Linehead assembly, printing device including the linehead assembly, and method for flowing fluid through the linehead assembly - Patents.com

Abstract

To provide a technique that can properly distribute an ink to line heads 20 in which circulation type heads 11 are arranged in a zigzag manner, and recover the ink.SOLUTION: A line head assembly 10 includes: a line head 20 including ten heads 11 arranged in a zigzag manner; and a tank 400 located above the line head 20. Each head 11 includes a first supply port 16. An ink is supplied from a first supply passage 450 of the tank 400 to the first supply ports 16 of the ten heads 11 arranged in the zigzag manner. Further, each head 11 includes a first discharge port 17. The ink discharged from the first discharge ports 17 of the ten heads 11 arranged in the zig zag manner is returned to a first discharge passage 460 of the tank 400.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a line head assembly having a plurality of recirculating heads arranged in a staggered pattern, a printing device including the same, and a method for flowing liquid through the line head assembly. [Background technology]

[0002] One known printing device includes a line head having two head rows (a first head row and a second head row) and an ink supply member having two tanks (a first tank and a second tank) corresponding to the two head rows, respectively (see, for example, Patent Document 1). The first head row and the second head row are arranged so as to be offset from each other in the direction in which the rows extend. As a result, the multiple heads included in the two head rows are arranged in a staggered pattern overall. Each head also has two nozzle rows (a first nozzle row and a second nozzle row). The inside of each tank is divided into a first ink chamber and a second ink chamber corresponding to the first nozzle row and the second nozzle row, respectively.

[0003] The first tank is disposed above the first head row. The first ink chamber of the first tank is located above the first nozzle row of the head included in the first head row. The second ink chamber of the first tank is located above the second nozzle row of the head included in the first head row. The same is true for the second tank. This makes it possible to easily form ink supply paths that connect the four ink chambers and the four nozzle rows, respectively, and to supply ink individually to the four nozzle rows included in the first and second head rows. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-214819 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, a recirculating head has been adopted in order to stabilize the state of the ink. In contrast, in the above-mentioned known printing device, the multiple heads arranged in a staggered pattern are not recirculating heads.

[0006] An object of the present invention is to provide a technique for appropriately distributing and recovering liquid such as ink to each head row in a line head in which a plurality of circulation type heads are arranged in a staggered pattern. [Means for solving the problem]

[0007] According to an aspect of the present invention, there is provided a line head having a first head, a second head, and a third head aligned in a first direction, the second head is disposed between the first head and the third head in the first direction, the first head and the third head are positioned at the same position in a second direction intersecting the first direction, a line head in which the first head and the third head are positioned differently from the second head in the second direction; a tank located above the line head in a vertical direction intersecting the first direction and the second direction, The first head, the second head, and the third head each have a first internal head flow path including a first pressure chamber and a first nozzle; a first supply port connected to one end of the first head internal flow path; a first outlet connected to the other end of the first head flow path, The tank is a first supply flow path communicating the first supply port of the first head, the first supply port of the second head, and the first supply port of the third head; a first discharge flow path that communicates the first discharge port of the first head, the first discharge port of the second head, and the first discharge port of the third head; 、 The first supply flow path includes a first main supply flow path and first branch supply flow paths A, B, and C, The first discharge flow path includes a first main discharge flow path and first branch discharge flow paths A, B, and C, The first main supply flow path is connected to one end of the first branch supply flow paths A, B, and C, the other end of the first branch supply flow path A is connected to the first supply port of the first head, the other end of the first branch supply flow path B is connected to the first supply port of the second head, and the other end of the first branch supply flow path C is connected to the first supply port of the third head, the one end of each of the first branch supply channels A, B, C, which is connected to the first main supply channel, is formed of a member that constitutes an inclined surface that intersects with a plane including the first direction and the second direction and also intersects with the up-down direction, The inclined surface forms a part of the upper surface of the first branch supply flow paths A, B, and C. A line head assembly is provided, comprising: Effect of the Invention

[0008] In the above configuration, the first to third heads of the line head are arranged in a staggered manner. Furthermore, the tank arranged above the line heads includes a first supply flow path connected to the first supply port of each head and a first discharge flow path connected to the first discharge port of each head. This allows liquid to be supplied from the first supply flow path to the first supply ports of the first to third heads, and the liquid can be collected from the first discharge ports of the first to third heads to the first discharge flow path. This makes it easy to realize a circulation type head. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view showing an outline of a printing device 1. As shown in FIG. [Diagram 2] FIG. 2 is a schematic diagram showing an outline of the printing device 1. As shown in FIG. [Diagram 3] FIG. 3 is a schematic diagram for explaining the arrangement of the heads 11 included in the line head 20. As shown in FIG. [Figure 4] FIG. 4 is a perspective view of the first housing 100 and the second housing 200. As shown in FIG. [Diagram 5] FIG. 5 is a schematic explanatory diagram of the line head assembly 10. As shown in FIG. [Figure 6] 1A is a top view of the relay substrate 300, and FIG. 1B is a bottom view of the relay substrate 300. FIG. [Figure 7] FIG. 7 is a rear view of the housing 100. [Figure 8] FIG. 8 is an exploded perspective view of the tank 400. [Figure 9] FIG. 9 is a perspective view of the tank body 413 as viewed from above. [Figure 10] FIG. 10 is a perspective view of the tank body 413 as seen from below. [Figure 11] FIG. 11 is a schematic top view of the head 11. [Figure 12] FIG. 12 is an explanatory diagram for explaining the flow paths within the tank 400. As shown in FIG. [Figure 13] 10, (a) is a cross-sectional view taken along line A in FIG. 10, (b) is a cross-sectional view taken along line B in FIG. 10, (c) is a cross-sectional view taken along line C in FIG. 10, and (d) is a cross-sectional view taken along line D in FIG. [Figure 14] FIG. 14 is an explanatory diagram showing the ink circulation path. [Figure 15] FIG. 15 is an explanatory diagram showing another ink circulation path. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A printing device 1 according to an embodiment of the present invention will be described below with reference to the drawings. In Fig. 1, the transport direction of the recording medium 4 corresponds to the front-rear direction of the printing device 1. The width direction of the recording medium 4 corresponds to the left-right direction of the printing device 1. A direction perpendicular to the front-rear and left-right directions, i.e., a direction perpendicular to the paper surface in Fig. 1, corresponds to the up-down direction of the printing device 1. The left-right direction is an example of a first direction in this embodiment, and the front-rear direction (transport direction) is an example of a second direction.

[0011] 1 and 2, the printing device 1 includes a platen 3 housed in a housing 2, three line head assemblies 10 (one example of a head assembly of the present invention), two transport rollers 5A and 5B, a controller 7, five ink reservoirs 8, etc. In order to simplify the drawings, only one ink reservoir 8 is shown in FIGS.

[0012] As shown in FIGS. 1 and 2, a recording medium 4 is placed on the upper surface of a platen 3. Three line head assemblies 10 are arranged above the platen 3 so as to face the platen 3. Ink is supplied to each line head assembly 10 from an ink reservoir 8. The structure of the line head assemblies 10 will be described later. The three line head assemblies 10 are fixed to an arch frame 41 so as to be aligned in the front-rear direction (the conveying direction of the recording medium 4). As shown in FIG. 2, the arch frame 41 has an arch shape, and the three line head assemblies 10 are arranged so as to be inclined at different angles with respect to the horizontal plane.

[0013] As shown in FIGS. 1 and 2, the two transport rollers 5A and 5B are disposed behind and in front of the platen 3, respectively. The two transport rollers 5A and 5B are driven by a motor (not shown). As shown in FIG. 2, the recording medium 4 is fed from a feed roll 4A wound in a roll shape and taken up by a take-up roll 4B. For example, roll paper can be used as the recording medium 4. The feed roll 4A and the take-up roll 4B are respectively fitted with rotating shafts 4C and 4D rotated by a motor (not shown). These two rotating shafts 4C and 4D and the two transport rollers 5A and 5B work together to feed the recording medium 4 from the feed roll 4A, transport it to the downstream side (forward) in the transport direction so as to pass over the platen 3, and take it up on the take-up roll 4B. The two rotating shafts 4C and 4D and the two transport rollers 5A and 5B are an example of a transport mechanism of the present invention.

[0014] As shown in FIG. 3, each line head assembly 10 includes a line head 20 having a plurality of heads 11 (ten heads 11 in this embodiment). The plurality of heads 11 form two head rows arranged in the front-rear direction. Each head row includes five heads 11 arranged in the left-right direction. The five heads 11 arranged in the left-right direction have the same positions in the front-rear direction. However, in the following description, the same positions does not mean that the positions are exactly the same, but that the positions are the same within the range of manufacturing error and installation error. The positions in the left-right direction of the heads 11 included in the two head rows are shifted from each other. In other words, the ten heads 11 are arranged in a staggered pattern.

[0015] The lower surface 11b of each head 11 is a nozzle surface on which a plurality of nozzles 11a are formed. As shown in Fig. 3, the plurality of nozzles 11a of the head 11 are arranged in rows along the left-right direction, which is the longitudinal direction of the line head 20 (line head assembly 10), to form two nozzle rows. An internal head flow path is formed inside the head 11, and the shape and the like of the internal head flow path will be described later.

[0016] As described above, the ten heads 11 of each line head assembly 10 (line head 20) form two head rows. As described above, each head 11 has two nozzle rows. Since each nozzle row can eject ink of a different color, each head 11 can eject ink of a maximum of two colors. The ten heads 11 of the line head assembly 10 arranged at the rearmost (most upstream in the transport direction) are supplied with white ink from one of the five ink reservoirs 8. The white ink can be used for undercoat printing. The ten heads 11 of the line head assembly 10 arranged second from the rear (second from the upstream side in the transport direction) are supplied with yellow ink and magenta ink from two of the five ink reservoirs 8. Yellow ink is ejected from the nozzle row at the rear (upstream side in the transport direction) of each head 11, and magenta ink is ejected from the nozzle row at the front (downstream side in the transport direction). The ten heads 11 of the line head assembly 10 arranged at the front (at the most downstream side in the transport direction) are supplied with cyan ink and black ink from two of the five ink reservoirs 8. Cyan ink is ejected from the nozzle row at the rear (upstream side in the transport direction) of each head 11, and black ink is ejected from the nozzle row at the front (downstream side in the transport direction). In this manner, in this embodiment, inks of light to dark colors are ejected in order from the upstream side to the downstream side in the transport direction from the three line head assemblies 10 arranged in the transport direction. In this embodiment, the white ink, yellow ink, magenta ink, cyan ink, and black ink are all UV curable inks. The viscosity of UV curable ink varies greatly depending on the temperature. In order to prevent ejection defects, it is necessary to keep the viscosity of the ink within an appropriate range. To this end, it is necessary to keep the temperature of the UV curable ink at an appropriate temperature.

[0017] The controller 7 includes a field programmable gate array (FPGA), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), etc. The controller 7 may also include a central processing unit (CPU) or an application specific integrated circuit (ASIC), etc. The controller 7 is connected to an external device 9 (see FIG. 1) such as a PC so as to be able to communicate data with the external device 9, and controls each part of the printer 1 based on print data sent from the external device 9.

[0018] The controller 7 controls the motors that drive the rotating shafts 4C and 4D and the motors that drive the transport rollers 5A and 5B to cause the two transport rollers 5A and 5B to transport the recording medium 4 in the transport direction. The controller 7 also controls the three line head assemblies 10 to eject ink from the nozzles 11a toward the recording medium 4. As a result, an image is printed on the recording medium 4.

[0019] <Structure of the line head assembly 10> Next, the structure of the line head assembly 10 will be described with reference to the drawings. Since the three line head assemblies 10 have the same structure, one of them will be described. As described above, the three line head assemblies 10 are arranged so as to be inclined at different angles with respect to the horizontal plane. However, for the sake of simplicity, in the following description, the direction is defined as the line head assembly 10 being arranged perpendicular to the horizontal plane. As shown in FIG. 5, each line head assembly 10 mainly includes a first housing 100, a second housing 200, a line head 20 including ten heads 11, ten rigid boards 110, ten flexible boards 280, a fan 120, a relay board 300, a tank 400, a heater 250, and a plurality of tubes 416 connecting the heads 11 and the tank 400. In FIG. 5, five of the ten flexible boards 280 are illustrated.

[0020] <First Housing 100 and Second Housing 200> As shown in Figs. 4 and 5, the first housing 100 is disposed so as to be stacked above the second housing 200. The first housing 100 defines a first space S1 therein, and the second housing 200 defines a second space S2 therein. In Figs. 4 and 5, the front and rear side walls of the first housing 100 and the second housing 200 have been removed in order to make the first space S1 and the second space S2 easier to see. The left-right direction corresponds to the depth direction of the first housing 100 and the second housing 200, and the front-rear direction corresponds to the width direction of the first housing 100 and the second housing 200. The depth direction is perpendicular to both the up-down direction and the width direction.

[0021] As shown in FIG. 4, the first housing 100 has a substantially rectangular parallelepiped shape. A first grip 108 is provided on a top plate 101 that defines the upper surface of the first housing 100. A ventilation hole 103 is opened in a right side wall 102R of the first housing 100. A fan 120 is attached to the ventilation hole 103. As described later, the fan 120 can blow air in the arrangement direction (left-right direction, depth direction) of the row of rigid boards 110. Furthermore, an opening 105 is formed in the bottom surface of the first housing 100.

[0022] The second housing 200 has a shape like a combination of two rectangular parallelepipeds with different heights, and is, for example, approximately L-shaped when viewed from the front-rear direction. The upper surface of the second housing 200 has a first top plate 201a, a second top plate 201b located on the right side and above the first top plate 201a, and a connecting wall 201c that connects the first top plate 201a and the second top plate 201b and extends in the vertical direction. The connecting wall 201c spreads in the width direction (front-rear direction) and the vertical direction, and is perpendicular to the depth direction (left-right direction). An opening 205 is formed in the first top plate 201a. The opening area of ​​the opening 105 formed in the lower surface of the first housing 100 and the opening area of ​​the opening 205 formed in the first top plate 201a of the second housing 200 are approximately the same. When the first housing 100 is placed on top of the top surface (first top plate 201a) of the second housing 200, the two openings 105, 205 overlap each other in the vertical direction.

[0023] A second grip 208a is provided on the left side wall 202L of the second housing 200, and a third grip 208b is provided on the second top plate 201b. A power input port 211, four ink ports 221, and a set of cooling water ports 225 are provided on the right side wall 202R of the second housing 200. The cooling water port 225 is a port for circulating cooling water for cooling the head 11. A piezoelectric actuator (not shown) provided inside the head 11 generates heat when driven. Therefore, if the head 11 is not sufficiently cooled, temperature unevenness occurs in the head 11, which may cause the viscosity of ink to differ between a certain nozzle 11a and another nozzle 11a. In that case, even if a drive signal of the same waveform is input, there may be a difference in the size of the ink droplets ejected from the certain nozzle 11a and another nozzle 11a, which may lead to a deterioration in print quality. Therefore, in this embodiment, cooling water is introduced from the cooling water port 225 to cool the head 11. A power cable (not shown) from an external power source (not shown) is connected to the power input port 211. The four ink ports 221 have a first ink supply port 222f, a second ink supply port 223f, a first ink discharge port 222d, and a second ink discharge port 223d. The first ink supply port 222f and the first ink discharge port 222d form a pair and are connected to the same ink reservoir 8 (see FIG. 14). That is, the same ink flows through the pair of the first ink supply port 222f and the first ink discharge port 222d. The first ink supply port 222f and the first ink discharge port 222d are connected to the first supply port 458 and the first discharge port 468 (see FIG. 9) of the tank 400, respectively. The second ink supply port 223f and the second ink discharge port 223d form another pair and are connected to the same ink reservoir 8 (see FIG. 15). In other words, the same ink flows through the pair of the second ink supply port 223f and the second ink discharge port 223d.The ink flowing through the pair of the first ink supply port 222f and the first ink discharge port 222d and the ink flowing through the pair of the second ink supply port 223f and the second ink discharge port 223d do not necessarily have to be the same ink, and may be, for example, ink of a different color. The second ink supply port 223f and the second ink discharge port 223d are connected to the second supply port 478 and the second discharge port 488 of the tank 400, respectively (see FIG. 9).

[0024] 4 and 5, the four ink ports 221 are disposed below the power input port 211, so that even if ink leaks from the ink ports 221 and drips downward, there is no risk of the ink adhering to the power input port 211. This makes it possible to prevent the power input port 211 from being soiled or a short circuit caused by the adhesion of ink.

[0025] 5, the relay board 300 is attached to the second housing 200 so as to cover an opening 205 formed in the first top plate 201a of the second housing 200 from below. The upper surface of the relay board 300 is exposed from the opening 105 of the first housing 100, and the opening of the first housing 100 is covered by the upper surface of the relay board 300. In other words, the relay board 300 covers both the opening 105 on the lower surface of the first housing 100 and the opening 205 on the upper surface of the second housing 200. As a result, the upper surface of the relay board 300 defines a part of the first space S1, and the lower surface of the relay board 300 defines a part of the second space S2.

[0026] <Relay board 300> As shown in Figs. 6(a) and 6(b), the relay board 300 includes ten first connectors 301, ten second connectors 302, and a power connector 303. The power connector 303 is disposed at the right end of the relay board 300. As described above, the power input port 211 is provided on the right side wall 202R of the second housing 200. As shown in Fig. 5, the power connector 303 and the power input port 211 of the relay board 300 are connected by a power cable 304. In addition, ten first connectors 301 are disposed on the upper surface of the relay board 300 exposed in the first space S1. In other words, ten first connectors 301 are disposed on the upper surface of the relay board 300 facing the first space S1. The ten first connectors 301 are arranged in two rows in the front-rear direction. Each row of the first connectors 301 includes five first connectors 301 arranged in the left-right direction. That is, the direction in which the row of the first connectors 301 extends (row direction) is parallel to the depth direction (left-right direction). Ten second connectors 302 are arranged on the lower surface of the relay board 300 exposed to the second space S2. In other words, ten second connectors 302 are arranged on the lower surface of the relay board 300 facing the second space S2. The ten second connectors 302 are also arranged in two rows in the width direction (front-back direction), and each row of the second connectors 302 includes five second connectors 302 arranged in the depth direction (left-right direction). That is, the direction in which the row of the second connectors 302 extends (row direction) is parallel to the depth direction (left-right direction). The upper surface of the relay board 300 corresponds to the first surface of the relay board of the present invention, and the lower surface of the relay board 300 corresponds to the second surface of the relay board of the present invention.

[0027] The relay board 300 includes wiring (not shown) connecting the ten first connectors 301 and the ten second connectors 302. This electrically connects the second connector 302 arranged on the lower surface of the relay board 300 to the first connector 301 arranged on the upper surface. Furthermore, the relay board 300 includes power wiring (not shown) connecting the power connector 303 and the ten first connectors 301, and power wiring (not shown) connecting the power connector 303 and the ten second connectors 302. This allows the relay board 300 to supply power from an external power source (not shown) to devices connected to the first connector 301 and the second connector 302. Note that the external power source (not shown) is different from the power source 112 of the rigid board 110 described later.

[0028] <Rigid board 110> As shown in Figs. 5 and 7, ten rigid substrates 110 are arranged in the first space S1. As shown in Fig. 7, the rigid substrate 110 is a rectangular substrate having a first surface 110a and a second surface 110b, and is a head control substrate for driving and controlling the head 11. A connector 111, a power source 112, and a plurality of circuit elements 113 are mounted on each rigid substrate 110. The power source 112 and some of the plurality of circuit elements 113 are mounted on the first surface 110a of the rigid substrate 110. The plurality of circuit elements 113 are mounted on the second surface 110b, which is the reverse surface of the first surface 110a. Note that the plurality of circuit elements 113 do not all include the same type of circuit elements, but include a plurality of types of circuit elements.

[0029] The power supply 112 mounted on the first surface 110a of the rigid substrate 110 is a power supply element for generating a drive signal for a piezoelectric actuator (not shown) included in the head 11. The power supply 112 is not mounted on the second surface 110b of the rigid substrate 110, and a plurality of circuit elements 113 are mounted thereon, which are circuit elements for processing high-speed signals. The height of the power supply 112 mounted on the first surface 110a of the rigid substrate 110 is higher than the height of the plurality of circuit elements 113 mounted on the second surface 110b. Note that the height here refers to the height from the first surface 110a and the second surface 110b in a normal direction perpendicular to the rigid substrate 110 (parallel to the front-rear direction in FIG. 5).

[0030] The connector 111 is disposed at the lower end of the rigid board 110 and is inserted into the first connector 301 of the relay board 300. As a result, the rigid board 110 is fixed so as to stand vertically relative to the relay board 300 (see FIG. 7). As described above, the first connectors 301 are arranged in two rows, so the rigid boards 110 are also arranged in two rows. As shown in FIG. 7, the rigid boards 110 in each row are arranged back to back in two rows so that the first surfaces 110a on which the power supplies 112 are mounted do not face each other in the width direction (front-rear direction). In other words, in two rigid boards 110 facing each other in the width direction (front-rear direction), the second surfaces 110b on which only the circuit elements 113 lower than the power supplies 112 are mounted face each other. Furthermore, with respect to two rigid boards 110 facing each other in the width direction (front-to-back direction), the front-to-back distance L1 between the front rigid board 110 and the front side of the first housing 100, and the front-to-back distance L2 between the rear rigid board 110 and the rear side of the first housing 100 are both greater than the front-to-back distance L3 between the two rigid boards 110 facing each other in the width direction (front-to-back direction).

[0031] As described above, fan 120 can send air in the arrangement direction (depth direction, left-right direction) of the row of rigid boards 110. The direction in which the air is sent is parallel to first surface 110a and second surface 110b of rigid board 110, so rigid board 110 does not obstruct the flow of air. Therefore, the air sent from fan 120 can be sent to the back along the arrangement direction (depth direction, left-right direction) of the row of rigid boards 110, and ten rigid boards 110 can be efficiently cooled.

[0032] The above-mentioned distances L1 and L2 correspond to the distance between the first surface 110a on which the power supply 112 is mounted and the side surface of the first housing 100, and the distance L3 corresponds to the distance between the second surfaces 110b on which the power supply 112 is not mounted. As described above, the distances L1 and L2 are greater than the distance L3, so that the power supply 112 which generates a large amount of heat can be efficiently cooled by blowing air therethrough.

[0033] Next, the members arranged in the second space S2 will be described. The lower surface of the relay substrate 300 is exposed in the second space S2 of the second housing 200. Furthermore, in the second space S2, the line head 20 including ten heads 11, ten flexible substrates 280, a tank 400, a heater 250, and a plurality of tubes 416 connecting the heads 11 and the tank 400 are arranged.

[0034] <Flexible PCB 280> One end of each flexible substrate 280 is connected to one of the second connectors 302 of the relay substrate 300. The other end of each flexible substrate 280 is connected to one of the heads 11. As described above, the second connector 302 of the relay substrate 300 is electrically connected to the first connector 301 arranged on the upper surface of the relay substrate 300, and the first connector 301 is further electrically connected to the connector 111 of the rigid substrate 110. That is, the rigid substrate 110, which is a head control substrate for driving and controlling the head 11, is connected to the head 11 via the relay substrate 300 and the flexible substrate 280. As a result, each rigid substrate 110 can transmit a control signal for the head 11, such as a drive signal for a piezoelectric actuator (not shown) of the head 11, to one of the heads 11 via the relay substrate 300 and the flexible substrate 280.

[0035] <Tank 400> As shown in FIG. 5, the tank 400 is disposed below the relay board 300 in the second space S2. The tank 400 has a shape of a substantially rectangular parallelepiped that is elongated in the left-right direction. As shown in FIG. 8, the tank 400 mainly includes a top plate 411, an upper seal rubber 412, a tank body 413, a lower seal rubber 414, a bottom plate 415, and a plurality of tubes 416. The tank body 413 is formed of resin, and can be formed by, for example, injection molding. The top plate 411 and the bottom plate 415 can be formed of resin or a metal material. The top plate 411 is fixed to the top of the tank body 413 with the upper seal rubber 412 sandwiched therebetween. The bottom plate 415 is fixed to the bottom of the tank body 413 with the lower seal rubber 414 sandwiched therebetween. The top plate 411 and the bottom plate 415 are screwed to the tank body 413 by a plurality of screws 417. As shown in FIG. 11, one head 11 is provided with a first supply port 16, a first discharge port 17, a second supply port 18, and a second discharge port 19. As described later, two ink circulation paths corresponding to two nozzle rows are provided in the head 11 (see FIGS. 14 and 15). As shown in FIG. 14, one end of one ink circulation path is connected to the first supply port 16, and the other end is connected to the first discharge port 17. Also, as shown in FIG. 15, one end of the other ink circulation path is connected to the second supply port 18, and the other end is connected to the second discharge port 19. The tank 400 and one head 11 are connected by four tubes 416. The first tube 416 communicates with the first supply port 16, the second tube 416 communicates with the first exhaust port 17, the third tube 416 communicates with the second supply port 18, and the fourth tube 416 communicates with the second exhaust port 19. Since the tank 400 is connected to ten heads 11, the tank 400 is connected to forty tubes 416. However, in order to simplify the drawing, a reduced number of tubes 416 are shown connected to the tank 400 in FIG. 8.

[0036] As shown in FIGS. 8 and 9, the tank body 413 is formed with a first supply flow path 450, a first discharge flow path 460, a second supply flow path 470, and a second discharge flow path 480. These four flow paths extend in the left-right direction. These four flow paths are arranged side by side in the front-rear direction. These four flow paths are arranged in the order of the first supply flow path 450, the first discharge flow path 460, the second discharge flow path 480, and the second supply flow path 470 from the rear to the front in the front-rear direction, that is, from the upstream side to the downstream side in the conveying direction. In FIGS. 8 and 9, in order to simplify the drawings, only a part of the first supply flow path 450, the first discharge flow path 460, the second supply flow path 470, and the second discharge flow path 480 is illustrated so that the length of the tank 400 in the left-right direction is shortened.

[0037] The right side wall 413R of the tank body 413 is provided with a first supply port 458 communicating with the first supply flow path 450, a first exhaust port 468 communicating with the first exhaust flow path 460, a second exhaust port 488 communicating with the second exhaust flow path 480, and a second supply port 478 communicating with the second supply flow path 470.

[0038] <Ink flow path inside the tank 400> Next, the ink flow paths formed inside the tank 400 will be described in more detail. As shown in FIGS. 10 and 12, the first supply flow path 450 has a first main supply flow path 451 and ten first branch supply flow paths 452 branched from the first main supply flow path 451 below the first main supply flow path 451. The ten first branch supply flow paths 452 correspond to the ten heads 11, respectively. In FIG. 10, in order to simplify the drawing, similarly to FIGS. 8 and 9, only a part of the first supply flow path 450, the first discharge flow path 460, the second supply flow path 470, and the second discharge flow path 480 is illustrated so that the length of the tank 400 in the left-right direction is shortened. In FIG. 10, only a part of the ten first branch supply flow paths 452 is illustrated. One end 452a of each first branch supply flow path 452 is connected to the first main supply flow path 451, and the other end 452b is connected to the tube 416.

[0039] 10 and 12, the first discharge flow path 460 has a first main discharge flow path 461 and ten first branch discharge flow paths 462 branching off from the first main discharge flow path 461 below the first main discharge flow path 461. The ten first branch discharge flow paths 462 correspond to the ten heads 11, respectively. Note that in FIG. 10, in order to simplify the drawing, only a portion of the ten first branch discharge flow paths 462 is shown. One end 462a of each of the first branch discharge flow paths 462 is connected to the first main discharge flow path 461, and the other end 462b is connected to the tube 416.

[0040] 10 and 12, the second supply flow path 470 has a second main supply flow path 471 and ten second branch supply flow paths 472 branching off from the second main supply flow path 471 below the second main supply flow path 471. The ten second branch supply flow paths 472 correspond to the ten heads 11, respectively. Note that in FIG. 10, in order to simplify the drawing, only a portion of the ten second branch supply flow paths 472 is shown. One end 472a of each second branch supply flow path 472 is connected to the second main supply flow path 471, and the other end 472b is connected to the tube 416.

[0041] 10 and 12, the second discharge flow path 480 has a second main discharge flow path 481 and ten second branch discharge flow paths 482 branching off from the second main discharge flow path 481 below the second main discharge flow path 481. The ten second branch discharge flow paths 482 correspond to the ten heads 11, respectively. Note that in FIG. 10, in order to simplify the drawing, only a portion of the ten second branch discharge flow paths 482 is shown. One end 482a of each second branch discharge flow path 482 is connected to the second main discharge flow path 481, and the other end 482b is connected to the tube 416.

[0042] 11, a first supply port 16, a first exhaust port 17, a second supply port 18, and a second exhaust port 19 are arranged on the upper surface of each head 11. The first supply port 16 and the first exhaust port 17 are aligned in the left-right direction, with the first supply port 16 located to the left of the first exhaust port 17. The second supply port 18 and the second exhaust port 19 are aligned in the left-right direction, with the second supply port 18 located to the right of the second exhaust port 19. In addition, the pair of the first supply port 16 and the first exhaust port 17 is located behind the pair of the second supply port 18 and the second exhaust port 19.

[0043] 12, the other end 452b of the first branch supply flow path 452, the other end 462b of the first branch exhaust flow path 462, the other end 472b of the second branch supply flow path 472, and the other end 482b of the second branch exhaust flow path 482 are also aligned in the same manner. That is, the other end 462b of the first branch exhaust flow path 462 and the other end 472b of the second branch supply flow path 472 are aligned in the left-right direction, and the other end 472b of the second branch supply flow path 472 and the other end 482b of the second branch exhaust flow path 482 are aligned in the left-right direction.

[0044] As described above, the ten heads 11 are arranged in a staggered manner to form two head rows extending in the left-right direction, and accordingly, the set of the other end 452b of the first branch supply flow path 452, the other end 462b of the first branch exhaust flow path 462, the other end 472b of the second branch supply flow path 472, and the other end 482b of the second branch exhaust flow path 482 corresponding to one head 11 is also arranged in a staggered manner to form two rows extending in the left-right direction, similar to the head 11. That is, the set of the other end 452b of the first branch supply flow path 452, the other end 462b of the first branch exhaust flow path 462, the other end 472b of the second branch supply flow path 472, and the other end 482b of the second branch exhaust flow path 482 corresponding to one head 11 is arranged at a position overlapping the first supply port 16, the first exhaust port 17, the second supply port 18, and the second exhaust port 19 of the head 11, respectively, in the up-down direction.

[0045] <Shape of the first branched supply flow path 452 (second branched supply flow path 472)> Next, the shape of the first branch supply flow path 452 will be described with reference to the drawings. Note that the second branch supply flow path 472 has a shape symmetrical to the first branch supply flow path 452 with respect to the line X in FIG. 12, and therefore a detailed description thereof will be omitted.

[0046] In the following description, the first trunk supply flow path 451, the first trunk discharge flow path 461, the second trunk supply flow path 471, and the second trunk discharge flow path 481 are collectively referred to as trunk flow paths. As shown in FIG. 12, the first trunk supply flow path 451 is located at the rearmost of the four trunk flow paths. As shown in FIG. 12, five first branch supply flow paths 452 extend forward from the first trunk supply flow path 451. The first branch supply flow path 452 bends leftward midway and then extends forward again. As shown in FIGS. 13(c) and 13(d), the first branch supply flow path 452 extends forward so as to go under the first trunk discharge flow path 461. The upper surface 452U of the first branch supply flow path 452 is inclined so as to descend downward as it approaches the other end 452b. The inclination angle of the upper surface 452U with respect to the horizontal plane is larger than the inclination angle between the nozzle surface of the line head assembly 10 and the horizontal plane when the line head assembly 10 is attached to the arch frame 41. Therefore, even when the line head assembly 10 is attached to the arch frame 41 so as to be inclined from the horizontal plane, the upper surface 452U of the first branch supply flow path 452 is inclined so as to descend downward as it approaches the other end 452b.

[0047] <Shape of the first branch exhaust flow path 462 (second branch exhaust flow path 482)> Next, the shape of the first branch exhaust flow path 462 will be described with reference to the drawings. Note that the second branch exhaust flow path 482 has a shape symmetrical to the first branch exhaust flow path 462 with respect to the line X in FIG. 12, and therefore a detailed description thereof will be omitted.

[0048] As shown in FIG. 12, the first main discharge flow path 461 is located second from the rear among the four main discharge flow paths. As shown in FIG. 12, five first branch discharge flow paths 462 extend forward from the first main discharge flow path 461. As shown in FIG. 13(b), the first branch discharge flow path 462 extends forward so as to go under the second main discharge flow path 481. The upper surface 462U of the first branch discharge flow path 462 is inclined so as to descend downward as it approaches the other end 462b. The inclination angle of the upper surface 462U with respect to the horizontal plane is larger than the inclination angle between the nozzle surface of the line head assembly 10 and the horizontal plane when the line head assembly 10 is attached to the arch frame 41. Therefore, even when the line head assembly 10 is attached to the arch frame 41 so as to be inclined from the horizontal plane, the upper surface 462U of the first branch discharge flow path 462 is inclined so as to descend downward as it approaches the other end 462b.

[0049] As shown in FIG. 12, five first branch discharge flow paths 462 extend rearward from the first main discharge flow path 461. As shown in FIG. 13(a), the first branch discharge flow path 462 extends rearward so as to go under the first main supply flow path 451. The upper surface 462U of the first branch discharge flow path 462 is inclined so as to descend downward as it approaches the other end 462b. The inclination angle of the upper surface 462U with respect to the horizontal plane is larger than the inclination angle between the nozzle surface of the line head assembly 10 and the horizontal plane when the line head assembly 10 is attached to the arch frame 41. Therefore, even when the line head assembly 10 is attached to the arch frame 41 so as to be inclined from the horizontal plane, the upper surface 462U of the first branch discharge flow path 462 is inclined so as to descend downward as it approaches the other end 462b.

[0050] <Connection between the tank 400 and the head 11> Next, the connection between the tank 400 and the head 11 will be described. Although not shown, the other end 452b of the first branched supply flow path 452 and the first supply port 16 of the head 11 are connected by a tube 416. Similarly, the other end 462b of the first branched exhaust flow path 462 and the first exhaust port 17 of the head 11 are connected by a tube 416. The other end 472b of the second branched supply flow path 472 and the second supply port 18 of the head 11 are connected by a tube 416. The other end 482b of the second branched exhaust flow path 482 and the second exhaust port 19 of the head 11 are connected by a tube 416. As described above, the other end 452b of the first branch supply flow path 452, the other end 462b of the first branch exhaust flow path 462, the other end 472b of the second branch supply flow path 472, and the other end 482b of the second branch exhaust flow path 482, which correspond to one head 11, are positioned to overlap in the vertical direction with the first supply port 16, the first exhaust port 17, the second supply port 18, and the second exhaust port 19 of the head 11, respectively. This allows the tubes 416 to be connected in an extended state so as not to cross each other, and allows the tubes 416 of the same length to be used.

[0051] <Heater 250> In this embodiment, since UV curable ink is used, it is necessary to maintain the temperature of the ink at a predetermined temperature. Therefore, the line head assembly 10 of this embodiment is provided with a heater 250 for heating the ink in the tube 416 connecting the tank 400 and the head 11. As shown in FIG. 5, the heater 250 is provided at a position overlapping the tube 416 in the front-rear direction. As the heater 250, for example, a carbon heater that generates heat by passing an electric current through a carbon sheet can be used. Note that, in order to pre-warm the ink in the tank 400, for example, a sheet-shaped heater can be attached to the lower surface of the tank 400.

[0052] <Ink circulation> Next, the ink circulation path will be described with reference to FIGS. 14 and 15. First, the ink circulation path corresponding to one of the two nozzle rows included in the head 11 will be described with reference to FIG. 14. As shown in FIG. 14, the ink reservoir 8 is fluidly connected to the first ink supply port 222f and the first ink discharge port 222d of the second housing 200 via the ink circulation mechanism 80. Note that the ink circulation mechanism 80 is a known ink circulation system equipped with a pump, a valve, an exhaust valve, and the like, and detailed description will be omitted. The ink supplied from the ink reservoir 8 flows toward the first ink supply port 222f of the second housing 200 by the ink circulation mechanism 80. Furthermore, the ink flows from the first ink supply port 222f of the second housing 200 to the first supply flow path 450 of the tank 400, and flows from the other end 452b of the first branch supply flow path 452 of the first supply flow path 450 through the tube 416 to the first supply port 16 of the head 11. Inside the head 11, a first supply manifold 14f, a plurality of pressure chambers 11p, a plurality of nozzles 11a, and a first return manifold 14r are formed as flow paths within the head. The first supply manifold 14f and the first return manifold 14r are provided in common to the plurality of pressure chambers 11p. The plurality of pressure chambers 11p and the plurality of nozzles 11a correspond one-to-one. Ink supplied from the first supply port 16 flows from the first supply manifold 14f into the plurality of pressure chambers 11p. By driving a piezoelectric actuator (not shown) to apply an ejection pressure to one of the pressure chambers 11p, ink droplets are ejected from the nozzle 11a communicating with the pressure chamber 11p. Ink not ejected from the nozzle 11a is sent to the first return manifold 14r, and flows into the first ejection flow path 460 of the tank 400 through the first ejection port 17 and the tube 416. The first discharge flow path 460 of the tank 400 is connected to the first ink discharge port 222d of the second housing 200. The ink that has flowed into the first discharge flow path 460 passes through the first ink discharge port 222d and flows toward the ink reservoir 8. In this manner, the ink can be circulated.

[0053] Next, the ink circulation path corresponding to the other nozzle row of the two nozzle rows included in the head 11 will be described with reference to FIG. 15. As shown in FIG. 15, the ink reservoir 8 is fluidly connected to the second ink supply port 223f and the second ink discharge port 223d of the second housing 200 via the ink circulation mechanism 80. The ink supplied from the ink reservoir 8 flows toward the second ink supply port 223f of the second housing 200 by the ink circulation mechanism 80. The ink further flows from the second ink supply port 223f of the second housing 200 to the second supply flow path 470 of the tank 400, and flows from the other end 472b of the second branch supply flow path 472 of the second supply flow path 470 through the tube 416 to the second supply port 18 of the head 11. Inside the head 11, a second supply manifold 15f, a plurality of pressure chambers 11p, a plurality of nozzles 11a, and a second return manifold 15r are formed as flow paths within the head. The second supply manifold 15f and the second return manifold 15r are provided in common to the multiple pressure chambers 11p. The multiple pressure chambers 11p and the multiple nozzles 11a correspond one-to-one. Ink supplied from the second supply port 18 flows from the second supply manifold 15f into the multiple pressure chambers 11p. By driving a piezoelectric actuator (not shown) to apply an ejection pressure to one of the pressure chambers 11p, ink droplets are ejected from the nozzle 11a communicating with the pressure chamber 11p. Ink that is not ejected from the nozzle 11a is sent to the second return manifold 15r and flows into the second ejection flow path 480 of the tank 400 through the second ejection port 19 and the tube 416. The second ejection flow path 480 of the tank 400 is connected to the second ink ejection port 223d of the second housing 200. The ink that flows into the second ejection flow path 480 flows toward the ink reservoir 8 through the second ink ejection port 223d. In this manner, the ink can be circulated.

[0054] <Effects of the embodiment>

[0055] The line head assembly 10 according to this embodiment includes a line head 20 including ten heads 11, and a tank 400 located above the line head 20. The ten heads 11 are arranged in two rows of five in the left-right direction. A head 11 in the adjacent row is arranged between two heads 11 adjacent to each other in the left-right direction. In other words, the ten heads 11 are arranged in a staggered manner. All of the ten heads 11 are circulating heads.

[0056] Each head 11 includes a first supply port 16. Ink is supplied from a first supply flow path 450 of the tank 400 to the first supply ports 16 of the ten heads 11 arranged in a staggered pattern. Each head 11 also includes a first discharge port 17. Ink discharged from the first discharge ports 17 of the ten heads 11 arranged in a staggered pattern is returned to a first discharge flow path 460 of the tank 400. With this configuration, ink can be appropriately distributed and collected to the line head 20 in which the heads 11 are arranged in a staggered pattern.

[0057] In the above embodiment, the first supply flow path 450 has a first main supply flow path 451 and ten first branch supply flow paths 452 branched from the first main supply flow path 451. The first discharge flow path 460 has a first main discharge flow path 461 and ten first branch discharge flow paths 462 branched from the first main discharge flow path 461. The other ends 452b of five of the ten first branch supply flow paths 452 are connected to the first supply ports 16 of five heads 11 aligned in a row in the left-right direction. Similarly, the other ends 452b of the other five of the ten first branch supply flow paths 452 are connected to the first supply ports 16 of five heads 11 aligned in a row in the left-right direction. Similarly, the other ends 462b of five of the ten first branch discharge flow paths 462 are connected to the first discharge ports 17 of five heads 11 aligned in a row in the left-right direction. And, the other ends 462b of the other five of the ten first branch supply flow paths 452 are connected to the first discharge ports 17 of other five heads 11 aligned in a row in the left-right direction. With this configuration, ink can be easily distributed and collected by utilizing the first branch supply flow paths 452 and the first branch discharge flow paths 462 formed in the tank 400.

[0058] In the above embodiment, the first branch supply flow path 452 is located below the first main supply flow path 451, and the first branch exhaust flow path 462 is located below the first main exhaust flow path 461. With this configuration, even if air bubbles get into the first branch supply flow path 452 and the first branch exhaust flow path 462, the air bubbles can be released to the first main supply flow path 451 and the first main exhaust flow path 461 located above. This makes it possible to prevent air from being trapped in the first branch supply flow path 452 and the first branch exhaust flow path 462, and makes it possible to easily remove air bubbles from the first branch supply flow path 452 and the first branch exhaust flow path 462.

[0059] In the above embodiment, the positions of the other ends 452b of the ten first branched supply flow paths 452 in the front-rear direction and the left-right direction correspond to the positions of the first supply ports 16 of the ten heads 11, respectively. In addition, the positions of the other ends 462b of the ten first branched exhaust flow paths 462 in the front-rear direction and the left-right direction correspond to the positions of the first exhaust ports 17 of the ten heads 11, respectively. Note that the positions being the same do not mean that they are exactly the same, but that they are the same within the range of manufacturing error and installation error. With this configuration, the tank 400 and the line head 20 are overlapped in the vertical direction, so that the installation area of ​​the tank 400 and the line head 20 can be made compact, and the line head assembly 10 can be made smaller.

[0060] In the above embodiment, the upper surface 452U of the first branch supply flow path 452 is inclined with respect to a plane including the front-rear direction and the left-right direction. Similarly, the upper surface 462U of the first branch exhaust flow path 462 is also inclined with respect to a plane including the front-rear direction and the left-right direction. With this configuration, it is possible to prevent air from being trapped in the first branch supply flow path 452 and the first branch exhaust flow path 462, and it is possible to easily remove air bubbles from the first branch supply flow path 452 and the first branch exhaust flow path 462.

[0061] In the above embodiment, the ten tubes 416 connecting the other ends 452b of the ten first branched supply flow paths 452 and the first supply ports 16 of the ten heads 11 are parallel to each other in the vertical direction. Similarly, the ten tubes 416 connecting the other ends 462b of the ten first branched exhaust flow paths 462 and the first exhaust ports 17 of the ten heads 11 are parallel to each other in the vertical direction. With this configuration, it is possible to prevent air pockets from forming in the tubes 416. In addition, in the above embodiment, these tubes 416 are all the same length. Note that the same length does not mean that the tubes 416 are strictly the same length. The lengths may differ within the range of manufacturing error. In such a case, tubes of the same specification can be used, so that manufacturing costs can be reduced.

[0062] In the above embodiment, the first main supply flow path 451, the first main exhaust flow path 461, the second main supply flow path 471, and the second main exhaust flow path 481 are aligned in the front-rear direction, and the second branch supply flow path 472 branching off from the second main supply flow path 471 located at the foremost position extends toward the rear. Also, the first branch supply flow path 452 branching off from the first main supply flow path 451 located at the rearmost position among the above four main flow paths extends toward the front.

[0063] Of the four trunk channels, the first trunk supply channel 451 and the second trunk supply channel 471 are arranged on the outside in the front-to-rear direction, and the first trunk exhaust channel 461 and the second trunk exhaust channel 481 are arranged on the inside in the front-to-rear direction. By arranging the trunk channels in this manner, it is possible to prevent a temperature difference from occurring in the two supply channels that supply ink to the head 11. Note that even if the first trunk supply channel 451 and the second trunk supply channel 471 are arranged on the inside in the front-to-rear direction, and the first trunk exhaust channel 461 and the second trunk exhaust channel 481 are arranged on the outside in the front-to-rear direction, it is possible to similarly prevent a temperature difference from occurring in the two supply channels that supply ink to the head 11.

[0064] In the above embodiment, the ink that has passed through the first main supply flow path 451 passes through the ten first branch supply flow paths 452 and flows into the first supply ports 16 of the ten heads 11. Then, the ink discharged from the first exhaust ports 17 of the ten heads 11 flows into the first main exhaust flow path 461 through the ten first branch exhaust flow paths 462. By flowing the ink in the line head assembly 10 in this manner, the ink can be easily circulated.

[0065] The embodiments disclosed herein are illustrative in all respects and are not restrictive. Not all of the configurations shown in the above embodiments are essential, and configurations can be omitted as necessary. For example, the number and arrangement of the line head assemblies 10, the number and arrangement of the heads 11 included in one line head 20, etc. can be changed as appropriate. Also, the number and arrangement of the nozzles 11a included in each head 11 can be changed as appropriate. Also, in the above embodiment, the controller 7 is provided in the printing device 1, but the present invention is not limited to such an aspect. For example, the controller 7 may be provided in the line head assembly 10.

[0066] In the above embodiment, a recording medium wound in a roll shape (for example, roll paper) is used as the recording medium 4. However, the present invention is not limited to such an embodiment, and a recording medium 4 of an appropriate shape and material can be used as necessary. In the above embodiment, the structure, shape, material, etc. of the tank 400 can be changed as appropriate. For example, in the above embodiment, the tank 400 is connected to ten heads 11. However, the present invention is not limited to such an embodiment. For example, the tank 400 may be divided into three, and each may be connected to four heads 11, four heads 11, or two heads 11. In addition, the printing device 1 in the above embodiment is provided with three line head assemblies 10 and is configured to eject five colors of ink, namely white ink, cyan ink, magenta ink, yellow ink, and black ink. The present invention is not limited to such an embodiment, and the printing device 1 can be configured to eject ink of an appropriate color. In addition, in the present embodiment, UV curable ink is used. However, the present invention is not limited to such an embodiment, and ink other than UV curable ink (for example, water-based ink, pigment ink, etc.) can be used.

[0067] Furthermore, the present invention is not limited to inkjet type printing devices that eject ink. The present teachings can also be applied to printing devices used for various purposes other than printing images, etc. For example, the present teachings can also be applied to printing devices that eject conductive liquid onto a substrate to form a conductive pattern on the substrate surface. The scope of the present invention is intended to include all modifications within the scope of the claims and equivalents to the scope of the claims. [Explanation of symbols]

[0068] 1 Printing device 10 Line Head Assembly 11 Head 400 Tank

Claims

1. A line head having a first head, a second head, and a third head aligned in a first direction, the second head is disposed between the first head and the third head in the first direction, the first head and the third head are positioned at the same position in a second direction intersecting the first direction, a line head in which a position in the second direction is different from that of the first head and the third head and from that of the second head; a tank located above the line head in a vertical direction intersecting the first direction and the second direction, The first head, the second head, and the third head each include a first internal head flow path including a first pressure chamber and a first nozzle; a first supply port connected to one end of the first head internal flow path; a first outlet connected to the other end of the first head internal flow path, The tank is a first supply flow path communicating the first supply port of the first head, the first supply port of the second head, and the first supply port of the third head; a first discharge flow path communicating the first discharge port of the first head, the first discharge port of the second head, and the first discharge port of the third head; The first supply flow path includes a first main supply flow path and first branch supply flow paths A, B, and C, The first discharge flow path includes a first main discharge flow path and first branch discharge flow paths A, B, and C, The first main supply flow path is connected to one end of each of the first branch supply flow paths A, B, and C, the other end of the first branch supply flow path A is connected to the first supply port of the first head, the other end of the first branch supply flow path B is connected to the first supply port of the second head, and the other end of the first branch supply flow path C is connected to the first supply port of the third head, the one end of each of the first branch supply flow paths (A, B, C) connected to the first main supply flow path is formed of a member constituting an inclined surface that intersects with a plane including the first direction and the second direction and also intersects with the up-down direction, A line head assembly, wherein the inclined surface forms a part of an upper surface of the first branch supply flow paths A, B, C.

2. The first main exhaust flow path is connected to one end of the first branch exhaust flow paths A, B, and C, The line head assembly of claim 1, wherein the other end of the first branch exhaust flow path A is connected to the first exhaust port of the first head, the other end of the first branch exhaust flow path B is connected to the first exhaust port of the second head, and the other end of the first branch exhaust flow path C is connected to the first exhaust port of the third head.

3. The line head assembly according to claim 2 , wherein, in the vertical direction, the first branch supply flow paths A, B, and C are located below the first main supply flow path, and the first branch exhaust flow paths A, B, and C are located below the first main exhaust flow path.

4. In a plane including the first direction and the second direction, a position of the other end of the first branch supply flow path A is the same as a position of the first supply port of the first head, a position of the other end of the first branch supply flow path B is the same as a position of the first supply port of the second head, a position of the other end of the first branch supply flow path C is the same as a position of the first supply port of the third head, a position of the other end of the first branch discharge flow path A is the same as a position of the first discharge port of the first head, a position of the other end of the first branched discharge flow path B is the same as a position of the first discharge port of the second head, The line head assembly according to claim 3 , wherein a position of the other end of the first branch discharge flow path C is the same as a position of the first discharge port of the third head.

5. The first main supply flow path and the first main discharge flow path are parallel to the first direction and aligned in the second direction, Each of the first branch supply channels A, B, and C has at least a portion extending in the second direction, The line head assembly according to claim 4 , wherein at least a portion of each of the first branch discharge flow paths A, B, and C extends in the second direction.

6. Further, a first supply tube A connecting the other end of the first branch supply flow path A and the first supply port of the first head; a first supply tube B that connects the other end of the first branch supply flow path B and the first supply port of the second head; a first supply tube C that connects the other end of the first branch supply flow path A and the first supply port of the third head; a first discharge tube A connecting the other end of the first branch discharge flow path A and the first discharge port of the first head; a first discharge tube B that connects the other end of the first branch discharge flow path B and the first discharge port of the second head; a first discharge tube C connecting the other end of the first branch discharge flow path A and the first discharge port of the third head, The line head assembly according to claim 4 or 5, wherein the first supply tubes A, B, C and the first discharge tubes A, B, C are parallel to the up-down direction.

7. A line head assembly as described in claim 6, wherein the first supply tubes A, B, C and the first exhaust tubes A, B, C have the same length.

8. The first head, the second head, and the third head each include a second internal head flow path including a second pressure chamber and a second nozzle; a second supply port connected to one end of the second head internal flow path; a second outlet port connected to the other end of the second head internal flow path, The tank is a second supply flow path communicating the second supply port of the first head, the second supply port of the second head, and the second supply port of the third head; The line head assembly according to any one of claims 1 to 7, further comprising: a second discharge flow path that communicates with the second discharge port of the first head, the second discharge port of the second head, and the second discharge port of the third head.

9. The first head, the second head, and the third head each include a second internal head flow path including a second pressure chamber and a second nozzle; a second supply port connected to one end of the second head internal flow path; a second outlet port connected to the other end of the second head internal flow path, The tank is a second supply flow path communicating the second supply port of the first head, the second supply port of the second head, and the second supply port of the third head; a second discharge flow path that communicates the second discharge port of the first head, the second discharge port of the second head, and the second discharge port of the third head; The second supply flow path includes a second main supply flow path and second branch supply flow paths A, B, and C, The second discharge flow path includes a second main discharge flow path and second branch discharge flow paths A, B, and C, The second main supply flow path is connected to one end of the second branch supply flow paths A, B, and C, the other end of the second branch supply flow path A is connected to the second supply port of the first head, the other end of the second branch supply flow path B is connected to the second supply port of the second head, and the other end of the second branch supply flow path C is connected to the second supply port of the third head, The second main discharge flow path is connected to one end of the second branch discharge flow paths A, B, and C, A line head assembly described in any one of claims 2 to 7, wherein the other end of the second branch exhaust flow path A is connected to the second exhaust port of the first head, the other end of the second branch exhaust flow path B is connected to the second exhaust port of the second head, and the other end of the second branch exhaust flow path C is connected to the second exhaust port of the third head.

10. A line head assembly as described in Claim 9, wherein, in the vertical direction, the second branch supply flow paths A, B, C are located below the second main supply flow path, and the second branch exhaust flow paths A, B, C are located below the second main exhaust flow path.

11. In a plane including the first direction and the second direction, a position of the other end of the second branch supply flow path A is the same as a position of the second supply port of the first head, a position of the other end of the second branch supply flow path B is the same as a position of the second supply port of the second head, a position of the other end of the second branch supply flow path C is the same as a position of the second supply port of the third head, a position of the other end of the second branch discharge flow path A is the same as a position of the second discharge port of the first head, a position of the other end of the second branch discharge flow path B is the same as a position of the second discharge port of the second head, The line head assembly according to claim 10 , wherein a position of the other end of the second branch discharge flow path C is the same as a position of the second discharge port of the third head.

12. The second main supply flow path and the second main discharge flow path are parallel to the first direction and aligned in the second direction, Each of the second branch supply channels A, B, and C extends at least partially in the second direction, The line head assembly according to claim 11 , wherein at least a portion of each of the second branch discharge flow paths A, B, and C extends in the second direction.

13. The tank is a body having a plurality of through holes formed therein that penetrate in the vertical direction, and the plurality of through holes are the first main supply flow path and first branch supply flow paths A, B, and C formed below the first main supply flow path; the first main exhaust flow path and first branch exhaust flow paths A, B, C formed below the first main exhaust flow path; the second main supply flow path and second branch supply flow paths A, B, C formed below the second main supply flow path; a main body in which the second main exhaust flow path and second branch exhaust flow paths A, B, C are formed below the second main exhaust flow path; a top plate that seals upper openings of the plurality of through holes of the main body; The line head assembly according to any one of claims 9 to 12, further comprising: a bottom plate that seals lower openings of the plurality of through holes of the main body.

14. The first and second main supply flow paths and the first and second main discharge flow paths are aligned in the second direction, among the first and second branch supply flow paths A, B, C and the first and second branch exhaust flow paths A, B, C, a flow path having one end closest to one side in the second direction extends toward the other side in the second direction, A line head assembly as described in any one of claims 9 to 13, wherein among the first and second branch supply flow paths A, B, C and the first and second branch exhaust flow paths A, B, C, the flow path having one end closest to the other side in the second direction extends toward the one side in the second direction.

15. A line head assembly as described in claim 14, wherein the first and second main supply flow paths are located on the outside in the second direction so as to sandwich the first and second main exhaust flow paths, or the first and second main exhaust flow paths are located on the outside in the second direction so as to sandwich the first and second main supply flow paths.

16. A line head assembly described in any one of claims 11 to 15, wherein the one end of the second branch supply flow path A, B, C that connects to the second main supply flow path is formed from a member that constitutes a surface that intersects with a plane including the first direction and the second direction and intersects with the vertical direction.

17. The first head, the second head, and the third head each include a second internal head flow path including a second pressure chamber and a second nozzle; a second supply port connected to one end of the second head internal flow path; a second outlet port connected to the other end of the second head internal flow path, The tank is a second supply flow path communicating the second supply port of the first head, the second supply port of the second head, and the second supply port of the third head; a second discharge flow path that communicates the second discharge port of the first head, the second discharge port of the second head, and the second discharge port of the third head; The second supply flow path includes a second main supply flow path and second branch supply flow paths A, B, and C, The second discharge flow path includes a second main discharge flow path and second branch discharge flow paths A, B, and C, The second main supply flow path is connected to one end of the second branch supply flow paths A, B, and C, the other end of the second branch supply flow path A is connected to the second supply port of the first head, the other end of the second branch supply flow path B is connected to the second supply port of the second head, and the other end of the second branch supply flow path C is connected to the second supply port of the third head, The second main discharge flow path is connected to one end of the second branch discharge flow paths A, B, and C, the other end of the second branched discharge flow path A is connected to the second discharge port of the first head, the other end of the second branched discharge flow path B is connected to the second discharge port of the second head, and the other end of the second branched discharge flow path C is connected to the second discharge port of the third head, The line head assembly further comprises: a second supply tube A connecting the other end of the second branch supply flow path A and the second supply port of the first head; a second supply tube B connecting the other end of the second branch supply flow path B and the second supply port of the second head; a second supply tube C connecting the other end of the second branch supply flow path A and the second supply port of the third head; a second discharge tube A connecting the other end of the second branch discharge flow path A and the second discharge port of the first head; a second discharge tube B connecting the other end of the second branch discharge flow path B and the second discharge port of the second head; a second discharge tube C connecting the other end of the second branch discharge flow path A and the second discharge port of the third head, The line head assembly according to claim 6 or 7, wherein the second supply tubes A, B, and C and the second discharge tubes A, B, and C are arranged in parallel in the vertical direction.

18. A line head assembly as described in claim 17, wherein the second supply tubes A, B, C and the second exhaust tubes A, B, C have the same length.

19. A line head assembly as described in claim 18, wherein the first supply tubes A, B, C, the first exhaust tubes A, B, C, the second supply tubes A, B, C, and the second exhaust tubes A, B, C are the same length.

20. A line head assembly according to any one of claims 1 to 19; a transport mechanism configured to transport a recording medium relative to a transport surface facing nozzle faces of the first head, the second head, and the third head.

21. A method for flowing liquid through a line head assembly, comprising: The line head assembly includes: A line head having a first head, a second head, and a third head aligned in a first direction, the second head is disposed between the first head and the third head in the first direction, the first head and the third head are positioned at the same position in a second direction intersecting the first direction, a line head in which a position in the second direction is different from that of the first head and the third head and from that of the second head; a tank located above the line head in a vertical direction intersecting the first direction and the second direction, The first head, the second head, and the third head each include a first internal head flow path including a first pressure chamber and a first nozzle; a first supply port connected to one end of the first head internal flow path; a first outlet connected to the other end of the first head internal flow path, The tank is a first supply flow path communicating the first supply port of the first head, the first supply port of the second head, and the first supply port of the third head; a first discharge flow path that communicates the first discharge port of the first head, the first discharge port of the second head, and the first discharge port of the third head; The first supply flow path includes a first main supply flow path and first branch supply flow paths A, B, and C, The first discharge flow path includes a first main discharge flow path and first branch discharge flow paths A, B, and C, The first main supply flow path is connected to one end of each of the first branch supply flow paths A, B, and C, the other end of the first branch supply flow path A is connected to the first supply port of the first head, the other end of the first branch supply flow path B is connected to the first supply port of the second head, and the other end of the first branch supply flow path C is connected to the first supply port of the third head, The first main discharge flow path is connected to one end of the first branch discharge flow paths A, B, and C, the other end of the first branched discharge flow path A is connected to the first discharge port of the first head, the other end of the first branched discharge flow path B is connected to the first discharge port of the second head, and the other end of the first branched discharge flow path C is connected to the first discharge port of the third head, the one end of each of the first branch supply flow paths (A, B, C) connected to the first main supply flow path is formed of a member constituting an inclined surface that intersects with a plane including the first direction and the second direction and also intersects with the up-down direction, the inclined surface forms a part of an upper surface of the first branch supply flow paths A, B, C, The method comprises: causing a first liquid to flow from the first main supply flow path through the first branch supply flow path A to the first supply port of the first head; causing the first liquid to flow from the first discharge port of the first head through the first branch discharge flow path A to the first main discharge flow path; causing the first liquid to flow from the first main supply flow path through the first branch supply flow path B to the first supply port of the second head; causing the first liquid to flow from the first discharge port of the second head through the first branch discharge flow path B to the first main discharge flow path; causing the first liquid to flow from the first main supply flow path through the first branch supply flow path C to the first supply port of the third head; A method for flowing liquid in a line head assembly, comprising: flowing the first liquid from the first outlet of the third head through the first branch exhaust flow path C to the first main exhaust flow path.

22. The first head, the second head, and the third head each include a second internal head flow path including a second pressure chamber and a second nozzle; a second supply port connected to one end of the second head internal flow path; a second outlet port connected to the other end of the second head internal flow path, The tank is a second supply flow path communicating the second supply port of the first head, the second supply port of the second head, and the second supply port of the third head; a second discharge flow path communicating the second discharge port of the first head, the second discharge port of the second head, and the second discharge port of the third head; The second supply flow path includes a second main supply flow path and second branch supply flow paths A, B, and C, The second discharge flow path includes a second main discharge flow path and second branch discharge flow paths A, B, and C, The second main supply flow path is connected to one end of the second branch supply flow paths A, B, and C, the other end of the second branch supply flow path A is connected to the second supply port of the first head, the other end of the second branch supply flow path B is connected to the second supply port of the second head, and the other end of the second branch supply flow path C is connected to the second supply port of the third head, The second main discharge flow path is connected to one end of the second branch discharge flow paths A, B, and C, the other end of the second branched discharge flow path A is connected to the second discharge port of the first head, the other end of the second branched discharge flow path B is connected to the second discharge port of the second head, and the other end of the second branched discharge flow path C is connected to the second discharge port of the third head, The method further comprises: causing a second liquid to flow from the second main supply flow path through the second branch supply flow path A to the second supply port of the first head; causing the second liquid to flow from the second discharge port of the first head through the second branch discharge flow path A to the second main discharge flow path; causing the second liquid to flow from the second main supply flow path through the second branch supply flow path B to the second supply port of the second head; causing the second liquid to flow from the second discharge port of the second head through the second branch discharge flow path B to the second main discharge flow path; causing the second liquid to flow from the second main supply flow path through the second branch supply flow path C to the second supply port of the third head; The method for flowing liquid to a line head assembly according to claim 21 , further comprising: flowing the second liquid from the second outlet of the third head through the second branch exhaust flow path C to the second main exhaust flow path.

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