Inkjet printers and inkjet heads

Abstract

The present invention provides an inkjet printer and inkjet head that contribute to the circulation of liquid via an adjustment member while suppressing deterioration of circulation performance. [Solution] The printer 1 includes a first flow path 50A connected to a first nozzle W1, a second flow path 60A connected to a second nozzle W2, a first adjustment member 34A located in the first flow path 50A, a second adjustment member 34B located in the second flow path 60A, a first filter 38A located downstream of the first adjustment member 34A in the first flow path 50A, a second filter 38B located downstream of the second adjustment member 34B in the second flow path 60A, and a first connecting flow path 73 that connects a first connection point P12 between the first adjustment member 34A and the first filter 38A in the first flow path 50A and a second connection point P22 between the second adjustment member 34B and the second filter 38B in the second flow path 60A.

Description

Technical Field

[0001] The present invention relates to an inkjet printer and an inkjet head.

Background Art

[0002] The inkjet recording apparatus described in Patent Document 1 includes a plurality of nozzles, a first flow path, a second flow path, and a bypass flow path. The plurality of nozzles eject liquid. The first flow path is connected to at least one nozzle among the plurality of nozzles. The second flow path is connected to at least one other nozzle among the plurality of nozzles. The bypass flow path connects the first flow path and the second flow path to each other.

[0003] The liquid flows through the first flow path toward the nozzle. The liquid that has flowed through the first flow path toward the nozzle flows from the first flow path toward the second flow path via the bypass flow path. The liquid that has flowed through the bypass flow path toward the second flow path flows through the second flow path in a direction opposite to the nozzle. Thereby, the liquid circulates.

Prior Art Literature

Patent Literature

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] In the above inkjet recording apparatus, it is conceivable that an adjustment member is disposed in each of the first flow path and the second flow path. The adjustment member is, for example, a damper for adjusting pressure applied to the nozzles, or a differential pressure valve for adjusting the flow rate of liquid to the nozzles.

[0006] Furthermore, in order to suppress the discharge of foreign matter from the nozzle, it is conceivable that filters be placed in both the first and second flow paths. In both the first and second flow paths, the filters are placed downstream of the adjustment member.

[0007] It is conceivable that the inkjet recording device circulates the liquid through a regulating member. For the inkjet recording device to circulate the liquid through the regulating member, the bypass channel may connect the points downstream of the regulating member in each of the first and second channels. The points downstream of the regulating member in each of the first and second channels include the points downstream of the filter in each of the first and second channels. Let's consider the assumption that the bypass channel connects the points downstream of the filter in each of the first and second channels.

[0008] In inkjet recording devices, for example, the flow path volume within the adjustment member may be larger than the flow path volume downstream of the filter. If the flow path volume within the adjustment member is larger than the flow path volume downstream of the filter, the flow rate within the adjustment member is likely to be higher than the flow rate downstream of the filter.

[0009] On the other hand, in inkjet recording devices, for example, the cross-sectional area of ​​the flow path downstream of the filter may be smaller than the cross-sectional area of ​​the flow path within the adjustment member. If the cross-sectional area of ​​the flow path downstream of the filter is smaller than the cross-sectional area of ​​the flow path within the adjustment member, the flow resistance downstream of the filter tends to be larger than the flow resistance within the adjustment member.

[0010] If the flow resistance downstream of the filter is greater than the flow resistance within the regulating member, the liquid flow rate per unit time within the regulating member may decrease. Connecting the bypass flow path to the downstream positions of the first and second flow paths, each downstream of the filter, may lead to the following possibilities due to the reduced liquid flow rate per unit time within the regulating member: for example, the circulation time may increase, or the liquid may not circulate completely. In other words, the circulation performance may deteriorate.

[0011] The objective of the present invention is to provide an inkjet printer and an inkjet head that contribute to circulating liquid via an adjustment member while suppressing deterioration of circulation performance. [Means for solving the problem]

[0012] An inkjet printer according to a first aspect of the present invention is characterized by comprising: a first flow path connected to a first nozzle for ejecting liquid; a second flow path connected to a second nozzle for ejecting the liquid; a first adjustment member, which is a damper or differential pressure valve, disposed in the first flow path; a second adjustment member, which is a damper or differential pressure valve, disposed in the second flow path; a first filter disposed downstream of the first adjustment member in the first flow path in a first supply direction in which the liquid flows through the first flow path toward the first nozzle; a second filter disposed downstream of the second adjustment member in the second flow path in a second supply direction in which the liquid flows through the second flow path toward the second nozzle; and a first connecting flow path that connects a first connection point between the first adjustment member and the first filter in the first supply direction in the first flow path and a second connection point between the second adjustment member and the second filter in the second supply direction in the second flow path.

[0013] According to the first embodiment, if the liquid circulates, for example, the liquid that flows through the first channel in the first supply direction will flow through the first connecting channel from the first channel to the second channel. Furthermore, the liquid that has flowed through the first connecting channel will flow through the second channel in the opposite direction to the second supply direction. Since the first connection point is located downstream of the first adjusting member in the first supply direction of the first channel, and the second connection point is located downstream of the second adjusting member in the second supply direction of the second channel, if the liquid circulates, the liquid will flow through the first adjusting member and the second adjusting member. Furthermore, since the first connection point is located upstream of the first filter in the first supply direction of the first channel, and the second connection point is located upstream of the second filter in the second supply direction of the second channel, insufficient liquid flow rate required for circulation is suppressed. Therefore, the inkjet printer contributes to circulating the liquid through the first adjusting member and the second adjusting member while suppressing deterioration of circulation performance.

[0014] The inkjet printer includes an intermediate member which is positioned between the first adjustment member and the first filter in the first supply direction, and between the second adjustment member and the second filter in the second supply direction, and which has a first partial flow path which is part of the first flow path and a second partial flow path which is part of the second flow path formed therein, and the first connecting flow path may be formed in the intermediate member.

[0015] Because the inkjet printer incorporates an intermediate component, it does not need to form the first partial channel, the second partial channel, and the first connecting channel with separate components. Therefore, the inkjet printer contributes to reducing the number of parts.

[0016] In the inkjet printer described above, the intermediate member has an end face on which the first downstream end in the first supply direction of the first partial flow path and the second downstream end in the second supply direction of the second partial flow path are arranged, and the first connecting flow path may be formed in the intermediate member on the end face.

[0017] If the first connecting channel were formed inside the intermediate member, it would be necessary to drill a hole in the intermediate member, for example. Since the first connecting channel is formed on the end face of the intermediate member, there is no need to drill a hole in the intermediate member to form the first connecting channel. Therefore, inkjet printers contribute to the easy manufacture of intermediate members.

[0018] In the inkjet printer described above, the end face and the first filter may be arranged in the order of the end face and the first filter from upstream to downstream in the first supply direction, and the end face and the second filter may be arranged in the order of the end face and the second filter from upstream to downstream in the second supply direction.

[0019] Since the end face and the first filter are arranged in the order of end face then first filter from upstream to downstream in the first supply direction, the distance of the first flow path from the first connection point to the first nozzle is suppressed to be longer compared to a configuration where the end face is far from the first filter. Since the end face and the second filter are arranged in the order of end face then second filter from upstream to downstream in the second supply direction, the distance of the second flow path from the second connection point to the second nozzle is suppressed to be longer compared to a configuration where the end face is far from the second filter. Therefore, the inkjet printer contributes to suppressing the flow rate of liquid necessary to discharge foreign matter in the first connection flow path from the first or second nozzle.

[0020] In the inkjet printer described above, the intermediate member is part of the first flow path and has a first wall protruding from the end face, part of the second flow path and has a second wall protruding from the end face, part of the first connecting flow path and has a first connecting wall protruding from the end face, and part of the first connecting flow path and has a second connecting wall protruding from the end face, wherein the first wall is a wall and extends from a first point to a second point around the first downstream end when viewed from the direction in which the first wall protrudes from the end face, the second wall extends from a third point to a fourth point around the second downstream end when viewed from the direction in which the second wall protrudes from the end face, the first connecting wall is connected to the first wall at the first point and to the second wall at the third point, the second connecting wall is connected to the first wall at the second point and to the second wall at the fourth point, and the first connecting wall and the second connecting wall may face each other with a gap between them.

[0021] The length of the first flow path from the first connection point to the first nozzle is further suppressed. The length of the second flow path from the second connection point to the second nozzle is further suppressed. Therefore, the inkjet printer contributes to further suppressing the flow rate of liquid required to expel foreign matter in the first connection flow path from the first or second nozzle.

[0022] In the inkjet printer described above, the first point and the second point may each be located at the end of the first wall in the direction from the first wall toward the second wall, and the third point and the fourth point may each be located at the end of the second wall in the direction from the second wall toward the first wall.

[0023] The length of the first connection channel is suppressed. Therefore, inkjet printers contribute to suppressing the deterioration of circulation performance.

[0024] In the inkjet printer, the width direction is a direction in which the first connecting wall and the second connecting wall face each other, the first wall includes a first opposing wall and a second opposing wall that face each other in the width direction, the second wall includes a third opposing wall and a fourth opposing wall that face each other in the width direction, and a width between the first connecting wall and the second connecting wall in the width direction may be smaller than a width between the first opposing wall and the second opposing wall in the width direction, and may also be smaller than a width between the third opposing wall and the fourth opposing wall in the width direction.

[0025] The inkjet printer contributes to reducing the ratio of the flow path cross-sectional area of the first connection flow path to the respective flow path cross-sectional areas of the first flow path and the second flow path.

[0026] The inkjet printer includes: a second connection flow path that connects, to each other, a third connection point, which is located upstream of the first adjustment member in the first supply direction in the first flow path, and a fourth connection point, which is located upstream of the second adjustment member in the second supply direction in the second flow path; a circulation pump provided in a first circulation flow path including the first flow path, the second flow path, the first connection flow path, and the second connection flow path; and a control unit, wherein the control unit may drive the circulation pump to perform a circulation process of circulating the liquid in the first circulation flow path.

[0027] The inkjet printer contributes to reliably circulating liquid through the circulation process in the first circulation flow path.

[0028] The inkjet printer comprises a cap that contacts the nozzle surface on which the first nozzle and the second nozzle are arranged and switches between a capped state that covers the first nozzle and the second nozzle and an uncapped state that is separated from the nozzle surface; a waste liquid pump provided in a waste liquid channel connected to the cap; a first valve located upstream of the third connection point in the first supply direction of the first channel; and a second valve located upstream of the fourth connection point in the second supply direction of the second channel, wherein the control unit is configured such that the cap is in the capped state and The control unit may further operate the circulation pump in the circulation process with the first valve open and the second valve closed, thereby circulating the liquid in the first circulation path.

[0029] The circulation process is performed with the first valve closed. Therefore, during the circulation process, the flow of liquid upstream from the first valve in the first flow path in the first supply direction is suppressed. The circulation process is performed with the second valve closed. Therefore, during the circulation process, the flow of liquid upstream from the second valve in the second flow path in the second supply direction is suppressed. Thus, the inkjet printer contributes to suppressing deterioration of circulation performance.

[0030] The inkjet printer comprises a first manifold channel located downstream of the first filter in the first supply direction of the first flow path, which guides the liquid flowing through the first flow path in the first supply direction to the first nozzle; a second manifold channel located downstream of the second filter in the second supply direction of the second flow path, which guides the liquid flowing through the second flow path in the second supply direction to the second nozzle; and a third connecting channel connecting the first manifold channel and the second manifold channel to each other. The control unit may, in the circulation process, drive the circulation pump to circulate the liquid in the first circulation channel and circulate the liquid in the second circulation channel, which includes the first flow path, the second flow path, the second connecting channel, and the third connecting channel.

[0031] Compared to cases where liquid circulation in the first circulation channel and liquid circulation in the second circulation channel are performed separately, inkjet printers contribute to suppressing the deterioration of circulation performance.

[0032] An inkjet head according to a second aspect of the present invention is characterized by comprising: a first flow path connected to a first nozzle for ejecting liquid; a second flow path connected to a second nozzle for ejecting the liquid; a first adjustment member which is a damper or differential pressure valve disposed in the first flow path; a second adjustment member which is a damper or differential pressure valve disposed in the second flow path; a first filter disposed downstream of the first adjustment member in the first flow path in a first supply direction in which the liquid flows through the first flow path toward the first nozzle; a second filter disposed downstream of the second adjustment member in the second flow path in a second supply direction in which the liquid flows through the second flow path toward the second nozzle; and a first connecting flow path that connects a first connection point between the first adjustment member and the first filter in the first supply direction in the first flow path and a second connection point between the second adjustment member and the second filter in the second supply direction in the second flow path.

[0033] The second embodiment contributes to achieving the same effects as the first embodiment. [Brief explanation of the drawing]

[0034] [Figure 1] This is a perspective view of printer 1. [Figure 2] This is a cross-sectional view taken along the line II-II shown in Figure 1. [Figure 3] This is a perspective view of head 3A. [Figure 4] This is an exploded perspective view of the internal unit 32. [Figure 5] This is a cross-sectional view of the nozzle plate 39, cut by a plane perpendicular to the vertical direction and passing through manifolds 30A and 30B. [Figure 6] This is a perspective view of the FE joint 36. [Figure 7] This is a bottom view of the FE joint 36. [Figure 8] This is a cross-sectional perspective view of the internal unit 32, cut by a plane that is perpendicular to the front-to-back direction and passes through the connecting channel 73. [Figure 9] This is a diagram showing the flow path configuration of printer 1. [Figure 10] This is a block diagram showing the electrical configuration of printer 1. [Figure 11] This is a flowchart of the main process. [Figure 12] Figure 11 is a flowchart showing the continuation of the main process. [Modes for carrying out the invention]

[0035] A printer 1 according to one embodiment of the present invention will be described with reference to the drawings. The top, bottom, lower left, upper right, lower right, and upper left of the printer 1 correspond to the top, bottom, front, rear, right, and left sides of the printer 1, respectively. In this embodiment, the mechanical elements in the drawings are shown to actual scale.

[0036] The printer 1 shown in Figure 1 is an inkjet printer. Printer 1 prints by ejecting ink onto a printing medium. The printing medium can be fabric, paper, etc. For example, a T-shirt can be used as the printing medium. Printer 1 can print color images onto the printing medium using five colors of ink: white, black, yellow, cyan, and magenta.

[0037] In the following, the white ink among the five ink colors will be referred to as "white ink." The four inks of black, cyan, yellow, and magenta among the five ink colors will be referred to collectively as "color ink," or if none of them are specified, they will be referred to as "color ink." When referring to both white ink and color ink collectively, or if none of them are specified, they will simply be referred to as "ink."

[0038] White ink is used in printing to represent the white areas of an image or as a base for color inks. Color inks are dispensed directly onto the printing medium or onto a white ink base and are used to print color images.

[0039] Referring to Figure 1, the schematic configuration of printer 1 will be described. Printer 1 comprises a frame 2, a platen 12, and a mounting section 8. The frame 2 is constructed in a grid pattern by multiple plates and multiple shafts extending in the front-to-back, left-to-right, or up-and-down directions.

[0040] An opening 13 is formed in the frame 2. The opening 13 is located in the center of the frame 2 when viewed from the front. The opening 13 extends rearward from the front end of the frame 2.

[0041] The platen 12 is positioned inside the opening 13 when viewed from the front. The platen 12 is plate-shaped. The platen 12 extends in the front-back, left-right, and right directions. A printing medium is placed on the platen 12. The platen 12 is supported from below by a support part 14.

[0042] The support portion 14 is fixed to the frame 2 within the opening 13. The support portion 14 includes a shaft. The support portion 14 extends in the front-rear direction.

[0043] The platen 12 moves in the front-rear direction along the support portion 14 by the drive of the sub-scanning motor 97 shown in Figure 10. Therefore, in this embodiment, the front-rear direction is the sub-scanning direction.

[0044] A pair of guide shafts 21 and 22 are fixed to the upper end of the frame 2. Guide shaft 21 is positioned at the front end of the frame 2. Guide shaft 21 extends horizontally from the left end to the right end of the frame 2.

[0045] Guide shaft 22 is positioned approximately in the center of the frame 2 in the front-to-back direction. Guide shaft 22 is located behind guide shaft 21. Guide shaft 22 extends horizontally from the left end to the right end of the frame 2. Guide shafts 21 and 22 support the carriage 6.

[0046] The carriage 6 is plate-shaped. The carriage 6 extends in the front-rear, left-right, and right directions. The carriage 6 extends from guide shaft 21 to guide shaft 22.

[0047] A drive belt 98 is connected to the carriage 6. The drive belt 98 is positioned on the guide shaft 21. The drive belt 98 extends in the left-right direction.

[0048] The drive belt 98 moves the carriage 6 along the guide shafts 21 and 22 in the left-right direction, driven by the main scanning motor 99 shown in Figure 10. Therefore, in this embodiment, the left-right direction is the main scanning direction. Figure 1 shows the state in which the carriage 6 is located at the left end of the range of motion.

[0049] The carriage 6 is equipped with heads 3A and 3B. Head 3A is located at the rear of the carriage 6. Head 3B is positioned in front of head 3A. Heads 3A and 3B are inkjet heads.

[0050] The head 3A has a nozzle surface 390 as shown in Figure 2. The nozzle surface 390 is located on the lower surface of the head 3A.

[0051] The nozzle surface 390 has nozzle groups W1 to W4 as shown in Figure 2. The head 3A ejects white ink from nozzle groups W1 to W4. The detailed structure of the head 3A will be described later.

[0052] Head 3B has the same configuration as head 3A. In this embodiment, the type of ink ejected by head 3B is different from the type of ink ejected by head 3A. Head 3B ejects color ink from its nozzle group.

[0053] The mounting section 8 is box-shaped. The mounting section 8 is fixed to the right side of the frame 2. Multiple ink pouches 23, 24, 25, 26, 27, and 28 are mounted on the mounting section 8.

[0054] Ink pouches 23-28 are cartridges that can be replaced for mounting section 8, respectively.

[0055] Ink pouch 23 stores the white ink 3 shown in Figure 9 for supply to the print head 3A. Ink pouch 24 stores the white ink for supply to the print head 3A.

[0056] Ink pouches 25-28 each store black, cyan, yellow, and magenta inks, respectively, to supply to printhead 3B.

[0057] In the above configuration, the heads 3A and 3B move horizontally together with the carriage 6. The area where the movement path of the platen 12 in the horizontal direction and the movement paths of the heads 3A and 3B in the front-to-back direction overlap vertically is called the "printing area 18". The area of ​​the movement paths of the heads 3A and 3B to the left of the movement path of the platen 12 is called the "non-printing area 19". When the heads 3A and 3B and the platen 12 are located in the printing area 18, the platen 12 and the heads 3A and 3B face each other vertically.

[0058] The printer 1 transports the printing medium relative to the heads 3A and 3B in the front-to-back and left-to-right directions within the printing area 18. In this embodiment, the printer 1 moves the platen 12 in the front-to-back direction, i.e., the sub-scanning direction, by driving the sub-scanning motor 97 shown in Figure 10 within the printing area 18. Furthermore, the printer 1 moves the carriage 6 in the left-to-right direction, i.e., the main scanning direction, by driving the main scanning motor 99 shown in Figure 10.

[0059] The operation in which the carriage 6 moves left and right while ejecting white ink from head 3A or color ink from head 3B is called "ejection scanning." Printer 1 prints on the printing medium by repeating ejection scanning and the movement of the platen 12 in the forward and backward directions. For example, during ejection scanning, printer 1 ejects white ink from head 3A to form a base layer on the printing medium. During ejection scanning, printer 1 ejects color ink from head 3B to print a color image on top of the base layer formed on the printing medium.

[0060] Referring to Figure 2, the configuration of the non-printing area 19 will be explained. The printer 1 is equipped with a cap mechanism 4. The cap mechanism 4 is provided in the non-printing area 19. The cap mechanism 4 comprises a cap support 47, a cap 41, and another cap.

[0061] The cap support portion 47 is plate-shaped. The cap support portion 47 extends in the front-rear, left-right, and right directions. The cap support portion 47 moves vertically by the drive of the cap motor 48 shown in Figure 10.

[0062] Cap 41 and the other cap are fixed to the upper surface of the cap support portion 47. Cap 41 and the other cap are located in the same positions as heads 3A and 3B in the front-to-back direction. Cap 41 and the other cap are made of an elastic material such as rubber. Cap 41 and the other cap open upwards.

[0063] According to the above configuration, when the carriage 6 is located at the left end of the range of movement, in the non-printing area 19, the nozzle surface 390 of head 3A and the nozzle surface of head 3B are positioned above cap 41 and another cap, respectively. The nozzle surface 390 of head 3A and the nozzle surface of head 3B face cap 41 and another cap in the vertical direction. The position of the carriage 6 when the nozzle surface 390 of head 3A and the nozzle surface of head 3B face cap 41 and another cap in the vertical direction, respectively, is called the "cap position".

[0064] When the carriage 6 is in the cap position and the cap support portion 47 moves upward, the cap 41 surrounds all of the nozzle group W1, W2, W3, and W4 on the head 3A and contacts the nozzle surface 390 from below. As a result, the cap 41 forms a cap space 42 between itself and the nozzle surface 390. The cap space 42 is the space enclosed by the cap 41 and the nozzle surface 390.

[0065] In the following, the state in which the cap 41 contacts the nozzle surface 390 from below in the head 3A to form a cap space 42 is referred to as the "capped state." In the capped state, the cap 41 contacts the nozzle surface 390 to an extent that can maintain the pressure difference between the cap space 42 and the atmosphere.

[0066] The state in which the cap 41 is separated downward from the nozzle surface 390 on the head 3A is called the "uncapped state".

[0067] Similar to cap 41, when the carriage 6 is in the cap position and the cap support portion 47 moves upward, the other cap contacts the nozzle surface of the head 3B from below. The other cap forms a cap space between itself and the nozzle surface of the head 3B.

[0068] The detailed structure of head 3A will be described with reference to Figures 3 to 5. As shown in Figure 3, head 3A comprises a housing 31 and an internal unit 32. The housing 31 is rectangular parallelepiped. The housing 31 has an opening 31A. The opening 31A is located on the lower surface of the housing 31.

[0069] The internal unit 32 is placed inside the housing 31. The internal unit 32 is fixed to the housing 31.

[0070] As shown in Figure 4, the internal unit 32 comprises flow channels 33A, 33B, 33C, 33D, dampers 34A, 34B, 34C, 34D, flow channels 35A, 35B, 35C, 35D, a front-end joint 36, a front-end plate 37, filters 38A, 38B, 38C, 38D, and a nozzle plate 39. Hereafter, the front end will be referred to as "FE".

[0071] In this embodiment, "flow channel" refers to a wall surface that defines the space through which the fluid flows. The flow channel may be, for example, the inner circumferential wall of a tube, or the inner circumferential wall of a through-hole formed in a block.

[0072] The channels 33A, 33B, 33C, and 33D are arranged from left to right in the order of 33A, 33B, 33C, and 33D. Each of the channels 33A, 33B, 33C, and 33D is a tube.

[0073] Flow path 33A is part of the first flow path 50A described later. Flow path 33B is part of the second flow path 60A described later. Flow path 33C is part of the first flow path 50B described later. Flow path 33D is part of the second flow path 60B described later.

[0074] As shown in Figure 3, the upper ends of each of the flow paths 33A, 33B, 33C, and 33D are exposed from the top surface of the housing 31.

[0075] As shown in Figure 4, damper 34A is connected to the lower end of flow path 33A. Similarly, dampers 34B, 34C, and 34D are connected to the lower ends of flow paths 33B, 33C, and 33D, respectively.

[0076] Dampers 34A, 34B, 34C, and 34D are each a type of adjustment member. Adjustment members regulate the pressure on the liquid passing through them.

[0077] Damper 34A includes a damper membrane. The damper membrane is welded to the upstream end of damper 34A.

[0078] The damper membrane is not limited to a specific configuration. In this embodiment, the damper membrane is a flexible film. The flexible film is, for example, a resin film. The resin film is made of, for example, polypropylene or polyethylene.

[0079] In this embodiment, damper 34A absorbs pressure changes to the white ink through a damper membrane. Damper 34A may also absorb pressure changes to the white ink due to deformation of the white ink flow path during scanning of the carriage 6. Since dampers 34B to 34D have functions and shapes common to or corresponding to damper 34A, for example, a description of dampers 34A to 34D will be omitted.

[0080] Flow path 35A is connected to the front end of damper 34A. Similarly, flow paths 35B, 35C, and 35D are each connected to the front end of damper 34A. Flow paths 35A, 35B, 35C, and 35D are each tubes.

[0081] Flow path 35A is part of the first flow path 50A described later. Flow path 35B is part of the second flow path 60A described later. Flow path 35C is part of the first flow path 50B described later. Flow path 35D is part of the second flow path 60B described later.

[0082] Flow paths 51A, 61A, 51B, and 61B are formed in the FE joint 36. Of the flow paths 51A, 61A, 51B, and 61B, flow path 51A is not shown in Figure 4 but is shown in Figure 8. The flow paths 51A, 61A, 51B, and 61B are arranged in the order of flow paths 51A, 61A, 51B, and 61B from left to right. Each of the flow paths 51A, 61A, 51B, and 61B is the inner circumferential wall of the through hole formed in the FE joint 36.

[0083] Flow path 51A is part of the first flow path 50A described later. Flow path 61A is part of the second flow path 60A described later. Flow path 51B is part of the first flow path 50B described later. Flow path 61B is part of the second flow path 60B described later.

[0084] The lower end of channel 35A is connected to channel 51A, as shown in Figure 8. Similarly, the lower ends of channels 35B, 35C, and 35D are connected to channels 61A, 51B, and 61B, respectively.

[0085] An end face 36A is formed at the lower end of the FE joint 36. The end face 36A extends in the front-rear, left-right, and right directions. The end face 36A faces downwards. Details of the shape of the end face 36A will be described later.

[0086] The material of the FE joint 36 is not limited to a specific material, but it could be resin, for example.

[0087] The FE plate 37 extends in the front, back, left, and right directions. Flow channels 37A, 37B, 37C, and 37D are formed at the front end of the FE plate 37. The flow channels 37A, 37B, 37C, and 37D are arranged in the order of flow channels 37A, 37B, 37C, and 37D from left to right.

[0088] Flow path 37A is part of the first flow path 50A described later. Flow path 37B is part of the second flow path 60A described later. Flow path 37C is part of the first flow path 50B described later. Flow path 37D is part of the second flow path 60B described later.

[0089] The material of the FE plate 37 is not limited to a specific material, but it is, for example, metal. The rigidity of the FE plate 37 is higher than that of the FE joint 36, for example.

[0090] The FE plate 37 is fixed to the end face 36A of the FE joint 36, for example, by screws.

[0091] Filters 38A, 38B, 38C, and 38D each have a plate-like shape. Filter 38A filters the white ink that passes through it. Filters 38B, 38C, and 38D also filter the white ink that passes through them, similar to filter 38A.

[0092] In this embodiment, filters 38A, 38B, 38C, and 38D are each porous metal pieces. Filters 38A, 38B, 38C, and 38D are not limited to any particular type. Filters 38A, 38B, 38C, and 38D may each be, for example, nonwoven fabric, woven fabric, or resin film. Filters 38A, 38B, 38C, and 38D may be of different types from each other.

[0093] The nozzle plate 39 extends in the front, back, left, and right directions. The nozzle plate 39 is composed of multiple plates stacked on top of each other. The upper surface of the nozzle plate 39 is fixed to the lower surface of the FE plate 37 via adhesive. The nozzle plate 39 is positioned at the lower end of the housing 31 shown in Figure 3.

[0094] The nozzle plate 39 has supply ports 39A, 39B, 39C, and 39D. The supply ports 39A to 39D are each located on the upper surface of the nozzle plate 39. The supply ports 39A to 39D are each located at the front end of the nozzle plate 39. The supply ports 39A to 39D are arranged from left to right in the order of supply ports 39A, 39B, 39C, and 39D.

[0095] Filter 38A fits into supply port 39A. Similarly, filters 38B, 38C, and 38D fit into supply ports 39B, 39C, and 39D, respectively.

[0096] As shown in Figure 3, the nozzle plate 39 has a nozzle surface 390. The nozzle surface 390 is located on the lower surface of the nozzle plate 39. The nozzle surface 390 is planar. The nozzle surface 390 extends in the front-back, left-right, and right directions.

[0097] The nozzle surface 390 is located above the platen 12 shown in Figure 1. The nozzle surface 390 is exposed downward from the housing 31 through the opening 31A. The nozzle surface 390 is exposed downward from the carriage 6 shown in Figure 1.

[0098] The nozzle plate 39 has a plurality of nozzles 391. The nozzles 391 are arranged on the nozzle surface 390. The plurality of nozzles 391 are openings.

[0099] The multiple nozzles 391 are arranged in a row of nozzles that are aligned in the front-to-back direction, and then arranged in multiple rows in the left-to-right direction. The multiple nozzle rows are divided into nozzle groups W1, W2, W3, and W4. The nozzle groups W1, W2, W3, and W4 are arranged from left to right in the order of W1, W2, W3, and W4.

[0100] Nozzle group W1 includes multiple first nozzle rows. Ink pouches 23 are connected to these multiple first nozzle rows via first flow paths 50A, which will be described later and are shown in Figures 4 and 9. Nozzle group W2 includes multiple second nozzle rows. Ink pouches 23 are connected to these multiple second nozzle rows via second flow paths 60A, which will be described later and are shown in Figures 4 and 9. Therefore, the white ink 3 supplied from the ink pouches 23 is ejected from nozzle group W1 and nozzle group W2, respectively.

[0101] Nozzle group W3 includes multiple third nozzle rows. Ink pouches 24 are connected to these third nozzle rows via another first flow path 50B shown in Figure 4. Nozzle group W4 includes multiple fourth nozzle rows. Ink pouches 24 are connected to these fourth nozzle rows via another second flow path 60B shown in Figure 4. Therefore, the white ink supplied from the ink pouches 24 is ejected from nozzle group W3 and nozzle group W4, respectively.

[0102] As shown in Figure 5, the nozzle plate 39 has manifolds 30A and 30B and a connecting channel 74. Manifold 30A is a channel for guiding the white ink that flows into manifold 30A via supply port 39A to nozzle group W1. Manifold 30B is a channel for guiding the white ink that flows into manifold 30B via supply port 39B to nozzle group W2.

[0103] Manifold 30A includes manifold passages 131, 132, 133, and 134. Manifold passages 131 to 134 each extend in the longitudinal direction from in front of the front end of nozzle group W1 to behind the rear end of nozzle group W1.

[0104] In the example shown in Figure 5, the nozzle group W1 includes the first nozzle rows L1, L2, L3, L4, L5, and L6. The first nozzle rows L1 to L6 and the manifold passages 131 to 134 are arranged from left to right in the following order: manifold passage 131, first nozzle rows L1 and L2, manifold passage 132, first nozzle rows L3 and L4, manifold passage 133, first nozzle rows L5 and L6, and manifold passage 134.

[0105] Manifold channel 131 is connected to the first nozzle row L1. Manifold channel 132 is connected to the first nozzle rows L2 and L3, respectively. Manifold channel 133 is connected to the first nozzle rows L4 and L5, respectively. Manifold channel 134 is connected to the first nozzle row L6.

[0106] The rear ends of each of the manifold passages 131 to 134 are connected to one another.

[0107] The manifold flow path 131 has a connection port 231. The connection port 231 is located at the front end of the manifold flow path 131. The manifold flow path 131 is connected to the supply port 39A shown in Figure 4 via the connection port 231.

[0108] Similarly, manifold passages 132 to 134 each have connection ports 232 to 234. Connection ports 232 to 234 are located at the respective front ends of manifold passages 132 to 134. Manifold passages 132 to 134 are each connected to the supply port 39A shown in Figure 4 via connection ports 232 to 234.

[0109] Manifold channel 131 guides the white ink flowing from supply port 39A to the first nozzle row L1 via connection port 231 as shown in Figure 4. Manifold channel 132 guides the white ink flowing from supply port 39A to the first nozzle row L2 and L3 as shown in Figure 4. Manifold channel 133 guides the white ink flowing from supply port 39A to the first nozzle row L4 and L5 as shown in Figure 4. Manifold channel 134 guides the white ink flowing from supply port 39A to the first nozzle row L6 as shown in Figure 4.

[0110] Similar to manifold 30A, manifold 30B includes manifold passages 135, 136, and 137. Manifold passages 135 to 137 each extend in the longitudinal direction from in front of the front end of nozzle group W2 to behind the rear end of nozzle group W2.

[0111] In the example shown in Figure 5, the nozzle group W2 includes the second nozzle rows L7, L8, L9, L10, L11, and L12. The second nozzle rows L8-L12 and the manifold passages 135-137 are arranged from left to right in the following order: second nozzle row L7, manifold passage 135, second nozzle rows L8, L9, manifold passage 136, second nozzle rows L10, L11, manifold passage 137, and second nozzle row L12.

[0112] Manifold passage 135 is connected to the second nozzle rows L7 and L8, respectively. Manifold passage 136 is connected to the second nozzle rows L9 and L10, respectively. Manifold passage 137 is connected to the second nozzle rows L11 and L12, respectively.

[0113] The rear ends of the manifold passages 135 to 137 are connected to each other.

[0114] Each of the manifold passages 135 to 137 has a connection port 235 to 237. The connection ports 235 to 237 are located at the front end of each of the manifold passages 135 to 137. Each of the manifold passages 135 to 137 is connected to the supply port 39B shown in Figure 4 via the connection ports 235 to 237.

[0115] Manifold channel 135 guides the white ink flowing from the supply port 39B shown in Figure 4 through the connection port 235 to the second nozzle rows L7 and L8, respectively. Manifold channel 136 guides the white ink flowing from the supply port 39B shown in Figure 4 through the connection port 236 to the second nozzle rows L9 and L10, respectively. Manifold channel 137 guides the white ink flowing from the supply port 39B shown in Figure 4 through the connection port 237 to the second nozzle rows L11 and L12, respectively.

[0116] The connecting channel 74 is located at the rear of the nozzle plate 39. The connecting channel 74 extends in the left-right direction. The connecting channel 74 connects the rear ends of the manifolds 30A and 30B to each other.

[0117] Referring to Figures 6 to 8, the detailed structure of the end face 36A will be explained. As shown in Figure 6, the FE joint 36 has flow channels 52, 62 and a connecting flow channel 73.

[0118] The channels 52, 62 and the connecting channel 73 are arranged on the end face 36A. The channels 52, 62 and the connecting channel 73 are positioned to the left of the center of the end face 36A in the left-right direction. The channels 52, 62 and the connecting channel 73 are arranged from left to right in the order of channel 52, connecting channel 73, and channel 62.

[0119] To the right of the center of the end face 36A in the left-right direction, two other channels and connecting channels are arranged, which connect to channels 35C and 35D, respectively. Since the other two channels and connecting channels have functions and shapes common to or corresponding to channels 52, 62, and connecting channel 73, a description of the other two channels and connecting channels will be omitted.

[0120] The flow path 52 is part of the first flow path 50A, which will be described later and is shown in Figure 9. The flow path 52 includes walls 52A, 52B, 52C, 52D, and 52E. Walls 52A, 52B, 52C, 52D, and 52E each protrude downward from the end face 36A.

[0121] The channel 62 is part of the second channel 60A, which will be described later and is shown in Figure 9. The channel 62 includes walls 62A, 62B, 62C, 62D, and 62E. Walls 62A, 62B, 62C, 62D, and 62E each protrude downward from the end face 36A.

[0122] The connecting channel 73 connects the channel 52 and the channel 62 to each other. The connecting channel 73 includes walls 73A and 73B, an end face 36A, and the upper surface of the FE plate 37. Walls 73A and 73B each protrude downward from the end face 36A.

[0123] In Figure 7, points P51, P52, P53, P54, P55, P56, P61, P62, P63, P64, P65, and P66 each indicate their positions on the end face 36A when viewed from below.

[0124] As shown in Figure 7, point P51 is located in the center of the end face 36A in the front-to-back direction. Point P52 is located in front of point P51. Wall 52A extends in the front-to-back direction from point P51 to point P52.

[0125] Point P53 is located to the left of point P52. Wall 52B connects to wall 52A at point P52. Wall 52B extends horizontally from point P52 to point P53.

[0126] Point P54 is located behind point P53. Wall 52C connects to wall 52B at point P53. Wall 52C extends in the front-to-back direction from point P53 to point P54.

[0127] Point P55 is located to the right of point P54. Wall 52D connects to wall 52C at point P54. Wall 52D extends horizontally from point P54 to point P55.

[0128] Point P56 is located in front of point P55. Point P56 is located behind point P51. Wall 52E connects to wall 52D at point P55. Wall 52E extends in the front-to-back direction from point P55 to point P56.

[0129] According to the above configuration, the flow path 52 extends from point P51 to point P52-P55, passing through points P52, P53, P54, and P55 in that order, and then to point P56, when viewed from below. In this embodiment, points P51 and P56 are located at the right end of the flow path 52, respectively. In other words, points P51 and P56 are located at the end of the flow path 52 in the direction from the flow path 52 towards the flow path 62, respectively.

[0130] Walls 52B and 52D face each other with a gap between them in the front-to-back direction. Wall 52C faces each of walls 52A and 52E with a gap between them in the left-to-right direction. The rear end of wall 52A and the front end of wall 52E are separated from each other in the front-to-back direction.

[0131] Walls 52A, 52B, 52C, 52D, and 52E, i.e., the flow channels 52, are connected to the lower end 511 of flow channel 51A. When viewed from below, flow channel 52 is arranged around the lower end 511 of flow channel 51A.

[0132] Point P61 is located to the right of point P51. Point P62 is located in front of point P61. Wall 62A extends in the front-to-back direction from point P61 to point P62.

[0133] Point P63 is located to the left of point P62. Wall 62B connects to wall 62A at point P62. Wall 62B extends horizontally from point P62 to point P63.

[0134] Point P64 is located behind point P63. Wall 62C connects to wall 62B at point P63. Wall 62C extends in the front-to-back direction from point P63 to point P64.

[0135] Point P65 is located to the right of point P64. Wall 62D connects to wall 62C at point P64. Wall 62D extends horizontally from point P64 to point P65.

[0136] Point P66 is located in front of point P65. Point P66 is located behind point P61. Wall 62E connects to wall 62D at point P65. Wall 62E extends in the front-to-back direction from point P65 to point P66.

[0137] According to the above configuration, the flow path 62 extends from point P61 to point P62-P65, passing through points P62, P63, P64, and P65 in that order, and then to point P66 when viewed from below. In this embodiment, points P61 and P66 are located at the left end of the flow path 62, respectively. In other words, points P61 and P66 are located at the end of the flow path 62 in the direction from the flow path 62 toward the flow path 52, respectively.

[0138] Walls 62B and 62D face each other with a gap between them in the front-to-back direction. Wall 62C faces each of walls 62A and 62E with a gap between them in the left-to-right direction. The rear end of wall 62A and the front end of wall 62E are separated from each other in the front-to-back direction.

[0139] Walls 62A, 62B, 62C, 62D, and 62E, i.e., the flow channels 62, are connected to the lower end 611 of flow channel 61A. When viewed from below, flow channel 62 is arranged around the lower end 611 of flow channel 61A.

[0140] Wall 73A connects to wall 52A at point P51. Wall 73A extends horizontally from point P51 to point P61. Wall 73A connects to wall 62A at point P61.

[0141] Wall 73B connects to wall 52E at point P56. Wall 73B extends horizontally from point P56 to point P66. Wall 73B connects to wall 62E at point P66.

[0142] Walls 73A and 73B face each other with a gap between them in the front-to-back direction.

[0143] In the front-to-back direction, the width W13 between wall 73A and wall 73B is smaller than the width W11 between wall 52B and wall 52D in the front-to-back direction. In the front-to-back direction, the width W13 between wall 73A and wall 73B is smaller than the width W12 between wall 62B and wall 62D in the front-to-back direction.

[0144] As shown in Figure 8, the lower ends of the flow path 52, that is, the lower ends of each of the walls 52A to 52E, are in surface contact with the upper surface of the FE plate 37. The FE plate 37 seals the flow path 52 to prevent white ink from leaking between each of the walls 52A to 52E and the FE plate 37.

[0145] The lower ends of the flow path 62, that is, the lower ends of each of the walls 62A to 62E, are in surface contact with the upper surface of the FE plate 37. The FE plate 37 seals the flow path 62 to prevent white ink from leaking between each of the walls 62A to 62E and the FE plate 37.

[0146] The lower ends of the connecting channel 73, that is, the lower ends of walls 73A and 73B respectively, are in surface contact with the upper surface of the FE plate 37. The FE plate 37 seals the connecting channel 73 to prevent white ink from leaking between walls 73A and 73B and the FE plate 37.

[0147] End face 36A is positioned above filters 38A, 38B, and filters 38C and 38D shown in Figure 4. In the vertical direction, end face 36A is aligned with filters 38A, 38B, and filters 38C and 38D shown in Figure 4. That is, end face 36A and filter 38A are aligned in the order of end face 36A, filter 38A from top to bottom. End face 36A and filter 38B are aligned in the order of end face 36A, filter 38B from top to bottom. End face 36A and filter 38C are aligned in the order of end face 36A, filter 38C from top to bottom. End face 36A and filter 38D are aligned in the order of end face 36A, filter 38D from top to bottom.

[0148] In this embodiment, "one member and another member are arranged in the order of one member, then the other member from one direction to the other direction" means that if one member is projected from the direction of its position to the other direction, part or all of the projection surface of one member will be projected onto the other member. For example, "the end face 36A and the filter 38A are arranged in the order of end face 36A, then the filter 38A from top to bottom" means that if the end face 36A is projected from top to bottom, part or all of the projection surface of end face 36A will be formed on the filter 38A.

[0149] Referring to Figure 9, the flow path configuration of printer 1 will be explained. Printer 1 is equipped with connecting flow paths 71, 72, 73, and 74, a first flow path 50A, and a second flow path 60A.

[0150] The connecting channel 71 is connected to the ink pouch 23 at point P1. The connecting channel 71 extends from point P1 to point P2. At point P2, the connecting channel 71 branches into a first channel 50A and a second channel 60A. That is, the first channel 50A is connected to the connecting channel 71 at point P2, and the second channel 60A is connected to the connecting channel 71 at point P2.

[0151] The first channel 50A is connected to the ink pouch 23 via the connecting channel 71. The first channel 50A extends from point P2 to point P14. At point P14, the first channel 50A is connected to the nozzle group W1.

[0152] The second channel 60A is connected to the ink pouch 23 via the connecting channel 71. The second channel 60A extends from point P2 to point P24. At point P24, the second channel 60A is connected to the nozzle group W2.

[0153] Damper 34A is located in the first flow path 50A. Filter 38A is located in the first flow path 50A. Manifold 30A is located in the first flow path 50A.

[0154] The damper 34B is located in the second flow path 60A. The filter 38B is located in the second flow path 60A. The manifold 30B is located in the second flow path 60A.

[0155] The first supply direction indicated by arrow A11 and the second supply direction indicated by arrow A12 are defined. The first supply direction is the direction in which the white ink 3 flows through the first channel 50A toward the nozzle group W1. In this embodiment, the first supply direction is from point P2 to point P14 in the first channel 50A.

[0156] The second supply direction is the direction in which the white ink 3 flows through the second channel 60A toward the nozzle group W2. In this embodiment, the second supply direction is from point P2 to point P24 in the second channel 60A.

[0157] Points P11, P12, and P13 are located on the first flow path 50A. In the first supply direction indicated by arrow A11, points P11, P12, and P13 are arranged in the order of P11, P12, and P13 from upstream to downstream.

[0158] Point P11 is located upstream of the damper 34A in the first supply direction indicated by arrow A11. In this embodiment, point P11 is located upstream of the head 3A in the first supply direction indicated by arrow A11.

[0159] Point P12 is located between the damper 34A and the filter 38A in the first supply direction indicated by arrow A11.

[0160] Points P21, P22, and P23 are located on the second flow path 60A. In the second supply direction indicated by arrow A12, points P21, P22, and P23 are arranged in the order of P21, P22, and P23 from upstream to downstream.

[0161] Point P21 is located upstream of the damper 34B in the second supply direction indicated by arrow A21. In this embodiment, point P21 is located upstream of the head 3A in the second supply direction indicated by arrow A21.

[0162] Point P22 is located between the damper 34B and the filter 38B in the second supply direction indicated by arrow A21.

[0163] The connecting channel 72 is connected to the first channel 50A at point P11. The connecting channel 72 extends from point P11 to point P21. At point P21, the connecting channel 72 is connected to the second channel 60A.

[0164] The connecting channel 73 is connected to the first channel 50A at point P12. The connecting channel 73 extends from point P12 to point P22. The connecting channel 73 is connected to the second channel 60A at point P22. In other words, the FE joint 36 is positioned between the damper 34A and the filter 38A in the first supply direction indicated by arrow A11, and between the damper 34B and the filter 38B in the second supply direction indicated by arrow A12.

[0165] The connecting channel 74 is connected to manifold 30A at point P13. The connecting channel 74 extends from point P13 to point P23. The connecting channel 74 is connected to manifold 30B at point P23.

[0166] Manifold 30A is located downstream of filter 38A in the first supply direction indicated by arrow A11. Manifold 30B is located downstream of filter 38B in the second supply direction indicated by arrow A12.

[0167] Printer 1 comprises a first valve 501, a second valve 601, and a circulation pump 721. The first valve 501 and the second valve 601 are, for example, solenoid valves.

[0168] The first valve 501 is positioned upstream of point P11 in the first flow path 50A in the first supply direction indicated by arrow A11. When the first valve 501 is open, the flow of white ink 3 through the first valve 501 is possible in the first flow path 50A from one of points P2 and P11 to the other. When the first valve 501 is closed, the flow of white ink 3 through the first valve 501 from one of points P2 and P11 to the other is blocked in the first flow path 50A.

[0169] The second valve 601 is positioned upstream of point P21 in the second flow path 60A in the second supply direction indicated by arrow A12. When the second valve 601 is open, the flow of white ink 3 through the second valve 601 is possible in the second flow path 60A from one of points P2 and P21 to the other. When the second valve 601 is closed, the flow of white ink 3 through the second valve 601 from one of points P2 and P21 to the other is blocked in the second flow path 60A.

[0170] The circulation pump 721 is positioned in the connecting channel 72. Driven by the pump motor 721M shown in Figure 10, the circulation pump 721 flows the white ink 3 in the connecting channel 72 from one point P11 and one point P12 to the other. In this embodiment, the circulation pump 721 flows the white ink 3 in the connecting channel 72 from point P21 to point P11.

[0171] The first circulation path indicated by arrow A21 and the second circulation path indicated by arrow A22 are defined. The first circulation path includes the first path 50A, the second path 60A, the connecting path 73, and the connecting path 72. The first circulation path is one of the paths when the white ink 3 is circulated by the drive of the circulation pump 721.

[0172] The second circulation channel includes the first channel 50A, the second channel 60A, the connecting channel 72, and the connecting channel 73. The second circulation channel is another channel when the white ink 3 is circulated by the drive of the circulation pump 721.

[0173] Printer 1 is equipped with a waste liquid channel 79 and a waste liquid pump 791. The waste liquid channel 79 is connected to the cap 41 at point P31. The waste liquid channel 79 extends from point P31 to the waste liquid tank.

[0174] The waste liquid pump 791 is positioned in the waste liquid passage 79. Driven by the pump motor 791M shown in Figure 10, the waste liquid pump 791 moves air or waste liquid in the cap space 42 from point P31 towards the waste liquid tank in the waste liquid passage 79.

[0175] Printer 1 includes multiple connection channels, a first channel 50B shown in Figure 4, and a second channel 60B also shown in Figure 4. The other multiple connection channels, the first channel 50B, and the second channel 60B have functions and shapes that are common to or correspond to connection channels 71-73, the first channel 50A, and the second channel 60A, respectively, so a description of the other multiple connection channels, the first channel 50B, and the second channel 60B is omitted. In Figure 9, the other multiple connection channels, the first channel 50B, and the second channel 60B are not shown.

[0176] For example, the other multiple connecting channels, the first channel 50B, and the second channel 60B differ from the connecting channels 71-73, the first channel 50A, and the second channel 60A in the following respects: The first channel 50B connects the ink pouch 24 and the nozzle group W3 to each other. The second channel 60B connects the ink pouch 24 and the nozzle group W4 to each other. The other multiple connecting channels each connect the first channel 50B and the second channel 60B to each other.

[0177] The correspondence between each flow path shown in Figure 9 and each flow path shown in Figures 4 to 8 will be explained. In the first flow path 50A shown in Figure 9, the flow path between point P11 and damper 34A in the first supply direction indicated by arrow A11 corresponds to the flow path 33A shown in Figure 4.

[0178] In the first flow path 50A shown in Figure 9, the flow path between the damper 34A and point P12 in the first supply direction indicated by arrow A11 corresponds to the flow path 35A shown in Figure 4 and the flow paths 51A and 52 shown in Figure 8. The lower end 511 of the flow path 51A shown in Figure 8 is the downstream end of the flow path 51A in the first supply direction indicated by arrow A11 in Figure 9.

[0179] Of the first flow path 50A shown in Figure 9, the flow path downstream of point P12 and upstream of manifold 30A in the first supply direction indicated by arrow A11 corresponds to the flow path including flow path 37A and supply port 39A shown in Figure 4.

[0180] In the second flow path 60A shown in Figure 9, the flow path between point P21 and damper 34B in the second supply direction indicated by arrow A12 corresponds to the flow path 33B shown in Figure 4.

[0181] In the second flow path 60A shown in Figure 9, the flow path between the damper 34B and point P22 in the second supply direction indicated by arrow A12 corresponds to the flow path 35B shown in Figure 4 and the flow paths 61A and 62 shown in Figure 8. The lower end 611 of the flow path 61A shown in Figure 8 is the downstream end of the flow path 61A in the second supply direction indicated by arrow A12 in Figure 9.

[0182] Of the second flow paths 60A shown in Figure 9, the flow path downstream of point P22 and upstream of manifold 30B in the second supply direction indicated by arrow A12 corresponds to the flow path including flow path 37B and supply port 39B shown in Figure 4.

[0183] In Figure 9, the first supply direction indicated by arrow A11 and the second supply direction indicated by arrow A12 correspond to downwards, for example in Figure 4. In Figure 9, the direction opposite to the first supply direction indicated by arrow A11 and the direction opposite to the second supply direction indicated by arrow A12 correspond to upwards, for example in Figure 4.

[0184] Referring to Figure 10, the electrical configuration of printer 1 will be described. Printer 1 includes a control board 80. A CPU 101, flash memory 102, and RAM 103 are arranged on the control board 80. The CPU 101, flash memory 102, and RAM 103 are electrically connected to each other.

[0185] CPU101 controls printer 1. CPU101 functions as a processor.

[0186] Flash memory 102 is a non-volatile memory. Flash memory 102 stores various types of data. For example, programs are stored in flash memory 102.

[0187] The program consists of computer-readable instructions. The program is executed by the CPU 101. When the program is executed by the CPU 101, it instructs the CPU 101 to perform various processes. The program includes a control program for executing the main process described later, as shown in Figures 11 and 12.

[0188] RAM103 temporarily stores various types of data. These include flags used in the main process, and data acquired, identified, calculated, generated, set, or determined during the main process.

[0189] The CPU 101 is electrically connected to the main scanning motor 99, sub-scanning motor 97, cap motor 48, head drive unit 301, coils 501C and 601C, pump motors 721M and 791M, and the operating unit 17. The main scanning motor 99, sub-scanning motor 97, cap motor 48, head drive unit 301, coils 501C and 601C, and pump motors 721M and 791M are driven by control from the CPU 101.

[0190] The head drive unit 301 is composed of, for example, a piezoelectric element or a heating element. The head drive unit 301 is provided in each of the multiple nozzles 391 shown in Figure 3 within the head 3A. The head drive unit 301 selectively ejects white ink from the multiple nozzles 391 to the head 3A at a timing driven by the CPU 101. Each of the multiple nozzles of the head 3B is also provided with a head drive unit for selectively ejecting color ink.

[0191] Coil 501C is positioned in the first valve 501 shown in Figure 9. When driven by the CPU 101, coil 501C closes the first valve 501. When not driven by the CPU 101, coil 501C opens the first valve 501.

[0192] Coil 601C is positioned in the second valve 601 shown in Figure 9. When driven by CPU 101, coil 601C closes the second valve 601. When not driven by CPU 101, coil 601C opens the second valve 601.

[0193] The pump motor 721M is positioned on the circulation pump 721 shown in Figure 9. The pump motor 721M is driven by the CPU 101 and performs suction using the circulation pump 721.

[0194] The pump motor 791M is positioned on the waste liquid pump 791 shown in Figure 9. The pump motor 791M is driven by the CPU 101 and performs suction by the waste liquid pump 791.

[0195] The control unit 17 is a user interface. The control unit 17 is a touch panel or the like. The control unit 17 outputs signals to the CPU 101 in response to user operations.

[0196] The main process will be explained with reference to Figures 11 and 12. When power is turned on to printer 1, the CPU 101 reads a control program from flash memory 102 and executes the main process. In the main process, ink introduction and ink circulation are controlled.

[0197] Ink introduction is performed, for example, when the first channel 50A and the second channel 60A are not filled with white ink 3. Ink introduction is performed, for example, to fill the first channel 50A and the second channel 60A with white ink 3. In other words, ink introduction is, for example, the initial introduction of white ink 3.

[0198] Ink circulation is performed, for example, when the first channel 50A and the second channel 60A are filled with white ink 3. Ink circulation is performed, for example, to resolve the uneven state of the white ink 3 in the first channel 50A and the second channel 60A.

[0199] As shown in Figure 11, when the main process starts, the CPU 101 determines whether ink is to be introduced (S11). The timing of ink introduction is not limited to a specific timing. For example, the user operates the operation unit 17 shown in Figure 10 and inputs an introduction instruction to the printer 1 to introduce ink.

[0200] If CPU 101 has not received an ink installation command, ink installation will not be performed. If ink installation is not performed (S11: NO), CPU 101 proceeds to the decision shown in S12 in Figure 12.

[0201] If CPU 101 receives an ink introduction command, ink introduction is performed. If ink introduction is performed (S11: YES), CPU 101 switches cap 41 from the uncapped state to the capped state shown in Figure 2 (S21).

[0202] In this embodiment, the CPU 101 raises the cap support portion 47 shown in Figure 2. The cap 41 contacts the nozzle surface 390 of the head 3A, forming a cap space 42. By forming the cap space 42 between the cap 41 and the nozzle surface 390, the cap 41 switches from the uncapped state to the capped state shown in Figure 2. The CPU 101 performs the following processing in the capped state.

[0203] The CPU 101 opens the first valve 501 shown in Figure 9 (S31). The CPU 101 closes the second valve 601 shown in Figure 9 (S32). As a result of the processes in S31 and S32, the first valve 501 is open and the second valve 601 is closed.

[0204] With the first valve 501 open and the second valve 601 closed, the CPU 101 drives the waste liquid pump 791 shown in Figure 9 (S33).

[0205] As shown in Figure 9, since the pouch is capped, when the process S33 shown in Figure 11 is performed, the waste liquid pump 791 sucks the white ink 3 from the ink pouch 23 through the first channel 50A. That is, as indicated by arrow A11, the white ink 3 in the ink pouch 23 flows through the connecting channel 71 from point P1 to point P2. Furthermore, the white ink 3 flows through the first channel 50A from point P2 to point P14.

[0206] In the process S33 shown in Figure 11, the CPU 101 drives the waste liquid pump 791 shown in Figure 9 by a first predetermined amount, and then stops driving the waste liquid pump 791.

[0207] The first predetermined amount is not limited to a specific drive amount. For example, the first predetermined amount is a drive amount sufficient to fill the first flow path 50A with white ink 3. For example, the flash memory 102 is pre-stored that the waste liquid pump 791 will be driven for a predetermined time and at a predetermined rotation speed as the first predetermined amount.

[0208] As shown in Figure 11, the CPU 101 closes the first valve 501 shown in Figure 9 (S41). The CPU 101 also opens the second valve 601 shown in Figure 9 (S42). As a result of the processes in S41 and S42, the first valve 501 is closed and the second valve 601 is open.

[0209] With the first valve 501 closed and the second valve 601 open, the CPU 101 drives the waste liquid pump 791 shown in Figure 9 (S43).

[0210] As shown in Figure 9, since the pouch is capped, when the process S43 shown in Figure 11 is performed, the waste liquid pump 791 sucks the white ink 3 from the ink pouch 23 through the second channel 60A. That is, as indicated by arrow A12, the white ink 3 in the ink pouch 23 flows through the connecting channel 71 from point P1 to point P2. Furthermore, the white ink 3 flows through the second channel 60A from point P2 to point P24.

[0211] In the process S43 shown in Figure 11, the CPU 101 stops driving the waste liquid pump 791 after it has driven the waste liquid pump 791 by a second predetermined amount.

[0212] The second predetermined amount is not limited to a specific drive amount. For example, the second predetermined amount is a drive amount sufficient to fill the second flow path 60A with white ink 3. The second drive amount may be the same as the first drive amount, or it may be greater than or less than the first drive amount. For example, the flash memory 102 is pre-stored with the second predetermined amount, which means that the waste liquid pump 791 will be driven for a predetermined time at a predetermined rotation speed.

[0213] As shown in Figure 11, the CPU 101 closes the first valve 501 shown in Figure 9 (S51). The CPU 101 also closes the second valve 601 shown in Figure 9 (S52). As a result of the processes in S51 and S52, the first valve 501 and the second valve 601 are closed.

[0214] With the first valve 501 closed and the second valve 601 closed, the CPU 101 drives the circulation pump 721 shown in Figure 9 (S53).

[0215] As shown in Figure 9, when the process S53 shown in Figure 11 is performed, the circulation pump 721 circulates the white ink 3 in the first circulation channel indicated by arrow A21 and also in the second circulation channel indicated by arrow A21. In this embodiment, when the process S53 shown in Figure 11 is performed, the circulation of the white ink 3 in the first circulation channel indicated by arrow A21 and the circulation of the white ink 3 in the second circulation channel indicated by arrow A22 are performed simultaneously. The white ink 3 flows due to the suction by the circulation pump 721 as described below.

[0216] White ink 3 flows through the connecting channel 72 from point P21 to point P11. Since the first valve 501 is closed, the white ink 3 that flowed through the connecting channel 72 from point P21 to point P11 flows through the first channel 50A from point P11 to point P12.

[0217] On the other hand, since the second valve 601 is closed, white ink 3 flows from point P22 through the second channel 60A to point P21. White ink 3 flows from point P12 through the connecting channel 73 to point P22, and also flows from point P23 through the second channel 60A to point P22.

[0218] White ink 3 flows from point P13 through the connecting channel 74 to point P23. White ink 3 also flows from point P12 through the first channel 50A to point P13.

[0219] The ratio of the amount of white ink 3 flowing from point P12 to point P22 via the connecting channel 73 to the amount of white ink 3 flowing from point P23 to point P22 via the second channel 60A is determined by the ratio of the flow resistance of the connecting channel 73 from point P12 to point P22 to the flow resistance of the first channel 50A, connecting channel 74, and second channel 60A from point P12 to point P22 via points P13 and P23. In this embodiment, the flow resistance of the connecting channel 73 from point P12 to point P22 is smaller than the flow resistance of the first channel 50A, connecting channel 74, and second channel 60A from point P12 to point P22 via points P13 and P23. Therefore, the amount of white ink 3 flowing from P12 to point P22 via the connecting channel 73 is greater than the amount of white ink 3 flowing from point P23 to point P22 via the second channel 60A.

[0220] In this embodiment, the size of the nozzle 391 shown in Figure 3 is so small that the flow resistance of the connecting flow path 74 is negligible compared to the flow resistance of the nozzle 391. Furthermore, the size of the nozzle 391 shown in Figure 3 is so small that the flow resistance of the first flow path 50A from point P12 to point P13 is negligible compared to the flow resistance of the nozzle 391. Therefore, the white ink 3 does not flow from point P13 to point P23 through the nozzle group W1, the cap space 42, and the nozzle group W2. In other words, in this embodiment, the white ink 3 does not circulate through the cap space 42 in the process S53 shown in Figure 11.

[0221] In the processes S33 and S43 shown in Figure 11, the white ink 3 does not easily flow into the connecting channels 72, 73, and 74. Because the white ink 3 does not easily flow into the connecting channels 72, 73, and 74, the air in the connecting channels 72, 73, and 74 tends to remain in them.

[0222] As shown in Figure 11, the process in S53 fills the connecting channels 72, 73, and 74 with white ink 3. As the white ink 3 flows through the connecting channels 72, 73, and 74, the air in the connecting channels 72, 73, and 74 flows from the connecting channels 72, 73, and 74 to the first channel 50A or the second channel 60A. In other words, the retention of air in the connecting channels 72, 73, and 74 is suppressed.

[0223] In the process S53 shown in Figure 11, the CPU 101 stops driving the circulation pump 721 after it has been driven by a third predetermined amount.

[0224] The third predetermined amount is not limited to a specific drive amount. For example, the third predetermined amount is a drive amount sufficient to move the air in the connecting passage 72 to the first passage 50A or the second passage 60A. For example, the third predetermined amount is pre-stored in the flash memory 102, which indicates that the circulation pump 721 will be driven for a predetermined time and at a predetermined rotational speed.

[0225] As shown in Figure 11, the CPU 101 opens the first valve 501 shown in Figure 9 (S61). The CPU 101 also opens the second valve 601 shown in Figure 9 (S62). As a result of the processes in S61 and S62, both the first valve 501 and the second valve 601 are open.

[0226] With the first valve 501 open and the second valve 601 open, the CPU 101 drives the waste liquid pump 791 shown in Figure 9 (S63).

[0227] As shown in Figure 9, since the pouch is capped, when the process S63 shown in Figure 11 is performed, the waste liquid pump 791 sucks the white ink 3 from the ink pouch 23 through the first channel 50A and the second channel 60A, respectively. As indicated by arrows A11 and A12, the white ink 3 is discharged from nozzle group W1 and nozzle group W2, respectively. In other words, the white ink 3 is purged by the process in S63.

[0228] In the process S63 shown in Figure 11, the CPU 101 drives the waste liquid pump 791 by a fourth predetermined amount and then stops driving the waste liquid pump 791.

[0229] The fourth predetermined amount is not limited to a specific drive amount. For example, the fourth predetermined amount is a drive amount such that air from the first flow path 50A is discharged from the nozzle group W1 and air from the second flow path 60A is discharged from the nozzle group W2. The fourth predetermined amount may be the same as the first predetermined amount or the second predetermined amount, may be greater than the first predetermined amount or the second predetermined amount, or may be less than the first predetermined amount or the second predetermined amount. For example, the fourth predetermined amount is pre-stored in the flash memory 102, which indicates that the waste liquid pump 791 is driven for a predetermined time at a predetermined rotation speed.

[0230] As shown in Figure 11, after processing in S63, the CPU 101 proceeds to the decision in S12 shown in Figure 12.

[0231] As shown in Figure 12, the CPU 101 determines whether ink circulation will occur (S12). The timing of ink circulation is not limited to a specific timing. For example, ink circulation is performed periodically. That is, if a predetermined interval has elapsed since the previous ink circulation, the next ink circulation will occur.

[0232] For example, if the interval time has not elapsed, ink circulation will not occur. If ink circulation does not occur (S12: NO), the CPU 101 returns to the decision shown in S11 in Figure 11.

[0233] For example, if the interval time has elapsed, ink circulation will be performed. If ink circulation is performed (S12: YES), CPU 101 will stop printing (S71). With printing stopped, CPU 101 will perform the following processing.

[0234] The CPU 101 closes the first valve 501 shown in Figure 9 (S81). The CPU 101 also closes the second valve 601 shown in Figure 9 (S82). As a result of the processes in S81 and S82, the first valve 501 and the second valve 601 are closed.

[0235] With the first valve 501 closed and the second valve 601 closed, the CPU 101 drives the circulation pump 721 shown in Figure 9 (S83).

[0236] As shown in Figure 9, when the process S83 shown in Figure 12 is performed, the circulation of white ink 3 in the first circulation channel indicated by arrow A21 and the circulation of white ink 3 in the second circulation channel indicated by arrow A22 occur simultaneously, similar to the process S53 shown in Figure 11.

[0237] In the process S83 shown in Figure 12, the CPU 101 stops driving the circulation pump 721 after it has been driven by a fifth predetermined amount.

[0238] The fifth predetermined amount is not limited to a specific drive amount. For example, the fifth predetermined amount is a drive amount sufficient to suppress the settling of the white ink 3 in the first and second circulation channels. The fifth predetermined amount may be the same as the third predetermined amount, or it may be more than the third predetermined amount, or it may be less than the third predetermined amount. For example, the fifth predetermined amount is pre-stored in the flash memory 102, which is set to drive the circulation pump 721 for a predetermined time and at a predetermined rotation speed.

[0239] As shown in Figure 12, after processing in S83, the CPU 101 returns to the decision shown in S11 in Figure 11.

[0240] The main effects of the above embodiment will now be described. The above embodiment also produces effects other than those described below. The present invention is not limited to the effects described below.

[0241] In the above embodiment, the first channel 50A is connected to the nozzle group W1. The second channel 60A is connected to the nozzle group W2.

[0242] Damper 34A is placed in the first flow path 50A. Damper 34B is placed in the second flow path 60A.

[0243] Filter 38A is positioned downstream of damper 34A in the first flow path 50A in the first supply direction. Filter 38B is positioned downstream of damper 34B in the second flow path 60A in the second supply direction.

[0244] The connecting channel 73 connects point P12 and point P22 to each other. Point P12 is located between the damper 34A and the filter 38A in the first supply direction of the first channel 50A. Point P22 is located between the damper 34B and the filter 38B in the second supply direction of the second channel 60A.

[0245] According to the above embodiment, if the white ink 3 is circulating, for example, the white ink 3 that has flowed in the first supply direction through the first channel 50A will flow in the connecting channel 73 from the first channel 50A to the second channel 60A. Furthermore, the white ink 3 that has flowed in the connecting channel 73 will flow in the second channel 60A in the opposite direction to the second supply direction.

[0246] The flow path cross-sectional areas of dampers 34A and 34B are larger than the flow path cross-sectional areas of the parts of the first flow path 50A and the second flow path 60A other than dampers 34A and 34B. The parts other than dampers 34A and 34B are, for example, flow paths 33A, 33B, 35A, and 35B. Because the flow path cross-sectional areas of dampers 34A and 34B are large, air tends to accumulate in dampers 34A and 34B more easily than in the parts other than dampers 34A and 34B. Point P12 is located downstream of damper 34A in the first supply direction of the first flow path 50A, and point P22 is located downstream of damper 34B in the second supply direction of the second flow path 60A. Therefore, if the white ink 3 is circulating, the white ink 3 will flow through dampers 34A and 34B. Thus, the accumulation of air in dampers 34A and 34B is suppressed.

[0247] Furthermore, since, for example, a manifold 30A exists in the portion of the first flow path 50A downstream of filter 38A in the first supply direction, the flow path cross-sectional area downstream of filter 38A is generally smaller than that upstream of filter 38A in the first supply direction of the first flow path 50A. Similarly, the flow path cross-sectional area downstream of filter 38B is generally smaller than that upstream of filter 38B in the second supply direction of the second flow path 60A. Therefore, the flow rate of white ink 3 in the portions downstream of filters 38A and 38B is unlikely to be large. Consequently, if point P12 is located downstream of filter 38A in the first supply direction of the first flow path 50A, and point P22 is located downstream of filter 38B in the second supply direction of the second flow path 60A, the flow rate of white ink 3 in the ink circulation is likely to be insufficient. If the flow rate of white ink 3 in the ink circulation is insufficient, air will not be easily discharged from dampers 34A and 34B and the connecting channel 73, and the settling of the white ink 3 components will not be easily resolved in dampers 34A and 34B and the connecting channel 73.

[0248] In the above embodiment, point P12 is located upstream of filter 38A in the first supply direction of the first flow path 50A, and point P22 is located upstream of filter 38B in the second supply direction of the second flow path 60A, so that the flow rate of white ink 3 necessary for ink circulation is suppressed. Therefore, the printer 1 contributes to making it easier to discharge air from dampers 34A, 34B and connecting flow path 73, and to making it easier to eliminate the settling of the settling component of white ink 3 in dampers 34A, 34B and connecting flow path 73. In other words, the printer 1 contributes to circulating white ink 3 via dampers 34A and 34B while suppressing deterioration of circulation performance.

[0249] In the above embodiment, the FE joint 36 is positioned between the damper 34A and the filter 38A in the first supply direction, and between the damper 34B and the filter 38B in the second supply direction. A flow path 51A and a flow path 61A are formed in the FE joint 36. A connecting flow path 73 is formed in the FE joint 36.

[0250] Since printer 1 is equipped with an FE joint 36, printer 1 does not need to form the flow path 51A, flow path 61A, and connecting flow path 73 with separate components. Therefore, printer 1 contributes to reducing the number of parts.

[0251] In the above embodiment, in the FE joint 36, the lower end 511 of the flow path 51A and the lower end 611 of the flow path 61A are arranged on the end face 36A, and the connecting flow path 73 is formed on the end face 36A of the FE joint 36.

[0252] If the connecting channel 73 were formed inside the FE joint 36, it would be necessary to drill a hole in the FE joint 36, for example. Since the connecting channel 73 is formed on the end face 36A of the FE joint 36, there is no need to drill a hole in the FE joint 36 to form the connecting channel 73. Therefore, the printer 1 contributes to the easy manufacture of the FE joint 36.

[0253] If end face 36A is not aligned with filters 38A and 38B, then end face 36A is likely to be far from filters 38A and 38B. The further end face 36A is from filters 38A and 38B, the longer the flow path becomes from the lower end 511 of flow path 51A and the lower end 611 of flow path 61A to filters 38A and 38B. A longer flow path results in a larger flow path volume.

[0254] In the above embodiment, the end face 36A and the filter 38A are arranged in the order of end face 36A and filter 38A from upstream to downstream in the first supply direction. In the second supply direction, the end face 36A and the filter 38B are arranged in the order of end face 36A and filter 38B from upstream to downstream.

[0255] Since the end face 36A and filter 38A are arranged in the order of end face 36A and filter 38A from upstream to downstream in the first supply direction, the distance of the first flow path 50A from point P12 to nozzle group W1 is suppressed to be longer compared to a configuration where the end face 36A is separated from filter 38A. Since the end face 36A and filter 38B are arranged in the order of end face 36A and filter 38B from upstream to downstream in the second supply direction, the distance of the second flow path 60A from point P22 to nozzle group W2 is suppressed to be longer compared to a configuration where the end face 36A is separated from filter 38B. Therefore, the printer 1 contributes to suppressing the flow rate of white ink 3 necessary to discharge foreign matter in the connecting flow path 73 from nozzle group W1 or nozzle group W2.

[0256] In the above embodiment, the flow path 52 protrudes from the end face 36A. The flow path 62 protrudes from the end face 36A. Wall 73A protrudes from the end face 36A. Wall 73B protrudes from the end face 36A.

[0257] Viewed from below, channel 52 extends from point P51 to point P56 around the lower end 511 of channel 51A. Viewed from below, channel 62 extends from point P61 to point P66 around the lower end 611 of channel 61A. Wall 73A connects to channel 52 at point P51 and to channel 62 at point P61. Wall 73B connects to channel 52 at point P56 and to channel 62 at point P66. Walls 73A and 73B face each other with a gap between them.

[0258] The length of the first flow path 50A from point P12 to nozzle group W1 is further suppressed. The length of the second flow path 60A from point P22 to nozzle group W2 is further suppressed. Therefore, the printer 1 contributes to further suppressing the flow rate of white ink 3 necessary to discharge foreign matter in the connecting flow path 73 from nozzle group W1 or nozzle group W2.

[0259] If points P51 and P56 are located at the left end of channel 52, it will be difficult for connecting channel 73 to connect channel 52 and channel 62 in a straight line.

[0260] In the above embodiment, points P51 and P56 are located at the ends of the channel 52 in the direction from channel 52 to channel 62. Points P61 and P66 are located at the ends of the channel 62 in the direction from channel 62 to channel 52.

[0261] Therefore, the length of the connecting channel 73 is suppressed. In other words, the flow resistance in the connecting channel 73 is suppressed. Thus, the printer 1 contributes to suppressing insufficient flow rate of white ink 3 necessary for circulation. In other words, the printer 1 contributes to suppressing deterioration of circulation performance.

[0262] As mentioned above, the cross-sectional area of ​​the flow path downstream of filters 38A and 38B is generally small. Therefore, the larger the cross-sectional area of ​​the connecting flow path 73, the larger the ratio between the cross-sectional area of ​​the connecting flow path 73 and the cross-sectional area of ​​the flow path downstream of filters 38A and 38B. When the ratio becomes larger, in the process of S53, it becomes more difficult for the white ink 3 to flow from point P23 towards point P22 via the second flow path 60A.

[0263] In the above embodiment, walls 52B and 52D face each other in the front-to-back direction. Walls 62B and 62D face each other in the front-to-back direction. The width W13 between walls 73A and 73B in the front-to-back direction is smaller than the width W11 between walls 52B and 52D in the front-to-back direction, and also smaller than the width W12 between walls 62B and 62D in the front-to-back direction. Therefore, the printer 1 contributes to bringing the ratio of the cross-sectional area of ​​the connecting channel 73 to the cross-sectional area of ​​the channel downstream of filters 38A and 38B closer to 1. In other words, the printer 1 contributes to suppressing the difficulty of the white ink 3 flowing from point P23 towards point P22 via the second channel 60A in the processing of S53.

[0264] Furthermore, compared to the case where the width W13 is greater than the width W11 or width W12, the number of narrow portions in the mold for forming the FE joint 36 is reduced. Therefore, the printer 1 contributes to improving the strength of the mold for forming the FE joint 36.

[0265] Furthermore, the contact area between the end face 36A and the FE plate 37 is larger compared to the case where the width W13 is larger than the width W11 or width W12. Therefore, the printer 1 contributes to making it less likely for the FE plate 37 to come off the FE joint 36.

[0266] In the above embodiment, the connecting channel 72 connects point P11 and point P21 to each other. Point P11 is located upstream of damper 34A in the first supply direction of the first channel 50A. Point P21 is located upstream of damper 34B in the second supply direction of the second channel 60A. The circulation pump 721 is provided in the first circulation channel. The CPU 101 drives the circulation pump 721 and circulates the white ink 3 in the first circulation channel (S53 or S83).

[0267] Printer 1 contributes to the reliable circulation of white ink 3 in the first circulation channel through the processing in S83.

[0268] In the above embodiment, the waste liquid pump 791 is located in the waste liquid flow path 79. The first valve 501 is located upstream of point P11 in the first supply direction of the first flow path 50A. The second valve 601 is located upstream of point P21 in the second supply direction of the second flow path 60A.

[0269] With the cap 41 in the capped position, the first valve 501 open, and the second valve 601 closed, the CPU 101 drives the waste liquid pump 791 to flow the white ink 3 in the first supply direction through the first flow path 50A (S33). With the cap 41 in the capped position, the first valve 501 closed, and the second valve 601 open, the CPU 101 drives the waste liquid pump 791 to flow the white ink 3 in the second supply direction through the second flow path 60A (S43). Furthermore, with the first valve 501 closed and the second valve 601 closed, the CPU 101 drives the circulation pump 721 to circulate the white ink 3 in the first circulation flow path (S53).

[0270] Since the process in S53 is performed with the first valve 501 closed, the flow of white ink 3 upstream from the first valve 501 in the first flow path 50A in the first supply direction is suppressed during the execution of the process in S53. The process in S53 is performed with the second valve 601 closed. Therefore, the flow of white ink 3 upstream from the second valve 601 in the second flow path 60A in the second supply direction is suppressed during the execution of the process in S53. Thus, the printer 1 contributes to suppressing a shortage of the flow rate of white ink 3 necessary for ink circulation. In other words, the printer 1 contributes to suppressing deterioration of circulation performance.

[0271] In the above embodiment, manifold 30A guides the white ink 3 flowing through the first channel 50A in the first supply direction to the nozzle group W1. Manifold 30B guides the white ink 3 flowing through the second channel 60A in the second supply direction to the nozzle group W2. The connecting channel 74 connects manifold 30A and manifold 30B to each other. CPU 101 drives the circulation pump 721 to circulate the white ink 3 in the first circulation channel and also circulate the white ink 3 in the second circulation channel (S53 or S83).

[0272] In this case, compared to the case where the circulation of white ink 3 in the first circulation channel and the circulation of white ink 3 in the second circulation channel are performed separately, printer 1 contributes to suppressing the increase in the time required for the circulation of white ink 3. In other words, printer 1 contributes to suppressing the deterioration of circulation performance.

[0273] In the above embodiment, the white ink 3 corresponds to the "liquid" of the present invention. The nozzle group W1 corresponds to the "first nozzle" of the present invention. The first flow path 50A corresponds to the "first flow path" of the present invention. The nozzle group W2 corresponds to the "second nozzle" of the present invention. The second flow path 60A corresponds to the "second flow path" of the present invention.

[0274] Damper 34A corresponds to the "first adjustment member" of the present invention. Damper 34B corresponds to the "second adjustment member" of the present invention. Filter 38A corresponds to the "first filter" of the present invention. Filter 38B corresponds to the "second filter" of the present invention.

[0275] Point P12 corresponds to the "first connection point" of the present invention. Point P22 corresponds to the "second connection point" of the present invention. The connection channel 73 corresponds to the "first connection channel" of the present invention.

[0276] Flow channel 51A corresponds to the "first partial flow channel" of the present invention. Flow channel 61A corresponds to the "second partial flow channel" of the present invention. FE joint 36 corresponds to the "intermediate member" of the present invention. Lower end 511 corresponds to the "first downstream end" of the present invention. Lower end 611 corresponds to the "second downstream end" of the present invention.

[0277] End face 36A corresponds to the "end face" of the present invention. Flow channel 52 corresponds to the "first wall" of the present invention. Flow channel 62 corresponds to the "second wall" of the present invention. Wall 73A corresponds to the "first connecting wall" of the present invention. Wall 73B corresponds to the "second connecting wall" of the present invention.

[0278] Point P51 corresponds to the "first point" of the present invention. Point P56 corresponds to the "second point" of the present invention. Point P61 corresponds to the "third point" of the present invention. Point P66 corresponds to the "fourth point" of the present invention.

[0279] The front-to-back direction corresponds to the "width direction" of this invention. Wall 52B corresponds to the "first opposing wall" of this invention. Wall 52D corresponds to the "second opposing wall" of this invention. Wall 62B corresponds to the "third opposing wall" of this invention. Wall 62D corresponds to the "fourth opposing wall" of this invention.

[0280] Point P11 corresponds to the "third connection point" of the present invention. Point P21 corresponds to the "fourth connection point" of the present invention. Connection channel 72 corresponds to the "second connection channel" of the present invention. Circulation pump 721 corresponds to the "circulation pump" of the present invention.

[0281] CPU 101 corresponds to the "control unit" of the present invention. The processing in S53 or S83 corresponds to the "circular processing" of the present invention.

[0282] The nozzle surface 390 corresponds to the "nozzle surface" in the present invention. The cap 41 corresponds to the "cap" in the present invention. The waste liquid flow path 79 corresponds to the "waste liquid flow path" in the present invention. The waste liquid pump 791 corresponds to the "waste liquid pump" in the present invention.

[0283] The first valve 501 corresponds to the "first valve" in the present invention. The second valve 601 corresponds to the "second valve" in the present invention. The process of S33 corresponds to the "first supply process" in the present invention. The process of S43 corresponds to the "second supply process" in the present invention.

[0284] The manifold 30A corresponds to the "first manifold flow path" in the present invention. The manifold 30B corresponds to the "second manifold flow path" in the present invention. The connection flow path 74 corresponds to the "third connection flow path" in the present invention.

[0285] The present invention may be variously modified from the above embodiment. Various modified examples will be described below. Various modified examples may be combined with each other as long as no contradiction arises.

[0286] In the above embodiment, another ink may be used instead of the white ink 3.

[0287] In the above embodiment, the ink pouch 23 is a cartridge. In contrast, the printer 1 may be provided with a tank instead of the ink pouch 23. The ink pouches 25 to 28 may also be modified in the same manner as the ink pouch 23.

[0288] In the above embodiment, the ink pouch 23 may be a sub-tank. That is, the printer 1 may include a common main tank, and supply white ink from the common main tank to each of the ink pouches 23 and 24. The printer 1 may include a first main tank and a second main tank, supply white ink from the first main tank to the ink pouch 23, and supply white ink from the second main tank to the ink pouch 24.

[0289] In the above embodiment, the printer 1 may have one cartridge or one main tank instead of the ink pouches 23 and 24. The printer 1 may further have two sub-tanks, and white ink may be supplied to each of the two sub-tanks from one cartridge or one main tank. One of the sub-tanks corresponds to the ink pouch 23 shown in Figure 9.

[0290] In the above embodiment, the printer 1 may have one cartridge or one main tank instead of the ink pouches 23 and 24. The printer 1 may further have one sub-tank, and white ink may be supplied from one cartridge or main tank to one sub-tank. The sub-tank corresponds to the ink pouch 23 shown in Figure 9. Furthermore, the printer 1 may have other connection channels. The other connection channels may be connected to the connection channel 71 and to the first channel 50B and the second channel 60B, respectively, between points P1 and P2 in the connection channel 71. That is, one sub-tank may have one channel extending from the sub-tank and then be connected to nozzle groups W1 and W2, respectively, via the connection channel 71, and also to nozzle groups W3 and W4, respectively, via other connection channels.

[0291] In the above embodiment, the printer 1 may have one cartridge or one main tank instead of the ink pouches 23 and 24. The printer 1 may further have one sub-tank, and white ink may be supplied from one cartridge or main tank to one sub-tank. The sub-tank corresponds to the ink pouch 23 shown in Figure 9. Furthermore, the printer 1 may have other connection channels. The other connection channel, connection channel 71, is connected to the sub-tank and extends from the sub-tank. The other connection channel branches into a first channel 50B and a second channel 60B. The first channel 50B is connected to the sub-tank via the other connection channel. The second channel 60B is connected to the sub-tank via the other connection channel. In other words, one sub-tank may be connected to nozzle groups W1 and W2, respectively, via connection channel 71, and to nozzle groups W3 and W4, respectively, via the other connection channel.

[0292] In the above embodiment, nozzle group W1 may be a single nozzle 391. Nozzle group W2 may be a single nozzle 391.

[0293] In the above embodiment, the printer 1 may be equipped with a differential pressure valve in place of or in addition to the damper 34A. Similarly, the printer 1 may be equipped with a differential pressure valve in place of or in addition to the dampers 34B to 34D. A differential pressure valve is a type of adjustment member. A differential pressure valve comprises a spring and a valve body. In a differential pressure valve, the opening and closing state of the valve body is controlled by the biasing force of the spring in accordance with the pressure applied to the differential pressure valve. In this way, the differential pressure valve adjusts the amount of ink supplied from the differential pressure valve.

[0294] In the above embodiment, the printer 1 may omit the connection channel 71. That is, the first channel 50A and the second channel 60A may be connected directly to the ink pouch 23 without going through the connection channel 71.

[0295] In the above embodiment, the first channel 50A and the second channel 60A may be connected to different ink pouches. For example, the first channel 50A may be connected to ink pouch 23, and the second channel 60A may be connected to ink pouch 24.

[0296] In the above embodiment, nozzle group W1 and nozzle group W2 may be arranged on different heads. For example, nozzle group W1 may be arranged on head 3A and nozzle group W2 may be arranged on head 3B.

[0297] In the above embodiment, the connecting channel 73 may be formed on a member different from the FE joint 36. For example, the connecting channel 73 may be formed on the FE plate 37. The connecting channel 73 may also be formed by a tube.

[0298] In the above embodiment, the connecting channel 73 may be formed in a portion of the FE joint 36 that is different from the end face 36A. For example, the connecting channel 73 may be formed by providing a through hole in the central part of the FE joint 36 in the vertical direction.

[0299] In the above embodiment, the end face 36A does not need to be aligned vertically with each of the filters 38A to 38D.

[0300] In the above embodiment, points P51 and P56 may be located at the rear end of the flow path 52, at the left end of the flow path 52, or at the front end of the flow path 52.

[0301] In the above embodiment, points P61 and P66 may be located at the rear end of the flow path 62, at the left end of the flow path 62, or at the front end of the flow path 62.

[0302] In the above embodiment, the width W13 may be the same as the width W11, or it may be larger than the width W11. The width W13 may be the same as the width W12, or it may be larger than the width W12.

[0303] In the above embodiment, the printer 1 may omit the connection channel 73. The printer 1 may omit the connection channel 74.

[0304] In the above embodiment, the circulation pump 721 may be placed in any of the first circulation channels. For example, the circulation pump 721 may be placed in the first supply channel between points P11 and P12 in the first channel 50A. The circulation pump 721 may be placed in the second supply channel between points P21 and P22 in the second channel 60A. The circulation pump 721 may be placed in the connecting channel 73.

[0305] In the above embodiment, the printer 1 may omit the first valve 501. The printer 1 may omit the second valve 601.

[0306] In the above embodiment, the CPU 101 may drive the waste liquid pump 791 in the S33 process with both the first valve 501 and the second valve 502 open. In this case, the CPU 101 may omit the processes S41 to S43.

[0307] In the above embodiment, each of the filters 38A to 38D may be supported by the FE plate 37. Each of the filters 38A to 38D may be supported by the FE joint 36.

[0308] The filters 38A and 38B may be configured by a single filter. That is, the filters 38A and 38B may be connected to each other. Similarly, the filters 38C and 38D may be configured by a single filter. All of the filters 38A to 38D may be configured by a single filter.

[0309] In the above embodiment, the printer 1 may omit the FE plate 37.

[0310] In the above embodiment, the sum of the first predetermined amount, the second predetermined amount, and the fourth predetermined amount is preferably larger than a driving amount enough to fill the first flow path 50A and the second flow path 60A with the white ink 3. That is, it is preferable that the first flow path 50A and the second flow path 60A are filled with the white ink 3 at the time of the processing of S63.

[0311] In the above embodiment, the first predetermined amount may be smaller than a driving amount enough to fill the first flow path 50A with the white ink 3. For example, the first predetermined amount is preferably larger than a driving amount enough to fill a region from the point P2 to the point P11 with the white ink 3 in the first flow path 50A. The second predetermined amount may be smaller than a driving amount enough to fill the second flow path 60A with the white ink 3. For example, the second predetermined amount is preferably larger than a driving amount enough to fill a region from the point P2 to the point P21 with the white ink 3 in the second flow path 60A.

[0312] In the above embodiment, the CPU 101 may change the processing order within a range where no contradiction arises.

[0313] Instead of CPU101, a microcomputer, ASIC (Application Specific Integrated Circuits), FPGA (Field Programmable Gate Array), etc., may be used as the processor. The main processing may be distributed among multiple processors.

[0314] Non-temporary storage media such as flash memory 102 can be any storage medium capable of retaining information regardless of the storage period. Non-temporary storage media do not necessarily include temporary storage media. Temporary storage media are, for example, transmitted signals. The control program may be downloaded, for example, from a server connected to a network (not shown), i.e., transmitted as a transmission signal, and stored in flash memory 102. In this case, the control program only needs to be stored on a non-temporary storage medium such as an HDD provided in the server. [Explanation of Symbols]

[0315] 1. Printer 30A, 30B manifold 34A, 34B dampers 36 FE joint 38A, 38B filters 41 caps 50A First channel 60A second flow path 51A, 52, 61A, 62 channel Walls 52A-52D, 62A-62D, 73A, 73B 72-74 Connection channel 79 Wastewater flow path 101 CPU 501 First Valve 601 Second valve 721 Circulation pump 791 Waste liquid pump

Claims

1. A first flow path connected to a first nozzle that discharges liquid, A second flow path connected to a second nozzle that discharges the aforementioned liquid, A first adjusting member, which is a damper or differential pressure valve, is arranged in the first flow path. A second adjusting member, which is a damper or differential pressure valve, is arranged in the second flow path. In the first supply direction in which the liquid flows through the first channel toward the first nozzle, a first filter is provided which is located downstream of the first adjusting member in the first channel, In the second supply direction in which the liquid flows through the second flow path toward the second nozzle, a second filter is provided in the second flow path, which is located downstream of the second adjusting member. A first connecting channel that connects a first connection point between the first adjusting member and the first filter in the first supply direction of the first channel, and a second connection point between the second adjusting member and the second filter in the second supply direction of the second channel. An inkjet printer characterized by having the following features.

2. In the first supply direction, the member is disposed between the first adjusting member and the first filter, and in the second supply direction, the member is disposed between the second adjusting member and the second filter, and comprises an intermediate member in which a first partial flow path which is part of the first flow path and a second partial flow path which is part of the second flow path are formed. The first connecting channel is formed in the intermediate member The inkjet printer according to feature 1.

3. The aforementioned intermediate member is The first partial flow path has an end face on which the first downstream end in the first supply direction and the second downstream end in the second supply direction are located. The first connecting channel is formed on the end face of the intermediate member. The inkjet printer according to feature 2.

4. The end face and the first filter are arranged in the order of the end face and the first filter from upstream to downstream in the first supply direction. The end face and the second filter are arranged in the order of the end face and the second filter from upstream to downstream in the second supply direction. The inkjet printer according to feature 3.

5. The aforementioned intermediate member is A part of the first flow channel, comprising a first wall protruding from the end face, A second wall which is part of the second flow channel and protrudes from the end face, A part of the first connecting channel, comprising a first connecting wall protruding from the end face, A part of the first connecting channel, and a second connecting wall protruding from the end face It has, The first wall extends from a first point to a second point around the first downstream end, as viewed from the direction in which the first wall protrudes from the end face. The second wall extends from a third point to a fourth point around the second downstream end, as viewed from the direction in which the second wall protrudes from the end face. The first connecting wall is connected to the first wall at the first point and to the second wall at the third point. The second connecting wall is connected to the first wall at the second point and to the second wall at the fourth point, The first connecting wall and the second connecting wall face each other with a gap between them. The inkjet printer according to feature 3.

6. The first point and the second point are, respectively, located at the end of the first wall in the direction from the first wall toward the second wall. The third and fourth points are located at the end of the second wall in the direction from the second wall toward the first wall. The inkjet printer according to feature 5.

7. The width direction is the direction in which the first connecting wall and the second connecting wall face each other. The first wall includes a first opposing wall and a second opposing wall that face each other in the width direction, The second wall includes a third opposing wall and a fourth opposing wall that face each other in the width direction, In the width direction, the width between the first connecting wall and the second connecting wall is smaller than the width between the first opposing wall and the second opposing wall in the width direction, and smaller than the width between the third opposing wall and the fourth opposing wall in the width direction. The inkjet printer according to feature 6.

8. A second connecting channel that connects a third connection point in the first channel upstream of the first adjusting member in the first supply direction and a fourth connection point in the second channel upstream of the second adjusting member in the second supply direction, A circulation pump provided in the first circulation channel including the first channel, the second channel, the first connecting channel, and the second connecting channel, Control unit and Equipped with, The control unit, An inkjet printer according to any one of claims 1 to 7, characterized in that it drives the circulation pump and performs a circulation process to circulate the liquid in the first circulation channel.

9. A cap that contacts the nozzle surface on which the first nozzle and the second nozzle are arranged, and switches between a capped state that covers the first nozzle and the second nozzle and an uncapped state that is separated from the nozzle surface, A waste liquid pump is provided in the waste liquid flow path connected to the cap, A first valve is located upstream of the third connection point in the first supply direction of the first flow path, A second valve located upstream of the fourth connection point in the second supply direction of the second flow path, Equipped with, The control unit, With the cap in the capped state, the first valve open, and the second valve closed, the waste liquid pump is driven to flow the liquid in the first supply direction through the first flow path in a first supply process, With the cap in the capped state, the first valve closed, and the second valve open, the waste liquid pump is driven, and the liquid is flowed in the second supply direction through the second flow path in a second supply process. Perform The control unit further, The inkjet printer according to claim 8, characterized in that, in the circulation process, the circulation pump is driven with the first valve and the second valve closed, and the liquid is circulated in the first circulation channel.

10. The first manifold passage is located downstream of the first filter in the first supply direction of the first passage, and guides the liquid flowing through the first passage in the first supply direction to the first nozzle, The second flow path is located downstream of the second filter in the second supply direction and guides the liquid flowing through the second flow path in the second supply direction to the second nozzle, A third connecting channel that connects the first manifold channel and the second manifold channel to each other. Equipped with, The control unit, The inkjet printer according to claim 8, characterized in that, in the circulation process, the circulation pump is driven, the liquid is circulated in the first circulation channel, and the liquid is circulated in a second circulation channel including the first channel, the second channel, the second connecting channel, and the third connecting channel.

11. A first flow path connected to a first nozzle that discharges liquid, A second flow path connected to a second nozzle that discharges the aforementioned liquid, A first adjusting member, which is a damper or differential pressure valve, is arranged in the first flow path. A second adjusting member, which is a damper or differential pressure valve, is arranged in the second flow path. In the first supply direction in which the liquid flows through the first channel toward the first nozzle, a first filter is provided which is located downstream of the first adjusting member in the first channel, In the second supply direction in which the liquid flows through the second flow path toward the second nozzle, a second filter is provided in the second flow path, which is located downstream of the second adjusting member. A first connecting channel that connects a first connection point between the first adjusting member and the first filter in the first supply direction of the first channel, and a second connection point between the second adjusting member and the second filter in the second supply direction of the second channel. An inkjet head characterized by having the following features.

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