Wiping device

Abstract

To provide a wiping device that can prevent occurrence of liquid pool caused by contact of a wiper with an end part of an inkjet head.SOLUTION: The wiping device comprises: first-fifth wipers 21a-21e that wipe ejection ports of first-fifth heads having the ejection ports for ejecting ink; a washing liquid tank 20a that stores washing liquid for washing the first-fifth wipers 21a-21e; and a plate-like member 40 formed to contact end parts at upstream sides in a conveying direction of the first-fifth wipers 21a-21e of a surface on which the ejection ports of the first-fifth heads are arranged, extend in the opposite direction of a conveying direction of the first-fifth wipers 21a-21e and expose the ejection ports.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a wiping device having a cleaning liquid tank for storing a cleaning liquid for cleaning a wiper.

Background Art

[0002] Conventionally, an inkjet printing apparatus has been proposed that performs printing by discharging ink from an inkjet head onto a printing medium such as paper and film.

[0003] In an inkjet printing apparatus, ink may adhere to the ink discharge port of a nozzle, or dust such as paper powder generated from the paper may adhere thereto. When ink adheres to the ink discharge port of the nozzle or paper powder accumulates, ejection failures such as disturbance in the ejection direction of ink from the nozzle or non-ejection may occur.

[0004] In order to reduce such ejection failures, a series of operations are known in which so-called purging is performed to forcibly eject ink from the nozzles of the inkjet head, and then the wiper wipes over the ink discharge ports of the nozzles.

[0005] For example, Patent Document 1 proposes an inkjet printing apparatus in which a wiper is immersed in a cleaning liquid tank storing a cleaning liquid, and then the inkjet head is wiped by the wiper. As described in Patent Document 1, the dirt on the wiper can be removed by directly immersing the wiper in the cleaning liquid.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, as described in Patent Document 1, when the inkjet head is wiped by a wiper, as shown in FIG. 10, when the wiper 100 contacts the end of the inkjet head 101, the cleaning liquid attached to the wiper adheres to the side surface of the end of the inkjet head, thereby generating a liquid pool P1. When this liquid pool P accumulates, it drops during printing and stains the printing surface. In addition, to wipe off the liquid pool P1, there is a method of rubbing the side surface of the inkjet head with a cotton swab or the like. However, in order to bring the cotton swab into contact with the side surface of the inkjet head, it is necessary to insert a hand into a narrow space inside the apparatus, which is a difficult operation.

[0008] In Patent Document 2, a method has been proposed to prevent the cleaning liquid and ink from splashing (P2 shown in FIG. 10) when the wiper pressed against the inkjet head in an elastically deformed state returns vigorously when leaving the inkjet head, thereby preventing the surrounding area from being contaminated. However, nothing has been proposed regarding the method of preventing the above-described liquid pool P1.

[0009] An object of the present invention is to provide a wiping device capable of preventing the generation of a liquid pool due to the contact of a wiper with the end of an inkjet head.

Means for Solving the Problems

[0010] The wiping device of the present invention includes a wiper that wipes the discharge port of a discharge unit having a discharge port for discharging a liquid, a cleaning liquid tank that stores a cleaning liquid for cleaning the wiper, and a plate-shaped member that contacts the upstream end in the conveyance direction of the wiper among the surfaces where the discharge port of the discharge unit is disposed, extends in the direction opposite to the conveyance direction of the wiper, and is formed to expose the discharge port.

Effects of the Invention

[0011] According to the wiping device of the present invention, since it is provided with a plate-like member that contacts the end portion on the upstream side in the conveyance direction of the wiper, extends in the direction opposite to the conveyance direction of the wiper, and is formed so as to expose the discharge port, it is possible to prevent the generation of liquid pooling due to the contact of the wiper with the end portion of the discharge portion.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0013] Hereinafter, an inkjet printing apparatus using an embodiment of the wiping device of the present invention will be described in detail with reference to the drawings. The inkjet printing apparatus of this embodiment is characterized by the configuration of a wiping unit corresponding to the wiping device of the present invention. First, the configuration of the entire inkjet printing apparatus will be described. FIG. 1 is a schematic configuration diagram of the inkjet printing apparatus 1 of this embodiment. Further, FIG. 2 is a view of the inkjet printing apparatus 1 shown in FIG. 1 as viewed from the direction of arrow A. In the description of the embodiments shown below, the up, down, left, right, front, and rear indicated by arrows in FIG. 1 are taken as the up, down, left, right, front, and rear directions in the inkjet printing apparatus 1.

[0014] As shown in FIG. 1, the inkjet printing apparatus 1 of this embodiment includes a base 2, a pedestal 3, a platen 4, a rail portion 5, a head unit 10, and a wiping unit 20.

[0015] The base 2 is a columnar member extending in the front-rear direction and is arranged in parallel at intervals in the left-right direction. Two wheels 2a are provided on the bottom surfaces of the two bases 2, respectively.

[0016] A pedestal 3 is erected on each base 2. And a platen 4 is supported on the upper surfaces of the two pedestals 3 facing each other.

[0017] A front paper guide 4a and a rear paper guide 4b formed in an arc shape are extended in front of and behind the platen 4. Further, as shown in FIG. 2, a vacuum chamber 4c in which a fan 4d is installed is provided below the platen 4. In FIG. 1, the vacuum chamber 4c is not shown.

[0018] When the fan 4d in the vacuum chamber 4c rotates, the inside of the vacuum chamber 4c becomes a negative pressure, and a suction force is generated in the suction holes (not shown) formed in the platen 4. Due to the suction force generated in the suction holes of the platen 4, the printing paper P is adsorbed on the platen 4.

[0019] Also, behind the platen 4, as shown in FIG. 2, a drive roller 6 and a pressure roller 7 are provided facing each other. In FIG. 1, the drive roller 6 and the pressure roller 7 are not shown for simplicity.

[0020] The drive roller 6 is a long roller extending in the extending direction of the platen 4 and is rotated by a conveyance drive motor 61 (see FIG. 9) described later.

[0021] The pressure roller 7 is, like the drive roller 6, a long roller extending in the extending direction of the platen 4 and is supported so as to be movable up and down by a lifting mechanism (not shown).

[0022] Then, the printing paper P on the rear paper guide 4b is sandwiched between the drive roller 6 and the pressure roller 7, and the drive roller 6 rotates with the printing paper P being pressed by the pressure roller 7, whereby the printing paper P is fed forward.

[0023] On the front side of the base 2 of the inkjet printing apparatus 1, a take-up side core holder 8 is provided for detachably holding a core 8a for winding the printing paper P. The take-up side core holder 8 is linked to a take-up drive motor 81 (see FIG. 9) via a torque limiter (not shown), and is configured to rotate the take-up side core holder 8 by the take-up drive motor 81.

[0024] Also, on the rear side of the base 2 of the inkjet printing apparatus 1, a supply side core holder 9 is provided for detachably holding a core 9a of a roll paper around which the printing paper P is wound. The supply side core holder 9 is linked to a supply drive motor 91 (see FIG. 9) via a torque limiter (not shown), and is configured to rotate the supply side core holder 9 by the supply drive motor 91.

[0025] Then, as shown in FIG. 2, the roll paper (printing paper P) held by the supply-side core holding portion 9 is drawn out, passes between the rear paper guide 4b, the driving roller 6 and the pressure roller 7, on the platen 4, and via the front paper guide 4a, and is wound around the core 8a held by the winding-side core holding portion 8.

[0026] On the upper parts of the two pedestals 3, a rail portion 5 is installed via support members (not shown). The rail portion 5 includes a rail (not shown) extending in the left-right direction and a main scanning drive motor 54 (see FIG. 9) that reciprocates the head unit 10 in the left-right direction on the rail.

[0027] Also, a wiping unit 20 is provided at one end of the rail portion 5. Then, when the head unit 10 is disposed within the wiping unit 20, wiping by the wiping unit 20 is performed. In the present embodiment, the wiping unit 20 includes a configuration corresponding to the wiping device of the present invention.

[0028] FIG. 3 is a diagram showing a schematic configuration of the head unit 10. As shown in FIG. 3, the head unit 10 of the present embodiment is provided with five heads from the first head 11 to the fifth head 15. The first head 11, the second head 12, the third head 13, and the fourth head 14 are inkjet heads that eject inks of different colors, for example, C (cyan), M (magenta), Y (yellow), and K (black) inks.

[0029] The fifth head 15 has the same configuration as the first head 11 to the fourth head 14, but the liquid ejected is not ink but a pretreatment liquid. The pretreatment liquid is a liquid applied for pretreatment before performing a printing process by ejecting ink onto the printing paper P. As the pretreatment liquid, for example, a liquid for improving the color developability and uniform coating property of the ink can be used, but a known pretreatment liquid can be used.

[0030] The first to fifth heads 11 to 15 are arranged side by side in the moving direction (left - right direction) of the head unit 10 as shown in FIG. 3, but the first to fourth heads 11 to 14 and the fifth head 15 are stagger - arranged.

[0031] That is, the first to fourth heads 11 to 14 are arranged at the same position in the direction (front - back direction) orthogonal to the moving direction of the head unit 10, but the first to fourth heads 11 to 14 and the fifth head 15 are arranged at different positions in the direction (front - back direction) orthogonal to the moving direction of the head unit 10.

[0032] Next, the wiping unit 20 of the present embodiment will be described. FIG. 4 is a perspective view showing the schematic configuration of the wiping unit 20 of the present embodiment. The wiping unit 20 of the present embodiment includes a wiping unit main body 21 and a plate - like member 40. FIG. 5 is a cross - sectional view taken along line C - C of the wiping unit main body 21 shown in FIG. 4.

[0033] The wiping unit main body 21 includes a cleaning liquid tank 20a, first to fifth wipers 21a to 21e, first and second belt conveyor rollers 23, 24, and first and second conveyor belts 22, 25.

[0034] The first to fourth wipers 21a to 21d are wipers corresponding to the first to fourth heads 11 to 14, and wipe the ejection surfaces of the first to fourth heads 11 to 14. The ejection surface is the surface on which the ink ejection ports of the nozzles of the inkjet head are arranged.

[0035] The fifth wiper 21e is a wiper corresponding to the fifth head 15, and wipes the ejection surface of the fifth head 15.

[0036] The first to fifth wipers 21a to 21e are arranged at the same intervals as the intervals between the first to fifth heads 11 to 15 in the moving direction of the head unit 10.

[0037] The first to fourth wipers 21a to 21d are erected at the same position in the front-rear direction on the first conveyor belt 22. The fifth wiper 21e is erected on the second conveyor belt 25.

[0038] The first to fifth wipers 21a to 21e are formed of a flexible rubber or the like.

[0039] The cleaning liquid tank 20a stores the cleaning liquid. The cleaning liquid tank 20a has two recesses, a first cleaning liquid tank 20c and a second cleaning liquid tank 20d, and a partition wall 20b is provided between the first cleaning liquid tank 20c and the second cleaning liquid tank 20d. That is, the first cleaning liquid tank 20c and the second cleaning liquid tank 20d are formed as completely independent cleaning liquid tanks.

[0040] The cleaning liquid is a liquid having a function of dissolving the ink. As this cleaning liquid, for example, an aqueous solvent containing water and a surfactant can be used.

[0041] As the surfactant, for example, anionic surfactants such as sodium fatty acid, 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; cationic surfactants such as alkyltrimethylammonium, dialkyldimethylammonium; nonionic surfactants such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether; amphoteric surfactants such as alkylamino fatty acid sodium, alkyl betaine, alkylamine oxide can be used. Further, polymer surfactants, silicone surfactants, fluorine surfactants, acetylene glycol surfactants, etc. can also be used. Among these, it is preferable to use polyoxyethylene alkyl ether, and its HLB value is more preferably 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 6 to 25.

[0042] 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, a natural polymer, a semi-synthetic polymer, or a synthetic polymer can be used. As the natural polymer, for example, plant-based natural polymers such as gum arabic, carrageenan, guar gum, locust bean gum, pectin, tragacanth gum, corn starch, konjac mannan, agar; microbial-based natural polymers such as pullulan, xanthan gum, dextrin; animal-based natural polymers such as gelatin, casein, glue, can be used. As the semi-synthetic polymer, for example, cellulose-based semi-synthetic polymers such as ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose; starch-based semi-synthetic polymers such as hydroxyethyl starch, sodium carboxymethyl starch, cyclodextrin; alginic acid-based semi-synthetic polymers such as sodium alginate, 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-vinyl acetamide, polyacrylamide; polyethylene oxide, polyethyleneimine, polyurethane can be used. As the clay mineral thickener, for example, smectite clay minerals such as montmorillonite, hectorite, saponite can be used. Among these, it is preferable to use hydroxypropyl methyl cellulose.

[0043] 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, etc. as appropriate. The viscosity of the cleaning liquid is preferably 3 to 200 mPa·s at 23°C.

[0044] In the first cleaning liquid tank 20c, a first conveyor belt 22 with the first to fourth wipers 21a to 21d standing thereon is accommodated, and in the second cleaning liquid tank 20d, a second conveyor belt 25 with the fifth wiper 21e standing thereon is accommodated.

[0045] In addition, first and second belt conveyor rollers 23 and 24 are provided in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d. The first and second belt conveyor rollers 23 and 24 extend in the left-right direction across the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0046] The first and second belt conveyor rollers 23 and 24 are arranged in parallel with at least the interval of the length in the front-rear direction of the head unit 10. A first conveyor belt 22 and a second conveyor belt 25 are stretched between the first belt conveyor roller 23 and the second belt conveyor roller 24.

[0047] Then, as shown in FIG. 5, when the first belt conveyor roller 23 and the second belt conveyor roller 24 are rotated in the direction of arrow C by a belt drive motor 39 (see FIG. 9), the first and second conveyor belts 22 and 25 move. Thereby, the first to fifth wipers 21a to 21e move in the front-rear direction (the arrangement direction of the nozzles of the first to fifth heads 11 to 15), and wipe the discharge surfaces of the first to fifth heads 11 to 15. In the present embodiment, the first and second belt conveyor rollers 23 and 24, the first and second conveyor belts 22 and 25, and the belt drive motor 39 constitute a wiper conveyance unit that conveys the first to fifth wipers 21a to 21e so as to wipe the discharge ports of the first to fifth heads 11 to 15, and immerses the first to fifth wipers 21a to 21e in the first and second cleaning liquid tanks 20c and 20d.

[0048] In addition, in FIG. 5, only the state where the third head 13 is wiped by the third wiper 21c is shown as a representative example, but the states where the first to second and fourth to fifth wipers 21a, 21b, 21d, 21e wipe the first to second and fourth to fifth heads 11, 12, 14, 15 are the same. Also, L shown in FIG. 5 is a cleaning liquid, and the cleaning liquid L is stored up to the lower half position of the first and second conveyor belts 22 and 25 as shown in FIG. 5.

[0049] After the ejection surfaces of the first to fifth heads 11 to 15 are wiped by the first to fifth wipers 21a to 21e, the first belt conveyance roller 23 and the second belt conveyance roller 24 further rotate, causing the first to fifth wipers 21a to 21e to move downward (to the side opposite to the head unit 10 side), and dip into the cleaning liquid stored in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d, thereby cleaning the first to fifth wipers 21a to 21e.

[0050] Then, during the next wiping operation, the first belt conveyance roller 23 and the second belt conveyance roller 24 rotate, causing the first to fifth wipers 21a to 21e to move from the lower side to the upper side.

[0051] Next, the plate-like member 40 shown in FIG. 4 will be described. The plate-like member 40 is for preventing the liquid accumulation and splashing of the above-described cleaning liquid caused by the wiping operation.

[0052] FIG. 4 is a perspective view of the plate-like member 40. The plate-like member 40 of the present embodiment is installed in the direction of the arrow shown in FIG. 4 and is installed as a top plate on the upper surface of the cleaning liquid tank 20a of the wiping unit main body 21.

[0053] The plate-like member 40 is formed by overlapping a first plate member 41 formed in a rectangular shape and a second plate member 42 formed in a rectangular shape. The first plate member 41 is disposed on the side of the cleaning liquid tank 20a, and the second plate member 42 is disposed on the side of the head unit 10.

[0054] FIG. 6A shows a top view of the first plate member 41, and FIG. 6B shows a top view of the second plate member 42.

[0055] The first plate member 41 has openings 41a formed at locations corresponding to the first to fourth heads 11 to 14 and an opening 41b formed at a location corresponding to the fifth head 15. The second plate member 42 also has openings 42a formed at locations corresponding to the first to fourth heads 11 to 14 and an opening 42b formed at a location corresponding to the fifth head 15.

[0056] The lateral width Wa1 of the opening 41a of the first plate member 41 and the opening 42a of the second plate member 42 is slightly larger than the lateral arrangement width of the first to fourth wipers 21a to 21d, and the first to fourth wipers 21a to 21d are formed to be large enough to pass through the opening 41a of the first plate member 41 and the opening 42a of the second plate member 42.

[0057] Also, the longitudinal width Wa2 of the opening 41a of the first plate member 41 is smaller than the longitudinal width Wa3 of the opening 42a of the second plate member 42. That is, Wa2 < Wa3.

[0058] FIG. 7 is a diagram showing the positional relationship between the cross-sectional view taken along line B-B of the plate-like member 40 shown in FIG. 4 and the third head 13. As shown in FIG. 7, the first plate member 41 is formed such that the peripheral portion of its opening 41a contacts the discharge surface of the third head 13. Specifically, the peripheral portion of the opening 41a of the first plate member 41 contacts the discharge surface of the front end (the upstream side in the conveyance direction of the third wiper 21c) of the discharge surface of the third head 13 and extends in the direction opposite to the conveyance direction of the third wiper 21c. Also, the peripheral portion of the opening 41a of the first plate member 41 contacts the discharge surface of the rear end (the downstream side in the conveyance direction of the third wiper 21c) of the discharge surface of the third head 13 and extends in the conveyance direction of the third wiper 21c. And the opening 41a of the first plate member 41 is formed such that its longitudinal width Wa2 is larger than the nozzle arrangement area R shown in FIG. 7. The nozzle arrangement area R is the area between two nozzles arranged at both ends in the longitudinal direction. That is, the opening 41a of the first plate member 41 is formed to be large enough to expose the discharge ports of all the nozzles of the third head 13.

[0059] On the one hand, as shown in FIG. 7, the width Wa3 in the front-rear direction of the opening 42a of the second plate member 42 is larger than the width Wa2 in the front-rear direction of the opening 41a of the first plate member 41 and is also larger than the length in the front-rear direction of the third head 13. Then, the third head 13 is fitted into the opening 42a of the second plate member 42, and the discharge surface of the third head 13 abuts against the first plate member 41.

[0060] In addition, in FIG. 7, only the positional relationship between the plate-like member 40 and the third head 13 is shown, but the positional relationships between the other first, second, and fourth heads 11, 12, 14 and the plate-like member 40 are the same.

[0061] And, as shown in FIG. 7, the thickness of the second plate member 42 is larger than the thickness of the first plate member 41, and the second plate member 42 is formed of a material having higher rigidity than the first plate member 41. For example, the second plate member 42 is formed of metal, and the first plate member 41 is formed of a resin material such as thin (for example, 0.2 mm to 0.3 mm) PET (Polyethylene terephthalate).

[0062] By forming the first plate member 41 from a relatively soft material such as a resin material in this way, when the peripheral portion of the opening 41a of the first plate member 41 comes into contact with the discharge surfaces of the first to fourth heads 11 to 14, it is possible to prevent the discharge surfaces from being damaged.

[0063] Also, by forming the second plate member 42 from a material having high rigidity such as metal, the second plate member 42 can give rigidity to the first plate member 41. In particular, by giving rigidity to the peripheral portion of the opening 41a of the first plate member 41, the peripheral portion can maintain a horizontal state without being deflected downward due to its own weight and can be brought into close contact with the discharge surfaces of the first to fourth heads 11 to 14.

[0064] Note that the distance d1 between the front end face forming the opening 41a of the first plate member 41 shown in FIG. 7 and the front end face forming the opening 42a of the second plate member 42 is preferably set to a distance such that the peripheral portion of the opening 41a of the first plate member 41 can maintain a horizontal state without being deflected downward by its own weight. Similarly, the distance d2 between the rear end face forming the opening 41a of the first plate member 41 shown in FIG. 7 and the rear end face forming the opening 42a of the second plate member 42 is preferably set to a distance such that the peripheral portion of the opening 41a of the first plate member 41 can maintain a horizontal state without being deflected downward by its own weight.

[0065] In the above description, the relationship between the opening 41a formed at the position corresponding to the first to fourth heads 11 to 14 in the first plate member 41 and the opening 42a formed at the position corresponding to the first to fourth heads 11 to 14 in the second plate member 42 has been described. However, the same applies to the relationship between the opening 41b formed at the position corresponding to the fifth head 15 in the first plate member 41 and the opening 42b formed at the position corresponding to the fifth head 15 in the second plate member 42.

[0066] That is, the lateral width Wb1 of the opening 41b of the first plate member 41 and the opening 42b of the second plate member 42 is slightly larger than the lateral width of the fifth wiper 21e, and the fifth wiper 21e is formed so as to be able to pass through the opening 41b of the first plate member 41 and the opening 42b of the second plate member 42.

[0067] Also, the longitudinal width Wb2 of the opening 41b of the first plate member 41 is smaller than the longitudinal width Wb3 of the opening 42b of the second plate member 42. That is, Wb2 < Wb3.

[0068] The first plate member 41 is formed such that the peripheral portion of its opening 41b contacts the discharge surface of the fifth head 15. Specifically, the peripheral portion of the opening 41b of the first plate member 41 contacts the discharge surface of the end portion on the front side (the upstream side in the conveyance direction of the fifth wiper 21e) of the discharge surface of the fifth head 15 and extends in the direction opposite to the conveyance direction of the fifth wiper 21e. Also, the peripheral portion of the opening 41b of the first plate member 41 contacts the discharge surface of the end portion on the rear side (the downstream side in the conveyance direction of the fifth wiper 21e) of the discharge surface of the fifth head 15 and extends in the conveyance direction of the fifth wiper 21e.

[0069] The width Wb2 in the front-rear direction of the opening 41b of the first plate member 41 is formed to be larger than the nozzle arrangement area R. That is, the opening 41b of the first plate member 41 is formed to be large enough to expose the discharge ports of all the nozzles of the fifth head 15.

[0070] On the other hand, the width Wb3 in the front-rear direction of the opening 42b of the second plate member 42 is larger than the width Wb2 in the front-rear direction of the opening 41a of the first plate member 41 and larger than the length in the front-rear direction of the fifth head 15. The fifth head 15 is fitted into the opening 42b of the second plate member 42, and the discharge surface of the fifth head 15 abuts against the first plate member 41.

[0071] The distance between the rear end surface forming the opening 41b of the first plate member 41 and the rear end surface forming the opening 42b of the second plate member 42 is preferably set to a distance such that the peripheral portion of the opening 41b of the first plate member 41 can maintain a horizontal state without being deflected downward by its own weight. Similarly, the distance between the front end surface forming the opening 41b of the first plate member 41 and the front end surface forming the opening 42b of the second plate member 42 is preferably set to a distance such that the peripheral portion of the opening 41b of the first plate member 41 can maintain a horizontal state without being deflected downward by its own weight.

[0072] Then, the ejection surfaces of the first to fifth heads 11 to 15 are arranged in contact with the first plate member 41 of the plate-like member 40 configured as described above. As shown in FIG. 7, the ejection surfaces of the first to fifth heads 11 to 15 are wiped by the first to fifth wipers 21a to 21e. In the present embodiment, since the first plate member 41 is provided so as to contact the ejection surfaces of the front ends of the first to fifth heads 11 to 15, it is possible to prevent the formation of liquid pools on the front side surfaces of the first to fifth heads 11 to 15.

[0073] Further, since the first plate member 41 is provided so as to contact the ejection surfaces of the rear ends of the first to fifth heads 11 to 15, it is possible to prevent the scattering of the cleaning liquid and ink generated when the first to fifth wipers 21a to 21e pass through the rear sides of the first to fifth heads 11 to 15.

[0074] Also, it is not necessary to directly wipe the side surfaces of the first to fifth heads 11 to 15, and it is only necessary to wipe the dirt (cleaning liquid) adhering to the surface of the plate-like member 40, so that cleaning can be easily performed.

[0075] In the present embodiment, openings are formed in the plate-like member 40 (the first plate member 41 and the second plate member 42), and the first to fifth heads 11 to 15 are arranged in the openings, so that the plate-like member 40 is brought into contact with the ejection surfaces of the ends of the first to fifth heads 11 to 15. Therefore, the alignment of the plate-like member 40 with respect to the ejection surfaces of the ends of the first to fifth heads 11 to 15 can be easily performed.

[0076] Next, returning to FIG. 6, mounting position adjustment holes 41c are formed at the four corners of the first plate member 41, and mounting position adjustment holes 42c are formed at the four corners of the second plate member 42. The mounting position adjustment holes 41c and the mounting position adjustment holes 42c are formed in an elliptical shape extending in the front-rear direction with the same size, and are formed at the same positions on the surface of the plate-like member 40.

[0077] Then, as shown in FIG. 8, the plate-like member 40 is fixed to the upper surface of the cleaning liquid tank 20a by screws 50 passing through the attachment position adjustment holes 41c and 42c. At this time, by adjusting the position of the screws 50 in the front-rear direction within the attachment position adjustment holes 41c and 42c, the attachment position of the plate-like member 40 in the front-rear direction is adjusted. That is, the attachment position of the plate-like member 40 with respect to the first to fifth heads 11 to 15 can be adjusted. The sizes of the first to fifth heads 11 to 15 in the front-rear direction and the position of the nozzle arrangement area R may slightly change depending on the manufacturer or the like. Even in such a case, as described above, by adjusting the position of the plate-like member 40 with respect to the first to fifth heads 11 to 15 by the attachment position adjustment holes 41c and 42c, the length of the first to fifth heads 11 to 15 in the front-rear direction and the nozzle arrangement area R, and the positional relationship between the openings 41a and 41b of the first plate member 41 and the openings 42a and 42b of the second plate member 42 can be adjusted.

[0078] FIG. 9 is a block diagram showing the configuration of the control system of the inkjet printing apparatus 1 of the present embodiment. The inkjet printing apparatus 1 operates each part to be controlled shown in FIG. 9 in response to a control signal from the printing control apparatus 16.

[0079] The printing control apparatus 16 and the inkjet printing apparatus 1 are connected by a communication line such as a LAN (Local Area Network) or an Internet line, and are configured to be able to communicate with each other. The communication line may be wired or wireless.

[0080] The printing control apparatus 16 is composed of a computer including a CPU (Central Processing Unit), a semiconductor memory, a hard disk, and the like. The printing control apparatus 16 executes a printing control program stored in advance in a storage medium such as a semiconductor memory or a hard disk based on an input printing job or the like, and controls each part shown in FIG. 9 by operating an electric circuit.

[0081] Next, the printing operation of the inkjet printing apparatus 1 of the present embodiment will be described. Here, a case will be described in which a pretreatment liquid is discharged from the fifth head 15 and applied to the printing paper P, and then ink is discharged from the first to fourth heads 11 to 14 to perform printing on the printing paper P to which the pretreatment liquid is applied.

[0082] First, as shown in FIG. 2, a roll paper is installed in the supply-side core holder 9, and the roll paper (printing paper P) is pulled out and wound around the core 8a held by the take-up-side core holder 8 via the rear paper guide 4b, between the drive roller 6 and the pressure roller 7, on the platen 4, and the front paper guide 4a.

[0083] Then, the print control device 16 rotates the supply-side core holder 9, the take-up-side core holder 8, and the drive roller 6 to send out the printing paper P, and once the printing paper P reaches the printing initial position, the feeding of the printing paper P is temporarily stopped.

[0084] Next, the print control device 16 operates the main scanning drive motor 54 to move the head unit 10 in the first direction (either the left or right direction) on the rail unit 5. Then, as the head unit 10 moves, the print control device 16 operates the fifth head 15 of the head unit 10 to apply the pretreatment liquid to the first scanning line. Note that during the scanning of the first scanning line, ink ejection from the first to fourth heads 11 to 14 is not performed.

[0085] Next, the print control device 16 feeds out the printing paper P by one scanning line so that the first scanning line coated with the pretreatment liquid is disposed directly below the first to fourth heads 11 to 14.

[0086] Then, the printing control device 16 moves the head unit 10 in the second direction opposite to the first direction on the rail unit 5, and while moving, discharges ink from the first to fourth heads 11 to 14 to perform printing on the first scanning line. Also, the printing control device 16 performs printing on the first scanning line and operates the fifth head 15 to apply a pretreatment liquid to the second scanning line next to the first scanning line.

[0087] Subsequently, the printing control device 16 feeds out the printing paper P by one scanning line, arranges the second scanning line directly below the first to fourth heads 11 to 14, and arranges the third scanning line next to the second scanning line directly below the fifth head 15.

[0088] Then, the printing control device 16 moves the head unit 10 in the first direction on the rail unit 5, and by operating the first to fourth heads 11 to 14 and the fifth head 15 while moving, applies a pretreatment liquid to the third scanning line and performs printing on the second scanning line.

[0089] Thereafter, the printing control device 16 alternately repeats the feeding out of the printing paper P by one scanning line and the movement of the head unit 10 in the first or second direction on the rail unit 5, and sequentially applies a pretreatment liquid to the (n + 1)-th scanning line and performs printing on the n-th scanning line.

[0090] Next, the wiping operation of the inkjet printing device 1 of the present embodiment will be described.

[0091] The wiping operation is performed during a standby period when no printing process is performed. At this time, the printing control device 16 moves the head unit 10 on the rail unit 5 and arranges it above the plate-shaped member 40 of the wiping unit 20.

[0092] Then, the printing control device 16 moves the first to fifth wiper blades 21a to 21e that are immersed in the cleaning liquid in the first and second cleaning liquid tanks 20c and 20d by the first and second conveyor belts 22 and 25, and positions the tips of the first to fifth wiper blades 21a to 21e at the positions of the front ends of the corresponding first to fifth heads 11 to 15.

[0093] Next, the printing control device 16 moves the first to fifth heads 11 to 15 as they are, so that the tip portions of the first to fifth wiper blades 21a to 21e are pressed against the discharge surfaces of the first to fifth heads 11 to 15 and are in an elastically deformed state. At this time, in order to press the tips of the first to fifth wiper blades 21a to 21e against the discharge surfaces of the first to fifth heads 11 to 15, the printing control device 16 may move the head unit 10 downward or move the wiping unit 20 upward.

[0094] Then, while the tip portions of the first to fifth wiper blades 21a to 21e are pressed against the discharge surfaces of the first to fifth heads 11 to 15, the printing control device 16 further moves the first to fifth wiper blades 21a to 21e, thereby wiping the discharge surfaces of the first to fifth heads 11 to 15. At this time, in this embodiment, since the above-described plate-like member 40 is provided in contact with the discharge surfaces of the first to fifth heads 11 to 15, it is possible to prevent the generation of liquid pools due to the contact of the first to fifth heads 11 to 15 with the front end portions of the first to fifth heads 11 to 15.

[0095] Then, the printing control device 16 finishes the wiping by moving the tip portions of the first to fifth wiper blades 21a to 21e to the rear ends of the first to fifth heads 11 to 15. At this time, in this embodiment, since the above-described plate-like member 40 is provided in contact with the discharge surfaces of the first to fifth heads 11 to 15, it is possible to prevent the scattering of the cleaning liquid and ink that occurs when the first to fifth wiper blades 21a to 21e separate from the rear end portions of the first to fifth heads 11 to 15.

[0096] Subsequently, the printing control device 16 further moves the first to fifth wipers 21a to 21e and immerses them again in the cleaning liquids in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0097] Note that the wiping operation described above may be automatically performed immediately before starting the printing process, or may be performed in response to a user's instruction input. Further, it may be performed at every preset period or for every preset length of the printing range (the feeding amount of the printing paper P).

[0098] Regarding the present invention, the following additional remarks are further disclosed. (Additional remarks)

[0099] In the wiping device of the present invention, it is preferable that the plate-like member has an opening at a position corresponding to the discharge portion, the plate-like member around the opening contacts the surface of the end portion of the discharge portion on the upstream side in the conveyance direction of the wiper, and the opening is formed to have a size that exposes the discharge port.

[0100] In the wiping device of the present invention, it is preferable that the plate-like member around the opening contacts the surface of the end portion of the discharge portion on the downstream side in the conveyance direction of the wiper and extends in the conveyance direction of the wiper.

[0101] In the wiping device of the present invention, it is preferable that the plate-like member is formed by overlapping a first plate member that contacts the surface of the end portion of the discharge portion around the opening and a second plate member having higher rigidity than the first plate member.

[0102] In the wiping device of the present invention, it is preferable that the mounting position of the plate-like member in the conveyance direction of the wiper is configured to be adjustable.

[0103] The wiping device of the present invention includes a wiper that wipes a discharge port for discharging a liquid, a cleaning liquid tank that stores a cleaning liquid for cleaning the wiper, and a member that contacts the surface on which the discharge port is disposed, extends in the direction opposite to the conveyance direction of the wiper, and is formed to expose the discharge port.

Explanation of reference numerals

[0104] 1 Inkjet printing device 2 Base 2a Wheel 3 Leg 4 Platen 4a Front paper guide 4b Rear paper guide 4c Vacuum chamber 4d Fan 5 Rail part 6 Driving roller 7 Pressing roller 8 Take-up side core holder 8a Core 9 Supply side core holder 9a Core 10 Head unit 11 - 15 First - fifth heads 16 Printing control device 20 Wiping unit 20a Cleaning liquid tank 20b Partition wall 20c First cleaning liquid tank 20d Second cleaning liquid tank 21 Wiping unit body 21a - 21e First - fifth wipers 22 First conveyor belt 23 First belt conveyor roller 24 Second belt conveyor roller 25 Second conveyor belt 39 Belt drive motor 40 Plate - shaped member 41 First plate member 41a, 41b Opening 41c, 42c Mounting position adjustment hole 42 Second plate member 42a, 42b Opening 50 Screw 54 Main scanning drive motor 61 Conveyor drive motor 81 Take-up drive motor 91 Supply drive motor 100 Wiper 101 Inkjet Head L Cleaning Liquid P Printing Paper R Nozzle Arrangement Area

Claims

Claim 1 A wiper for wiping the discharge port of a discharge unit having a discharge port for discharging a liquid, a cleaning liquid tank for storing a cleaning liquid for cleaning the wiper, and a top plate formed in a plate shape for closing so as to cover the entire opening side of the cleaning liquid tank in a lid shape, wherein the top plate has an opening formed so as to expose the discharge port, and the surface on the discharge port side of the peripheral portion forming the opening contacts the surface of the end portion on the upstream side in the conveyance direction of the wiper among the surfaces on which the discharge port of the discharge unit is disposed. At the same time, a wiping device formed by overlapping a first plate member in which the surface on the discharge port side of the peripheral portion forming the opening contacts the surface of the end portion of the discharge unit and a second plate member having higher rigidity than the first plate member. Claim 2 The wiping device according to claim 1, wherein the surface on the discharge port side of the peripheral portion forming the opening also contacts the surface of the end portion on the downstream side in the conveyance direction of the wiper among the surfaces on which the discharge port of the discharge unit is disposed.

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