressing plate 25.

[0141] In the head system HS1 of the first embodiment and the head system HS2 of the second embodiment, the configuration of the flow paths within the flow path member 20 is not limited to that described above. The ink supply flow path can be any flow path that extends from a single supply port across (transverse) the first flow path member 21 and the second flow path member 22 and supplies ink to the head 60 in a crossflow manner. The ink discharge flow path can be any flow path that extends across (transverse) the first flow path member 21 and the second flow path member 22 and sends the flow path that has flowed in a crossflow manner within the head 60 to a single discharge port.

[0142] The above describes the embodiment and modified examples using as an example a case where ink is ejected from the head systems HS1 and HS2 to form an image on a medium PM. The head systems HS1 and HS2 may be liquid ejection systems that eject any liquid (e.g., UV ink) for image formation, and the medium PM on which the image is formed may be, for example, paper, cloth, resin, etc. The head systems HS1 and HS2 may also be used as head systems in a serial head printer.

[0143] The embodiments described in this specification are illustrative in all respects and should not be considered limiting. For example, the number and configuration of the head units 100 may be changed. The number of colors that the printer 1000 can print simultaneously is not limited, and the printer 1000 may be configured to be capable of single-color printing only. Furthermore, the number and arrangement of the individual flow channels iCH may be changed as appropriate. Furthermore, the technical features described in each embodiment may be combined with each other.

[0144] In the above description, the head systems HS1 and HS2 are arranged so that the first flow path member 21 of the flow path members 20 and 20' is located on the discharge side in the transport direction and the second flow path member 22 is located on the supply side in the transport direction, but this is not limiting. For example, the head systems HS1 and HS2 may be arranged so that the first flow path member 21 is located on the supply side in the transport direction and the second flow path member 22 is located on the discharge side in the transport direction. Furthermore, the head systems HS1 and HS2 may be arranged so that the first flow path member 21 and the second flow path member 22 of the flow path members 20 and 20' face each other in the medium width direction.

[0145] As long as the characteristics of the present invention are maintained, the present invention is not limited to the above-described embodiments, and other forms that can be conceived within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0146] 1. Pressure chamber 3 nozzles 20, 20' flow path member 21 first flow path member 22 second flow path member 23 Rubber Sheet 24 First holding plate 25 Second holding plate 30 Alignment Frame 40 Cooling Frame 50 front end frame 60 head 61 Flow path unit 62 Piezoelectric Actuator 70 Head heater mechanism 100 head unit 1000 printers HS1, HS2 head system

Claims

1. a head that ejects liquid; a flow path member disposed above the head and supplying the liquid to the head, The head four manifolds, each having a common flow path extending in a first direction and connected to a plurality of nozzles, and an inlet connected to one end of the common flow path; the four manifolds are arranged in the head in the order of a first manifold, a second manifold, a third manifold, and a fourth manifold along a second direction perpendicular to the first direction, The flow path member is a first member having a single supply port; a second member facing the first member in the second direction, a first supply flow path extending between the supply port and the inlet of the first manifold; a second supply flow path extending between the supply port and the inlet of the second manifold; a third supply flow path extending between the supply port and the inlet of the third manifold; a flow path member having a fourth supply flow path formed therein, the fourth supply flow path extending between the supply port and the inlet of the fourth manifold; In a first manifold group including two of the first to fourth manifolds, the inlet is connected to an end of the common flow path on one side in the first direction, and in a second manifold group including the remaining two of the first to fourth manifolds, the inlet is connected to an end of the common flow path on the other side in the first direction, the first manifold group includes the first manifold and the third manifold and the second manifold group includes the second manifold and the fourth manifold, or the first manifold group includes the first manifold and the fourth manifold and the second manifold group includes the second manifold and the third manifold; A head system in which the third supply flow path and the fourth supply flow path are each formed in both the first member and the second member.

2. the first supply flow path includes a main supply flow path extending from the supply port and a first branch supply flow path extending between a downstream end of the main supply flow path and the inlet of the first manifold, the second supply flow path includes the main supply flow path and a second branch supply flow path extending between a downstream end of the main supply flow path and the inlet of the second manifold, the third supply flow path includes the main supply flow path and a third branch supply flow path extending between a downstream end of the main supply flow path and the inlet of the third manifold, 2. The head system according to claim 1, wherein the fourth supply flow path includes the main supply flow path and a fourth branch supply flow path extending between a downstream end of the main supply flow path and the inlet of the fourth manifold.

3. the flow path member further includes a seal member sandwiched between the first member and the second member, 3. The head system according to claim 2, wherein the liquid is supplied from the supply port of the first member to the third supply branch channel and the fourth supply branch channel of the second member via the seal member.

4. the supply port is provided at a center of the first member in the first direction, the main supply channel includes a first main supply channel extending from the supply port to one side in the first direction, and a second main supply channel extending from the supply port to the other side in the first direction, when the first manifold group includes the first manifold and the third manifold and the second manifold group includes the second manifold and the fourth manifold, the first main supply channel is connected to the first branch supply channel and the third branch supply channel, and the second main supply channel is connected to the second branch supply channel and the fourth branch supply channel, 4. The head system of claim 3, wherein, when the first manifold group includes the first manifold and the fourth manifold and the second manifold group includes the second manifold and the third manifold, the first main supply channel is connected to the first branch supply channel and the fourth branch supply channel, and the second main supply channel is connected to the second branch supply channel and the third branch supply channel.

5. the first main supply channel is connected to the first branch supply channel and the third branch supply channel, and the second main supply channel is connected to the second branch supply channel and the fourth branch supply channel; the second main supply channel extends from the supply port to the second member via the seal member, the second branch supply flow path extends from a downstream end of the second main supply flow path provided in the second member to the first member via the seal member and is connected to the inlet of the second manifold, The head system according to claim 4, wherein the fourth supply branch flow path extends from the downstream end of the second supply main flow path provided in the second member, through the interior of the second member, and is connected to the inlet of the fourth manifold.

6. the first main supply channel is connected to the first branch supply channel and the third branch supply channel, and the second main supply channel is connected to the second branch supply channel and the fourth branch supply channel; the first branch supply flow path extends from a downstream end of the first main supply flow path provided in the first member through the first member and is connected to the inlet of the first manifold, A head system as described in claim 4 or 5, wherein the third branch supply flow path extends from the downstream end of the first main supply flow path provided in the first member to the second member via the sealing member and is connected to the inlet of the third manifold.

7. 7. The head system according to claim 3, wherein the sealing member is an elastic member.

8. 8. The head system according to claim 2, wherein in the head, each of the four manifolds has an outlet connected to the other end of the common flow path in the first direction.

9. In the flow path member, the second member has a single outlet; a first discharge flow path formed in both the first member and the second member and extending between the discharge port and the outlet of the first manifold; a second discharge flow path formed in both the first member and the second member and extending between the discharge port and the outlet of the second manifold; a third discharge flow path extending between the discharge port and the outlet of the third manifold; a fourth discharge flow path is formed extending between the discharge port and the outlet of the fourth manifold, The head system of claim 8, wherein the outlet is connected to an end of the first manifold group on the other side in the first direction, and the outlet is connected to an end of the second manifold group on one side in the first direction.

10. the first discharge flow path includes a main discharge flow path extending from the discharge port and a first branch discharge flow path extending between an upstream end of the main discharge flow path and the outlet of the first manifold, the second discharge flow path includes the main discharge flow path and a second branch discharge flow path extending between an upstream end of the main discharge flow path and the outlet of the second manifold, the third discharge flow path includes the main discharge flow path and a third branch discharge flow path extending between an upstream end of the main discharge flow path and the outlet of the third manifold, the fourth discharge flow path includes the main discharge flow path and a fourth branch discharge flow path extending between an upstream end of the main discharge flow path and the outlet of the fourth manifold, the main supply channel, the first branch supply channel, the second branch supply channel, the first branch discharge channel, and the second branch discharge channel are formed in the first member, The head system according to claim 9 , wherein the main discharge channel, the third branch supply channel, the fourth branch supply channel, the third branch discharge channel, and the fourth branch discharge channel are formed in the second member.

11. The flow path member is a first metal plate provided on the opposite side of the first member from the second member and pressing the first member toward the second member; The head system according to any one of claims 1 to 10, further comprising a second metal plate provided on the opposite side of the second member from the first member and pressing the second member toward the first member.

12. The head system according to claim 11 , wherein the first metal plate and the second metal plate are fixed to each other with screws.

13. A head system according to any one of claims 1 to 12, wherein the flow resistance of the first supply flow path, the flow resistance of the second supply flow path, the flow resistance of the third supply flow path, and the flow resistance of the fourth supply flow path are the same.

14. 14. The head system according to claim 1, further comprising a heater provided between the head and the flow path member, for heating the liquid in the head.

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