JP7501706B2 - Liquid ejection device - Google Patents

Description

The present invention relates to a liquid ejection device that is suitable for long-term storage after discontinuing use.

As an example of a liquid ejection device that ejects liquid from nozzles in a head to print on a sheet, the inkjet recording device described in Patent Document 1 is known. The inkjet recording device in Patent Document 1 uses a first ink and a second ink with different specific gravities. The first ink is an ink used for image recording. The second ink is an ink that is used to replace the first ink when it has not been used for a long period of time.

JP 2012-25822 A

The first ink described in Patent Document 1 is a so-called pigment ink, and is suitable for recording images on plain paper or glossy paper. The second ink is used to wash the first ink. On the other hand, for recording media that are not permeable to moisture, such as coated paper with a coating applied to the image recording surface or a sheet with a synthetic resin layer, the ink is required to dry quickly. If the ink ejected onto the recording media does not dry quickly, the recorded image will be disturbed when the ink on the recording media comes into contact with a member such as a roller. On the other hand, ink with excellent quick-drying properties is prone to solidification in the nozzles and flow paths of the head. In particular, ink is prone to solidification when the device has not been used for a long period of time and ink remains in the head or flow paths.

The object of the present invention is to provide a storage liquid suitable for storing a liquid ejection device that uses ink with excellent quick-drying properties.

(1) The liquid ejection device according to the present invention includes a cartridge mounting section in which a cartridge that stores liquid is mounted, a head that is connected to the cartridge mounting section so that liquid can flow therethrough and ejects liquid from nozzles that are openings in a nozzle face, and an ejection mechanism that ejects liquid from the nozzles of the head, the liquid being at least ink, a storage liquid, or a mixture thereof, and the cartridges include a first cartridge that stores ink and a second cartridge that stores the storage liquid. The ink includes a pigment, resin particles, an organic solvent, a surfactant, and water. The storage liquid includes a water-soluble polymer, an organic solvent, a surfactant, and water.

It has excellent substitution properties, allowing it to replace ink that dries quickly on the recording medium with a storage liquid, and also has excellent redispersibility, allowing it to redisperse solidified ink. In this specification, "liquid" includes ink, storage liquid, and a mixture of ink and storage liquid.

(2) The liquid discharge device may further include a controller, and the controller may execute a first discharge process of driving the discharge mechanism to discharge a first liquid from the nozzles of the head, and a second discharge process of driving the discharge mechanism to discharge a storage liquid from the nozzles of the head when a second cartridge is attached to the cartridge attachment section.

The user can replace the ink in the head with storage liquid at any time. This allows the liquid ejection device to be stored according to the user's planned use.

(3) The liquid ejection device further includes a tank connected to the cartridge mounting section by a first flow path, and a second flow path that supplies liquid from the tank to the head, and the controller may further execute a return process that returns ink from the tank to the first cartridge mounted in the cartridge mounting section through the first flow path when the liquid ejection device is in storage mode.

The ink in the tank is returned to the first cartridge by the return process, so less ink is wasted during storage. It also makes it easier to replace the ink in the head and flow path with storage liquid.

(4) The controller may transition the liquid discharge device to the storage mode in response to receiving a predetermined instruction command while the first cartridge is attached to the cartridge attachment section.

(5) In the return process, the controller may determine whether the first cartridge is attached to the cartridge attachment portion based on the identification information acquired from the first cartridge.

(6) The liquid discharge device may further include a third flow path that discharges liquid from the head to the tank, and the controller may further execute, prior to the second discharge process, a preservation liquid supply process that supplies preservation liquid from the second cartridge to the tank while the second cartridge is mounted in the cartridge mounting section, and a preservation liquid circulation process that circulates the preservation liquid stored in the tank between the head and the tank via the second flow path and the third flow path.

(7) The controller may further execute an ink circulation process to circulate ink stored in the tank between the head and the second flow path and the third flow path when the first cartridge is mounted in the cartridge mounting section.

(8) The controller may further determine whether the second cartridge is attached to the cartridge attachment portion based on the identification information acquired from the second cartridge during the second ejection process.

(9) The controller may repeat the storage solution circulation process and the second discharge process multiple times.

(10) The discharge mechanism has a cap that contacts the nozzle face in a covering position and is spaced apart from the nozzle face in a retracted position, and a fourth flow path that communicates with the internal space of the cap, and the controller may further perform a cleaning process in which a cleaning liquid is circulated through the internal space of the cap and the fourth flow path.

(11) After executing the second discharge process, the controller may further store storage information in memory indicating that the device is in storage and turn off the power.

(12) The controller may further drive the discharge mechanism to discharge the preservation liquid from the nozzles of the head when storage information is stored in the memory and the first cartridge is mounted in the cartridge mounting section.

(13) It is preferable that the viscosity of the ink is greater than the viscosity of the storage liquid.

(14) The surfactant contained in the preservative solution is preferably an anionic surfactant.

(15) The weight-average molecular weight of the water-soluble polymer contained in the storage solution is preferably within the range of 8,500 to 20,000.

(16) The water-soluble polymer contained in the preservative solution preferably contains an aromatic alkyl group or a lactam group in its structure.

(17) It is preferable that the organic solvent contained in the ink contains a glycol ether having a propylene oxide group, and that the organic solvent contained in the storage solution contains a glycol ether having an ethylene oxide group.

(18) Of the organic solvents contained in the ink, it is preferable that the organic solvent that exists as a liquid on its own at 25°C is 10% by weight or less of the total amount of liquid.

(19) The resin particles contained in the ink are preferably acrylic resin.

(20) The ink set according to the present invention comprises an ink containing a pigment, resin particles, an organic solvent, a surfactant, and water, and a storage liquid containing a water-soluble polymer, an organic solvent, a surfactant, and water.

According to the present invention, a liquid discharge device that uses ink with excellent quick-drying properties can be stored for a long period of time using a preservative.

FIG. 1 is a perspective view showing the appearance of an image recording device 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1, showing a state in which the head 38 is in the recording position, the first support mechanism 51 is in the first position, and the maintenance mechanism 60 is in the standby position. FIG. 3 is a cross-sectional view showing a state in which the upper housing 31 in FIG. 2 is in the open position. FIG. 4 is a bottom view of the head 38. FIG. 5 is a perspective view of the maintenance mechanism 60. FIG. 6 is a bottom view of the maintenance mechanism 60. FIG. 7 is a cross-sectional view of the liquid flow path 153 of the support base 61 cut along a plane parallel to the flow direction of the liquid flow path 153 . FIG. 8 is a cross-sectional view of the caps 62A, 62B, and 62C in the maintenance position. FIG. 9 is a schematic diagram showing the ink circuit 113. FIG. 10 is a block diagram of the image recording device 100. As shown in FIG. FIG. 11 is a cross-sectional view taken along line II-II of FIG. 1, showing a state in which the head 38 is in the capped position, the first support mechanism 51 is in the first attitude, and the maintenance mechanism 60 is in the maintenance position. FIG. 12 is a cross-sectional view taken along line II-II of FIG. 1, showing a state in which the head 38 is in the wiped position, the first support mechanism 51 is in the first posture, and the maintenance mechanism 60 is in the wiping position. 13 is a cross-sectional view showing the II-II section of FIG. 1, and shows the state in which the head 38 is in the recording position, the first support mechanism 51 is in the second posture, and the maintenance mechanism 60 is in a position supported by the first support mechanism 51. FIG. 14 is a cross-sectional view taken along line II-II of FIG. 1, showing a state in which the head 38 is in the recording position, the first support mechanism 51 is in the second posture, and the maintenance mechanism 60 is in the standby position. FIG. 15 is a flowchart showing the storage process. FIG. 16 is a flowchart showing the storage process. FIG. 17 is a flowchart showing the return process. FIG. 18 is a flowchart showing the return process.

The following describes a preferred embodiment of the present invention. Note that this embodiment is merely one embodiment of the present invention, and it goes without saying that the embodiment can be changed without changing the gist of the present invention. In the following description, the direction is expressed as the progress from the start point of the arrow to the end point, and the direction is expressed as the movement on the line connecting the start point and end point of the arrow. In the following description, the up-down direction 7 is defined based on the state in which the image recording device 100 is installed and ready for use (the state in FIG. 1), the front-rear direction 8 is defined with the side where the discharge port 33 is provided as the near side (front), and the left-right direction 9 is defined when the image recording device 100 is viewed from the near side (front).

[External Configuration of Image Recording Apparatus 100]
An image recording apparatus 100 (an example of a liquid discharging apparatus) shown in FIG. 1 records an image on a sheet S forming a roll body 37 (see FIG. 2) by an inkjet recording method.

As shown in FIG. 1, the image recording device 100 includes a housing 30. The housing 30 includes an upper housing 31 and a lower housing 32. The upper housing 31 and the lower housing 32 are generally rectangular shaped overall, and are large enough to be placed on a table. In other words, the image recording device 100 is suitable for use while placed on a table. Of course, the image recording device 100 may also be used while placed on the floor or a rack.

As shown in FIG. 2, the housing 30 is divided from the outside into an internal space 31A inside the upper housing 31 and an internal space 32A inside the lower housing 32.

As shown in Figs. 2 and 3, the upper housing 31 is rotatably supported by the lower housing 32. The upper housing 31 can be rotated around a rotation axis 15 provided at the rear lower end and extending in the left-right direction 9 between a closed position shown in Fig. 2 and an open position shown in Fig. 3.

As shown in FIG. 1, a slit-shaped discharge port 33 that is long in the left-right direction 9 is formed on the front surface 32F of the lower housing 32. A sheet S (see FIG. 2) on which an image has been recorded is discharged from the discharge port 33.

An operation panel 44 is provided on the front surface 31F of the upper housing 31. A user inputs to the operation panel 44 to operate the image recording device 100 and to confirm various settings. The operation panel 44 has a display section 44A that indicates that a cover member 82, which will be described later, is attached to the support member 81.

[Internal configuration of image recording device 100]
As shown in Fig. 2, the internal spaces 31A and 32A are provided with the holder 35, tensioner 45, conveyor roller pair 36, conveyor roller pair 40, head 38, first support mechanism 51, heater 39, support portion 46, second support mechanism 52, CIS 25, cutter unit 26, ink tank 34, cleaning liquid tank 76, waste liquid tank 77, maintenance mechanism 60, wiper cleaning mechanism 80, and controller 130 (see Fig. 10). Although not shown in Fig. 2, the internal space 32A is provided with the controller 130. The controller 130 controls the operation of the image recording device 100.

A partition wall 41 is provided in the internal space 32A. The partition wall 41 divides the rear lower part of the internal space 32A to define the sheet storage space 32C. The sheet storage space 32C is surrounded by the partition wall 41 and the lower housing 32.

A roll body 37 is accommodated in the sheet accommodation space 32C. The roll body 37 has a core tube and a long sheet S. The sheet S is wound around the core tube in a roll shape in the circumferential direction of the axis of the core tube.

As shown in FIG. 2, a holder 35 extending along the left-right direction 9 is located in the sheet storage space 32C. When installed, the holder 35 supports the roll body 37 so that the axis of the core tube of the roll body 37 is aligned with the left-right direction 9 and the roll body 37 can rotate circumferentially around the axis. The holder 35 rotates by the driving force transmitted from the conveying motor 53 (see FIG. 10). As the holder 35 rotates, the roll body 37 supported by the holder 35 also rotates.

As shown in FIG. 2, the sheet storage space 32C opens upward at the rear. A gap 42 is formed between the partition 41 and the rear surface 32B, i.e., above the rear end of the roll body 37. As the conveying roller pair 36, 40 rotates, the sheet S is pulled upward from the rear end of the roll body 37 and guided to the tensioner 45 through the gap 42.

The tensioner 45 is located at the rear of the internal space 32A and above the partition wall 41. The tensioner 45 has an outer peripheral surface 45A that faces the outside of the lower housing 32. The upper end of the outer peripheral surface 45A is located at approximately the same vertical position as the nip D of the conveying roller pair 36 in the vertical direction 7.

The sheet S pulled out from the roll body 37 is hung and abuts against the outer peripheral surface 45A. The sheet S curves forward along the outer peripheral surface 45A, extends in the conveying direction 8A, and is guided to the conveying roller pair 36. The conveying direction 8A is forward along the front-rear direction 8.

The pair of conveying rollers 36 is located in front of the tensioner 45. The pair of conveying rollers 36 includes a conveying roller 36A and a pinch roller 36B. The conveying roller 36A and the pinch roller 36B come into contact with each other at a vertical position roughly the same as the upper end of the outer peripheral surface 45A to form a nip D.

The conveying roller pair 40 is located in front of the conveying roller pair 36. The conveying roller pair 40 has a conveying roller 40A and a pinch roller 40B. The conveying roller 40A and the pinch roller 40B come into contact with each other at a vertical position roughly the same as the upper end of the outer peripheral surface 45A to form a nip.

The conveying rollers 36A and 40A are rotated by a driving force transmitted from a conveying motor 53 (see FIG. 10). The conveying roller pair 36 rotates while nipping the sheet S extending from the tensioner 45 in the conveying direction 8A, thereby sending the sheet in the conveying direction 8A along the conveying surface 43A of the conveying path 43 described below. The conveying roller pair 40 rotates while nipping the sheet S sent out from the conveying roller pair 36, thereby sending the sheet in the conveying direction 8A. In addition, the rotation of the conveying roller pair 36 and 40 pulls the sheet S from the sheet storage space 32C through the gap 42 toward the tensioner 45.

2, the internal space 32A is formed with a conveying path 43 extending from the upper end of the outer peripheral surface 45A to the discharge port 33. The conveying path 43 extends almost linearly along the conveying direction 8A, and is a space through which the sheet S can pass. In detail, the conveying path 43 extends in the conveying direction 8A and the left-right direction 9 and is along a conveying surface 43A that is long in the conveying direction 8A. In FIG. 2, the conveying surface 43A is indicated by a two-dot chain line indicating the conveying path 43. The conveying path 43 is partitioned by a guide member (not shown) located apart in the vertical direction 7, the head 38, the conveying belt 101, the support portion 46, the heater 39, and the like. In other words, the head 38, the conveying belt 101, the support portion 46, and the heater 39 are located along the conveying path 43.

The head 38 is located above the transport path 43 and downstream of the transport roller pair 36 in the transport direction 8A. The head 38 has a plurality of nozzles 38A that open in a nozzle surface 50 (see FIG. 4). Ink is ejected downward from the plurality of nozzles 38A toward the sheet S supported by the transport belt 101. This causes an image to be recorded on the sheet S. The configuration of the head 38 will be described later.

The first support mechanism 51 is located below the conveying path 43 and downstream of the conveying roller pair 36 in the conveying direction 8A. The first support mechanism 51 faces the head 38 below the head 38. The first support mechanism 51 has a conveying belt 101 and a support member 104. The conveying belt 101 supports the sheet S that is conveyed by the conveying roller pair 36 in the conveying direction 8A and positioned directly below the head 38. The conveying belt 101 conveys the supported sheet S in the conveying direction 8A. The support member 104 is capable of supporting the maintenance mechanism 60.

The first support mechanism 51 includes a conveyor belt 101, a drive roller 102, a driven roller 103, a support member 104, a gear 105, and a gear 106. Note that the teeth of the gears 105 and 106 are not shown in each figure.

The driving roller 102 and the driven roller 103 are rotatably supported by a support member 104. The driving roller 102 and the driven roller 103 are spaced apart from each other in the front-rear direction 8 (conveying direction 8A). The conveying belt 101 is an endless belt. The conveying belt 101 is stretched around the driving roller 102 and the driven roller 103. The conveying belt 101 is disposed within the conveying path 43 in the left-right direction 9.

The driving roller 102 rotates by the driving force provided by the conveying motor 53 (see FIG. 10), and rotates the conveying belt 101. The rotation of the conveying belt 101 causes the driven roller 103 to rotate. The conveying belt 101 has a conveying surface 108. The conveying surface 108 is the upper part of the outer circumferential surface of the conveying belt 101, and extends along the conveying direction 8A. The conveying surface 108 faces the nozzle 38A of the head 38 across the conveying path 43. The conveying surface 108 applies a conveying force to the sheet S while supporting the sheet S conveyed between the conveying roller pair 36, 40 from below. As a result, the conveying belt 101 conveys the sheet S located on the conveying path 43 in the conveying direction 8A along the conveying surface 108.

The support member 104 has a shaft 109A. The shaft 109A is rotatably supported by the lower housing 32. The shaft 109A extends in the left-right direction 9 (a direction perpendicular to the conveying direction 8A and parallel to the nozzle surface 50 of the ejection module 49). The shaft 109A is provided upstream of the drive roller 102 in the conveying direction 8A. The shaft 109A is located below the conveying roller pair 36.

The shaft 109A rotates by receiving a driving force from the shaft motor 59 (see FIG. 10). When the shaft 109A rotates, the support member 104 rotates around the shaft 109A. The rotation tip 51A of the first support mechanism 51 is located downstream of the shaft 109A in the conveying direction 8A.

The support member 104 can be changed between a first position (see FIG. 2) parallel to the nozzle surface 50 of the ejection module 49 and a second position (see FIG. 13) in which the support member 104 is tilted from the first position around the axis 109A, with the tip 51A of the rotation being positioned below the axis 109.

As shown in FIG. 2, when the first support mechanism 51 is in the first position, the conveying surface 108 of the conveying belt 101 extends along the front-rear direction 8. This allows the conveying belt 101 to convey the sheet S located in the conveying path 43 forward and send it to the support portion 46.

As shown in FIG. 13, when the first support mechanism 51 is in the second position, the conveying surface 108 of the conveying belt 101 extends along an inclined direction 6 that slopes downward as it moves forward. The inclined direction 6 is perpendicular to the left-right direction 9 and intersects with the conveying direction 8A.

As shown in FIG. 2, the gears 105 and 106 are rotatably supported by the support member 104 of the first support mechanism 51. The gear 106 is connected to the first motor 55 (see FIG. 10) directly or via another gear, and is provided with a driving force from the first motor 55.

The heater 39 is located downstream of the head 38 in the conveying direction 8A below the conveying path 43 and upstream of the conveying roller pair 40 in the conveying direction 8A. The heater 39 is supported by the frame in front of the first support mechanism 51 and extends in the left-right direction 9. The heater 39 has a heat transfer plate (not shown) and a film heater (not shown). The heat transfer plate is made of metal and has a support surface that extends in the front-rear and left-right directions at approximately the same vertical position as the conveying surface 108 of the conveyor belt 101. The sheet S sent out from the first support mechanism 51 is conveyed forward on the support surface of the heat transfer plate. The film heater is fixed to the lower surface of the heat transfer plate and generates heat under the control of the controller 130. This heat is transferred to the sheet S on the heat transfer plate via the heat transfer plate. The heat from the heater 39 is also collected by a duct 145 arranged above the heater 39.

The duct 145 is located above the conveying path 43, downstream of the conveying direction 8A of the head 38 and upstream of the conveying roller pair 40.

The support section 46 is located below the transport path 43. The support section 46 is located downstream of the head 38 and the first support mechanism 51 in the transport direction 8A. The heater 39 is located at the rear of the support section 46. The front of the support section 46 faces the transport roller 40A. The support section 46 is located upstream of the cutter unit 26 in the transport direction 8A.

The support part 46 is supported by the lower housing 32 so as to be rotatable around an axis (not shown) extending in the left-right direction 9. As shown in FIG. 3, when the upper housing 31 is in the open position, the support part 46 can be rotated between a laid-down position shown by a solid line in FIG. 3 and an upright position shown by a dashed line in FIG. 3.

When the support portion 46 is in the collapsed position, the pivot tip 46B of the support portion 46 is located forward of the pivot base end 46A (downstream in the conveying direction 8A). When the support portion 46 is in the collapsed position, the support portion 46 constitutes part of the conveying path 43 and can support the sheet S conveyed in the conveying direction 8A by the conveying belt 101. When the support portion 46 is in the upright position, the pivot tip 46B of the support portion 46 is located higher than when the support portion 46 is in the collapsed position, and the maintenance mechanism 60 can be exposed to the outside. The shaft of the support portion 46 is provided at the rear end of the support portion 46 and extends in the left-right direction 9.

The second support mechanism 52 is supported by the lower housing 32 so as to be movable in an orthogonal direction 10 perpendicular to the tilt direction 6 and the left-right direction 9. The second support mechanism 52 is capable of supporting the maintenance mechanism 60. The second support mechanism 52 is disposed so as to extend in the tilt direction 6 as a whole, and is capable of moving in a direction toward and away from the wiper cleaning mechanism 80 by a ball screw (not shown). The second support mechanism 52 supports the maintenance mechanism 60, and slidably supports the movement of the maintenance mechanism 60.

Gears 118, 119, and 120 are rotatably supported by the main body 115 of the second support mechanism 52. Gear 120 meshes with gears 118 and 119. When gear 120 rotates, gears 118 and 119 rotate in the same direction. Gear 120 is connected to the second motor 56 (see FIG. 10) directly or via other gears, and is provided with driving force from the second motor 56. Gears 118 and 119 can mesh with rack 154 of the maintenance mechanism 60 located in the opposing position.

The CIS 25 is located above the conveying path 43 and downstream of the conveying roller pair 40 in the conveying direction 8A. The CIS 25 can read the image on the printing surface of the sheet.

The cutter unit 26 is located above the transport path 43 and downstream of the CIS 25 in the transport direction 8A. The cutter unit 26 has a cutter 28 mounted on a cutter carriage 27. The movement of the cutter 28 cuts the sheet S located on the transport path 43 in the left-right direction 9.

The mounting case 110 (an example of a cartridge mounting section) is located near the front and bottom ends of the lower housing 32 and has a box shape that opens toward the front. An ink tank 34 (an example of a first cartridge) is inserted backward into the mounting case 110. An ink needle 112 extending forward is located on the rear end surface 111 of the mounting case 110. The front end of the ink needle 112 is open, and the rear end is connected to an ink circuit 113 (see FIG. 9). The ink circuit 113 connects the internal space of the ink needle 112 to the head 38 so that ink can flow through it. When the ink tank 34 is mounted in the mounting case 110, the ink needle 112 is inserted into the outlet of the ink tank 34. As a result, the ink stored in the ink tank 34 is supplied to the head 38 through the ink needle 112 and the ink circuit 113. The configuration of the ink circuit 113 will be described later. A contact 114 is located on the end surface 111. When the ink tank 34 is attached to the mounting case 110, the contacts 114 are electrically connected to the IC board 70 of the ink tank 34. The controller 130 can access the storage area of the IC board 70 through the contacts 114.

The ink tank 34 stores ink. Ink is a liquid that contains pigments and the like. The internal space of the ink tank 34 is a storage chamber that stores the ink. The storage chamber may be one that is connected to the outside atmosphere, or may be a bag-like structure such as a pouch that can contract as ink flows out. Ink is supplied to the head 38 from the ink tank 34 mounted in the mounting case 110 through the ink circuit 113. An IC board 70 is located on the rear surface of the ink tank 34. The IC board 70 stores identification information indicating that it is an ink tank 34 in a memory area.

The preservation liquid tank 11 (an example of a second cartridge) shown in FIG. 9 has a similar configuration to the ink tank 34, except that the liquid stored therein is preservation liquid. The preservation liquid tank 11 can also be attached to the mounting case 110. Preservation liquid is supplied to the head 38 from the preservation liquid tank 11 attached to the mounting case 110 through the ink circuit 113. An IC board 12 is located on the rear surface of the preservation liquid tank 11. The IC board 12 stores identification information in a memory area that indicates that it is a preservation liquid tank 11.

As shown in FIG. 2, the cleaning liquid tank 76 stores cleaning liquid. The cleaning liquid is for cleaning the nozzle 38A of the head 38. The cleaning liquid tank 76 is located below the second support mechanism 52 described later. The internal space of the cleaning liquid tank 76 is a storage chamber for storing ink. The storage chamber may be connected to the outside and the atmosphere, or may be a bag-like container such as a pouch that can contract as ink flows out. The waste liquid tank 77 is a container from which the cleaning liquid is discharged and is connected to the outside and the atmosphere. Note that the cleaning liquid tank 76 and the waste liquid tank 77 may be detachable from the image recording device 100, similar to the ink tank 34. The waste liquid tank 77 may be provided in the same housing as the cleaning liquid tank 76. In that case, the cleaning liquid may be contained in a pouch, and the waste liquid may be stored in the internal space of the housing of the tank. The cleaning liquid tank 76 may be composed of a main tank in which the cleaning liquid is stored, and a sub-tank in which the cleaning liquid supplied from the main tank is stored.

The maintenance mechanism 60 is used to perform maintenance on the head 38. The maintenance mechanism 60 is configured to be movable, and is moved to directly below the head 38 when maintenance on the head 38 is performed (see Figures 11 and 12).

Maintenance of the head 38 includes purging, cap cleaning, and wiping. As shown in FIG. 11, the purging process is a process in which the nozzle surface 50 is covered with a cap 62 of the maintenance mechanism 60 (described later) and ink is sucked from the nozzles 38A by a suction pump 74. The cap cleaning process is a process in which the nozzle surface 50 of the head 38 is cleaned with cleaning liquid sent into the internal spaces 67A, 67B, and 67C of the cap 62 while the nozzle surface 50 is covered with the cap 62. As shown in FIG. 12, the wiping process is a process in which the nozzle surface 50 of the head 38 is wiped with a sponge wiper 64 of the maintenance mechanism 60 (described later). The configuration of the maintenance mechanism 60 will be described later.

The wiper cleaning mechanism 80 is for cleaning the cap 62 and rubber wiper 63 of the maintenance mechanism 60. The maintenance mechanism 60 is moved directly below the wiper cleaning mechanism 80 when cleaning the cap 62 and rubber wiper 63. The surface of the wiper cleaning mechanism 80 that faces the maintenance mechanism 60 is formed of a sponge and holds the maintenance liquid. The wiper cleaning mechanism 80 can come into contact with the lip 66 and rubber wiper 63 that are located in the retracted position. In this way, the wiper cleaning mechanism 80 wipes off ink adhering to the lip 66 of the cap 2 and the rubber wiper 63.

[Head 38]
2 and 4, the head 38 has a generally rectangular parallelepiped shape that is long in the left-right direction 9. The head 38 includes a frame 48 and three ejection modules 49A, 49B, and 49C. Hereinafter, the three ejection modules 49A, 49B, and 49C will be collectively referred to as the ejection modules 49. Note that the number of ejection modules 49 is not limited to three and may be, for example, one.

As shown in Figures 2 and 4, the discharge module 49 is supported by the frame 48. The lower surface of the discharge module 49 is exposed downward. The discharge module 49 is disposed within the conveying path 43 in the left-right direction 9.

As shown in FIG. 4A, the discharge modules 49A and 49B are arranged at the same position in the conveying direction 8A. The discharge modules 49A and 49B are arranged at an interval in the left-right direction 9. The discharge module 49C is arranged downstream of the discharge modules 49A and 49B in the conveying direction 8A. The discharge module 49C is arranged between two adjacent discharge modules 49A and 49B in the left-right direction 9. The left end of the discharge module 49C is located to the left of the right end of the discharge module 49A. The right end of the discharge module 49C is located to the right of the left end of the discharge module 49B. In other words, the end of the discharge module 49C overlaps with the ends of the discharge modules 49A and 49B in the left-right direction 9.

Each ejection module 49A, 49B, 49C has a plurality of nozzles 38A. Each nozzle 38A opens in a nozzle surface 50 of each ejection module 49A, 49B, 49C. The nozzle surface 50 is a surface that extends in the front-rear direction 8 and the left-right direction 9. As described above, ink is ejected downward from the plurality of nozzles 38A toward the sheet S supported by the conveyor belt 101 of the first support mechanism 51, and an image is recorded on the sheet S.

As shown in FIG. 4B, the ejection module 49 has an inflow port 22 and an outflow port 23 connected to the ink circuit 113. The inflow port 22 and the outflow port 23 are each connected to a manifold 24. The manifold 24 is connected to a plurality of nozzles 38A. The ink that flows into the manifold 24 through the inflow port 22 is ejected to the outside through the nozzles 38A by driving a piezoelectric element (not shown) positioned corresponding to each nozzle 38A. The ink in the manifold 24 can be circulated through the inflow port 22 and the outflow port 23.

The head 38 moves along the vertical direction 7 to the recording position shown in Figs. 13 and 14, the capped position shown in Fig. 11, the wiped position shown by the solid line in Fig. 12, and the uncapped position shown by the dashed line in Fig. 12. The recording position is the position of the head 38 when an image is recorded on the sheet S supported by the conveyor belt 101. The capped position is the position of the head 38 when the ejection module 49 is covered by the cap 62 of the maintenance mechanism 60. The capped position is a position above the recording position (a position farther from the first support mechanism 51 than the recording position). The wiped position is the position of the head 38 when the sponge wiper 64 of the maintenance mechanism 60 wipes the nozzle surface 50 of the ejection module 49. The wiped position is a position above the capped position. The uncapped position is the position of the head 38 when the head 38 is completely separated from the maintenance mechanism 60. The uncapped position is a position above the wiped position.

2, the head 38 is moved by a ball screw 29. The ball screw 29 includes a screw shaft 29A and a nut member 29B. The screw shaft 29A is supported by the lower housing 32 so as to be rotatable about an axis along the vertical direction 7. The screw shaft 29A rotates by receiving a driving force from the head motor 54 (see FIG. 10). The nut member 29B moves upward by the forward rotation of the screw shaft 29A and moves downward by the reverse rotation of the screw shaft 29A. Note that the configuration for moving the head 38 up and down is not limited to the configuration using the ball screw 29, and various known configurations can be adopted.

[Maintenance mechanism 60]
5, the maintenance mechanism 60 (an example of a discharge mechanism) includes a support stand 61, a sponge wiper 64, a rubber wiper 63, and a cap 62. In the following description of the maintenance mechanism 60, it is assumed that the maintenance mechanism 60 is supported by the first support mechanism 51 and the second support mechanism 52 in the second posture.

The support base 61 has a base 61A, a main body 61B that is placed on the base 61A, and a wiper holder 61C that holds the sponge wiper 64 and the rubber wiper 63 on the main body 61B. The base 61A has a box-like shape that is open at the top. The base 61A has a first bottom plate 121, a first edge plate 122 that stands upward from the periphery of the first bottom plate 121, an extension piece 125, and a rack 154 (see Figure 2).

The first bottom plate 121 is flat and extends in the inclination direction 6 and the left-right direction 9. The upper and lower surfaces of the first bottom plate 121 are formed in a rectangular shape that is longer in the left-right direction 9 than in the inclination direction 6. The lower surface of the first bottom plate 121 can abut against the upper surface of the first support mechanism 51 from above. This allows the maintenance mechanism 60 to be supported by the first support mechanism 51. The lower surface of the first bottom plate 121 can abut against the upper surface of the second support mechanism 52 from above. This allows the maintenance mechanism 60 to be supported by the second support mechanism 52.

The first edge plate 122 is a rectangular frame in plan view. The extension piece 125 extends rightward from the lower end of the right wall of the first edge plate 122. The extension piece 125 extends from one end of the right wall of the first edge plate 122 in the inclination direction 6 to the other end.

As shown in FIG. 6, the rack 154 is formed on the underside of the extension piece 125. The rack 154 extends from one end of the extension piece 125 in the inclination direction 6 to near the other end. The rack 154 can face the upper surface of the first support mechanism 51 from above and below.

The rack 154 can mesh with the gear 105 of the first support mechanism 51. When the rack 154 and the gear 105 are meshed with each other, the gear 105 rotates, causing the maintenance mechanism 60 to slide along the upper surface of the first support mechanism 51.

The rack 154 can mesh with the gears 118, 119 of the second support mechanism 52. When the gear 120 rotates with the rack 154 meshing with at least one of the gears 118 and 119, the maintenance mechanism 60 slides along the upper surface of the second support mechanism 52.

As a result, the maintenance mechanism 60 can move to the standby position shown in FIG. 2, the retracted position shown by the dashed line in FIG. 12, the maintenance position shown in FIG. 11, and the wiping position shown in FIG. 12, as described below. The maintenance mechanism 60 in the maintenance position and wiping position faces the nozzle surface 50 of the ejection module 49 of the head 38 in the up-down direction 7. The maintenance mechanism 60 in the standby position and retracted position is spaced apart from the nozzle surface 50.

As shown in FIG. 5, the main body 61B is generally box-shaped with an open top. The main body 61B is fixed to the base 61A. The main body 61B includes a second bottom plate 151, a second edge plate 152 standing upward from the second bottom plate 151, and a liquid flow path 153 (see FIG. 7) that circulates the cleaning liquid stored in the cleaning liquid tank 76.

As shown in Figs. 5 and 7, the second bottom plate 151 is a flat plate extending in the inclination direction 6 and the left-right direction 9. The upper and lower surfaces of the second bottom plate 151 are formed in a rectangular shape that is longer in the left-right direction than in the inclination direction 6. The second edge plate 152 is a rectangular frame in a plan view.

As shown in FIG. 7, the liquid flow path 153 is formed on the upper surface of the second bottom plate 151. The liquid flow path 153 is a groove recessed downward from the upper surface of the second bottom plate 151 and opens upward. In a plan view, the liquid flow path 153 has a continuous U-shape that extends in the left-right direction 9 and then turns back to make a U-turn. The liquid flow path 153 extends so as to connect in series the sponge wipers 64A, 64B, and 64C that are arranged on the groove. The liquid flow path 153 has a first flow path 153A, an intermediate flow path 153B, and a second flow path 153C.

The first flow path 153A is located upstream of the liquid flow path 153 in the direction of flow of the cleaning liquid. The first flow path 153A is a portion that extends in the left-right direction 9 at the front side of the main body 61B.

The intermediate flow path 153B is located downstream of the first flow path 153A in the flow direction of the cleaning liquid. The intermediate flow path 153B extends in a forward inclined direction 5 from the downstream end of the first flow path 153A to the middle of the inclined direction 6 of the main body 61b.

The second flow path 153C is located downstream in the direction of flow of the cleaning liquid in the liquid flow path 153. The second flow path 153C extends to the right from the downstream end of the intermediate flow path 153B.

As shown in FIG. 9, an inlet 171 through which the cleaning liquid flows into the first flow path 153A is opened on the inner wall surface of the groove at the upstream end of the first flow path 153A. One end of a first supply tube 175 is connected to the inlet 171. The other end of the first supply tube 175 reaches the outside of the first support mechanism 51, is connected to the cleaning liquid tank 76, and opens at a position lower than the water level of the cleaning liquid stored in the cleaning liquid tank 76.

An outlet 174 through which the cleaning liquid flows out is opened on the inner wall surface at the downstream end of the second flow path 153C. One end of a return tube 176 is connected to the outlet 174. The other end of the return tube 176 reaches the outside of the first support mechanism 51, is connected to the cleaning liquid tank 76, and opens at a position higher than the water level of the cleaning liquid stored in the cleaning liquid tank 76. A return pump 75 is provided on the return tube 176 (see FIG. 2). The operation of the return pump 75 is controlled by the controller 130.

As shown in FIG. 5, the wiper holder 61C has a sponge wiper 64 and a rubber wiper 63. The sponge wiper 64 and the rubber wiper 63 are supported on the main body 61B by the wiper holder 61C.

[Sponge Wiper 64]
The sponge wiper 64 is made of sponge. In this embodiment, three sponge wipers 64 (64A, 64B, 64C) are provided. Hereinafter, the three sponge wipers 64A, 64B, 64C will be collectively referred to as sponge wiper 64. The sponge wiper 64 is formed in a rectangular parallelepiped shape whose length in the left-right direction 9 is longer than its lengths in the inclination direction 6 and the up-down direction 7. The length of the sponge wiper 64 in the up-down direction 7 is longer than its length in the inclination direction 6.

Sponge wiper 64A and sponge wiper 64B are arranged in first flow path 153A of liquid flow path 153. Sponge wiper 64A is arranged upstream of sponge wiper 64B. Sponge wiper 64C is arranged in second flow path 153C of liquid flow path 153.

Sponge wiper 64A, sponge wiper 64B, and sponge wiper 64C correspond to discharge module 49A, discharge module 49B, and discharge module 49C, respectively, in the up-down direction 7. Sponge wiper 64A and sponge wiper 64B are positioned at a distance from each other in the left-right direction 9. Sponge wiper 64C is positioned at a distance in the forward inclination direction 5 from sponge wipers 64A and 64B. Sponge wiper 64C is positioned midway between sponge wipers 64A and 64B in the left-right direction 9.

The sponge wiper 64A corresponds to the discharge module 49A and can face the discharge module 49A in the up-down direction 7. As shown in Figures 5 and 7, the sponge wiper 64A is disposed to the right of the center of the first flow path 153A in the left-right direction 9.

[Rubber wiper 63]
The rubber wiper 63 is made of rubber. In this embodiment, three rubber wipers (63A, 63B, 63C) are provided as the rubber wiper 63. Hereinafter, the three rubber wipers 63A, 63B, 63C will be collectively referred to as the rubber wipers 63.

The rubber wiper 63 is formed in a flat plate shape that extends in the up-down direction 7 and the left-right direction 9. The length of the rubber wiper 63 in the inclination direction 6 is shorter than the length of the sponge wiper 64 in the inclination direction 6. This makes it easier for the rubber wiper 63 to bend when it comes into contact with the nozzle surface 50 of the ejection module 49 during the wiping process. The length of the rubber wiper 63 in the left-right direction 9 is slightly longer than the length of the sponge wiper 64 in the left-right direction 9. The length of the rubber wiper 63 from the support base 61 is longer than the length of the sponge wiper 64 from the support base 61. The rubber wiper 63 is located outside the left-right direction 9 of both ends of the sponge wiper 64 in the left-right direction 9. The upper end of the rubber wiper 63 is tapered. This makes it easier for the upper end of the rubber wiper 63 to come into contact with the nozzle surface 50 of the ejection module 49 during the wiping process.

The rubber wipers 63A and 63B are disposed outside the liquid flow path 153. The rubber wipers 63A, 63B, and 63C correspond to the ejection modules 49A, 49B, and 49C in the up-down direction 7, respectively. The rubber wipers 63A, 63B, and 63C are disposed on the support base 61 at intervals in the rearward inclination direction 4 from the sponge wipers 64A, 64B, and 64C, respectively.

[Cap 62]
5, the cap 62 is supported by a support base 61. A plurality of caps 62 are provided. In this embodiment, the cap 62 is composed of three caps 62A, 62B, and 62C. Hereinafter, the three caps 62A, 62B, and 62C will be collectively referred to as cap 62.

The cap 62 is made of an elastic material such as rubber or silicone. The cap 62 has a box shape that is open at the top.

Cap 62A, cap 62B, and cap 62C can face discharge module 49A, discharge module 49B, and discharge module 49C, respectively, in the up-down direction 7. Cap 62A, cap 62B, and cap 62C are arranged at intervals in the forward inclination direction 5 from sponge wiper 64A, sponge wiper 64B, and sponge wiper 64C, respectively. When maintenance mechanism 60 is located in the maintenance position, lips 66A, 66B, and 66C (see FIG. 8) of cap 62A, cap 62B, and cap 62C abut against nozzle surface 50 and seal internal spaces 67A, 67B, and 67C. Cap 62A, cap 62B, and cap 62C have cap flow paths 68A, 68B, and 68C that communicate internal spaces 67A, 67B, and 67C with the outside, respectively. The cap flow paths 68A, 68B, and 68C have supply flow paths 20A, 20B, and 20C through which the cleaning liquid flows into the internal spaces 67A, 67B, and 67C of the caps 62, and discharge flow paths 21A, 21B, and 21C (an example of a fourth flow path) through which the cleaning liquid flows out of the internal spaces 67A, 67B, and 67C of the caps 62A, 62B, and 62C.

Hereinafter, the three lips 66A, 66B, and 66C are collectively referred to as the lip 66. Similarly, the internal spaces 67A, 67B, and 67C, the cap flow paths 68A, 68B, and 68C, the supply flow paths 20A, 20B, and 20C, and the discharge flow paths 21A, 21B, and 21C are also referred to as the internal space 67, the cap flow path 68, the supply flow path 20, and the discharge flow path 21, respectively.

8, the cap 62A corresponds to the discharge module 49A and can face the discharge module 49A in the up-down direction 7. The cap 62A is disposed at a distance from the sponge wiper 64A in the forward inclination direction 5. A supply flow path 20A through which the cleaning liquid flows into the cap 62A and a discharge flow path 21A through which the cleaning liquid flows out of the cap 62A are formed in the bottom plate 69 of the cap 62A. One end of the second supply tube 177 is connected to the supply flow path 20A of the cap 62A. The other end of the second supply tube 177 reaches the outside of the maintenance mechanism 60 and is connected to the cleaning liquid tank 76 (see FIG. 2). One end of the first waste liquid tube 178 is connected to the discharge flow path 21A. The other end of the first waste liquid tube 178 reaches the outside of the maintenance mechanism 60 and is connected to the waste liquid tank 77 (see FIG. 2).

The cap 62B corresponds to the discharge module 49B and can face the discharge module 49B in the up-down direction 7. The cap 62B is arranged at a distance from the sponge wiper 64B in the forward inclined direction 5. A supply flow path 20B through which the cleaning liquid flows into the cap 62B and a discharge flow path 21B through which the cleaning liquid flows out of the cap 62B are formed in the bottom plate 69 of the cap 62B. One end of a third supply tube 179 branched from the second supply tube 177 is connected to the supply flow path 20B. One end of a second waste liquid tube 180 is connected to the discharge flow path 21B. The other end of the second waste liquid tube 180 merges with the first waste liquid tube 178 outside the maintenance mechanism 60.

The cap 62C corresponds to the discharge module 49C and can face the discharge module 49C in the up-down direction 7. The cap 62C is disposed at a distance from the sponge wiper 64C in the forward inclined direction 5. A supply flow path 20C through which the cleaning liquid flows into the cap 62C and a discharge flow path 21C through which the cleaning liquid flows out of the cap 62C are formed in the bottom plate 69 of the cap 62C. One end of a fourth supply tube 201 branched from the second supply tube 177 is connected to the supply flow path 20C. One end of a third waste liquid tube 202 is connected to the discharge flow path 21C. The other end of the third waste liquid tube 202 joins the first waste liquid tube 178 outside the maintenance mechanism 60.

A cap cleaning valve 72 (see FIG. 9) is provided upstream of the branch point of the third supply tube 179 and the fourth supply tube 201 in the second supply tube 177. The opening and closing of the cap cleaning valve 72 is controlled by the controller 130.

The second waste liquid tube 180 and the third waste liquid tube 202 in the first waste liquid tube 178 are each provided with a suction pump 74 (see FIG. 2) upstream of the junction. The three suction pumps 74 are driven by a single suction pump motor 58 (see FIG. 10).

The total volume Ta of the supply flow path 20A, the discharge flow path 21A, the first waste liquid tube 178 upstream of the suction pump 74, and the internal space of the cap 62A is equal to the total volume Tb of the supply flow path 20B, the discharge flow path 21B, the second waste liquid tube 180 upstream of the suction pump 74, and the internal space of the cap 62B, and the total volume Tc of the supply flow path 20C, the discharge flow path 21C, the third waste liquid tube 202 upstream of the suction pump 74, and the internal space of the cap 62C (total Ta = total Tb = total Tc).

[Ink circuit 113]
9, the mounting case 110 and the ejection module 49 are connected by an ink circuit 113. The ink circuit 113 has an ink subtank 181, flow paths 182, 183, and 184, an atmospheric flow path 185, a bypass flow path 186, a refill valve 187, a purge cutoff valve 188, a bypass valve 189, an atmospheric release valve 190, a positive pressure pump 191, and a liquid level sensor 192.

The ink subtank 181 is located above the mounting case 110 in the internal space of the housing 30. The ink subtank 181 stores ink in its internal space. The internal space of the ink subtank 181 is connected to the ink needle 112 of the mounting case 110 by a flow path 182 (an example of a first flow path). When the ink tank 34 is mounted in the mounting case 110, the ink stored in the ink tank 34 can flow into the ink subtank 181 through the flow path 182. When the preservative liquid tank 11 is mounted in the mounting case 110, the preservative liquid stored in the preservative liquid tank 11 can flow into the ink subtank 181 through the flow path 182. A refill valve 187 is located in the flow path 182. The refill valve 187 is controlled by the controller 130 to open and close the flow path 182.

The internal space of the ink subtank 181 and the inlet port 22 of the ejection module 49 are connected by a flow path 183 (an example of a second flow path). The ink or storage liquid stored in the internal space of the ink subtank 181 can be supplied to the ejection module 49 through the flow path 183. A positive pressure pump 191 is located in the flow path 183. The positive pressure pump 191 is operated by the controller 130 controlling the drive of the pump motor 138 (see FIG. 10).

The internal space of the ink subtank 181 and the outlet port 23 of the ejection module 49 are connected by a flow path 184 (an example of a third flow path). The ink or storage liquid in the manifold 24 of the ejection module 49 can be discharged to the ink subtank 181 through the flow path 184. A purge shutoff valve 188 is located in the flow path 184. The purge shutoff valve 188 is controlled by the controller 130 to open and close the flow path 184.

A bypass flow path 186 connects between the positive pressure pump 191 and the inlet port 22 in the flow path 183 and between the purge shutoff valve 188 and the ink subtank 181 in the flow path 184. A bypass valve 189 is located in the bypass flow path 186. The bypass valve 189 is controlled by the controller 130 to open and close the bypass flow path 186.

The internal space of the ink subtank 181 is connected to the outside by an air flow path 185. An air release valve 190 is located in the air flow path 185. The air release valve 190 is controlled by the controller 130 to open and close the air flow path 185.

A liquid level sensor 192 is located in the ink subtank 181. The liquid level sensor 192 detects the presence or absence of ink at a predetermined height in the internal space of the ink subtank 181. The liquid level sensor 192 outputs a detection signal to the controller 130. The liquid level sensor 192 outputs an ON signal as a detection signal when ink is detected, and outputs an OFF signal as a detection signal when ink is not detected. The controller 130 determines whether the liquid level has reached a predetermined height in the internal space of the ink subtank 181 based on the detection signal output by the liquid level sensor 192.

A decompression pump 193 is connected to the ink subtank 181. The decompression pump 193 reduces the pressure in the internal space of the ink subtank 181 by discharging the gas in the internal space of the ink subtank 181 to the outside.

[Controller 130]
10, the controller 130 includes a CPU 131, a ROM 132, a RAM 133, an EEPROM 134, and an ASIC 135, which are connected by an internal bus 137. The ROM 132 stores programs for controlling various operations of the CPU 131. The RAM 133 is used as a storage area for temporarily recording data and signals used when the CPU 131 executes the programs, or as a working area for data processing. The EEPROM 134 stores settings, flags, etc. that should be retained even after the power is turned off.

The ASIC 135 is connected to the transport motor 53, head motor 54, first motor 55, second motor 56, return pump motor 47, suction pump motor 58, pump motors 138, 139, shaft motor 59, up-down drive motor 163, operation panel 44, display unit 44A, contacts 114, and liquid level sensor 192. The ASIC 135 is also connected to the cap cleaning valve 72, refill valve 187, purge shutoff valve 188, bypass valve 189, and atmospheric release valve 190. Each valve is connected to the ASIC 135 via a drive circuit for driving the valve.

The ASIC 135 generates a drive signal for rotating each motor and controls each motor based on this drive signal. Each motor rotates forward or backward according to the drive signal from the ASIC 135. The controller 130 controls the drive of the conveying motor 53 to rotate the holder 35, the conveying roller 36A, the conveying roller 40A, and the drive roller 102. The controller 130 controls the drive of the head motor 54 to rotate the screw shaft 29A and move the head 38 along the vertical direction 7. The controller 130 controls the drive of the shaft motor 59 to rotate the first support mechanism 51. The controller 130 controls the drive of the first motor 55 to rotate the gear 106 of the first support mechanism 51. The controller 130 controls the drive of the vertical drive motor 163 to rotate the screw shaft 161 and move the second support mechanism 52 along the orthogonal direction 10. The controller 130 controls the driving of the second motor 56 to rotate the gear 120 of the second support mechanism 52. The controller 130 controls the driving of the return pump motor 78 to drive the return pump 75. The controller 130 controls the driving of the suction pump motor 58 to drive the three suction pumps 74. The controller 130 controls the driving of the pump motor 138 to drive the positive pressure pump 191. The controller 130 controls the driving of the pump motor 139 to drive the decompression pump 193.

The ASIC 35 is connected to an operation panel 44, a display unit 44A, a contact 114, a liquid level sensor 192, and a piezoelectric element (not shown). The operation panel 44 outputs an operation signal to the controller 130 in response to an operation by a user. The operation panel 44 may have, for example, a push button or a touch sensor superimposed on the display. The display unit 44A displays that the cover member 82 is attached to the support member 81. The controller 130 reads or writes data from the memory area of the IC board 70 of the ink tank 34 or the IC board 12 of the storage liquid tank 11 through the contact 114. The controller 130 receives a detection signal from the liquid level sensor 192. The piezoelectric element operates when power is supplied by the controller 130 via a drive circuit (not shown). The controller 130 controls the power supply to the piezoelectric element to selectively eject ink droplets from the multiple nozzles 38A.

[ink]
The ink is described in detail below. The ink contains resin particles, a coloring material, an organic solvent, a surfactant, and water. The ink is an aqueous ink in which the resin particles, the coloring material, and the organic solvent are dissolved in water.

The ink has wettability to hydrophobic recording media such as coated paper, plastic, film, and OHP sheets, but is not limited thereto, and may be suitable for image recording on recording media other than hydrophobic recording media such as plain paper, glossy paper, and matte paper. "Coated paper" refers to plain paper with pulp as the main component, such as high-grade printing paper or medium-grade printing paper, to which a coating agent has been applied in order to improve smoothness, whiteness, gloss, etc., and specific examples include high-grade coated paper and medium-grade coated paper.

As the resin microparticles, for example, those containing at least one of methacrylic acid and acrylic acid as a monomer can be used, and for example, commercially available products may be used. The resin microparticles may further contain, for example, styrene, vinyl chloride, etc. as a monomer. The resin microparticles may be, for example, those contained in an emulsion. The emulsion is, for example, composed of resin microparticles and a dispersion medium (for example, water, etc.). The resin microparticles are not in a dissolved state in the dispersion medium, but are dispersed within a specific particle size range. Examples of the resin microparticles include acrylic acid-based resins, maleic acid-based ester resins, vinyl acetate-based resins, carbonate-based resins, polycarbonate-based resins, styrene-based resins, ethylene-based resins, polyethylene-based resins, propylene-based resins, polypropylene-based resins, urethane-based resins, polyurethane-based resins, polyester-based resins, and copolymer resins thereof, but acrylic resins are preferable.

For example, a resin having a glass transition temperature (Tg) in the range of 0°C or more and 200°C or less is used as the resin microparticles. More preferably, the glass transition temperature (Tg) is 20°C or more and 180°C or less, and even more preferably, 30°C or more and 150°C or less.

As the emulsion, for example, commercially available products may be used. Examples of commercially available products include "Superflex (registered trademark) 870" (Tg: 71°C) and "Superflex (registered trademark) 150" (Tg: 40°C) manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Mobinyl (registered trademark) 6760" (Tg: -28°C) and "Mobinyl (registered trademark) DM774" (Tg: 33°C) manufactured by Japan Coating Resins Co., Ltd., "Polysol (registered trademark) AP-3270N" (Tg: 27°C) manufactured by Showa Denko K.K., and "Hi-Loss-X (registered trademark) KE-1062" (Tg: 112°C) and "Hi-Loss-X (registered trademark) QE-1042" (Tg: 69°C) manufactured by Seiko PMC Co., Ltd.

The average particle diameter of the resin microparticles is, for example, in the range of 30 nm to 200 nm. The average particle diameter can be measured as the arithmetic mean diameter, for example, using a dynamic light scattering particle size distribution measuring device "LB-550" manufactured by Horiba, Ltd.

The content (R) of resin microparticles in the total amount of ink is, for example, preferably in the range of 0.1 wt% to 30 wt%, more preferably in the range of 0.5 wt% to 20 wt%, and particularly preferably in the range of 1.0 wt% to 15.0 wt%. One type of resin microparticle may be used alone, or two or more types may be used in combination.

The coloring material is, for example, a pigment that can be dispersed in water by a pigment dispersion resin (resin dispersant). Examples of the coloring material include carbon black, inorganic pigments, and organic pigments. Examples of carbon black include furnace black, lamp black, acetylene black, and channel black. Examples of inorganic pigments include titanium oxide, iron oxide-based inorganic pigments, and carbon black-based inorganic pigments. Examples of organic pigments include azo pigments such as azo lake, insoluble azo pigments, condensed azo pigments, and chelate azo pigments; polycyclic pigments such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments; dye lake pigments such as basic dye lake pigments and acid dye lake pigments; nitro pigments; nitroso pigments; aniline black daylight fluorescent pigments; and the like.

The solid content of the coloring material in the total amount of ink is not particularly limited and can be appropriately determined, for example, depending on the desired optical density or saturation. The solid content of the coloring material is, for example, preferably in the range of 0.1 wt % to 20.0 wt %, more preferably in the range of 1.0 wt % to 15.0 wt %. The solid content of the coloring material is the weight of the pigment only, and does not include the weight of the resin microparticles. One type of coloring material may be used alone, or two or more types may be used in combination.

There are no particular limitations on the organic solvent, and any organic solvent can be used. Examples of organic solvents include propylene glycol, ethylene glycol, 1,2-butanediol, propylene glycol monobutyl ether, dipropylene glycol monopropyl ether, triethylene glycol monobutyl ether, 1,2-hexanediol, and 1,6-hexanediol, and glycol ethers having a propylene oxide group are preferred. Other examples of organic solvents include alkyl alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol; glycerin, ethylene glycol monomethyl (or ethyl, propyl, or butyl) ether, and diethylene glycol monomethyl (or ethyl, propyl, or butyl) ether. ) ether, triethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, tetraethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, propylene glycol monomethyl (or ethyl, propyl, butyl) ether, dipropylene glycol monomethyl (or ethyl, propyl, butyl) ether, tripropylene glycol monomethyl (or ethyl, propyl, butyl) ether, tetrapropylene glycol monomethyl (or ethyl) ether, and other lower alkyl ethers of alkylene glycols; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and the like.

The content of organic solvent in the total amount of ink is preferably 10 wt % or less, and more preferably 9 wt %, of organic solvent that exists as a liquid at 25°C.

The water is preferably ion-exchanged water or pure water. The water content of the total amount of ink is, for example, preferably in the range of 15 wt % to 95 wt %, more preferably in the range of 25 wt % to 85 wt %. The water content may be, for example, the remainder of the other components.

The ink may further contain additives known in the art, if necessary. Examples of additives include surfactants, pH adjusters, viscosity adjusters, surface tension adjusters, preservatives, antifungal agents, leveling agents, defoamers, light stabilizers, antioxidants, nozzle drying inhibitors, polymer components such as emulsions, dyes, etc. The surfactant may further contain cationic surfactants, anionic surfactants, or nonionic surfactants. For example, commercially available products may be used as these surfactants. Examples of commercially available products include "Olfine (registered trademark) E1010", "Olfine (registered trademark) E1006", "Olfine (registered trademark) E1004", "Silface SAG503A", and "Silface SAG002" manufactured by Nissin Chemical Industry Co., Ltd. The content of the surfactant in the total amount of ink is, for example, 5 wt% or less, 3 wt% or less, or 0.1 wt% to 2 wt%. Examples of viscosity adjusters include polyvinyl alcohol, cellulose, water-soluble resins, etc.

The ink can be prepared, for example, by uniformly mixing resin particles, coloring material, organic solvent, water, and other additives as necessary using a conventional method, and then removing insoluble matter using a filter or the like.

[Preservative solution]
The preservation solution contains a water-soluble polymer, a water-soluble organic solvent, a surfactant, and water.

As the water-soluble polymer, any one can be used without any particular limitation. Examples of the water-soluble polymer include polyvinylpyrrolidone and polyethylene glycol. Other water-soluble polymers include polyvinyl alcohols, polyvinylpyrrolidones, polyacrylic acids, styrene-acrylic acid copolymers, and acrylic acid-acrylic acid ester copolymers. As the water-soluble polymer, a commercially available product may be used. Examples of commercially available products include Joncryl (registered trademark) manufactured by BASF, Aqualic (registered trademark) manufactured by Nippon Shokubai Co., Ltd., and Aron (registered trademark) manufactured by Toa Gosei Co., Ltd. The water-soluble polymer preferably contains an aromatic alkyl group or a lactam group in the structure. The weight-average molecular weight of the water-soluble polymer is preferably within the range of 8,500 to 20,000, more preferably within the range of 9,000 to 15,000.

There are no particular limitations on the water-soluble organic solvent, and any solvent can be used. Examples of water-soluble organic solvents include ethylene oxide, propylene glycol, ethylene glycol, 1,2-butanediol, propylene glycol propyl ether, dipropylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, diethylene glycol monobutyl ether, 1,6-hexanediol, and the like, with glycol ethers having an ethylene oxide group being preferred. Examples of other organic solvents include alkyl alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol; glycerin, ethylene glycol monomethyl (or ethyl, propyl, or butyl) ether, and diethylene glycol monomethyl (or ethyl, propyl, or butyl) ether. ) ether, triethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, tetraethylene glycol monomethyl (or ethyl, propyl, butyl, hexyl) ether, propylene glycol monomethyl (or ethyl, propyl, butyl) ether, dipropylene glycol monomethyl (or ethyl, propyl, butyl) ether, tripropylene glycol monomethyl (or ethyl, propyl, butyl) ether, tetrapropylene glycol monomethyl (or ethyl) ether, and other lower alkyl ethers of alkylene glycols; N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and the like.

One type of water-soluble organic solvent may be used alone, or two or more types may be used in combination. The content of the water-soluble organic solvent in the total amount of the maintenance liquid is preferably, for example, in the range of 5 wt% to 50 wt%, and more preferably, in the range of 25 wt% to 35 wt%.

As the surfactant, for example, a commercially available product may be used. Examples of commercially available anionic surfactants include Sanol (registered trademark) manufactured by Lion Corporation, Emal (registered trademark) manufactured by Kao Corporation, Sandet (registered trademark) and Viewlite (registered trademark) manufactured by Sanyo Chemical Industries, Ltd. One type of anionic surfactant may be used alone, or two or more types may be used in combination. The content of the anionic surfactant in the total amount of the storage solution is preferably, for example, in the range of 0.01 wt% to 10 wt%, and more preferably, in the range of 0.1 wt% to 10 wt%.

The surfactant contained in the preservative solution may be only an anionic surfactant, or may contain a cationic surfactant and/or a nonionic surfactant in addition to the anionic surfactant.

The water is preferably ion-exchanged water or pure water. The water content in the total amount of the storage solution is, for example, 10% to 90% by mass, or 20% to 80% by mass. The water content may be, for example, the remainder of the other components.

The storage liquid preferably does not contain a colorant, but may contain a colorant. If the maintenance liquid contains a colorant, it is preferable that the amount is such that it does not affect the recorded image.

The preservative solution may further contain conventionally known additives as necessary. Examples of additives include wetting agents, pH adjusters, viscosity adjusters, surface tension adjusters, and antifungal agents. Examples of viscosity adjusters include polyvinyl alcohol, cellulose, and water-soluble resins.

The preservative solution can be prepared, for example, by uniformly mixing a water-soluble polymer, a water-soluble organic solvent, a surfactant, and water using a conventional method.

The viscosity of the storage liquid is preferably smaller than that of the ink. The viscosity of the ink and storage liquid can be measured, for example, using a cone-plate type rotational viscometer.

The operation of the maintenance mechanism 60 will be described below along with the purging process, cleaning process, wiping process, and image recording process. In this embodiment, the cleaning liquid is supplied and discharged in addition to the above processes.

[Purging and cleaning processes]
When the image recording process is not being performed, the image recording device 100 is in a standby state. In the standby state, as shown in Fig. 11, the head 38 is located in the capped position, the first support mechanism 51 is located in the first posture while supporting the maintenance mechanism 60, and the maintenance mechanism 60 is located in the maintenance position. At this time, the cap 62 covers the nozzle surface 50.

When in standby, the controller 130 executes the purge process at a predetermined timing or when an external command is received. The following describes the process when the controller 130 receives an external command to execute the purge process when the image recording device 100 is in standby.

In the purge process, the controller 130 drives the suction pump 74 with the purge shutoff valve 188 and the bypass valve 189 open and the refill valve 187, the air release valve 190, and the cap cleaning valve 72 closed. This causes the ink in the nozzle 38A to be sucked out and discharged from the internal spaces 67A, 67B, and 67C of the cap 62 through the discharge flow paths 21A, 21B, and 21C to the first waste liquid tube 178, the second waste liquid tube 180, and the third waste liquid tube 202 into the waste liquid tank 77. At this time, since the cap cleaning valve 72 is closed, cleaning liquid is not supplied from the cleaning liquid tank 76 to the caps 62A, 62B, and 62C through the second supply tube 177, the third supply tube 179, and the fourth supply tube 201.

The controller 130 executes the cleaning process at a predetermined timing or when it receives an external command. The following describes the process when the controller 130 executes the cleaning process after the purge process is performed when the image recording device 100 is in a standby state.

In the cleaning process, the controller 130 drives the suction pump 74 while opening the cap cleaning valve 72 and closing the refill valve 187, the purge shutoff valve 188, the bypass valve 189, and the air release valve 190. This causes cleaning liquid to be supplied from the cleaning liquid tank 76 to the internal spaces of the caps 62A, 62B, and 62C through the second supply tube 177, the third supply tube 179, and the fourth supply tube 201. Because the purge shutoff valve 188 and the bypass valve 189 are closed, ink is not discharged from the nozzle 38A of the head 38 into the internal spaces of the caps 62A, 62B, and 62C.

The controller 130 then moves the head 38 to the uncapped position and drives the suction pump 74 with the cap cleaning valve 72 closed. This causes the cleaning liquid to be discharged from the internal spaces 67A, 67B, 67C of the cap 62 through the discharge flow paths 21A, 21B, 21C, the first waste liquid tube 178, the second waste liquid tube 180, and the third waste liquid tube 202 to the waste liquid tank 77. This causes the ink remaining in the internal spaces 67A, 67B, 67C of the cap 62, the discharge flow paths 21A, 21B, 21C, the first waste liquid tube 178, the second waste liquid tube 180, and the third waste liquid tube 202 to be washed away by the cleaning liquid.

When the image recording device 100 is not performing an image recording process, the image recording device 100 is in a standby state. When the image recording device 100 is in a standby state, the controller 130 executes a cleaning liquid supply process in which the cap cleaning valve 72 is opened and the replenishment valve 187, the purge shutoff valve 188, the bypass valve 189, and the air release valve 190 are closed, and the suction pump 74 is driven. The cleaning liquid supply process supplies cleaning liquid from the cleaning liquid tank 76 through the second supply tube 177, the third supply tube 179, and the fourth supply tube 201 to the internal spaces of the caps 62A, 62B, and 62C. Since the purge shutoff valve 188 and the bypass valve 189 are closed, ink is not discharged from the nozzle 38A of the head 38 to the internal spaces of the caps 62A, 62B, and 62C.

[Wipping process]
The controller 130 executes the wiping process in a state where the sponge wipers 64A, 64B, and 64C are soaked in the cleaning liquid. The wiping process will be described below.

In the wiping process, the controller 130 drives the return pump 75. This causes the cleaning liquid to be supplied from the cleaning liquid tank 76 to the support base 61 through the first supply tube 175. The cleaning liquid supplied to the support base 61 flows into the first flow path 153A in the liquid flow path 153 through the inlet 171. The cleaning liquid that flows into the first flow path 153A flows through the intermediate flow path 153B and the second flow path 153C in order, and is discharged from the outlet 174. At this time, the sponge wipers 64A, 64B, and 64C are impregnated with the cleaning liquid, and the sponge wipers 64A, 64B, and 64C are in a state in which they are sufficiently filled with the cleaning liquid. The cleaning liquid supplied to the liquid flow path 153 is returned to the cleaning liquid tank 76.

The controller 130 moves the head 38 downward from the uncapped position shown by the dashed line in FIG. 12 to the wiped position shown by the solid line.

The maintenance mechanism 60 in the maintenance position is supported by the first support mechanism 51, with the rack 154 meshing with the gear 105. In this state, when the first motor 55 is driven and the gear 106 rotates clockwise in FIG. 11, the gear 105 rotates counterclockwise in FIG. 11. As a result, the maintenance mechanism 60 in the maintenance position moves forward (downstream in the conveying direction 8A) along the front-rear direction 8 (conveying direction 8A) and reaches the wiping position (see FIG. 12).

In the process of the maintenance mechanism 60 moving from the maintenance position to the wiping position, the tip (upper end) of the sponge wiper 64 and the rubber wiper 63 slide against the nozzle surface 50 of the ejection module 49 while abutting against the nozzle surface 50. Specifically, the sponge wipers 64A, 64B, 64C and the rubber wipers 63A, 63B, 63C slide against the nozzle surface 50 of the ejection modules 49A, 49B, 49C while in contact with each other. As a result, the nozzle surface 50 of each ejection module 49A, 49B, 49C is wiped by the sponge wipers 64A, 64B, 64C, and then wiped by the rubber wipers 63A, 63B, 63C. As a result, foreign matter adhering to the nozzle surface 50 and the nozzle 38A opened in the nozzle surface 50 is removed.

When the maintenance mechanism 60 is in the wiping position, the first motor 55 is driven and the gear 106 rotates counterclockwise in FIG. 12, causing the gear 105 to rotate clockwise in FIG. 12. As a result, the maintenance mechanism 60 in the wiping position moves backward (upstream in the conveying direction 8A) and reaches the maintenance position (see FIG. 11).

The controller 130 drives the axial motor 59 to change the position of the first support mechanism 51 from the first position to the second position (see FIG. 13).

[Movement of the maintenance mechanism 60]
13 and 14 , the maintenance mechanism 60 can move to a standby position along the inclination direction 6 by sliding relative to the first support mechanism 51 and the second support mechanism 52 in the second posture while being supported by the first support mechanism 51 and the second support mechanism 52. In other words, the first support mechanism 51 and the second support mechanism 52 can support the maintenance mechanism 60 located at the maintenance position, the standby position, and between these two positions.

Specifically, the controller 130 first drives the first motor 55. As a result, the gear 106 rotates clockwise in FIG. 19, and the gear 105 rotates counterclockwise, and the maintenance mechanism 60 at the maintenance position moves to the forward tilt direction 5 and is transferred onto the second support mechanism 52.

The controller 130 drives the second motor 56. As a result, the gear 120 rotates clockwise in FIG. 20, and the gears 118 and 119 rotate counterclockwise, and the maintenance mechanism 60, which has slid from the first support mechanism 51, reaches the standby position on the second support mechanism 52 (see FIG. 14).

The controller 130 drives the vertical drive motor 163. This rotates the screw shaft 161, so that the second support mechanism 52 moves upward from the standby position along the orthogonal direction 10, and the maintenance mechanism 60 reaches the standby position. This causes the lips 66A, 66B, and 66C of the caps 62A, 62B, and 62C and the rubber wipers 63A, 63B, and 63C to come into contact with the wiper cleaning mechanism 80.

[Image recording processing]
The process when an image is recorded on the sheet S (image recording process) will be described below.

When the controller 130 receives a command to record an image on the sheet S from an external device, such as the operation panel 44 or an information processing device connected to the image recording device 100 via a LAN or the like, it moves the maintenance mechanism 60 from the maintenance position to the standby position as described above. Then, the controller 130 drives the vertical drive motor 163 to move the maintenance mechanism 60 from the standby position to the retract position. The controller 130 drives the shaft motor 59 to change the position of the first support mechanism 51 from the second position to the first position.

Next, the controller 130 moves the head 38 downward to move it from the capped position to the recording position. Then, the transport of the sheet S is started, and ink is ejected from the nozzles 38A when the sheet S is positioned directly below the head 38. This causes an image to be recorded on the sheet S. The ink adhering to the sheet S is fixed to the sheet S by being heated as it passes through the heater 39. The transported sheet S is then cut to a predetermined size by the cutter unit 26 and discharged after the image recorded on it is checked by the CIS 25.

After the image recording process on the sheet S, when the maintenance mechanism 60 moves to the maintenance position, the above-mentioned process is performed in reverse.

In the image recording process, an ink circulation process is performed to circulate ink between the ink subtank 181 and the ejection module 49. The controller 130 closes the bypass valve 189 and the supply valve 187, and drives the positive pressure pump 191. When the positive pressure pump 191 is driven, ink is supplied from the ink subtank 181 to the ejection module 49 through the flow path 183. Ink that flows into the manifold 24 from the inlet port 22 of the ejection module 49 returns to the ink subtank 181 through the flow path 184 from the outlet port 23. That is, ink circulates between the ink subtank 181 and the ejection module 49.

[Storage processing]
The storage process will be described below with reference to Fig. 15 and Fig. 16. The storage process is executed in the image recording device 100 when the execution of the storage process is instructed by the user. The user may instruct the execution of the storage process when the image recording device 100 is not used for a long period of time. A long period of time is, for example, one month or more, but is not limited to this.

The image recording device 100 is in a standby state. In the standby state, when the controller 130 receives a storage instruction command based on input from the operation panel 44, it transitions to storage mode and executes storage processing. When the controller 130 receives the storage instruction command, it displays on the display unit 44A of the operation panel 44 that it is in storage mode and that the ink tank 34 should not be removed.

As shown in Figures 15 and 16, the controller 130 drives the conveying motor 53 in the reverse direction for a certain period of time to rotate the drive roller 102, the holder 35, and the conveying rollers 36A and 40A in the direction opposite to the conveying direction 8A (S10). As a result, the sheet S located in the conveying path 43 moves in the direction opposite to the conveying direction 8A and is wound up on the roll body 37.

After stopping the transport motor 53, the controller 130 determines whether the ink tank 34 is attached to the mounting case 110 (S11). Specifically, the controller 130 determines whether the ink tank 34 is attached to the mounting case 110 by reading the identification information stored in the memory area of the IC board 70 through the contacts 114. If the controller 130 determines that the ink tank 34 is not attached to the mounting case 110 (S11: No), the controller 130 displays a message on the display unit 44A indicating that the ink tank 34 should be attached, and waits until the ink tank 34 is attached.

When the controller 130 determines that the ink tank 34 is attached to the mounting case 110 (S11: Yes), it opens the refill valve 187 and the air release valve 190 (S12, an example of a return process). As a result, the ink stored in the ink subtank 181 is returned to the ink tank 34 through the flow path 182 due to gravity, and the ink subtank 181 is no longer stored. Note that the ink does not have to be completely empty in the ink subtank 181. For example, the ink below the position of the flow path 182 that opens into the internal space of the ink subtank 181 does not return to the ink tank 34 due to gravity, but some ink may remain in the internal space of the ink subtank 181 in this way.

The controller 130 opens the purge shutoff valve 188, the bypass valve 189, and the air release valve 190, and closes the refill valve 187 and the cap cleaning valve 72 (S12-1). After that, the controller 130 drives the suction pump 74 for a certain period of time (S12-2, an example of a first discharge process). When the suction pump 74 is driven, the internal space 67 of the cap 62 becomes negative pressure, and the ink remaining in the flow paths 183, 184, and 186 is discharged from the discharge module 49 through the manifold 24 and the nozzle 38A to the internal space 67 of the cap 62, and further through the flow path 178 to the waste liquid tank 77. At this time, since the refill valve 187 is closed, the ink stored in the ink tank 34 is not supplied to the ink subtank 181 through the flow path 182. In this way, most of the ink remaining in the flow paths 183, 184, 186, the manifold 24, the nozzle 38A, and the internal space 67 of the cap 62 is discharged into the waste tank 77 through the flow path 178.

If the detection signal of the liquid level sensor 192 of the ink subtank 181 is an OFF signal (S13: Yes), the controller 130 displays on the display unit 44A that the storage liquid tank 11 is to be attached instead of the ink tank 34, and determines whether the storage liquid tank 11 is attached to the mounting case 110 (S14). Specifically, the controller 130 determines whether the storage liquid tank 11 is attached to the mounting case 110 by reading the identification information stored in the memory area of the IC board 12 through the contacts 114. If the controller 130 determines that the storage liquid tank 11 is not attached to the mounting case 110 (S14: No), it displays on the display unit 44A that the storage liquid tank 11 is to be attached, and waits until the storage liquid tank 11 is attached.

When the controller 130 determines that the preservative liquid tank 11 is attached to the mounting case 110 (S14: Yes), the controller 130 closes the cap cleaning valve 72, the purge shutoff valve 188, the bypass valve 189, and the atmospheric release valve 190 (S15). The controller 130 then drives the pressure reduction pump 193 (S16, an example of a preservative liquid supply process).

When the decompression pump 193 is driven, the internal space of the ink subtank 181 becomes negative pressure, and the storage liquid stored in the storage liquid tank 11 is supplied to the ink subtank 181 through the flow path 182.

When the detection signal of the liquid level sensor 192 of the ink subtank 181 is an OFF signal (S17: No), the controller 130 continues to drive the pressure reduction pump 193 (S16). When the detection signal of the liquid level sensor 192 is an ON signal (S17: Yes), the controller 130 stops driving the pressure reduction pump 193 (S18). When the liquid level sensor 192 becomes an ON signal, the storage liquid is stored up to a predetermined height in the ink subtank 181.

Next, the controller 130 closes the bypass valve 189 and the supply valve 187 (S19) and drives the positive pressure pump 191 for a certain period of time (S20, an example of a storage liquid circulation process). When the positive pressure pump 191 is driven, the storage liquid is supplied from the ink subtank 181 to the ejection module 49 through the flow path 183. The storage liquid that flows into the manifold 24 from the inlet port 22 of the ejection module 49 returns to the ink subtank 181 through the flow path 184 from the outlet port 23. In other words, the storage liquid circulates between the ink subtank 181 and the ejection module 49. Note that the inner diameter of the nozzle 38A is small, and the internal space 67 of the cap 62 is not under negative pressure, so that the storage liquid is unlikely to enter the nozzle 38A from the manifold 24 in the ejection module 49.

After stopping the positive pressure pump 191, the controller 130 opens the refill valve 187 and the bypass valve 189 (S21). After that, the controller 130 drives the suction pump 74 for a certain period of time (S22, an example of a second discharge process). When the suction pump 74 is driven, the internal space 67 of the cap 62 becomes negative pressure, and the preservation liquid is discharged from the discharge module 49 through the nozzle 38A into the internal space 67 of the cap 62, and through the flow path 178, the preservation liquid is discharged into the waste liquid tank 77. Accordingly, the preservation liquid is supplied from the ink subtank 181 to the discharge module 49 through the flow paths 183 and 184. In addition, the preservation liquid stored in the preservation liquid tank 11 is supplied to the ink subtank 181 through the flow path 182.

After stopping the suction pump 74, the controller 130 counts up the number of repetitions N by 1 (N=N+1, S23) and determines whether the counted-up number of repetitions N is equal to a threshold value (S24). The threshold value is preset and stored in the EEPROM 134 of the controller 130, for example, to 3 times.

When the controller 130 determines that the number of repetitions N is not the threshold value (S24: No), the controller 130 closes the cap cleaning valve 72 and the refill valve 187, and opens the purge shutoff valve 188, the bypass valve 189, and the atmospheric release valve 190 (S25). The controller 130 then drives the suction pump 74 (S26).

When the suction pump 74 is driven, the internal space 67 of the cap 62 becomes negative pressure, and the storage liquid is discharged from the discharge module 49 through the nozzle 38A into the internal space 67 of the cap 62. As a result, the storage liquid moves from the ink subtank 181 to the discharge module 49 through the flow paths 183 and 184, and is similarly discharged into the internal space 67 of the cap 62 through the nozzle 38A, and the storage liquid is discharged into the waste liquid tank 77 through the flow path 178. Note that since the cap cleaning valve 72 is closed, cleaning liquid is not supplied from the cleaning liquid tank 76 to the cap 62.

If the detection signal of the liquid level sensor 192 of the ink subtank 181 is not an OFF signal (S27: No), the controller 130 continues to drive the suction pump 74 (S26). If the detection signal of the liquid level sensor 192 is an OFF signal (S27: Yes), the controller 130 drives the suction pump 74 for a certain period of time and then stops it (S28). When the liquid level sensor 192 turns to an OFF signal, the liquid level of the preservation liquid in the ink subtank 181 falls below a predetermined height, and the suction pump 74 is further driven, so that most of the preservation liquid stored in the ink subtank 181 is discharged to the waste liquid tank 77. Note that since the refill valve 187 is closed, no preservation liquid is supplied from the preservation liquid tank 11 to the ink subtank 181. After that, the controller 130 executes steps S15 to S24.

In response to determining that the number of repetitions N is equal to the threshold value (S24: Yes), the controller 130 resets the number of repetitions N, opens the cap cleaning valve 72 (S29), and drives the suction pump 74 for a fixed period of time (S30, an example of a cleaning process). As a result, cleaning liquid is supplied from the cleaning liquid tank 76 through the second supply tube 177 to the internal space 67 of the cap 62, and cleaning liquid is discharged from the internal space 67 to the waste liquid tank 77 through the first waste liquid tube 178.

After stopping the suction pump 74, the controller 130 updates the storage flag stored in the EEPROM 134 to ON (S31) and turns off the power to the image recording device 100 (S32). This ends the storage process.

[Return process]
The restoration process will be described below with reference to Figures 17 and 18. The restoration process is performed when the image recording device 100 is in a stored state, the user decides to resume use, and turns on the power of the image recording device 100.

The image recording device 100 is in a storage state and in a standby state. In the storage state and in the standby state, the controller 130 executes a recovery process in response to a user's power-on operation. The controller 130 displays a message on the display unit 44A indicating that the ink tank 34 should be installed.

As shown in FIG. 16, the controller 130 determines whether the storage flag stored in the EEPROM 134 is ON (S40). If the controller 130 determines that the storage flag is not ON (S40: No), the controller 130 maintains the standby state (S61).

In response to determining that the storage flag is ON (S40: Yes), the controller 130 determines whether an ink tank 34 is attached to the mounting case 110 (S41). Specifically, the controller 130 determines whether an ink tank 34 is attached to the mounting case 110 by reading the identification information stored in the memory area of the IC board 70 through the contacts 114. In response to determining that an ink tank 34 is not attached to the mounting case 110 (S41: No), the controller 130 displays a message on the display unit 44A indicating that the ink tank 34 should be attached, and waits until the ink tank 34 is attached.

When the controller 130 determines that the ink tank 34 is attached to the attachment case 110 (S41: Yes), it opens the purge shutoff valve 188, the bypass valve 189, and the air release valve 190, and closes the cap cleaning valve 72 and the refill valve 187 (S42). The controller 130 then drives the suction pump 74 (S43).

When the suction pump 74 is driven, the internal space 67 of the cap 62 becomes negative pressure, and the storage liquid is discharged from the discharge module 49 to the internal space 67 of the cap 62 through the nozzle 38A. As a result, the storage liquid moves from the ink subtank 181 to the discharge module 49 through the flow paths 183 and 184, and is similarly discharged to the internal space 67 of the cap 62 through the nozzle 38A, and the storage liquid is discharged to the waste liquid tank 77 through the flow path 178. Since the cap cleaning valve 72 is closed, cleaning liquid is not supplied from the cleaning liquid tank 76 to the cap 62. Furthermore, since the refill valve 187 is closed, ink is not supplied from the ink tank 34 to the ink subtank 181.

If the detection signal of the liquid level sensor 192 of the ink subtank 181 is not an OFF signal (S44: No), the controller 130 continues to drive the suction pump 74 (S43). If the detection signal of the liquid level sensor 192 is an OFF signal (S44: Yes), the controller 130 drives the suction pump 74 for a certain period of time and then stops it (S45). When the liquid level sensor 192 turns to an OFF signal, the liquid level of the storage liquid in the ink subtank 181 falls below a predetermined height, and when the suction pump 74 is further driven, most of the storage liquid stored in the ink subtank 181 is discharged to the waste liquid tank 77. Note that since the refill valve 187 is closed, ink is not supplied from the ink tank 34 to the ink subtank 181.

After stopping the suction pump 74, the controller 130 closes the purge shutoff valve 188, the bypass valve 189, and the atmospheric release valve 190, and opens the supply valve 187 (S46). The controller 130 then drives the decompression pump 193 (S47).

When the decompression pump 193 is driven, the internal space of the ink subtank 181 becomes negative pressure, and the ink stored in the ink tank 34 is supplied to the ink subtank 181 through the flow path 182.

If the detection signal of the liquid level sensor 192 of the ink subtank 181 is an OFF signal (S48: No), the controller 130 continues driving the pressure reduction pump 193 (S47). If the detection signal of the liquid level sensor 192 is an ON signal (S48: Yes), the controller 130 stops driving the pressure reduction pump 193 (S49). When the liquid level sensor 192 becomes an ON signal, ink is stored up to a predetermined height in the ink subtank 181.

The controller 130 closes the bypass valve 189 and the supply valve 187 (S50) and drives the positive pressure pump 191 for a certain period of time (S51). When the positive pressure pump 191 is driven, ink is supplied from the ink subtank 181 to the ejection module 49 through the flow path 183. The ink that flows into the manifold 24 from the inlet port 22 of the ejection module 49 returns to the ink subtank 181 through the flow path 184 from the outlet port 23. That is, ink circulates between the ink subtank 181 and the ejection module 49. Note that the inner diameter of the nozzle 38A is small, and the internal space 67 of the cap 62 is not under negative pressure, so that ink does not easily enter the nozzle 38A from the manifold 24 in the ejection module 49.

After stopping the positive pressure pump 191, the controller 130 opens the refill valve 187 and the bypass valve 189 (S52). After that, the controller 130 drives the suction pump 74 for a fixed period of time (S53). When the suction pump 74 is driven, the internal space 67 of the cap 62 becomes negative pressure, and ink is discharged from the ejection module 49 to the internal space 67 of the cap 62 through the nozzle 38A, and the ink is discharged to the waste liquid tank 77 through the flow path 178. Accordingly, ink is supplied from the ink subtank 181 to the ejection module 49 through the flow paths 183 and 184. Also, ink stored in the ink tank 34 is supplied to the ink subtank 181 through the flow path 182.

After stopping the suction pump 74, the controller 130 counts up the number of repetitions N by 1 (N=N+1, S54) and determines whether the counted-up number of repetitions N is equal to a threshold value (S55). The threshold value is preset and stored in the EEPROM 134 of the controller 130, for example, to 3 times.

When the controller 130 determines that the number of repetitions N is not the threshold value (S55: No), the controller 130 closes the cap cleaning valve 72, the atmospheric release valve 190, and the refill valve 187, and opens the purge shutoff valve 188, the bypass valve 189, and the atmospheric release valve 190 (S56). The controller 130 then drives the suction pump 74 (S57).

When the suction pump 74 is driven, the internal space 67 of the cap 62 becomes negative pressure, and ink is discharged from the ejection module 49 into the internal space 67 of the cap 62 through the nozzle 38A. As a result, ink moves from the ink subtank 181 to the ejection module 49 through the flow paths 183 and 184, and is similarly discharged into the internal space 67 of the cap 62 through the nozzle 38A, and ink is discharged into the waste liquid tank 77 through the flow path 178. Note that because the cap cleaning valve 72 is closed, cleaning liquid is not supplied from the cleaning liquid tank 76 to the cap 62.

If the detection signal of the liquid level sensor 192 of the ink subtank 181 is not an OFF signal (S58: No), the controller 130 continues to drive the suction pump 74 (S57). If the detection signal of the liquid level sensor 192 is an OFF signal (S58: Yes), the controller 130 drives the suction pump 74 for a certain period of time and then stops it (S59). When the liquid level sensor 192 turns to an OFF signal, the ink level in the ink subtank 181 falls below a predetermined height, and the suction pump 74 is further driven, causing most of the ink stored in the ink subtank 181 to be discharged to the waste liquid tank 77. Note that since the refill valve 187 is closed, no ink is supplied from the ink tank 34 to the ink subtank 181. After that, the controller 130 executes steps S46 to S55.

When the controller 130 determines that the number of repetitions N is equal to the threshold value (S55: Yes), it resets the number of repetitions N, updates the storage flag stored in the EEPROM 134 to OFF (S60), and goes into a standby state (S61). This ends the recovery process.

[Effects of the embodiment]
According to the embodiment described above, the ink has excellent quick-drying properties on the recording medium, and has excellent replacement properties for replacing the ink with a storage liquid, and also has excellent re-dispersibility for dispersing the dried solid product of the ink back into a solvent.

In addition, the user can replace the ink in the ejection module 49 with storage liquid at any time. This allows the image recording device 100 to be stored according to the user's planned use.

In addition, in the storage process, the ink in the ink subtank 181 is returned to the ink tank 34, so less ink is wasted during storage. It also becomes easier to replace the ink in the ejection module 49 and each flow path 182, 183, 184, etc. with storage liquid.

In addition, during the storage process, a process of supplying storage liquid from the storage liquid tank 11 to the ink subtank 181 and a process of circulating the storage liquid stored in the ink subtank 181 between the ink subtank 181 and the ejection module 49 are performed, so that ink remaining in the ink subtank 181, the ejection module 49, and the flow paths 183 and 184 is dispersed into the storage liquid.

In addition, in the storage process, the process of discharging the storage liquid from the ejection module 49, the process of supplying the storage liquid from the storage liquid tank 11 to the ink subtank 181, and the process of circulating the storage liquid stored in the ink subtank 181 between the ejection module 49 are repeatedly performed, so the replacement rate of the ink remaining in the ink subtank 181, the ejection module 49, and the flow paths 183 and 184 with the storage liquid is increased.

In addition, during the storage process, the storage liquid is not returned from the ink subtank 181 to the storage liquid tank 11, so the storage liquid mixed with the ink returns to the storage liquid tank 11, and the storage liquid mixed with the ink is not used from the storage liquid tank 11 during the next storage process.

[Variations]
In the image recording device 100, three caps 62A, 62B, and 62C are provided on the support base 61, but the number of caps 62 is not particularly limited as long as it corresponds to the number of discharge modules 49A. For example, the number of caps 62 may be four or more, or two or less. In addition, the sponge wiper 64 and the rubber wiper 63 are not essential components.

In the image recording device 100, the maintenance mechanism 60 moves along the front-rear direction 8, but the movement of the maintenance mechanism 60 is not particularly limited. In addition, the ejection module 49 may move relative to the maintenance mechanism 60.

In the image recording device 100, the ink tank 34 and the storage liquid tank 11 are separate and are replaced in the mounting case 110, but the ink tank 34 and the storage liquid tank 11 may be integrally constructed and mounted in the mounting case 110.

The storage process and restoration process may be executed according to a user's instruction, or may be executed on the condition that no input has been made to the image recording device 100 for a certain period of time. In this case, the restoration process may be executed on the condition that, for example, a print instruction command has been received. However, when the image recording device 100 is not used for a long period of time, it is expected that the image recording device 100 will not be supplied with power because the power plug has been unplugged, and the controller 130 will not function due to the lack of power. Therefore, it is convenient for the user to be able to execute the storage process according to their convenience.

In addition, in the first discharge process and the second discharge process, the positive pressure pump 191 may also be driven in addition to the suction pump 74.

In the above-described embodiment, ink is described as an example of a liquid, but instead of ink, for example, a pretreatment liquid that is ejected onto paper prior to the ink during printing, or a posttreatment liquid that overcoats ink that has adhered to the paper, may be used. The storage liquid may also be used as a cleaning liquid for cleaning the head 38.

The following is an example of the present invention.

[Pigment dispersion A]
Pure water was added to 20 wt % pigment (carbon black) and 7 wt % of a styrene-acrylic acid copolymer neutralized with sodium hydroxide (acid value 175 mg KOH/g, weight average molecular weight 10,000) to make the total 100 wt %, and the mixture was stirred and mixed to obtain a mixture. This mixture was placed in a wet sand mill filled with zirconia beads of 0.3 mm diameter, and subjected to a dispersion treatment for 6 hours. Thereafter, the zirconia beads were removed using a separator, and the mixture was filtered through a cellulose acetate filter with a pore size of 3.0 μm to obtain pigment dispersion liquid A. The styrene-acrylic acid copolymer is a water-soluble polymer that is generally used as a pigment dispersion liquid.

Example 1: Water-based ink
The aqueous ink used contained pigment dispersion A having 5 wt % carbon black as the pigment solid content, 10.0 wt % Mowinyl 6899D (Tg = 49°C, 46 wt %) as resin fine particles, 5.0 wt % 1,2-hexanediol (liquid at 25°C) and 2.0 wt % dipropylene glycol monopropyl ether (liquid at 25°C) as organic solvents, 2.0 wt % Silface SAG503A as a surfactant, and the balance ion-exchanged water.

Example 2: Water-based ink
The composition was the same as in Example 1, except that 7.0 wt % 1,2-hexanediol (liquid at 25° C.) and 3.0 wt % dipropylene glycol monopropyl ether (liquid at 25° C.) were used as the organic solvent.

Example 3: Water-based ink
The composition was the same as in Example 1, except that 8.0 wt % 1,2-hexanediol (liquid at 25° C.) and 3.0 wt % dipropylene glycol monopropyl ether (liquid at 25° C.) were used as the organic solvent.

Example 4: Water-based ink
The composition was the same as in Example 1, except that 5.0 wt % 1,2-hexanediol (liquid at 25° C.) and 2.0 wt % propylene glycol monobutyl ether (liquid at 25° C.) were used as the organic solvent.

Example 5: Water-based ink
The composition was the same as in Example 1, except that 5.0 wt % 1,2-hexanediol (liquid at 25° C.) and 2.0 wt % triethylene glycol monobutyl ether (liquid at 25° C.) were used as the organic solvent.

Example 6: Water-based ink
The composition was the same as in Example 1, except that 11.0 wt % Mowinyl 6969D (Tg=71° C., 42 wt %) was used as the resin fine particles.

Example 7: Water-based ink
The composition was the same as in Example 1, except that 15.3 wt % Superflex 820 (Tg=46° C., 30 wt %) was used as the resin particles.

Example 8: Water-based ink
The composition was the same as in Example 1, except that 7.0 wt % 1,2-hexanediol (liquid at 25° C.), 1.0 wt % 1,6-hexanediol (solid at 25° C.), and 3.0 wt % dipropylene glycol monopropyl ether (liquid at 25° C.) were used as organic solvents.

Example 11: Preservation Solution
The storage solution used contained 0.2 wt % polyvinylpyrrolidone (PVP, weight average molecular weight 10,000) as a water-soluble polymer, 40.0 wt % glycerin as a wetting agent, 5.0 wt % triethylene glycol monobutyl ether as an organic solvent, 3.0 wt % Sannol NL-1430 (28 wt %) as a surfactant, and ion-exchanged water as the balance.

Example 12: Preservation Solution
The composition was the same as in Example 11, except that 0.6 wt % Joncryl 62 (weight average molecular weight 8,500, 34 wt %) was used as the water-soluble polymer.

Example 13: Preservation Solution
The composition was the same as in Example 11, except that 0.2 wt % polyethylene glycol 20,000 (weight average molecular weight 20,000) was used as the water-soluble polymer.

Example 14: Preservation Solution
The composition was the same as in Example 11, except that 0.4 wt % Joncryl 57 (weight average molecular weight 4,900, 45 wt %) was used as the water-soluble polymer.

Example 15: Preservation Solution
The composition was the same as in Example 11, except that 0.2 wt % polyethylene glycol 35000 (weight average molecular weight 35,000) was used as the water-soluble polymer.

Example 16: Preservation Solution
The composition was the same as in Example 11, except that 5.0 wt % diethylene glycol monobutyl ether was used as the organic solvent.

Example 17: Preservation Solution
The composition was the same as in Example 11, except that 5.0 wt % dipropylene glycol monopropyl ether was used as the organic solvent.

Example 18: Preservation Solution
The composition was the same as in Example 11, except that 3.0 wt % Olfine E1010 was used as the surfactant.

(Comparative Example 1: Water-based ink)
Pigment dispersion A having 5 wt % carbon black as the pigment solid content, containing no resin fine particles, 5.0 wt % 1,2-hexanediol (liquid at 25° C.) and 2.0 wt % dipropylene glycol monopropyl ether (liquid at 25° C.) as organic solvents, 2.0 wt % Silface SAG002 as a surfactant, and the balance ion-exchanged water was used as the aqueous ink.

(Comparative Example 2: Water-based ink)
The aqueous ink used was a pigment dispersion A containing 5 wt % carbon black as the pigment solid content, 10.0 wt % Mowinyl 6899D (Tg = 49°C) as resin microparticles, no organic solvent, 2.0 wt % Silface SAG002 as a surfactant, and the remainder ion-exchanged water.

Comparative Example 11: Preservation Solution
The storage solution used contained no water-soluble polymer and contained 40.0 wt % glycerin as a wetting agent, 5.0 wt % triethylene glycol monobutyl ether as an organic solvent, 3.0 wt % Sannol NL-1430 as a surfactant, and ion-exchanged water as the balance.

(Comparative Example 12: Preservation Solution)
The storage solution used was 0.2 wt % polyvinylpyrrolidone (PVP, weight average molecular weight 10,000) as a water-soluble polymer, 40.0 wt % glycerin as a wetting agent, 5.0 wt % triethylene glycol monobutyl ether as an organic solvent, no surfactant, and ion-exchanged water as the balance.

[Printing method]
In the following, the image recording apparatus 100 and the aqueous ink were used to eject the aqueous ink onto coated paper, and the ink was heated by a heater to form a film of the aqueous ink on the coated paper.

[Quick-drying test]
The coated paper on which the aqueous ink film had been formed was rubbed with a cotton swab, and stains were visually evaluated according to the following criteria.
A: No stain when rubbed immediately after heating B: No stain when rubbed 2 seconds after heating C: No stain when rubbed 5 seconds after heating D: Stain when rubbed 10 seconds after heating

[Redispersibility test]
The aqueous ink and the storage solution were mixed in a ratio of 10:90 or 5:95, and 12 μL was dropped onto a polypropylene plate and left for 7 days in an environment of 60° C. and 30% humidity. After leaving it, 20 mL of pure water was dropped onto the coagulated mixed solution, which was then manually shaken and visually evaluated according to the following evaluation criteria.
A: When observed with an optical microscope at 200x magnification, no dry solids are present in the liquid. B: When observed with the naked eye, no dry solids are present in the liquid. C: When observed with the naked eye, more than 50% of the total dry solids are dispersed in the liquid after pure water is added. D: When observed with the naked eye, less than 50% of the total dry solids are dispersed in the liquid after pure water is added.

[Substitution test]
The ink tank 34 was attached to the image recording device 100 and an image was recorded. A storage process (repeated once) was performed in the image recording device 100 using a storage liquid, and the replacement rate of the liquid in the ink subtank 181 after the storage process was measured. The replacement rate was calculated by measuring the absorbance (500 nm) of the liquid after replacement using an absorptiometer (Shimadzu Corporation, UV-3600) and expressing the ratio to the absorbance of the aqueous ink alone (1-absorbance of the liquid after replacement/absorbance of the aqueous ink alone).
A: The replacement rate was 90% or more. B: The replacement rate was less than 90% and 80% or more.

[Quick-drying test results]
The quick-drying test results for Examples 1-8 and Comparative Example 1-2 are shown in Table 1. As shown in Table 1, Comparative Example 1-2 was rated D, whereas Example 1-8 was rated A to C, indicating that the quick-drying property of the water-based ink of Example 1-8 is excellent. The acrylic resin fine particles contained in the water-based ink are quick-drying and have high storage stability compared to other resin fine particles such as urethane fine particles, and furthermore, have high abrasion resistance due to their high film hardness.

In addition, Examples 1-4 and 6-8, which contain a glycol ether having a propylene oxide group as an organic solvent, had better quick-drying properties than Example 5, which does not contain a glycol ether having a propylene oxide group as an organic solvent. The glycol ether having a propylene oxide group contained in the water-based ink is thought to have excellent quick-drying properties because it has a film-increasing agent effect for the resin particles. Furthermore, the quick-drying properties of Examples 1, 2, 4, and 6-8, in which the proportion of organic solvent that is liquid at 25°C to the total amount is 10% or less, were particularly excellent. When the water-based ink is fixed to the paper surface, if there is a large amount of liquid component, it takes time for the water-based ink to lose its fluidity, which is thought to result in poor quick-drying properties.

[Redispersion test results]
The compositions and viscosities of Examples 11-18 and Comparative Examples 3-4 are shown in Table 2. The redispersibility test results and the replacement test are shown in Table 3. The redispersibility of the aqueous ink of Example 1 was evaluated as D for Comparative Example 11-12, whereas the redispersibility of Examples 11-18 was evaluated as A to C, indicating that the storage solution of Examples 11-18 has excellent redispersibility. Furthermore, the storage solution of Example 11 was also evaluated as A to C when used with the aqueous inks of Examples 4, 5, and 7. Furthermore, Example 11-17, which contains Sannol NL-1430, an anionic surfactant, was superior to Example 18, which contains Olfin E1010, a nonionic surfactant. When redispersing the dried solid matter that has solidified from the mixture of the aqueous ink and the storage solution remaining in the flow path or head in water, it is considered that a surfactant having a charge increases the mutual repulsive force between the particles in water when adsorbed to the particles such as the dried solid matter, and makes it easier to redisperse the dried solid matter.

In addition, Examples 11-13, which contain a water-soluble polymer with a weight-average molecular weight of 8500 to 20,000, were superior to Examples 14 and 15, which contain a water-soluble polymer with a weight-average molecular weight outside the range of 8500 to 20,000. When the mixture of the remaining aqueous ink and the storage liquid in the flow path or head dries, the distance between the pigment particles in the aqueous ink decreases as the amount of solvent decreases. The water-soluble polymer acts as a steric obstacle between the approaching pigment particles, which is thought to improve redispersibility. In addition, water-soluble polymers with bulky structures such as aromatics and lactams are thought to function more easily as steric obstacles. In addition, if the molecular weight of the water-soluble polymer is small, it is thought that it is difficult for it to function as a steric obstacle, while if the molecular weight is large, it is thought that it is difficult for it to be redissolved in the solvent after drying.

In addition, Examples 11-16 and 18, which contained a glycol ether having an ethylene oxide group as an organic solvent, had better redispersibility than Example 17, which did not contain an organic solvent containing a glycol ether having an ethylene oxide group. Since organic solvents containing glycol ethers having an ethylene oxide group are highly water-soluble, they are thought to act as an auxiliary agent for redissolving or redispersing highly hydrophobic substances such as dry solids, pigments, and resin fine particles in water.

[Substitution test]
As shown in Table 3, the replacement property of the aqueous ink of Example 1 was excellent for both the storage liquids of Examples 11-18 and the storage liquids of Comparative Examples 3-4. However, the replacement property of the storage liquid of Example 15, which has a higher viscosity than the aqueous ink of Example 1, was rated B, and was rated worse than the other Examples and Comparative Examples. It is considered that when liquids with different viscosities (aqueous ink and storage liquid) come into contact with each other, the liquid with the lower viscosity moves into the liquid with the higher viscosity and is mixed. When the aqueous ink is replaced with the storage liquid, if the aqueous ink remains in the flow path or in the fine parts of the head, the remaining aqueous ink may solidify. Therefore, since it is desired that the aqueous ink is replaced with the storage liquid even in the fine parts of the flow path or the head, it is considered that the replacement property is improved when the viscosity of the storage liquid is lower than that of the aqueous ink. In addition, the lower the viscosity of the storage liquid, the easier it is for the aqueous ink in the flow path downstream of the cap 62 to flow to the waste liquid tank 77.

11: Storage solution tank (second cartridge)
21...Discharge flow path (fourth flow path)
34: Ink tank (first cartridge)
38A... Nozzle 49... Discharge module (head)
60...Maintenance mechanism (discharge mechanism)
62: Cap 100: Image recording device (liquid discharging device)
110: Mounting case (cartridge mounting section)
130: Controller 134: EEPROM (memory)
181...Ink subtank (tank)
182...flow path (first flow path)
183...flow path (second flow path)
184...flow path (third flow path)

Claims (20)

a cartridge mounting portion in which a cartridge for storing liquid is mounted;
a head that is connected to the cartridge mounting section so that liquid can flow therethrough and that ejects liquid from nozzles that are openings in a nozzle surface;
a discharge mechanism for discharging liquid from the nozzles of the head,
the liquid is at least ink, a storage liquid, or a mixture thereof, and the cartridge includes a first cartridge for storing ink and a second cartridge for storing storage liquid;
The ink contains a pigment, resin particles, an organic solvent, a surfactant, and water,
The preservation solution includes a water-soluble polymer, an organic solvent, a surfactant, and water;
A liquid discharging device , wherein the water-soluble polymer contained in the storage solution has a weight average molecular weight in the range of 8,500 to 20,000 . a cartridge mounting portion in which a cartridge for storing liquid is mounted;
a head that is connected to the cartridge mounting section so that liquid can flow therethrough and that ejects liquid from nozzles that are openings in a nozzle surface;
a discharge mechanism for discharging liquid from the nozzles of the head,
the liquid is at least ink, a storage liquid, or a mixture thereof, and the cartridge includes a first cartridge for storing ink and a second cartridge for storing storage liquid;
The ink contains a pigment, resin particles, an organic solvent, a surfactant, and water,
The preservation solution includes a water-soluble polymer, an organic solvent, a surfactant, and water;
A liquid discharge device, wherein the water-soluble polymer contained in the storage solution contains an aromatic alkyl group or a lactam group in its structure. a cartridge mounting portion in which a cartridge for storing liquid is mounted;
a head that is connected to the cartridge mounting section so that liquid can flow therethrough and that ejects liquid from nozzles that are openings in a nozzle surface;
a discharge mechanism for discharging liquid from the nozzles of the head,
the liquid is at least ink, a storage liquid, or a mixture thereof, and the cartridge includes a first cartridge for storing ink and a second cartridge for storing storage liquid;
The ink contains a pigment, resin particles, an organic solvent, a surfactant, and water,
The preservation solution includes a water-soluble polymer, an organic solvent, a surfactant, and water;
the organic solvent contained in the ink contains a glycol ether having a propylene oxide group,
A liquid discharging device, wherein the organic solvent contained in the storage solution includes a glycol ether having an ethylene oxide group. Further comprising a controller,
The above controller is
a first discharge process for driving the discharge mechanism to discharge ink from the nozzles of the head;
The liquid ejection device according to any one of claims 1 to 3 , further comprising: a second ejection process for driving the ejection mechanism to eject storage liquid from the nozzles of the head when a second cartridge is attached to the cartridge mounting section. a tank connected to the cartridge mounting portion by a first flow path;
a second flow path for supplying liquid from the tank to the head,
The controller further comprises:
With the fluid ejector in storage mode,
5. The liquid discharging device according to claim 4 , further comprising a return process for returning ink from the tank to the first cartridge mounted in the cartridge mounting portion through the first flow path. 6. The liquid discharging device according to claim 5 , wherein the controller transitions the liquid discharging device to the storage mode in response to receiving a prescribed instruction command in a state in which the first cartridge is mounted in the cartridge mounting portion. The liquid discharging device according to claim 6 , wherein the controller, in the return process, determines whether the first cartridge is attached to the cartridge attachment portion based on the identification information acquired from the first cartridge. Further comprising a third flow path for discharging liquid from the head to the tank,
The controller further comprises:
Before the second discharge process,
a preservation liquid supply process for supplying a preservation liquid from the second cartridge to the tank while the second cartridge is mounted in the cartridge mounting section;
The liquid discharging device according to claim 5 , further comprising a storage liquid circulation process for circulating the storage liquid stored in the tank between the head and the second flow path and the third flow path. The controller further comprises:
A liquid ejection device as described in claim 8, wherein, when the first cartridge is attached to the cartridge mounting section, an ink circulation process is performed to circulate ink stored in the tank between the head through the second flow path and the third flow path. The liquid discharging device according to claim 8 , wherein the controller further determines whether the second cartridge is attached to the cartridge mounting portion based on identification information acquired from the second cartridge in the second discharging process. The liquid discharging device according to claim 8 , wherein the controller repeatedly executes the storage liquid circulation process and the second discharging process a plurality of times. The discharge mechanism includes:
a cap that contacts the nozzle face at a covering position and is spaced apart from the nozzle face at a retracted position;
and a fourth flow path communicating with an internal space of the cap,
The liquid discharging device according to claim 4 , wherein the controller further executes a cleaning process of circulating a cleaning liquid through an internal space of the cap and the fourth flow path. 5. The liquid discharging device according to claim 4 , wherein the controller further stores storage information indicating a storage state in a memory and turns off a power supply after executing the second discharging process. The liquid ejection device according to claim 13, wherein the controller further drives the ejection mechanism to eject storage liquid from the nozzles of the head when storage information is stored in the memory and the first cartridge is attached to the cartridge mounting section. 5. The fluid ejection device of claim 4 , wherein the viscosity of the ink is greater than the viscosity of the storage liquid. 5. The liquid discharging device according to claim 4 , wherein the surfactant contained in the storage liquid is an anionic surfactant. 4. The liquid discharging device according to claim 2, wherein the water-soluble polymer contained in the storage solution has a weight average molecular weight in the range of 8,500 to 20,000. The liquid discharging device according to claim 3 , wherein the water-soluble polymer contained in the storage solution contains an aromatic alkyl group or a lactam group in its structure. 5. The liquid discharging device according to claim 4 , wherein the organic solvent contained in the ink contains 10% by weight or less of the total amount of the liquid at 25[deg.] C. as a single organic solvent. 5. The liquid discharging device according to claim 4 , wherein the resin particles contained in the ink are acrylic resin.

Images