Inkjet printer

Abstract

To suppress droplets of ink generated by flushing from adhering to a nozzle.SOLUTION: A printer 10 comprises a recording head 50 having a plurality of first nozzles 51a that respectively discharge first ink and an ink receiving member 61 that receives the first ink discharged from the plurality of first nozzles 51. The printer 10 performs first flushing for making the plurality of first nozzles 51a discharge the first ink of first amounts to the ink receiving member 61. The printer 10 performs second flushing for making the plurality of first nozzles 51a discharge the first ink of second amounts smaller than the first amounts to the ink receiving member 61, after the first flushing.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to inkjet printers. [Background technology]

[0002] Inkjet printers have been known for some time, which are provided with a recording head having a plurality of nozzles and form an image on a recording medium by ejecting ink from the plurality of nozzles. Some inkjet printers are configured to perform nozzle cleaning, such as ink suction or wiping, to prevent or eliminate nozzle clogging. In general, after nozzle cleaning, a so-called flushing process is performed in which ink is ejected outside the printing area. For example, Patent Document 1 discloses an inkjet printer that has a liquid ejection head formed with a plurality of nozzle rows in which a plurality of nozzles are linearly arranged, and alternates between a first flushing process in which ink is ejected from nozzles included in one of the nozzle rows of odd-numbered and even-numbered nozzle rows, and a second flushing process in which ink is ejected from nozzles included in the other of the nozzle rows of odd-numbered and even-numbered nozzle rows. According to Patent Document 1, by performing flushing alternately between the even-numbered and odd-numbered nozzle rows, it is possible to prevent fine ink mist from adhering to the nozzle surface due to air currents that are generated when adjacent nozzle rows are driven simultaneously. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-36382 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, a method such as that described in Patent Document 1 is expected to be able to suppress adhesion of ink mist to the nozzle surface during flushing. However, in reality, it is not always possible to completely eliminate the adhesion of ink droplets (here, this refers to a general term for ink flying objects generated by flushing, such as scattered ink droplets and ink mist, the same applies below) generated by flushing to the nozzle surface, and ink droplets may adhere to the nozzle surface. In particular, if ink droplets adhere to a nozzle, problems such as poor ink discharge or color mixing (when droplets of ink of a color different from the ink of the nozzle adhere to the nozzle) may occur.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an inkjet printer capable of reducing adhesion of ink droplets generated by flushing to the nozzles. [Means for solving the problem]

[0006] The inkjet printer disclosed herein includes a support table having a support surface for supporting a recording medium, a recording head having a plurality of first nozzles for ejecting a first ink downward and disposed above the support surface, an ink receiving member disposed below the plurality of first nozzles and configured to receive the first ink ejected from the plurality of first nozzles, a moving device for moving the recording head relative to the support table and the ink receiving member, and a control device for controlling the recording head and the moving device. The control device includes a movement control unit, a first flushing control unit, and a second flushing control unit. The movement control unit controls the moving device to move the recording head to a first position where the plurality of first nozzles face the support surface and a second position where the plurality of first nozzles face the ink receiving member. The first flushing control unit ejects a first amount of the first ink from the plurality of first nozzles to the ink receiving member while the recording head is positioned at the second position. The second flushing control unit ejects a second amount of the first ink, which is smaller than the first amount, from the multiple first nozzles onto the ink receiving member after the first flushing control unit ejects the first ink.

[0007] According to the inkjet printer, the first flushing control unit ejects the first ink in a large amount, so that there is a high risk that droplets of the first ink will adhere to the first nozzles, but normal flushing can be performed. Even if droplets of the first ink adhere to the first nozzles due to the ejection of the first ink by the first flushing control unit, the droplets of the first ink that have adhered to the nozzles can be removed by subsequently ejecting the first ink by the second flushing control unit. Since the second flushing control unit ejects the first ink in a small amount, the amount of droplets of the first ink that are generated is small even if this is performed, and therefore re-adhesion of the first ink to the first nozzles is small. Thus, according to the inkjet printer, adhesion of droplets of ink generated by flushing to the nozzles can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a front view of a printer according to an embodiment. [Diagram 2] 4 is a plan view illustrating a schematic configuration of the lower surface of the carriage. FIG. [Diagram 3] FIG. 2 is a front view of the capping device and the wiping device. [Figure 4] FIG. 2 is a block diagram of a printer. [Diagram 5] 1 is a flow chart illustrating an example of a cleaning and flushing process. [Figure 6] FIG. 11 is a plan view that illustrates the state of the nozzle surface after minute flushing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An inkjet printer according to one embodiment will be described below with reference to the drawings. It should be noted that the embodiment described here is, of course, not intended to limit the present invention in any particular way. In the following description, when the inkjet printer is viewed from the front, the side going away from the inkjet printer is referred to as the front, and the side going toward the inkjet printer is referred to as the rear. Also, the symbols F, Rr, L, R, U, and D in the drawings represent front, rear, left, right, top, and bottom, respectively. However, these directions are merely provided for the sake of convenience in the description, and do not limit the installation mode of the inkjet printer, etc.

[0010] 1 is a front view of a large-format inkjet printer (hereinafter, simply referred to as "printer") 10 according to one embodiment. The printer 10 prints an image on the recording medium 5 by moving a roll-shaped recording medium 5 in the front-rear direction and ejecting ink from a recording head 50 mounted on a carriage 20 that moves in the left-right direction.

[0011] The recording medium 5 is an object on which an image is printed. The recording medium 5 is not particularly limited. For example, the recording medium 5 may be paper such as plain paper or inkjet printing paper, or may be a transparent sheet made of resin or glass. It may be a sheet made of metal or rubber. It may also be a fabric.

[0012] As shown in FIG. 1, the printer 10 includes a carriage 20, a head moving device 30, a transport device 40, a recording head 50, a capping device 60, a wiping device 70, and a control device 100.

[0013] The head moving device 30 includes a guide rail 31, a belt 32, left and right pulleys 33a and 33b, and a scan motor 34. The carriage 20 is slidably engaged with the guide rail 31. The guide rail 31 extends in the left-right direction. The guide rail 31 guides the movement of the carriage 20 in the left-right direction. The belt 32 is fixed to the carriage 20. The belt 32 is an endless belt. The belt 32 is wound around a pulley 33a provided on the right side of the guide rail 31 and a pulley 33b provided on the left side. The scan motor 34 is attached to the left pulley 33a. The scan motor 34 is electrically connected to the control device 100. The scan motor 34 is controlled by the control device 100. When the scan motor 34 is driven, the pulley 33a rotates and the belt 32 runs. As a result, the carriage 20 moves in the left-right direction along the guide rail 31.

[0014] A platen 15 is provided below the carriage 20. The platen 15 is an example of a support table that supports the recording medium 5. The platen 15 extends in the front-rear and left-right directions. The upper surface of the platen 15 constitutes a support surface 15a that supports the recording medium 5. The support surface 15a of the platen 15 faces upward. The recording medium 5 on the platen 15 is moved in the front-rear direction by a conveying device 40. The conveying device 40 includes a pinch roller 41, a grit roller 42, and a feed motor 43. The pinch roller 41 is provided above the platen 15 and presses down the recording medium 5 from above. The platen 15 is provided with a grit roller 42. The grit roller 42 is provided at a position facing the pinch roller 41. The grit roller 42 is connected to the feed motor 43 and rotates in the front-rear direction by receiving a driving force from the feed motor 43. The feed motor 43 is electrically connected to the control device 100 and controlled by the control device 100. When the grit roller 42 rotates with the recording medium 5 sandwiched between the pinch roller 41 and the grit roller 42, the recording medium 5 is transported in the front-rear direction.

[0015] FIG. 2 is a plan view showing a schematic configuration of the lower surface of the carriage 20. As shown in FIG. 2, the recording head 50 is provided on the lower surface of the carriage 20. The recording head 50 is provided above the support surface 15a (see FIG. 1) of the platen 15. The recording head 50 has a plurality of nozzle rows 51 to 58 each composed of a plurality of nozzles 51a to 58a. In each of the nozzle rows 51 to 58, the plurality of nozzles 51a to 58a are arranged linearly in the front-rear direction. The nozzle rows 51 to 58 are arranged in the left-right direction. Hereinafter, the plurality of nozzle rows 51 to 58 are also referred to as the first nozzle row 51 to the eighth nozzle row 58 in order from the left, and the nozzles belonging to the first nozzle row 51 to the eighth nozzle row 58 are also referred to as the first nozzle 51a to the eighth nozzle 58a, respectively. For example, the first nozzle row 51 is composed of a plurality of first nozzles 51a arranged in the front-rear direction. The first nozzle 51a to the eighth nozzle 58a are each configured to eject ink downward. The bottom surface of the recording head 50 constitutes a nozzle surface 50s in which a plurality of nozzles 51a to 58a are formed.

[0016] In this embodiment, the recording head 50 has only one ink head (meaning a unit in which a nozzle surface is formed), but the number of ink heads included in the recording head 50 is not limited. The number of nozzle rows included in one ink head is also not limited. Also, here, all the nozzle rows 51 to 58 are arranged in the same position in the front-rear direction, but some of the nozzle rows may be arranged in positions shifted from the other nozzle rows in the front-rear direction.

[0017] The recording head 50 is connected to a plurality of ink cartridges (not shown) through a plurality of ink supply paths (not shown). The material of the ink is not limited, and various materials that have been used as ink materials for inkjet printers can be used. The ink may be, for example, a solvent-based pigment ink or a water-based pigment ink. Alternatively, the ink may be a water-based dye ink or a UV-curable pigment ink that is cured by receiving UV light. The color of the ink is not particularly limited, and may include process color inks such as CMYK, and special color inks such as white and clear (transparent) ink. Hereinafter, the inks ejected from the first nozzle 51a to the eighth nozzle 58a are also referred to as the first ink to the eighth ink, respectively, as necessary. In this embodiment, the first ink to the eighth ink are inks of different colors. However, some or all of the inks ejected from the nozzles of the plurality of nozzle rows may be the same type of ink.

[0018] As shown in FIG. 1, the capping device 60 and the wiping device 70 are provided to the right of the platen 15. FIG. 3 is a front view of the capping device 60 and the wiping device 70. As shown in FIG. 3, the capping device 60 includes a cap 61, a cap moving device 62, and a suction pump 63. The cap 61 is configured to be able to receive ink ejected from the first nozzle 51a to the eighth nozzle 58a of the recording head 50 during flushing. The cap 61 is an example of an ink receiving member that receives ink during flushing. In this embodiment, the cap 61 of the recording head 50 is used as an ink receiving member, thereby reducing the number of members of the printer 10. However, the printer 10 may include an ink receiving member other than the cap 61.

[0019] As shown in FIG. 3, the cap 61 includes a bottom 61a and a side wall 61b extending upward from the bottom 61a. The side wall 61b is provided around the entire circumference of the bottom 61a. The cap 61 is a container-shaped member with a bottom and an open top. The cap 61 is provided below the nozzle surface 50s of the recording head 50 (hence, below the first nozzles 51a to the eighth nozzles 58a). Although illustration in the front-rear direction is omitted, the opening of the upper surface of the cap 61 is located outside the first nozzle row 51 to the eighth nozzle row 58 in a plan view and is located inside the outer edge of the nozzle surface 50s. The cap 61 is formed of an elastic material, such as rubber. For example, a sponge that absorbs ink may be provided in the internal space 61c of the cap 61 formed by the bottom 61a and the side wall 61b.

[0020] The cap moving device 62 is configured to move the cap 61 in the vertical direction to bring the upper edge of the side wall 61b into contact with the nozzle surface 50s of the recording head 50 or to separate it from the nozzle surface 50s. The cap moving device 62 may move the cap 61 in a direction other than the vertical direction, for example, in the front-rear direction, and in that case, the cap 61 may be moved in an oblique vertical direction. When the upper edge of the side wall 61b of the cap 61 comes into contact with the nozzle surface 50s of the recording head 50, the first nozzle row 51 to the eighth nozzle row 58 are accommodated inside the upper edge of the side wall 61b and are covered by the cap 61. The configuration of the cap moving device 62 is not particularly limited. The cap moving device 62 may include, for example, a drive motor and a ball screw, not shown.

[0021] The suction pump 63 is connected to the bottom 61a of the cap 61. The suction pump 63 is configured to reduce the pressure in the internal space 61c of the cap 61 when the cap 61 is in close contact with the nozzle surface 50s. The suction pump 63 is, for example, a tube pump. When the suction pump 63 is driven with the cap 61 in close contact with the nozzle surface 50s, ink is sucked out from the nozzles 51a to 58a of the recording head 50. The ink sucked by the suction pump 63 is discarded into a waste liquid tank (not shown) via a tube (not shown) or the like.

[0022] As shown in FIG. 1, the wiping device 70 is provided between the capping device 60 and the platen 15 in the left-right direction. As shown in FIG. 3, the wiping device 70 includes a wiper 71 and a wiper moving device 72. The wiper 71 is configured to be able to wipe the nozzle surface 50s. The wiper 71 is a flat plate-shaped member extending in the left-right direction and the up-down direction. The upper edge of the wiper 71 is located slightly above the nozzle surface 50s of the recording head 50. The wiper 71 is made of, for example, rubber. The wiper moving device 72 moves the wiper 71 along the nozzle surface 50s so as to come into contact with the nozzle surface 50s of the recording head 50. Here, the wiper moving device 72 is configured to move the wiper 71 in the front-rear direction (the extension direction of the nozzle rows 51 to 58). However, the direction in which the wiper moving device 72 moves the wiper 71 is not limited. The wiper 71 comes into contact with the nozzle surface 50s or moves away from the nozzle surface 50s in the front-rear direction by being moved by the wiper moving device 72. When the wiper 71 is moved in the front-rear direction while in contact with the nozzle surface 50s, the nozzle surface 50s is wiped by the wiper 71 (hereinafter, also referred to as wiping). By wiping, ink adhering to the nozzle surface 50s is wiped away.

[0023] As shown in FIG. 1, the head moving device 30 moves the recording head 50 relative to the platen 15 and the cap 61. More specifically, the head moving device 30 is configured to be able to move the recording head 50 to a position P1 where the first nozzles 51a to the eighth nozzles 58a face the platen 15, and a position P2 where the first nozzles 51a to the eighth nozzles 58a face the cap 61. Hereinafter, the position of the recording head 50 where the first nozzles 51a to the eighth nozzles 58a face the platen 15 is also referred to as a printing position P1. In addition, the position of the recording head 50 where the first nozzles 51a to the eighth nozzles 58a face the cap 61 is also referred to as a standby position P2. Here, the standby position P2 is the right end of the movable range of the recording head 50 by the head moving device 30.

[0024] In this embodiment, the moving device that changes the position of the recording head relative to the support base and the ink receiving member is the head moving device 30 that moves the recording head 50, but it may be, for example, a device that moves the support base and the ink receiving member, or a device that moves the recording head, the support base, and the ink receiving member. The movement of the recording head relative to the support base and the ink receiving member is relative, and there is no particular limitation on which members are moved.

[0025] As shown in FIG. 1, the printer 10 includes a control device 100 that controls the operation of each unit. FIG. 4 is a block diagram of the printer 10 according to this embodiment. As shown in FIG. 4, the control device 100 is electrically connected to the scan motor 34, the feed motor 43, the recording head 50, the cap moving device 62, the suction pump 63, and the wiper moving device 72. The control device 100 controls the operations of these devices. The control device 100 includes a movement control unit 101, a print control unit 102, a capping control unit 103, a suction control unit 104, a wiping control unit 105, a first flushing control unit 106, and a second flushing control unit 107. The control device 100 may include other control units, but illustration and description thereof will be omitted here.

[0026] The configuration of the control device 100 is not particularly limited. The control device 100 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, but includes, for example, an interface (I / F) that receives print data and the like from an external device such as a host computer, a central processing unit (CPU) that executes instructions of a control program, a read only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as a memory that stores the above program and various data.

[0027] The movement control unit 101 controls the head moving device 30 to move the recording head 50 to the printing position P1 and the standby position P2. The movement control unit 101 basically positions the recording head 50 at the standby position P2 except when printing. The movement control unit 101 moves the recording head 50 to the printing position P1 at least when printing.

[0028] The print control unit 102 ejects the first to eighth inks from the first nozzles 51a to eighth nozzles 58a onto the recording medium 5 on the platen 15 while moving the recording head 50 in the left-right direction above the platen 15, thereby forming an image on the recording medium 5. The print control unit 102 also controls the conveying device 40 to convey the recording medium 5 intermittently forward. As a result, the entire print image is formed on the recording medium 5.

[0029] The capping control unit 103 controls the cap moving device 62 to attach and detach the cap 61 to and from the recording head 50. The capping control unit 103 basically attaches the cap 61 to the recording head 50 except during printing, wiping, and flushing. The capping control unit 103 attaches the cap 61 to the recording head 50 at least when the suction pump 63 is suctioning ink.

[0030] The suction control unit 104 drives the suction pump 63 to reduce the pressure in the internal space 61c of the cap 61 while the cap 61 is attached to the recording head 50, thereby sucking the first ink to the eighth ink from the first nozzle 51a to the eighth nozzle 58a, respectively. The suction control unit 104 may be configured to appropriately drive the suction pump 63 to discharge the ink inside the cap 61 even when the cap 61 is separated from the recording head 50.

[0031] The wiping control unit 105 controls the wiper moving device 72 to move the wiper 71 along the nozzle surface 50s of the recording head 50 and cause the wiper 71 to wipe the nozzle surface 50s. Hereinafter, the ink suction and the subsequent wiping are collectively referred to as cleaning of the nozzles 51a to 58a.

[0032] The first flushing control unit 106 ejects the first amount of the first ink to the eighth ink from the first nozzle 51a to the eighth nozzle 58a to the cap 61, respectively, when the recording head 50 is positioned at the standby position P2. The first amount is not particularly limited as long as it is an amount equal to or greater than the amount by which the first ink to the eighth ink in the first nozzle 51a to the eighth nozzle 58a are replaced, but here, it is an amount equivalent to or greater than 20,000 shots of ink ejection for each nozzle. The first amount is set to an amount that can reliably eliminate color mixing, for example, even if the corresponding ink of another nozzle row gets into the nozzle due to wiping and color mixing occurs. For example, the first amount is 480,000 pl / nozzle when the number of shots is 20,000 shots in a model in which the number of nozzles in one nozzle row is 180 nozzles and the ejection amount per shot of one nozzle is 24 ng. The first amount is preferably 450,000 pl / nozzle or more and 900,000 pl / nozzle or less. Hereinafter, the ink ejection in which the first amounts of the first to eighth inks are ejected from the first to eighth nozzles 51a to 58a onto the cap 61, respectively, will also be referred to as normal flushing.

[0033] The first amount may be changed depending on the timing of performing flushing, for example. For example, when normal flushing is performed immediately after wiping, the first amount may be a smaller amount within the range of the above-mentioned suitable amount, for example, 450000pl / nozzle. When normal flushing is performed before printing, not immediately after wiping, the first amount may be a larger amount within the range of the above-mentioned suitable amount, for example, 900000pl / nozzle. The first amount may also change depending on the number of nozzles in one nozzle row, the properties of the ink, back pressure, etc. The first amount may be an ink amount equivalent to 20000 shots or more and 40000 shots or less of ink ejection per nozzle. Since the suitable ink ejection amount in normal flushing may also change depending on the type of ink, the first amount may be increased according to the ink with the largest flushing amount (for example, for white ink, which is prone to noticeable color mixing, the amount is twice that of other colors).

[0034] The first flushing control unit 106 may be set to eject ink from all the nozzles 51a to 58a simultaneously in normal flushing. Alternatively, the first flushing control unit 106 may be set to perform normal flushing by shifting some or all of the timings of the first nozzles 51a to 8th nozzles 58a. For example, the first flushing control unit 106 may eject a first amount of ink from the first nozzle 51a, the third nozzle 53a, the fifth nozzle 55a, and the seventh nozzle 57a (nozzles in odd-numbered rows) simultaneously onto the cap 61, and eject the first amount of ink from the second nozzle 52a, the fourth nozzle 54a, the sixth nozzle 56a, and the eighth nozzle 58a (nozzles in even-numbered rows) simultaneously onto the cap 61, but at a timing different from that of the nozzles in the odd-numbered rows.

[0035] The second flushing control unit 107 ejects the second amount of the first ink to the eighth ink from the first nozzle 51a to the eighth nozzle 58a to the cap 61 after the normal flushing by the first flushing control unit 106. The second amount is set to an amount less than the first amount. The second amount is not particularly limited, but for example, in a model in which the number of nozzles in one nozzle row is 180 nozzles and the ejection amount per shot from one nozzle is 24 ng, the amount is 2400 pl / nozzle, which is an amount equivalent to 100 shots of ink ejection per nozzle. The second amount may be, for example, an amount equivalent to 100 shots or more and 200 shots or less of ink ejection per nozzle. The second amount is preferably 1 / 100 or less of the first amount. The second amount may be an amount necessary for the mixed ink generated by the normal flushing to be replaced with the ink that is not mixed. The second amount is preferably 2200 pl / nozzle or more and 4500 pl / nozzle or less. For example, the second amount may vary depending on the number of nozzles in one nozzle row, the properties of the ink, back pressure, etc., or the type of ink used, as in the case of the first amount. Hereinafter, the flushing by the second flushing control unit 107 is also referred to as a minute amount flushing. The minute amount flushing is a flushing in which the amount of ink ejected is minute so as to reduce ink splashes. Herein, the second flushing control unit 107 is configured to eject the second amount of ink simultaneously from the first nozzle 51a to the eighth nozzle 58a toward the cap 61. However, the second flushing control unit 107 may be set to shift the timing of the minute amount flushing of the first nozzle 51a to the eighth nozzle 58a in part or in whole.

[0036] In this embodiment, the first flushing control unit 106 and the second flushing control unit 107 are set to eject at least the first ink to the eighth ink onto the cap 61 after wiping is performed by the wiping control unit 105. That is, the first flushing control unit 106 executes normal flushing of at least the first nozzles 51a to the eighth nozzles 58a after wiping is performed by the wiping control unit 105. Thereafter, the second flushing control unit 107 executes minute amount flushing of the first nozzles 51a to the eighth nozzles 58a. However, the normal flushing and the minute amount flushing may be performed for other reasons, such as discharging ink that has not been used for a predetermined period of time.

[0037] The cleaning and flushing process by the printer 10 according to this embodiment will be described below. FIG. 5 is a flow chart showing an example of the cleaning and flushing process. However, the process shown here is merely a preferred example, and the process is not limited thereto. In the preferred example shown in FIG. 5, the cleaning is composed of ink suction S10 and wiping S20. As shown in FIG. 5, in step S11 of ink suction S10, the recording head 50 is moved to the standby position P2. In the following step S12, the cap 61 is attached to the recording head 50. If the recording head 50 is already positioned at the standby position P2 and the cap 61 is attached to the recording head 50, steps S11 and S12 may be omitted. In step S13, the suction pump 63 is driven, and the first ink to the eighth ink are sucked from the first nozzle 51a to the eighth nozzle 58a. Thereafter, in step S14, the cap 61 is separated from the recording head 50. During step S13, since inks of multiple colors are mixed inside the cap 61, there is a risk that ink from other nozzle rows will adhere to the nozzles, causing color mixing.

[0038] In step S21 of wiping S20, the recording head 50 is moved to a position where it overlaps with the wiper 71 in the left-right direction. In the following step S22, the wiper 71 is moved forward and wipes the nozzle surface 50s. At this time, too, there is a risk of ink being carried by the wiper 71 and pushed into the nozzles, causing color mixing. For this reason, it is preferable to perform flushing after wiping. In the following step S23, the recording head 50 is moved again to the standby position P2. In step S24, the wiper 71 returns to the position before wiping.

[0039] In step S31 of the flushing S30, normal flushing is performed. Normal flushing is performed with the cap 61 separated from the recording head 50. The same applies to the minute amount flushing. Here, normal flushing is performed simultaneously for the first nozzle 51a to the eighth nozzle 58a. For example, 20,000 shots of the first ink to the eighth ink are ejected from the first nozzle 51a to the eighth nozzle 58a, respectively. As a result, the first ink to the eighth ink in the first nozzle 51a to the eighth nozzle 58a are discharged, and color mixing caused by ink suction or wiping is eliminated.

[0040] However, when normal flushing is performed, ink droplets such as ink mist or droplets fly or fly in the air. These ink droplets may adhere to any of the first nozzles 51a to the eighth nozzles 58a of the recording head 50. If the ink droplets adhere to any of the nozzles 51a to 58a, problems such as poor ink discharge or color mixing may occur in the nozzle to which the ink adheres. Color mixing occurs when droplets of ink other than the corresponding ink adhere to a nozzle.

[0041] In conventional inkjet printers, the flushing was only normal flushing, so after cleaning but before printing started, the nozzles may be in a state where ink droplets as described above are attached. If printing is started in such a state, problems such as poor ink ejection and color mixing may occur immediately after printing starts.

[0042] The printer 10 according to this embodiment is configured to eliminate the above-mentioned state by performing a small amount of flushing. As shown in FIG. 5, in step S32 of this embodiment, a small amount of flushing is performed. Here, the small amount of flushing is performed simultaneously for the first nozzle 51a to the eighth nozzle 58a. For example, 100 shots of the first ink to the eighth ink are ejected from the first nozzle 51a to the eighth nozzle 58a, respectively. As a result, even if droplets of ink are attached to the first nozzle 51a to the eighth nozzle 58a, these droplets are expelled.

[0043] In the micro-amount flushing, an extremely small amount of ink is ejected compared to the normal flushing. In the micro-amount flushing, the generation of ink droplets is suppressed by ejecting only a small amount of ink. Therefore, the possibility that the ink droplets will adhere again to the first nozzle 51a to the eighth nozzle 58a is suppressed to be low. Moreover, the number of shots in the micro-amount flushing is set to a number of shots sufficient to remove the ink droplets even if the ink droplets adhere to the first nozzle 51a to the eighth nozzle 58a in the normal flushing. Therefore, by performing the micro-amount flushing, it is possible to reduce the adhesion of the ink droplets generated by the flushing to the nozzles 51a to 58a. The ink ejection amount (second amount) of each nozzle 51a to 58a in the micro-amount flushing is obtained, for example, by a trial using an actual machine.

[0044] FIG. 6 is a plan view showing a schematic state of the nozzle surface 50s after minute-amount flushing. As shown in FIG. 6, when ink droplets I1 adhere to the nozzle surface 50s by normal flushing, the ink droplets I1 may remain in places other than the first nozzle 51a to the eighth nozzle 58a of the nozzle surface 50s even after minute-amount flushing. However, even when ink droplets I1 adhere to the nozzle surface 50s by normal flushing, the ink droplets I1 are removed from the first nozzle 51a to the eighth nozzle 58a after minute-amount flushing (FIG. 6 shows the droplets I1 as being interrupted on the nozzle rows 55 and 56 shown as elongated rectangular regions). In a color printer using ink of multiple colors as in this embodiment, ink droplets adhering to the nozzles often cause color mixing, greatly impairing print quality, so minute-amount flushing is particularly effective.

[0045] A preferred embodiment of the present invention has been described above. However, the above embodiment is merely an example, and the technology disclosed herein can be embodied in various other forms. For example, in the above embodiment, the wiper moving device 72 is configured to move the wiper 71 in a direction intersecting the moving direction of the recording head 50, and is a device separate from the head moving device 30. However, the wiper moving device may be shared with the head moving device. In other words, the wiper may move relative to the recording head as the recording head is moved by the head moving device. In that case, the wiping proceeds in the direction of movement of the recording head.

[0046] The time interval between normal flushing and minute amount flushing is not particularly limited. The minute amount flushing may be performed immediately after the normal flushing, or may be performed after a predetermined time has elapsed for the ink mist during the normal flushing to converge. The work performed on one nozzle row between normal flushing and minute amount flushing for the other nozzle row is not particularly limited, and for example, normal flushing or minute amount flushing may be performed in between.

[0047] The amount of ink ejected during normal flushing may differ for each nozzle row. For example, the nozzles of the first nozzle row may eject a first amount of ink during normal flushing, and the nozzles of the second nozzle row may eject a third amount of ink during normal flushing. The same is true for the minute amount flushing, where the nozzles of the first nozzle row may eject a second amount of ink during minute amount flushing, and the nozzles of the second nozzle row may eject a fourth amount of ink during minute amount flushing. The fourth amount may be less than the first amount and the third amount, and is preferably less than one hundredth of the first amount and the third amount.

[0048] The configuration of the inkjet printer is not limited unless otherwise specified. For example, the technology disclosed herein can be used for flatbed type inkjet printers. It can also be used for devices that incorporate an inkjet printer as a part thereof, such as inkjet printers with cutting heads. [Explanation of symbols]

[0049] 5 Recording media 10. Inkjet Printer 15 Platen (support) 30 Head moving device (moving device) 50 Recording head 50s nozzle surface 51-58 1st to 8th nozzle rows 51a to 58a No. 1 to No. 8 nozzles 60 Capping device 61 Cap (ink receiving part) 62 Cap moving device 63 Suction Pump 70 Wiping device 71 Wiper 72 Wiper moving device 100 Control device 101 Movement control unit 102 Print control unit 103 Capping control section 104 Suction control unit 105 Wiping control section 106 First flushing control section 107 Second flushing control section I1 Ink Splash P1 Printing position (1st position) P2 Standby position (2nd position)

Claims

1. a support table having a support surface for supporting a recording medium; a recording head having a plurality of first nozzles that eject a first ink downward, the recording head being disposed above the support surface; an ink receiving member provided below the first nozzles and configured to receive the first ink ejected from the first nozzles; a moving device for moving the recording head relatively to the support base and the ink receiving member; a control device for controlling the recording head and the moving device; Equipped with The control device includes: a movement control unit that controls the moving device to move the recording head to a first position where the plurality of first nozzles face the support surface and a second position where the plurality of first nozzles face the ink receiving member; a first flushing control unit that ejects a first amount of the first ink from the first nozzles onto the ink receiving member while the recording head is positioned at the second position; a second flushing control unit that ejects a second amount of the first ink from the first nozzles onto the ink receiving member after a predetermined time has elapsed for ink mist to converge when the first flushing control unit ejects the first ink, the second amount being smaller than the first amount; Equipped with The second amount is 100 times smaller than the first amount. Inkjet printer.

2. the recording head has a nozzle surface in which the first nozzles are formed, a wiping device including a wiper capable of wiping the nozzle surface, and a wiper moving device that moves the wiper along the nozzle surface so as to contact the nozzle surface, the control device further includes a wiping control unit that controls the wiper moving device to move the wiper along the nozzle surface, the first flushing control unit and the second flushing control unit eject the first ink onto the ink receiving member at least after the wiper is moved along the nozzle surface by the wiping control unit; 2. The inkjet printer according to claim 1.

3. the recording head has a nozzle surface in which the first nozzles are formed, the receiving member is a cap of the recording head, the cap having a bottom and a side wall extending upward from the bottom over an entire periphery of the bottom, a receiving member moving device that moves the ink receiving member at least in a vertical direction to bring an upper edge of the side wall into contact with the nozzle face or separates the upper edge from the nozzle face, 3. The inkjet printer according to claim 1 or 2.

4. A support table having a support surface for supporting a recording medium; a recording head having a plurality of first nozzles that eject a first ink downward and a plurality of second nozzles that eject a second ink downward, the second ink having a color different from that of the first ink, the recording head being disposed above the support surface; an ink receiving member that is provided below the plurality of first nozzles and the plurality of second nozzles and is configured to be able to receive the first ink ejected from the plurality of first nozzles and the second ink ejected from the plurality of second nozzles; a moving device for moving the recording head relatively to the support base and the ink receiving member; a control device for controlling the recording head and the moving device; Equipped with The control device includes: a movement control unit that controls the moving device to move the recording head to a first position where the plurality of first nozzles and the plurality of second nozzles face the support surface and a second position where the plurality of first nozzles and the plurality of second nozzles face the ink receiving member; a first flushing control unit that ejects a first amount of the first ink from the first nozzles onto the ink receiving member and ejects a third amount of the second ink from the second nozzles onto the ink receiving member while the recording head is positioned at the second position; a second flushing control unit that causes the first ink to be ejected from the first nozzles onto the ink receiving member in a second amount smaller than the first amount, and causes the second ink to be ejected from the second nozzles onto the ink receiving member in a fourth amount smaller than the first amount and the third amount; Equipped with the first flushing control unit is configured to eject the third amount of the second ink from the plurality of second nozzles at a timing different from a timing at which the first amount of the first ink is ejected from the plurality of first nozzles; the second flushing control unit causes the first ink to be ejected from the first nozzles in the second amount and the second ink to be ejected from the second nozzles in the fourth amount after the first flushing control unit ejects the first ink and the second ink. Inkjet printer.

5. the second amount being 100 times smaller than the first amount; The fourth amount is 100 times smaller than the third amount.

5. The inkjet printer according to claim 4.

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