JP2018001421A - Inkjet printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress ink from being accumulated in a gap between a nozzle surface and a nozzle guard of an inkjet head.SOLUTION: An inkjet printing device 1 comprises: an inkjet head which has a nozzle surface to which a nozzle opens and a nozzle guard for covering the nozzle surface through a gap, in which an opening part for exposing the nozzle is formed; a porous wiper, formed of a porous material, whose center part is inserted into the opening part of the nozzle guard to wipe the nozzle surface; a cleaning fluid removing part 57 for removing cleaning fluid impregnated into the porous wiper; and a control part 5 which performs control so that the porous wiper impregnated with the cleaning fluid wipes the nozzle surface and then the porous wiper from which the cleaning fluid is removed by the cleaning fluid removing part 57 wipes the nozzle surface.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an ink jet printing apparatus that prints by discharging ink from an ink jet head onto a print medium.

  In an ink jet printing apparatus, if ink or foreign matter adheres to the nozzle surface of an ink jet head, ink ejection failure may occur. Therefore, in the inkjet printing apparatus, as the maintenance of the inkjet head, the nozzle surface is wiped with a wiper to remove ink or the like adhering to the nozzle surface.

  Incidentally, some inkjet printing apparatuses use an inkjet head provided with a nozzle guard for preventing a print medium from contacting the nozzle surface. Patent Document 1 discloses an ink jet printing apparatus that performs maintenance on an ink jet head having a nozzle guard.

  The ink jet printing apparatus of Patent Document 1 has a nozzle guard that is fixed in close contact with the nozzle surface of the ink jet head and protrudes from the nozzle surface. The ink jet printing apparatus has two rubber wipers, one wiper made of a porous member, and a cleaning tank in which a cleaning liquid is stored. In this inkjet printing apparatus, cleaning liquid is adhered to each wiper, and the nozzle guard and the nozzle surface are wiped to perform cleaning. The rubber wiper is divided into three parts by slits, and the nozzle guard can be wiped at both sides, and the nozzle surface that is recessed with respect to the surface of the nozzle guard can be wiped at the center. Yes.

Japanese Unexamined Patent Publication No. 2016-32930

  Incidentally, some ink jet heads having a nozzle guard have a gap between the nozzle surface and the nozzle guard. In the maintenance for such an ink jet head, the one divided into three parts is generally used, similar to the rubber wiper of Patent Document 1 described above. The central portion of the wiper is inserted into an opening formed in the nozzle guard for exposing the nozzle, and the nozzle surface is wiped.

  At this time, part of the ink adhering to the nozzle surface may enter the gap between the nozzle surface and the nozzle guard. If the ink that has entered the gap accumulates, the ink may become a lump and fall from the opening to the printed material, which may contaminate the printed material.

  The present invention has been made in view of the above, and an object of the present invention is to provide an ink jet printing apparatus that can suppress ink accumulation in a gap between a nozzle surface of an ink jet head and a nozzle guard.

  In order to achieve the above object, a first feature of an ink jet printing apparatus according to the present invention is a nozzle surface that opens a nozzle and covers the nozzle surface through a gap, and an opening that exposes the nozzle. An ink-jet head having a nozzle guard formed with a porous member, and at least a part of the ink-jet head is inserted into the opening to wipe the nozzle surface; and the first wiper is impregnated Control is performed such that the nozzle surface is wiped by the cleaning liquid removing unit for removing the cleaning liquid and the first wiper impregnated with the cleaning liquid, and then the nozzle surface is wiped by the first wiper from which the cleaning liquid is removed by the cleaning liquid removing unit. And a control unit.

  A second feature of the ink jet printing apparatus according to the present invention is that the ink jet printing apparatus further includes a second wiper that is formed of an elastic member and that is at least partially inserted into the opening to wipe the nozzle surface. The nozzle surface is wiped by the second wiper after the nozzle surface is wiped by the first wiper impregnated with the nozzle and before the nozzle surface is wiped by the first wiper from which the cleaning liquid has been removed. There is.

  A third feature of the ink jet printing apparatus according to the present invention is that, when the nozzle surface is wiped by the first wiper from which the cleaning liquid has been removed, the control is performed so as to perform wiping at a lower speed than at the time of other wiping. There is to do.

  According to the first feature of the inkjet printing apparatus according to the present invention, the first wiper from which the cleaning liquid has been removed by wiping the nozzle surface with the first wiper from which the cleaning liquid has been removed by the cleaning liquid removing unit The ink in the gap with the nozzle guard is adsorbed and removed by capillary force. As a result, ink accumulation in the gap between the nozzle surface and the nozzle guard can be suppressed.

  According to the second feature of the ink jet printing apparatus according to the present invention, since the nozzle surface is wiped by the second wiper, the deposits on the nozzle surface 36a can be more easily removed and the cleaning effect can be further enhanced.

  According to the third aspect of the ink jet printing apparatus of the present invention, when wiping the nozzle surface with the first wiper from which the cleaning liquid has been removed, the wiping is performed at a lower speed than during other wiping operations. More ink can be adsorbed to the first wiper. Thereby, accumulation of ink in the gap between the nozzle surface and the nozzle guard can be further suppressed.

1 is an overall perspective view of an inkjet printing apparatus according to an embodiment. It is a front view which shows typically schematic structure of the inkjet printing apparatus shown in FIG. It is a perspective view of an inkjet head. It is sectional drawing along the AA line of FIG. It is a perspective view of a maintenance part. It is a perspective view of a wiper. It is a perspective view of a washing liquid removal part. It is a control block diagram of the inkjet printing apparatus shown in FIG. It is a flowchart for demonstrating a maintenance operation | movement. It is an operation | movement figure for demonstrating a maintenance operation | movement. It is an operation | movement figure for demonstrating a maintenance operation | movement. It is an operation | movement figure for demonstrating a maintenance operation | movement. It is an operation | movement figure for demonstrating a maintenance operation | movement. It is an operation | movement figure for demonstrating a maintenance operation | movement. It is an operation | movement figure for demonstrating a maintenance operation | movement. It is a figure which shows a mode that a porous wiper adsorb | sucks the ink of the clearance gap between a nozzle surface and a nozzle guard.

  Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals.

  The following embodiments exemplify devices for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, arrangement, etc. of each component. Is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

  FIG. 1 is an overall perspective view of an ink jet printing apparatus according to an embodiment of the present invention. FIG. 2 is a front view schematically showing a schematic configuration of the ink jet printing apparatus shown in FIG. FIG. 3 is a perspective view of the inkjet head. 4 is a cross-sectional view taken along line AA in FIG. FIG. 5 is a perspective view of the maintenance unit. FIG. 6 is a perspective view of the wiper. FIG. 7 is a perspective view of the cleaning liquid removing unit. FIG. 8 is a control block diagram of the ink jet printing apparatus shown in FIG. In the following description, the vertical and horizontal directions indicated by the arrows in FIG.

  As shown in FIGS. 1 and 2, the ink jet printing apparatus 1 according to the present embodiment includes a shuttle base unit 2, a flat bed unit 3, a shuttle unit 4, and a control unit 5.

  The shuttle base unit 2 supports the shuttle unit 4 and moves the shuttle unit 4 in the front-rear direction (sub-scanning direction). The shuttle base unit 2 includes a gantry 11 and a sub-scanning drive motor 12.

  The gantry 11 supports the shuttle unit 4. The gantry 11 is formed in a rectangular frame shape. Sub-scanning drive guides 13A and 13B extending in the front-rear direction are formed on the left and right frames of the gantry unit 11, respectively. The sub-scanning drive guides 13A and 13B guide the shuttle unit 4 to move in the front-rear direction.

  The sub-scanning drive motor 12 moves the shuttle unit 4 in the front-rear direction.

  The flat bed unit 3 holds a print medium 15 made of a base material such as a building material or a decorative panel. The flat bed unit 3 is disposed inside the gantry 11 of the shuttle base unit 2. The flat bed unit 3 has a medium placement surface 3a that is a horizontal surface on which the print medium 15 is placed. The flat bed unit 3 can adjust the height of the medium placement surface 3a by an elevating mechanism such as a hydraulic drive mechanism.

  The shuttle unit 4 prints an image on the print medium 15. As shown in FIGS. 1, 2, and 8, the shuttle unit 4 includes a housing 21, a main scanning drive guide 22, a main scanning drive motor 23, a head lifting guide 24, a head lifting motor 25, and a head. A unit 26 and a maintenance unit 27 are provided.

  The housing 21 houses each part such as the head unit 26. The casing 21 is formed in a gate shape straddling the flat bed unit 3 in the left-right direction. The casing 21 is supported by the gantry 11 of the shuttle base unit 2 and is movable along the sub-scanning drive guides 13A and 13B.

  The main scanning drive guide 22 guides the head unit 26 to move in the left-right direction (main scanning direction). The main scanning drive guide 22 is formed in a long shape extending in the left-right direction.

  The main scanning drive motor 23 moves the head unit 26 in the left-right direction.

  The head lifting guide 24 guides the head unit 26 to move in the vertical direction. The head lifting guide 24 is formed in an elongated shape in the vertical direction. The head raising / lowering guide 24 is configured to be movable in the left-right direction along the main scanning drive guide 22 together with the head unit 26.

  The head lifting motor 25 moves the head unit 26 up and down.

  The head unit 26 prints an image by ejecting ink onto the print medium 15 while moving in the left-right direction along the main scanning drive guide 22. The head unit 26 includes four inkjet heads 31.

  The inkjet head 31 discharges aqueous ink to the print medium 15. The four inkjet heads 31 are arranged in parallel in the left-right direction. The four inkjet heads 31 eject inks of different colors (for example, cyan, black, magenta, and yellow). As shown in FIGS. 3 and 4, the inkjet head 31 has a nozzle plate 36 and a nozzle guard 37.

  The nozzle plate 36 is a member on which nozzles 38 that eject ink are formed. The nozzle plate 36 is provided at the lower end of the inkjet head 31. The nozzle plate 36 is formed in a rectangular plate shape. A plurality of nozzles 38 are opened on a nozzle surface 36 a that is the surface (lower surface) of the nozzle plate 36. The plurality of nozzles 38 are arranged along the front-rear direction.

  The nozzle guard 37 protects the nozzle surface 36 a of the inkjet head 31. The nozzle guard 37 is installed at the lower end of the inkjet head 31. The nozzle guard 37 includes a rectangular bottom plate 41 that covers the nozzle surface 36 a via the gap 40, and a side wall 42 that stands on the periphery of the bottom plate 41. The bottom plate 41 is formed with an opening 46 for exposing the nozzle 38 of the inkjet head 31. The opening 46 is formed in a rectangular shape elongated in the front-rear direction, and is disposed at a position where all the nozzles 38 are exposed.

  The maintenance unit 27 cleans the nozzle surface 36 a and the nozzle guard 37 of the inkjet head 31. As shown in FIGS. 5 and 8, the maintenance unit 27 includes four porous wipers (corresponding to the first wiper in the claims) 51, four porous wiper fixing portions 52, and four rubber wipers (in the claims). (Corresponding to the second wiper) 53, four rubber wiper fixing parts 54, a wiper driving part 55, four cleaning liquid storage parts 56, and four cleaning liquid removing parts 57.

  The porous wiper 51 applies the cleaning liquid while wiping the nozzle surface 36 a and the nozzle guard 37 of the inkjet head 31. Further, the porous wiper 51 adsorbs and removes the ink and the cleaning liquid by wiping the nozzle surface 36a of the inkjet head 31 and the lower surface of the nozzle guard 37 in a state where the cleaning liquid is removed. The porous wiper 51 is formed of a porous member such as sponge or non-woven fabric that can be impregnated with the cleaning liquid.

  As shown in FIG. 6, the porous wiper 51 is divided into three parts, that is, a central part 51a, a left part 51b, and a right part 51c. The central portion 51 a is a portion that is inserted into the opening 46 of the nozzle guard 37 and wipes the nozzle surface 36 a of the inkjet head 31. The tips of the central portion 51a protrude from the tips of the left portion 51b and the right portion 51c. The width (length in the left-right direction) of the central portion 51 a is slightly smaller than the width of the opening 46 of the nozzle guard 37. The left portion 51 b and the right portion 51 c are portions that wipe the lower surface of the nozzle guard 37.

  The porous wiper fixing part 52 fixes the porous wiper 51 to a wiper drive belt 61 described later.

  The rubber wiper 53 wipes the nozzle surface 36 a and the nozzle guard 37 of the inkjet head 31 to which the cleaning liquid is applied by the porous wiper 51. The rubber wiper 53 is formed of rubber that is an elastic member. As shown in FIG. 6, the rubber wiper 53 has the same shape as the porous wiper 51, and the tip side is divided into three parts: a central part 53 a, a left part 53 b, and a right part 53 c.

  The rubber wiper fixing portion 54 fixes the rubber wiper 53 to a wiper drive belt 61 described later.

  The wiper driving unit 55 drives the porous wiper 51 and the rubber wiper 53. The wiper drive unit 55 includes four wiper drive belts 61, a drive roller 62, and driven rollers 63 and 64.

  The wiper drive belt 61 is an annular belt that is stretched around the drive roller 62 and the driven rollers 63 and 64. Four wiper drive belts 61 are provided corresponding to each of the four inkjet heads 31. A porous wiper 51 is attached to each wiper drive belt 61 via a porous wiper fixing portion 52. A rubber wiper 53 is attached to each wiper drive belt 61 via a rubber wiper fixing portion 54. Accordingly, one porous wiper 51 and one rubber wiper 53 are provided for each inkjet head 31.

  The wiper drive belt 61 rotates in a direction indicated by an arrow in FIG. 5 (counterclockwise direction when viewed from the left side), and moves the porous wiper 51 and the rubber wiper 53. As a result, the porous wiper 51 and the rubber wiper 53 move from the front side to the rear side in the horizontal section of the wiper drive belt 61 stretched between the drive roller 62 and the driven roller 63, while the nozzle surface 36a and Wipe the nozzle guard 37.

  The drive roller 62 rotates the wiper drive belt 61. The drive roller 62 is rotationally driven by a motor (not shown).

  The driven rollers 63 and 64 support the four wiper drive belts 61 together with the drive roller 62. The driven rollers 63 and 64 are driven to rotate by the driving roller 62 via the wiper driving belt 61. The driven roller 63 has the same height as the drive roller 62 and is disposed behind the drive roller 62. The driven roller 64 is disposed below an intermediate position between the driving roller 62 and the driven roller 63 in the front-rear direction.

  The cleaning liquid storage unit 56 stores cleaning liquid for cleaning the nozzle surface 36 a and the nozzle guard 37. The four cleaning liquid reservoirs 56 are provided corresponding to each of the four inkjet heads 31. The cleaning liquid storage unit 56 is disposed below the wiper drive belt 61. Thereby, when the porous wiper 51 and the rubber wiper 53 pass through the vicinity of the driven roller 64 by the rotation of the wiper driving belt 61, the porous wiper 51 and the rubber wiper 53 are immersed in the cleaning liquid in the cleaning liquid storage section 56. .

  The cleaning liquid has a function of dissolving ink. As this cleaning liquid, for example, an aqueous solvent containing water and a surfactant can be used.

  Examples of the surfactant include fatty acid sodium, sodium alkylbenzene sulfonate, sodium alkyl sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfate ester, sodium alkyl ether sulfate ester, sodium α-sulfo fatty acid ester, sodium alkyl phosphate ester. Anionic surfactant such as alkyl cationic trimethylammonium, dialkyldimethylammonium, etc .; sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl Nonionic surfactants such as phenyl ethers; sodium alkylamino fatty acids, alkylbetaines, alkylamines Amphoteric surfactants such as oxide can be used. In addition, polymer surfactants, silicone surfactants, fluorine surfactants, acetylene glycol surfactants, and the like can also be used. Among these, it is preferable to use polyoxyethylene alkyl ether, the HLB value is 11 to 17, the number of carbon atoms of the alkyl group is 8 to 15, and the number of added moles of ethylene oxide is more preferably 6 to 25.

  The cleaning liquid preferably further contains a thickener. As the thickener, a water-soluble polymer thickener or a clay mineral thickener can be used. As the water-soluble polymer thickener, natural polymers, semi-synthetic polymers, and synthetic polymers can be used. Examples of natural polymers include plant-based natural polymers such as gum arabic, carrageenan, guar gum, locust bean gum, pectin, tragacanth gum, corn starch, konjac mannan, agar; Animal-based natural polymers such as gelatin, casein, and glue can be used. Examples of semi-synthetic polymers include cellulose-based semi-synthetic polymers such as ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, and hydroxypropyl methyl cellulose; starch-based compounds such as hydroxyethyl starch, sodium carboxymethyl starch, and cyclodextrin. Semi-synthetic polymers; Alginate-based semi-synthetic polymers such as sodium alginate and propylene glycol alginate; sodium hyaluronate can be used. As the synthetic polymer, for example, vinyl-based synthetic polymers such as polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, poly N-vinylacetamide, and polyacrylamide; polyethylene oxide, polyethyleneimine, and polyurethane can be used. As the clay mineral-based thickener, for example, smectite-based clay minerals such as montmorillonite, hectorite, and saponite can be used. Among these, it is preferable to use hydroxypropyl methylcellulose.

  Furthermore, in addition to the above components, the cleaning liquid can optionally contain a water-soluble organic solvent, a pH adjuster, an antioxidant, a preservative, and the like. The viscosity of the cleaning liquid is preferably 5 to 200 mPa · s at 23 ° C., and more preferably 10 to 100 mPa · s.

  The cleaning liquid removing unit 57 removes the cleaning liquid impregnated in the porous wiper 51. As shown in FIG. 7, the cleaning liquid removing unit 57 has a pair of squeezing rollers 66 and 67 that squeeze and sandwich the porous wiper 51. The squeezing rollers 66 and 67 are rotatably supported at one end portions of the arm portions 68 and 69, respectively. The other end of the arm portion 68 is connected to the drive gear 70. The other end of the arm 69 is connected to a driven gear 71 that meshes with the drive gear 70. The drive gear 70 is rotated by a motor (not shown), and the driven gear 71 is rotated in the opposite direction to the drive gear 71 by the rotation of the drive gear 70. As the drive gear 70 and the drive gear 71 rotate in the opposite directions, the arm portions 68 and 69 rotate in the opposite directions around the rotation axes of the drive gear 70 and the drive gear 71, respectively. As a result, the squeezing rollers 66 and 67 can be separated from each other.

  The cleaning liquid removing unit 57 is disposed at a position on the lower right side of the wiper driving unit 55 where the porous wiper 51 moving from the driven roller 64 toward the driving roller 62 can be sandwiched.

  The control unit 5 controls the operation of the entire inkjet printing apparatus 1. The control unit 5 includes a CPU, a RAM, a ROM, a hard disk, and the like.

  The control unit 5 controls to wipe the nozzle surface 36 a and the nozzle guard 37 with the porous wiper 51 impregnated with the cleaning liquid and then wipe the nozzle surface 36 a and the nozzle guard 37 with the rubber wiper 53 during the maintenance of the inkjet head 31. To do. After repeating this for a predetermined number of times, the control unit 5 removes the cleaning liquid impregnated in the porous wiper 51 by the cleaning liquid removing unit 57, and wipes the nozzle surface 36a and the nozzle guard 37 with the porous wiper 51 from which the cleaning liquid has been removed. Control to do.

  Next, the printing operation of the inkjet printing apparatus 1 will be described.

  In the inkjet printing apparatus 1, the shuttle unit 4 is disposed at the standby position in the standby state before the start of the printing operation. The standby position of the shuttle unit 4 is the position of the shuttle unit 4 indicated by a solid line in FIG.

  When a print job is input, the control unit 5 controls the sub-scanning drive motor 12 to move the shuttle unit 4 from the standby position to the print processing start position. The printing process start position of the shuttle unit 4 is the position of the shuttle unit 4 indicated by a two-dot chain line in FIG. Prior to the input of the print job, the print medium 15 is placed on the medium placement surface 3 a of the flat bed unit 3.

  Next, the control unit 5 controls the ink jet head 31 based on the print job to eject ink from the nozzles 38 while controlling the main scanning drive motor 23 to move the head unit 26 in the main scanning direction, thereby causing the 1 Print the pass. Next, the control unit 5 controls the sub-scanning drive motor 12 to move the shuttle unit 4 backward to the printing position of the next pass. The controller 5 forms an image on the print medium 15 by alternately repeating the printing for one pass and the movement of the shuttle unit 4.

  When printing for one sheet is completed, the control unit 5 controls the sub-scanning drive motor 12 to place the shuttle unit 4 at the standby position. Thereby, the printing operation is completed.

  Next, the maintenance operation of the inkjet head 31 in the inkjet printing apparatus 1 will be described.

  The maintenance operation is performed, for example, at a timing for each preset number of printed sheets or a timing according to a user instruction.

  FIG. 9 is a flowchart for explaining the maintenance operation. Here, prior to the start of the processing of the flowchart of FIG. 9, the control unit 5 immerses the porous wiper 51 in the cleaning liquid in the cleaning liquid storage unit 56 to impregnate the porous wiper 51 with the cleaning liquid. Further, the controller 5 performs a purge to suck out ink from the nozzles 38 of the inkjet head 31 by driving a suction pump (not shown) in a state where the opening 46 of the nozzle guard 37 is capped with a capping unit (not shown). Thereby, the thickened ink in the nozzle 38 is discharged. Then, the ink is attached to the nozzle surface 36a. Further, the control unit 5 controls the main scanning drive motor 23 to move it above the maintenance unit 27, and then controls the head lifting motor 25 to lower the head unit 26 and place it at the maintenance position. The maintenance position of the head unit 26 is a position of the head unit 26 for wiping the nozzle surface 36 a and the nozzle guard 37 with the porous wiper 51 and the rubber wiper 53.

  In step S <b> 1 of FIG. 9, the control unit 5 wipes the nozzle surface 36 a and the nozzle guard 37 with the porous wiper 51 impregnated with the cleaning liquid. Specifically, the control unit 5 starts the rotation of the wiper driving belt 61 by starting the rotation of the driving roller 62 of the wiper driving unit 55. Here, when the rotation of the wiper drive belt 61 is started, the porous wiper 51 and the rubber wiper 53 are placed on the inkjet head 31 prior to the rubber wiper 53 when the rotation of the wiper drive belt 61 is started. It is in a positional relationship to reach.

  When the porous wiper 51 is moved by the rotation of the wiper driving belt 61 and reaches the front end of the ink jet head 31, first, the central portion 51 a, the left side portion 51 b, and the right side portion 51 c of the porous wiper 51 are moved to the nozzle guard 37. Wipe the front edge of the underside. Thereby, the deposit on the front end portion of the lower surface of the nozzle guard 37 is wiped off, and the cleaning liquid 82 is applied to the front end portion of the lower surface of the nozzle guard 37.

  When the porous wiper 51 reaches the front end of the opening 46 of the nozzle guard 37, the central portion 51 a of the porous wiper 51 is inserted into the opening 46 as shown in FIG. 10. Thereafter, the porous wiper 51 moves backward, so that the central portion 51a of the porous wiper 51 wipes the nozzle surface 36a. As a result, as shown in FIGS. 10 and 11, the ink 81 and other deposits adhered to the nozzle surface 36a are wiped off by the purge, and the cleaning liquid 82 is applied to the nozzle surface 36a.

  At this time, the left portion 51 b and the right portion 51 c of the porous wiper 51 wipe the left portion and the right portion of the opening 46 on the lower surface of the nozzle guard 37, respectively. As a result, deposits on the left and right portions of the opening 46 on the lower surface of the nozzle guard 37 are wiped off, and the cleaning liquid 82 is applied to those portions.

  When the porous wiper 51 reaches the rear end of the opening 46 of the nozzle guard 37, the central portion 51 a of the porous wiper 51 comes out of the opening 46. Thereafter, the central portion 51a, the left portion 51b, and the right portion 51c of the porous wiper 51 wipe the rear end portion of the lower surface of the nozzle guard 37. As a result, deposits on the rear end of the lower surface of the nozzle guard 37 are wiped off, and the cleaning liquid 82 is applied to the rear end of the lower surface of the nozzle guard 37.

  Next, in step S <b> 2 of FIG. 9, the control unit 5 causes the rubber wiper 53 to wipe the nozzle surface 36 a and the nozzle guard 37. Specifically, the control unit 5 continues the rotation of the wiper drive belt 61. As a result, the rubber wiper 53 reaches the inkjet head 31. A rubber wiper 53 that moves rearward below the inkjet head 31 wipes the nozzle surface 36 a and the nozzle guard 37.

  At this time, as shown in FIGS. 12 and 13, the central portion 53a of the rubber wiper 53 is inserted into the opening 46 of the nozzle guard 37 in the same manner as in the case of wiping with the porous wiper 51 described above, and the nozzle surface 36a is wiped. To do. Further, the front end portion and the rear end portion of the lower surface of the nozzle guard 37 are wiped by the central portion 53a, the left portion 53b, and the right portion 53c of the rubber wiper 53. The left part and the right part of the opening 46 on the lower surface of the nozzle guard 37 are wiped by the left part 53b and the right part 53c of the rubber wiper 53, respectively.

  By the wipe by the rubber wiper 53, the cleaning liquid 82 applied to the lower surface of the nozzle surface 36a and the nozzle guard 37 is wiped off. Further, ink or the like fixed to the lower surface of the nozzle surface 36 a and the nozzle guard 37 is scraped off by the rubber wiper 53. The ink fixed to the lower surface of the nozzle surface 36 a and the nozzle guard 37 is dissolved by the cleaning liquid 82 applied to the lower surface of the nozzle surface 36 a and the nozzle guard 37 by the porous wiper 51 and is easily scraped off.

  Next, in step S3 of FIG. 9, the control unit 5 determines whether or not the number of wipes has reached a specified number. Here, the number of wipes refers to the number of times the combination of the wipe by the porous wiper 51 impregnated with the cleaning liquid in Step S1 and the wipe by the rubber wiper 53 in Step S2 is performed. The specified number of wipes is set according to the number of printed sheets between maintenance operations, for example. This specified number of times may be changed according to, for example, the inspection result of the frequency of occurrence of ejection defects in the printed matter.

  When it is determined that the number of wipes has not reached the specified number (step S3: NO), the control unit 5 returns to step S1.

  If it is determined that the number of wipes has reached the specified number (step S3: YES), in step S4, the control unit 5 controls the cleaning liquid removing unit 57 to remove the cleaning liquid impregnated in the porous wiper 51.

  Specifically, when the sensor (not shown) detects that the porous wiper 51 moving by the rotation of the wiper drive belt 61 has reached a predetermined position, the control unit 5 detects the squeezing roller of the cleaning liquid removing unit 57. 66 and 67 are controlled to approach each other. Thereby, as shown in FIG. 14, the squeezing rollers 66 and 67 sandwich the porous wiper 51. With the squeezing rollers 66 and 67 sandwiching the porous wiper 51, the movement of the porous wiper 51 by the rotation of the wiper driving belt 61 is continued, so that the porous wiper 51 comes out of the squeezing rollers 66 and 67. At this time, the squeezed rollers 66 and 67 are used to squeeze. As a result, the cleaning liquid is removed from the porous wiper 51.

  Next, in step S5 of FIG. 9, the control unit 5 wipes the nozzle surface 36a and the nozzle guard 37 with the porous wiper 51 from which the cleaning liquid has been removed. Specifically, the control unit 5 continues the rotation of the wiper drive belt 61. Thereby, the porous wiper 51 reaches the inkjet head 31. Then, as shown in FIG. 14, the porous wiper 51 that moves rearward below the inkjet head 31 wipes the nozzle surface 36 a and the nozzle guard 37.

  Here, the control unit 5 performs control so that the wipe by the porous wiper 51 in step S5 is performed at a lower speed than that in the above-described steps S1 and S2. That is, the control unit 5 wipes the wiper drive unit 55 so that the movement speed of the porous wiper 51 in step S5 is lower than the movement speed of the porous wiper 51 and the rubber wiper 53 in steps S1 and S2. To control.

  The porous wiper 51 from which the cleaning liquid has been removed wipes the nozzle surface 36a and the nozzle guard 37, thereby adsorbing the ink and the cleaning liquid remaining on the lower surface of the nozzle surface 36a and the nozzle guard 37 by the capillary force of the porous member.

  Here, when the central portion 51 a of the porous wiper 51 wipes the nozzle surface 36 a in step S <b> 1 described above, a part of the ink 81 wiped from the nozzle surface 36 a is a gap 40 between the nozzle surface 36 a and the nozzle guard 37. Get in. Further, when the central portion 53a of the rubber wiper 53 wipes the nozzle surface 36a in step S2, a part of the ink scraped off from the nozzle surface 36a enters the gap 40 together with the cleaning liquid. For this reason, as shown in FIGS. 13 to 15, the gap 40 after the combination of the wipe by the porous wiper 51 impregnated with the cleaning liquid in step S <b> 1 and the wipe by the rubber wiper 53 in step S <b> 2 is performed a predetermined number of times as shown in FIGS. 81 remains.

  On the other hand, in step S5, the wiper 51 is wiped by the porous wiper 51 from which the cleaning liquid has been removed. Therefore, as shown in FIG. 16, the ink 81 in the gap 40 together with the cleaning liquid has a porous wiper due to the capillary force of the porous member. 51 is adsorbed.

  When the wipe with the porous wiper 51 from which the cleaning liquid has been removed is completed, the control unit 5 stops the rotation of the drive roller 62 of the wiper drive unit 55 and ends the maintenance operation.

  As described above, in the inkjet printing apparatus 1, the control unit 5 wipes the nozzle surface 36a with the porous wiper 51 and the rubber wiper 53 impregnated with the cleaning liquid, and then the nozzle surface 36a with the porous wiper 51 from which the cleaning liquid has been removed. Control to wipe. Thereby, the porous wiper 51 from which the cleaning liquid has been removed adsorbs and removes the ink that has entered the gap 40 between the nozzle surface 36a and the nozzle guard 37 by capillary force, so that accumulation of ink in the gap 40 can be suppressed.

  Further, the control unit 5 performs the wiping by the porous wiper 51 from which the cleaning liquid has been removed at a lower speed than the other wiping (wiping by the porous wiper 51 impregnated with the cleaning liquid and wiping by the rubber wiper 53). Control as follows. As a result, more ink in the gap 40 can be adsorbed to the porous wiper 51. As a result, ink accumulation in the gap 40 can be further suppressed.

  In the above-described embodiment, the wiper is wiped by the rubber wiper 53 after the wipe by the porous wiper 51 impregnated with the cleaning liquid and before the wipe by the porous wiper 51 from which the cleaning liquid is removed. 53 may be omitted. Even in this case, the lower surface of the nozzle surface 36 a and the nozzle guard 37 is cleaned by wiping with the porous wiper 51 impregnated with the cleaning liquid and the porous wiper 51 from which the cleaning liquid is removed, and the ink in the gap 40 is removed from the porous wiper 51. It is possible to adsorb to. Of course, wiping with the rubber wiper 53 is preferable because adhered matter such as ink adhered to the lower surface of the nozzle surface 36a and the nozzle guard 37 can be more easily removed and the cleaning effect can be further enhanced.

  In the embodiment described above, the porous wiper 51 and the rubber wiper 53 have a shape in which the tip is divided into three parts and the central parts 51a and 53a are inserted into the opening 46 to wipe the nozzle surface 36a. The shapes of the wiper 51 and the rubber wiper 53 are not limited to this. The porous wiper 51 and the rubber wiper 53 are only required to be inserted at least in part into the opening 46 and wipe the nozzle surface 36a.

  In the embodiment described above, the cleaning liquid removing unit 57 removes the cleaning liquid impregnated in the porous wiper 51 by squeezing the porous wiper 51. However, the means for removing the cleaning liquid impregnated in the porous wiper 51 is not limited to this. Not limited to. For example, the cleaning liquid impregnated in the porous wiper 51 may be removed by suction.

  In the above-described embodiment, the porous wiper 51 is immersed in the cleaning liquid in the cleaning liquid storage unit 56 and the porous wiper 51 is impregnated with the cleaning liquid. However, means for applying the cleaning liquid to the porous wiper 51 is not limited thereto. For example, the structure which provides a washing | cleaning liquid to the porous wiper 51 by spraying a washing | cleaning liquid may be sufficient.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

DESCRIPTION OF SYMBOLS 1 Inkjet printing apparatus 2 Shuttle base unit 3 Flat bed unit 4 Shuttle unit 5 Control part 26 Head unit 27 Maintenance part 31 Inkjet head 36 Nozzle plate 36a Nozzle surface 38 Nozzle 37 Nozzle guard 46 Opening 51 Porous wiper 53 Rubber wiper 55 Wiper drive Section 56 Cleaning liquid storage section 57 Cleaning liquid removal section

Claims (3)

An inkjet head having a nozzle surface where the nozzle is opened, and a nozzle guard which covers the nozzle surface via a gap and is formed with an opening for exposing the nozzle;
A first wiper formed of a porous member and having at least a portion inserted into the opening to wipe the nozzle surface;
A cleaning liquid removing unit that removes the cleaning liquid impregnated in the first wiper;
A controller that controls the nozzle surface to be wiped by the first wiper impregnated with the cleaning liquid, and then the nozzle surface is wiped by the first wiper from which the cleaning liquid has been removed by the cleaning liquid removing unit. Inkjet printing apparatus. A second wiper formed of an elastic member, at least a portion of which is inserted into the opening and wipes the nozzle surface;
The controller may wipe the nozzle surface by the second wiper after wiping the nozzle surface by the first wiper impregnated with the cleaning liquid and before wiping the nozzle surface by the first wiper from which the cleaning liquid has been removed. The inkjet printing apparatus according to claim 1, wherein the inkjet printing apparatus is controlled to perform wiping.   3. The control unit according to claim 1, wherein when the nozzle surface is wiped by the first wiper from which the cleaning liquid has been removed, the control unit performs a wiping operation at a lower speed than other wiping operations. Inkjet printing device.