Wiper Cleaning Device

Abstract

To provide a wiper washing device that can prevent an ejection passage of a washing liquid tank from clogging.SOLUTION: The wiper washing device comprises: a washing liquid tank 20a that stores washing liquid for washing first-fifth wipers 21a-21e; a washing liquid storage part 26 that stores unused washing liquid; a supply part 27 that supplies washing liquid stored in the washing liquid storage part 26 to the washing liquid tank 20a; and a printing control device 16 that controls the supply part 27 so that the unused washing liquid is supplied to the washing liquid tank 20a, while ejecting used washing liquid from the washing liquid tank 20a.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a wiper cleaning device having a cleaning liquid tank that stores cleaning liquid for cleaning a wiper. [Background technology]

[0002] 2. Description of the Related Art Inkjet printing devices have been proposed that perform printing by ejecting ink from an inkjet head onto a print medium such as paper or film.

[0003] In an inkjet printing device, ink may adhere to the ink ejection openings of the nozzles, or dirt such as paper dust generated from the paper may adhere to the ink ejection openings of the nozzles. If ink adheres to the ink ejection openings of the nozzles or paper dust accumulates, ejection defects such as disturbance of the ink ejection direction from the nozzles or failure to eject ink may occur.

[0004] In order to reduce such ejection defects, a series of operations is known in which ink is forcibly ejected from the nozzles of the inkjet head, that is, a so-called purge is performed, and then the ink ejection openings of the nozzles are wiped with a wiper.

[0005] For example, Patent Document 1 proposes an inkjet printing device in which a wiper is immersed in a cleaning liquid tank that stores cleaning liquid and then the wiper is used to wipe the inkjet head. As described in Patent Document 1, dirt on the wiper can be removed by immersing the wiper directly in the cleaning liquid. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-154490 A [Patent Document 2] JP 2019-1028 A Summary of the Invention [Problem to be solved by the invention]

[0007] Here, the cleaning liquid stored in the above-mentioned cleaning liquid tank is composed of 60% to 90% water, and if it is left in the air, the water evaporates and the viscosity increases. For example, if the water content decreases by 40%, the viscosity increases by about 2.5 times.

[0008] If the viscosity of the cleaning liquid stored in the cleaning liquid tank becomes high in this way, there is a problem that the drainage path may become clogged when the cleaning liquid is discharged from the cleaning liquid tank, for example, when the cleaning liquid is replaced.

[0009] Patent Document 2 proposes a method of periodically discharging the cleaning liquid at a preset timing in order to prevent clogging of the drainage path of the cleaning liquid tank.

[0010] However, even with the method described in Patent Document 2, the viscosity of the cleaning liquid increases due to evaporation of water during a fixed period, and the drainability of the cleaning liquid decreases. In addition, in the device described in Patent Document 2, if the device body cannot be turned on for a long period of time, for example due to a power outage, the drain path will become clogged when the cleaning liquid is drained the next time the power is turned on unless all the cleaning liquid is drained from the cleaning liquid tank. Also, draining all the cleaning liquid from the cleaning liquid tank is time-consuming.

[0011] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a wiper cleaning device capable of preventing clogging of the drainage path of the cleaning liquid tank. [Means for solving the problem]

[0012] The wiper cleaning device of the present invention includes a cleaning liquid tank for storing cleaning liquid used to clean the wiper, a cleaning liquid storage section for storing unused cleaning liquid, a supply section for supplying the cleaning liquid stored in the cleaning liquid storage section to the cleaning liquid tank, and a control section for controlling the supply section to supply unused cleaning liquid to the cleaning liquid tank while discharging used cleaning liquid from the cleaning liquid tank. Effect of the Invention

[0013] The wiper cleaning device of the present invention is equipped with a cleaning liquid storage section for storing unused cleaning liquid, and a supply section for supplying the cleaning liquid stored in the cleaning liquid storage section to a cleaning liquid tank.The supply section is controlled to supply unused cleaning liquid to the cleaning liquid tank while discharging used cleaning liquid from the cleaning liquid tank.Therefore, the supply of unused cleaning liquid makes it possible to reduce the viscosity of the used cleaning liquid in the cleaning liquid tank while discharging it, and prevents clogging of the drainage path of the cleaning liquid tank. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an inkjet printing apparatus using an embodiment of a wiper cleaning device of the present invention; [Diagram 2] A view of the inkjet printing device shown in Figure 1 from the direction of arrow A. [Diagram 3] FIG. 1 is a diagram showing a schematic configuration of an example of a head unit; [Figure 4] FIG. 2 is a perspective view showing a schematic configuration of a wiping unit; [Diagram 5] Cross-sectional view of the wiping unit taken along line BB in Figure 4. [Figure 6] A block diagram showing the configuration of a control system of an inkjet printing apparatus. [Figure 7] A flowchart for explaining an operation of discharging used cleaning liquid in the wiping unit. [Figure 8] FIG. 11 is a block diagram showing the configuration of a control system of an inkjet printing apparatus using another embodiment of the wiper cleaning device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An inkjet printing apparatus using an embodiment of the wiper cleaning device of the present invention will be described in detail below with reference to the drawings. The inkjet printing apparatus of this embodiment is characterized by the configuration of a wiping unit that corresponds to the wiper cleaning device of the present invention, but first, the configuration of the entire inkjet printing apparatus will be described. FIG. 1 is a schematic diagram of an inkjet printing apparatus 1 of this embodiment. 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 following description of the embodiment, the up, down, left, right, front, back, and rear indicated by arrows in FIG. 1 are defined as the up, down, left, right, front, and rear directions of the inkjet printing apparatus 1.

[0016] As shown in FIG. 1, the inkjet printing apparatus 1 of this embodiment includes a base 2, a foot stand 3, a platen 4, a rail section 5, a head unit 10, and a wiping unit 20.

[0017] The bases 2 are columnar members extending in the front-rear direction and arranged in parallel with a gap in the left-right direction. Two wheels 2a are provided on the bottom surface of each of the two bases 2.

[0018] A foot stand 3 is provided upright on each base 2. A platen 4 is supported on the upper surfaces of the two foot stands 3 facing each other.

[0019] An arc-shaped front paper guide 4a and a rear paper guide 4b extend from the front and rear of the platen 4. Also, as shown in Fig. 2, a vacuum chamber 4c in which a fan 4d is installed is provided below the platen 4. Note that the vacuum chamber 4c is not shown in Fig. 1.

[0020] When the fan 4d in the vacuum chamber 4c rotates, a negative pressure is created inside the vacuum chamber 4c, and a suction force is generated in the suction holes (not shown) formed in the platen 4. The printing paper P is attracted to the platen 4 by the suction force generated in the suction holes of the platen 4.

[0021] 2, a drive roller 6 and a pressure roller 7 are provided behind the platen 4 so as to face each other. Note that the drive roller 6 and the pressure roller 7 are omitted from FIG.

[0022] The drive roller 6 is an elongated roller extending in the extension direction of the platen 4, and is rotated by a transport drive motor 61 (see FIG. 6) which will be described later.

[0023] The pressure roller 7, like the drive roller 6, is an elongated roller extending in the extension direction of the platen 4, and is supported by a lifting mechanism (not shown) so as to be movable up and down.

[0024] Then, the printing paper P on the rear paper guide 4b is clamped between the drive roller 6 and the pressure roller 7, and as the drive roller 6 rotates with the printing paper P pressed by the pressure roller 7, the printing paper P is sent forward.

[0025] Provided on the front side of the base 2 of the inkjet printing device 1 is a take-up core holder 8 that detachably holds a core 8a that takes up the printing paper P. The take-up core holder 8 is linked to a take-up drive motor 81 (see FIG. 6) via a torque limiter (not shown), and is configured so that the take-up core holder 8 is rotated by the take-up drive motor 81.

[0026] Further, a supply-side core holding section 9 is provided on the rear side of the base 2 of the inkjet printing device 1, which detachably holds a core 9a of roll paper on which printing paper P is wound in a roll shape. The supply-side core holding section 9 is linked to a supply drive motor 91 (see FIG. 6) via a torque limiter (not shown), and is configured so that the supply-side core holding section 9 is rotated by the supply drive motor 91.

[0027] As shown in Figure 2, the roll paper (printing paper P) held by the supply side core holding section 9 is pulled out and passed through the rear paper guide 4b, between the drive roller 6 and the pressure roller 7, over the platen 4, and the front paper guide 4a, before being wound onto the core 8a held by the winding side core holding section 8.

[0028] A rail section 5 is installed via a support member (not shown) on the upper part of the two legs 3. The rail section 5 includes a rail (not shown) extending in the left-right direction and a main scanning drive motor 54 (see FIG. 6) that moves the head unit 10 back and forth in the left-right direction on the rail.

[0029] A wiping unit 20 is provided at one end of the rail portion 5. The head unit 10 is disposed inside the wiping unit 20, whereby wiping is performed by the wiping unit 20. In this embodiment, the wiping unit 20 includes a configuration equivalent to the wiper cleaning device of the present invention.

[0030] Fig. 3 is a diagram showing a schematic configuration of the head unit 10. As shown in Fig. 3, the head unit 10 of this embodiment is provided with five heads, namely a first head 11 to a 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 ink of different colors, for example, C (cyan), M (magenta), Y (yellow), and K (black).

[0031] The fifth head 15 has a similar configuration to the first head 11 to the fourth head 14, but ejects a pretreatment liquid instead of ink. The pretreatment liquid is a liquid that is applied for pretreatment before ink is ejected onto the printing paper P to perform printing processing. As the pretreatment liquid, for example, a liquid for improving the color development and uniform application of the ink is used, but a pretreatment liquid that is already known can be used.

[0032] As shown in FIG. 3, the first to fifth heads 11 to 15 are arranged side by side in the movement direction (left and right direction) of the head unit 10, but the first to fourth heads 11 to 14 and the fifth head 15 are arranged in a staggered manner.

[0033] That is, the first to fourth heads 11 to 14 are arranged at the same position in a direction perpendicular to the movement direction of the head unit 10 (front-to-back direction), but the first to fourth heads 11 to 14 and the fifth head 15 are arranged at different positions in a direction perpendicular to the movement direction of the head unit 10 (front-to-back direction).

[0034] Next, the wiping unit 20 of this embodiment will be described. Fig. 4 is a perspective view showing a schematic configuration of the wiping unit 20 of this embodiment. Fig. 5 is a cross-sectional view of the wiping unit 20 shown in Fig. 4 taken along line BB.

[0035] The wiping unit 20 includes a cleaning liquid tank 20a, first to fifth wipers 21a to 21e, first and second belt conveying rollers 23 and 24, and first and second conveying belts 22 and 25.

[0036] 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 surfaces are surfaces on which the ink ejection ports of the nozzles of the inkjet heads are arranged.

[0037] The fifth wiper 21e is a wiper that corresponds to the fifth head 15 and wipes the ejection surface of the fifth head 15.

[0038] The first to fifth wipers 21a to 21e are arranged at intervals equal to the intervals between the first to fifth heads 11 to 15 in the movement direction of the head unit 10.

[0039] The first to fourth wipers 21a to 21d are erected at the same positions in the front-rear direction on the first conveyor belt 22. The fifth wiper 21e is erected on the second conveyor belt 25.

[0040] The first to fifth wipers 21a to 21e are made of flexible rubber or the like.

[0041] 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. In other words, the first cleaning liquid tank 20c and the second cleaning liquid tank 20d are formed as completely independent cleaning liquid tanks.

[0042] The cleaning liquid is a liquid that has a function of dissolving ink. For example, an aqueous solvent containing water and a surfactant can be used as the cleaning liquid.

[0043] Examples of the surfactant include anionic surfactants such as sodium fatty acid, sodium alkylbenzenesulfonate, sodium alkylsulfonate, sodium α-olefinsulfonate, sodium alkyl sulfate, sodium alkyl ether sulfate, sodium α-sulfofatty acid ester, and sodium alkyl phosphate; cationic surfactants such as alkyltrimethylammonium and dialkyldimethylammonium; nonionic surfactants such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, and polyoxyethylene alkylphenyl ether; and amphoteric surfactants such as sodium alkylamino fatty acid, alkyl betaine, and alkylamine oxide. Polymer surfactants, silicone surfactants, fluorine surfactants, and acetylene glycol surfactants can also be used. Among these, it is preferable to use polyoxyethylene alkyl ether, and it is more preferable that the HLB value is 11 to 17, the number of carbon atoms in the alkyl group is 8 to 15, and the number of moles of ethylene oxide added is 6 to 25.

[0044] The cleaning solution 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, a plant-based natural polymer such as gum arabic, carrageenan, guar gum, locust bean gum, pectin, tragacanth gum, corn starch, konjac mannan, agar, etc.; a microbial natural polymer such as pullulan, xanthan gum, dextrin, etc.; an animal-based natural polymer such as gelatin, casein, or glue can be used. As the semi-synthetic polymer, for example, a cellulose-based semi-synthetic polymer such as ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, or hydroxypropyl methyl cellulose can be used; a starch-based semi-synthetic polymer such as hydroxyethyl starch, sodium carboxymethyl starch, or cyclodextrin; an alginic acid-based semi-synthetic polymer such as sodium alginate or propylene glycol alginate; or sodium hyaluronate can be used. Examples of synthetic polymers that can be used include vinyl synthetic polymers such as polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, poly N-vinylacetamide, and polyacrylamide; polyethylene oxide, polyethyleneimine, and polyurethane. Examples of clay mineral thickeners that can be used include smectite clay minerals such as montmorillonite, hectorite, and saponite. Among these, it is preferable to use hydroxypropyl methylcellulose.

[0045] Furthermore, in addition to the above components, the cleaning solution may optionally contain water-soluble organic solvents, pH adjusters, antioxidants, preservatives, etc. The viscosity of the cleaning solution at 23°C is preferably 3 to 200 mPa·s.

[0046] The first cleaning liquid tank 20c contains a first conveyor belt 22 having first to fourth wipers 21a to 21d arranged thereon, and the second cleaning liquid tank 20d contains a second conveyor belt 25 having a fifth wiper 21e arranged thereon.

[0047] Further, the first cleaning liquid tank 20c and the second cleaning liquid tank 20d are provided with first and second belt conveying rollers 23, 24. The first and second belt conveying rollers 23, 24 are provided to extend in the left-right direction across the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0048] The first and second belt conveying rollers 23, 24 are arranged in parallel with a gap of at least the length of the head unit 10 in the front-to-rear direction, and the first conveying belt 22 and the second conveying belt 25 are stretched between the first belt conveying roller 23 and the second belt conveying roller 24.

[0049] 5, the first belt conveying roller 23 and the second belt conveying roller 24 are rotated in the direction of the arrow C by the belt driving motor 39 (see FIG. 6), thereby moving the first and second conveying belts 22, 25. As a result, the first to fifth wipers 21a to 21e move in the front-to-rear direction (the direction in which the nozzles of the first to fifth heads 11 to 15 are arranged) to wipe the ejection surfaces of the first to fifth heads 11 to 15. In this embodiment, the first and second belt conveying rollers 23, 24, the first and second conveying belts 22, 25, and the belt driving motor 39 correspond to the wiper conveying section of the present invention.

[0050] 5 shows only the third head 13 being wiped by the third wiper 21c as a representative example, the first, second and fourth and fifth wipers 21a, 21b, 21d and 21e wipe the first, second and fourth and fifth heads 11, 12, 14 and 15 in the same manner. 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.

[0051] 4 and 5, a cleaning liquid storage section 26 is provided behind the cleaning liquid tank 20a. The cleaning liquid storage section 26 includes a cleaning liquid storage tank 26a and a lid section 26b. The cleaning liquid storage tank 26a is a tank that stores unused cleaning liquid, and the lid section 26b functions as a lid for the cleaning liquid storage tank 26a and suppresses evaporation of water from the cleaning liquid storage tank 26a.

[0052] One end of a cleaning liquid supply pipe 28 is connected to the bottom of the cleaning liquid storage tank 26a, and the other end of the cleaning liquid supply pipe 28 is connected to a cleaning liquid supply hole 28a formed in the side wall of the cleaning liquid tank 20a. The cleaning liquid supply hole 28a is formed in each of the first cleaning liquid tank 20c and the second cleaning liquid tank 20d. Between a supply unit 27 described later and the first cleaning liquid tank 20c and the second cleaning liquid tank 20d, the cleaning liquid supply pipe 28 is bifurcated and is connected to the cleaning liquid supply hole 28a formed in the first cleaning liquid tank 20c and the cleaning liquid supply hole 28a formed in the second cleaning liquid tank 20d, respectively.

[0053] The cleaning liquid supply pipe 28 is provided with the above-mentioned supply unit 27. The supply unit 27 has a pump, a valve, and the like, and supplies unused cleaning liquid stored in the cleaning liquid storage tank 26a through the cleaning liquid supply pipe 28 to each of the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0054] Further, the first cleaning liquid tank 20c and the second cleaning liquid tank 20d each have a discharge hole 29a in their sidewalls, and a discharge pipe 29b is connected to the discharge hole 29a. When replacing the cleaning liquid in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d, the cleaning liquid is discharged from the discharge hole 29a to the discharge pipe 29b. A discharge unit 29 having a pump and a valve is provided in the discharge pipe 29b, and the discharge unit 29 is controlled by the print control device 16 to control the discharge of the cleaning liquid.

[0055] The first cleaning liquid tank 20c and the second cleaning liquid tank 20d are provided with a liquid volume detector 30 shown in FIG. 5. The liquid volume detector 30 is omitted in FIG. 4. The liquid volume detector 30 detects the amount of cleaning liquid stored in the first cleaning liquid tank 20c. The liquid volume detector 30 may be configured with a sensor that detects the liquid level of the cleaning liquid, or may be configured with a sensor that directly detects the amount of cleaning liquid. In this embodiment, the first cleaning liquid tank 20c and the second cleaning liquid tank 20d have the same amount of reduced cleaning liquid (amount of water evaporated), and the liquid volume detector 30 is provided only in the first cleaning liquid tank 20c. However, the liquid volume detector 30 may be provided in both the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0056] When the used cleaning liquid stored in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d is discharged, the amount of used cleaning liquid stored in the first cleaning liquid tank 20c (the height of the liquid surface) is detected by the liquid volume detection unit 30, and the detection signal is output to the print control device 16 described later.

[0057] Based on the input detection signal, the print control device 16 outputs a control signal to the supply unit 27, and the supply unit 27 drives pumps, valves, etc. in response to the control signal output from the print control device 16, and supplies unused cleaning liquid from the cleaning liquid storage tank 26a to the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0058] Specifically, the print control device 16 continues to supply unused cleaning liquid until the amount of cleaning liquid detected by the liquid amount detection unit 30 reaches a preset threshold value.

[0059] Then, after stopping the supply of unused cleaning liquid, the print control device 16 rotates the first belt conveying roller 23 and the second belt conveying roller 24 in the direction of arrow C, thereby moving the first to fifth wipers 21a to 21e and agitating the liquid in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d; this agitation operation will be described in detail later.

[0060] After the above-mentioned supply and stirring operation of the unused cleaning liquid, the print control device 16 controls the supply unit 27 to supply unused cleaning liquid from the cleaning liquid storage tank 26a to the first cleaning liquid tank 20c and the second cleaning liquid tank 20d while discharging the used cleaning liquid from the first cleaning liquid tank 20c and the second cleaning liquid tank 20d. At this time, it is preferable to control the supply amount of unused cleaning liquid and the discharge amount of used cleaning liquid to be the same.

[0061] In this way, by supplying unused cleaning liquid while discharging used cleaning liquid from the first cleaning liquid tank 20c and the second cleaning liquid tank 20d, the viscosity of the used cleaning liquid in the first and second cleaning liquid tanks 20c, 20d can be reduced by the supply of unused cleaning liquid while it is discharged, thereby preventing clogging of the discharge pipe 29b.

[0062] Furthermore, as described above, unused cleaning liquid is supplied based on the amount of used cleaning liquid detected by the liquid volume detection unit 30, so that unused cleaning liquid can be supplied in an amount equivalent to the amount lost due to evaporation, thereby reducing the viscosity of the used cleaning liquid and controlling the amount of cleaning liquid in the first and second cleaning liquid tanks 20c, 20d to a predetermined amount.

[0063] Fig. 6 is a block diagram showing the configuration of a control system of the inkjet printing apparatus 1 of this embodiment. The inkjet printing apparatus 1 operates each of the controlled units shown in Fig. 6 in response to a control signal from the print control device 16. In this embodiment, the print control device 16 includes a configuration equivalent to the control unit of the present invention.

[0064] The print control device 16 and the inkjet printing device 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.

[0065] The print control device 16 is composed of a computer equipped with a CPU (Central Processing Unit), a semiconductor memory, a hard disk, etc. The print control device 16 executes a print control program stored in advance in a storage medium such as a semiconductor memory or a hard disk based on an input print job, etc., and controls each part shown in FIG. 6 by operating an electric circuit.

[0066] Next, a printing operation of the inkjet printing apparatus 1 of this embodiment will be described. Note that, here, a case will be described in which a pretreatment liquid is ejected from the fifth head 15 to apply it to the printing paper P, and then ink is ejected from the first to fourth heads 11 to 14 to print on the printing paper P to which the pretreatment liquid has been applied.

[0067] First, as shown in Figure 2, a roll of paper is placed on the supply side core holding section 9, and the roll of paper (printing paper P) is pulled out and passed through the rear paper guide 4b, between the drive roller 6 and the pressure roller 7, over the platen 4, and the front paper guide 4a, before being wound around the core 8a held by the take-up side core holding section 8.

[0068] Then, the printing control device 16 feeds out the printing paper P by rotating the supply side core holding unit 9, the winding side core holding unit 8, and the drive roller 6, and temporarily stops the feeding of the printing paper P when it reaches the initial printing position.

[0069] Next, the print control device 16 operates the main scanning drive motor 54 to move the head unit 10 in a first direction (either left or right) on the rail portion 5. Then, together with the movement of the head unit 10, the print control device 16 operates the fifth head 15 of the head unit 10 to apply pretreatment liquid to the first scan line. Note that, when scanning the first scan line, ink is not ejected from the first to fourth heads 11 to 14.

[0070] Next, the print control device 16 advances the print paper P by one scan line so that the first scan line, to which the pretreatment liquid is applied, is positioned directly below the first to fourth heads 11 to .

[0071] Then, the print control device 16 moves the head unit 10 on the rail portion 5 in a second direction opposite to the first direction, and, along with the movement, ejects ink from the first to fourth heads 11 to 14 to print the first scan line. Furthermore, while printing the first scan line, the print control device 16 also operates the fifth head 15 to apply the pretreatment liquid to a second scan line that is next to the first scan line.

[0072] Next, the print control device 16 feeds out the printing paper P by one scan line, and places a second scan line directly below the first to fourth heads 11 to 14, and places a third scan line immediately below the fifth head 15.

[0073] Then, the print control device 16 moves the head unit 10 in the first direction on the rail portion 5, and in conjunction with the movement, operates the first to fourth heads 11 to 14 and the fifth head 15 to apply pretreatment liquid to the third scan line and print on the second scan line.

[0074] Thereafter, the printing control device 16 alternately repeats the process of feeding out one scan line of printing paper P and moving the head unit 10 on the rail portion 5 in the first direction or the second direction, in the same manner as described above, to sequentially apply pretreatment liquid to the (n+1)th scan line and print on the nth scan line.

[0075] Next, the wiping operation of the inkjet printing apparatus 1 of this embodiment will be described.

[0076] The wiping operation is performed during a standby period when no printing process is being performed, and at this time, the print control device 16 moves the head unit 10 on the rail section 5 and positions it above the wiping unit 20 as shown in FIG.

[0077] Then, the printing control device 16 moves the first to fifth wipers 21a to 21e, which are immersed in the cleaning liquid in the first and second cleaning liquid tanks 20c and 20d, using the first and second conveyor belts 22 and 25, and positions the tips of the first to fifth wipers 21a to 21e at the front end positions of the corresponding first to fifth heads 11 to 15.

[0078] Next, the print control device 16 moves the first to fifth wipers 11 to 15 as they are, so that the tips of the first to fifth wipers 21a to 21e are pressed against the ejection 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 wipers 21a to 21e against the ejection surfaces of the first to fifth heads 11 to 15, the print control device 16 may move the head unit 10 downward or move the wiping unit 20 upward.

[0079] Then, while the tips of the first to fifth wipers 21a to 21e are pressed against the ejection surfaces of the first to fifth heads 11 to 15, the print control device 16 further moves the first to fifth wipers 21a to 21e, thereby wiping the ejection surfaces of the first to fifth heads 11 to 15.

[0080] Then, after wiping is completed by moving the tip ends of the first to fifth wipers 21a to 21e to the rear ends of the first to fifth heads 11 to 15, the print control device 16 further moves the first to fifth wipers 21a to 21e so that they are again immersed in the cleaning liquid in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0081] The wiping operation may be performed automatically just before the start of the printing process, or in response to a user's instruction input. It may also be performed at preset intervals or at preset intervals for the length of the printing range (the amount of paper P fed out).

[0082] Next, a description will be given of the cleaning liquid discharging operation in the wiping unit 20 of the inkjet printing apparatus 1 of this embodiment with reference to the flowchart shown in FIG.

[0083] First, the amount of cleaning liquid stored in the first cleaning liquid tank 20c is monitored by the liquid amount detector 30 (S10).

[0084] When the amount of cleaning liquid stored in the first cleaning liquid tank 20c becomes equal to or less than a preset threshold value (S12, YES), the liquid amount detector 30 outputs a detection signal to the print control device 16.

[0085] When the print control device 16 receives a detection signal from the liquid amount detection unit 30, it controls the supply unit 27 to supply unused cleaning liquid from the cleaning liquid storage unit 26 to the first cleaning liquid tank 20c and the second cleaning liquid tank 20d when the wiping unit 20 is in a standby state (S14). Note that the state when the wiping unit 20 is in a standby state does not mean when the wiping operation described above is in progress, but when the first to fifth wipers 21a to 21e are immersed in the cleaning liquid in the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0086] Then, after the supply of unused cleaning liquid has begun, if the liquid volume detection unit 30 detects that the amount of cleaning liquid stored in the first cleaning liquid tank 20c has exceeded a preset threshold value (S16, YES), a detection signal is output to the print control device 16, and the print control device 16 controls the supply unit 27 to stop the supply of unused cleaning liquid (S18).

[0087] Next, the print control device 16 rotates the first belt conveying roller 23 and the second belt conveying roller 24 in the direction of the arrow C, and moves the first to fifth wipers 21a to 21e in the standby state, thereby performing the stirring operation (S20). In this embodiment, the print control device 16 moves the first to fifth wipers 21a to 21e until they return to their original standby positions. That is, the print control device 16 in this embodiment moves the first to fifth wipers 21a to 21e by the same distance as the length of the first and second conveying belts 22 and 25. This stirs the liquid in the first and second cleaning liquid tanks 20c and 20d, and the used cleaning liquid can be mixed with the newly supplied unused cleaning liquid. In addition, since the stirring is performed by moving the first to fifth wipers 21a to 21e, there is no need to provide a new stirring mechanism, and costs can be reduced.

[0088] It is preferable that the moving speed of the first to fifth wipers 21a to 21e during the stirring operation is faster than the moving speed during the wiping operation described above, thereby improving the stirring performance of the liquid in the first and second cleaning liquid tanks 20c and 20d.

[0089] In the present embodiment, the first to fifth wipers 21a to 21e are rotated once during the stirring operation, but the present invention is not limited to this and may be rotated two or more times.

[0090] Then, after the above-mentioned stirring operation, the print control device 16 controls the supply unit 27 and the discharge unit 29 to discharge used cleaning liquid from the first and second cleaning liquid tanks 20c, 20d to the discharge pipe 29b, while supplying unused cleaning liquid from the cleaning liquid storage tank 26a to the first and second cleaning liquid tanks 20c, 20d (S22).

[0091] Then, after the used cleaning liquid is discharged and unused cleaning liquid is supplied for a preset period of time, the process returns to S10 again, and the amount of cleaning liquid is monitored by the liquid amount detector 30.

[0092] The above is a description of the operation of discharging the cleaning liquid in the wiping unit 20.

[0093] In the above embodiment, water is supplied from one cleaning liquid reservoir 26 to two cleaning liquid tanks, the first cleaning liquid tank 20c and the second cleaning liquid tank 20d, but a cleaning liquid reservoir 26 and a supply unit 27 may be provided for each of the first cleaning liquid tank 20c and the second cleaning liquid tank 20d. The supply of unused cleaning liquid to the first cleaning liquid tank 20c and the second cleaning liquid tank 20d and the discharge of used cleaning liquid may be controlled independently based on the detection signal of a liquid volume detection unit 30 provided in each of the first cleaning liquid tank 20c and the second cleaning liquid tank 20d.

[0094] In addition, in the above embodiment, when the amount of used cleaning liquid detected by the liquid amount detection unit 30 falls below a preset threshold value, the operation of draining the used cleaning liquid is performed. However, this is not limited to this. For example, as shown in FIG. 8, a time measurement unit 31 may be provided in the print control device 16, and the operation of draining the used cleaning liquid may be started based on the elapsed time measured by the time measurement unit 31.

[0095] Specifically, for example, the time elapsed since the previous operation of discharging used cleaning liquid was completed may be measured by the time measurement unit 31, and when the measured elapsed time reaches a preset threshold value, the print control device 16 may control the supply unit 27 and the discharge unit 29 to perform the above-mentioned discharge operation.

[0096] In addition, in the above embodiment, when performing the discharge operation, in S16, unused cleaning liquid is supplied until the amount of cleaning liquid detected by the liquid amount detection unit 30 reaches a preset threshold value. However, this is not limited to this, and the time elapsed from the point in time when the supply of unused cleaning liquid began may be measured by the time measurement unit 31, and unused cleaning liquid may be supplied until the elapsed time reaches a preset threshold value.

[0097] In the above embodiment, the first to fifth wipers 21a to 21e are used to stir the liquid in the first and second cleaning liquid tanks 20c and 20d, but a stirring mechanism may be provided for the first and second conveyor belts 22 and 25, the first belt conveyor roller 23, or the second belt conveyor roller 24 in addition to the first to fifth wipers 21a to 21e, and the stirring mechanism may be used to rotate the first and second belt conveyor rollers 23 and 24 to perform the stirring operation. This can improve the stirring performance.

[0098] The present invention further discloses the following supplementary notes. (Additional Note)

[0099] In the wiper cleaning device of the present invention, a liquid volume detection unit can be provided which detects the amount of cleaning liquid stored in the cleaning liquid tank, and the control unit can control the supply unit to supply unused cleaning liquid to the cleaning liquid tank based on the amount of cleaning liquid detected by the liquid volume detection unit, and after that supply, can supply unused cleaning liquid to the cleaning liquid tank while discharging the used cleaning liquid from the cleaning liquid tank.

[0100] In addition, the wiper cleaning device of the present invention can be provided with a wiper transport unit that moves the wiper to wipe the outlet that discharges liquid, and that immerses the wiper in the cleaning liquid tank and moves it after wiping, and the control unit can control the wiper transport unit to immerse the wiper in the cleaning liquid tank and move it thereafter after unused cleaning liquid is supplied to the cleaning liquid tank based on the amount of cleaning liquid detected by the liquid volume detection unit, and then agitate the cleaning liquid tank with the wiper.

[0101] In addition, in the wiper cleaning device of the present invention, the control unit can control the wiper transport unit so that the movement speed of the wiper when agitating the cleaning liquid tank is faster than the movement speed of the wiper when wiping the outlet. [Explanation of symbols]

[0102] 1 Inkjet printing device 2 Base 2a wheels 3 pedestal 4 Platen 4a Front paper guide 4b Rear paper guide 4c Vacuum chamber 4d fan 5 Rail section 6 Drive roller 7 Pressure roller 8. Winding side core holder 8a Core body 9 Supply side core holding part 9a Core body 10 Head Unit 11~15 Heads 1~5 16 Printing control device 20 Wiping unit 20a Cleaning solution tank 20b Bulkhead 20c First cleaning solution tank 20d Second cleaning solution tank 21a to 21e 1st to 5th wipers 22 First conveyor belt 23 First belt conveyor roller 24 Second belt conveyor roller 26 Water storage section 26a Water storage tank 26b Lid 27 Supply section 28 Water supply pipe 28a Water supply hole 29 Discharge section 29b Discharge pipe 29a Discharge hole 30 Liquid volume detection unit 31 Time measurement section 39 Belt drive motor 54 Main scanning drive motor 61 Transport drive motor 81 Winding drive motor 91 Supply drive motor L Cleaning Solution P Print paper

Claims

1. a cleaning liquid tank for storing a cleaning liquid for cleaning the wiper; a cleaning liquid storage section for storing unused cleaning liquid; a supply unit that supplies the cleaning liquid stored in the cleaning liquid storage unit to the cleaning liquid tank; a control unit that controls the supply unit to supply the unused cleaning liquid to the cleaning liquid tank while discharging used cleaning liquid from the cleaning liquid tank; a liquid amount detection unit that detects an amount of the cleaning liquid stored in the cleaning liquid tank, A wiper cleaning device in which the control unit controls the supply unit to supply unused cleaning liquid to the cleaning liquid tank based on the amount of cleaning liquid detected by the liquid volume detection unit, and after the supply, supplies the unused cleaning liquid to the cleaning liquid tank while discharging the used cleaning liquid from the cleaning liquid tank.

2. a wiper transport unit that moves the wiper so as to wipe the discharge port that discharges the liquid, and that immerses the wiper after the wiping in the cleaning liquid tank and transports it; 2. The wiper cleaning device according to claim 1, wherein the control unit controls the wiper transport unit to immerse and move the wiper in the cleaning liquid tank after the unused cleaning liquid is supplied to the cleaning liquid tank based on the amount of cleaning liquid detected by the liquid volume detection unit, and agitates the cleaning liquid tank with the wiper.

3. The wiper cleaning device according to claim 2 , wherein the control unit controls the wiper transport unit so that the movement speed of the wiper when stirring the cleaning liquid tank by the wiper is faster than the movement speed of the wiper when wiping the outlet.

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