Ink jet printing apparatus

Abstract

To provide an ink jet printer equipped with an ink receiving part capable of keeping moisture in a moisture-retaining body during temporary ejection and preventing the moisture-retaining body from being stained with ink.SOLUTION: In the inkjet printer A having an ink receiving part 1 for receiving ink temporarily discharged from an ink head 6 at an appropriate time to prevent clogging, the ink receiving part 1 includes a tray part 11, a moisture retaining body 12 placed on the tray part 11 and supplied with water or a water-based solvent, and a sheet body 13 installed on an upper surface of the moisture retaining body 12, and the sheet body 13 absorbs landed ink.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inkjet printing device, and more particularly to an inkjet printing device having an ink receiving section that absorbs ink ejected by preliminary ejection to prevent clogging. [Background technology]

[0002] Inkjet printers print by ejecting ink onto a print medium located opposite an ink head. In addition, the width of the print medium is not always constant in inkjet printers, and print media of different widths may be used. In this case, the nozzles of the ink head in the area that does not correspond to the print medium (that is, the non-print area) will not perform printing at all while printing is being performed on that print medium.

[0003] If an ink head does not eject ink for a long period of time, the ink solidifies and the nozzles become clogged, which makes it impossible to print properly when an ink head with such nozzles is used. Furthermore, if an ink head has nozzles that are ejecting ink and nozzles that are not, the ink in the nozzles that are not ejecting ink may be pulled by the ejected ink, causing the area around the nozzle to become even drier. For this reason, it is preferable to maintain the meniscus of the ink head by ejecting ink from all nozzles at the appropriate time. Therefore, when nozzles in the non-printing area occur due to the width of the printing medium as described above, the nozzles of the ink head in the non-printing area perform provisional ejection to eject ink at the appropriate time. Therefore, ink jet printing devices have been developed that include an ink receiving section for receiving ink ejected by preliminary ejection.

[0004] For example, the blank discharge receiver 80 (ink receiving portion) described in Patent Document 1 includes an absorbing member 81 that absorbs liquid (ink), and causes the absorbing member 81 to absorb the liquid and transfer it to a liquid holding member 82. In other words, the absorbing member 81 directly receives the ink, and the ink absorbed by the absorbing member 81 is held in the liquid holding member 82. The liquid ejecting device (ink receiving unit) described in Patent Document 2 is an empty ejection receiver 800 having a first absorbing member 801 made of melamine foam, and moves the ink to a second absorbing member 802. That is, similar to the invention described in Patent Document 1, the first absorbing member 801 directly absorbs the ink, and the second absorbing member 802 holds the ink. The blank discharge receiver 800 (ink receiving section) of Patent Document 3 has a first absorbing member 801 divided into blocks, and causes the absorbing member 801 to absorb liquid (ink) and transfers it to a second absorbing member 802. That is, similar to the invention described in Patent Document 2, the first absorbing member 801 directly absorbs the ink, and the second absorbing member 802 holds the ink. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-064145 [Patent Document 2] Japanese Patent Application Publication No. 2020-049937 [Patent Document 3] Japanese Patent Publication No. 2020-044826 Summary of the Invention [Problem to be solved by the invention]

[0006] In the ink receiving units of Patent Documents 1 to 3, a sponge-like absorbing member directly absorbs the pre-ejected ink. The absorbed ink is then retained in the liquid holding member or the second absorbing member. Therefore, when pre-ejection is performed, the absorbing member becomes soiled with ink over time. This requires frequent replacement of the absorbing member, and if printing is in progress, printing must be stopped.

[0007] Furthermore, when the ink ejected by pre-ejection dries, it solidifies and adheres to the ink receiving section. Because ink ejected from the same nozzle is ejected to the same location, the solidified ink accumulates in that location on the ink receiving section, gradually increasing in height. As a result, the solidified ink may come into contact with the bottom of the ink head, causing poor printing or ink head failure. Therefore, in the devices described in Patent Documents 1 to 3, the absorbing member is impregnated with a moisturizing liquid, which is an organic solvent, so that the water contained in the ink does not evaporate and solidify. However, in the ink receiving sections of any of Patent Documents 1 to 3, if the moisturizing liquid evaporates and a sufficient amount is no longer maintained in the absorbing member, maintenance such as supplying moisturizing liquid to the absorbing member or replacing the absorbing member must be performed, and preliminary ejection must be stopped for maintenance.

[0008] The present invention was developed in response to the above-mentioned problems. That is, an object of the present invention is to provide an inkjet printing device having an ink receiving section that can maintain moisture in the moisturizing body while preliminary ejection is being performed and can prevent the moisturizing body from being soiled by ink. [Means for solving the problem]

[0009] As a result of extensive research, the inventors have found that the above-mentioned problems can be solved by providing a moisturizer that retains water and that is supplied with water, and by providing a sheet body that is separate from the moisturizer and that absorbs the ink that lands on the ink cartridge. The present invention is based on this finding.

[0010] The present invention resides in an inkjet printing device A having an ink receiving section 1 for receiving ink temporarily ejected from an ink head 6 at appropriate times to prevent clogging, the ink receiving section 1 comprising a receiving tray section 11, a moisturizing body 12 placed on the receiving tray section 11 and supplied with water or a water-based solvent, and a sheet body 13 placed on the upper surface of the moisturizing body 12, the sheet body 13 absorbing the ink that lands on the inkjet printing device A.

[0011] The present invention resides in the inkjet printing device A described above, in which the ink receiving section 1 further includes a tank 14 arranged next to the receiving tray section 11, water or a water-based solvent is stored in the tank 14, the end of the sheet body 13 on the tank 14 side is in contact with the water or water-based solvent, and the water or water-based solvent is supplied to the moisturizing body 12 via the sheet body 13.

[0012] The present invention resides in the inkjet printing device A described above, in which the inner bottom surface of the receiving tray portion 11 is positioned higher than the inner bottom surface of the tank 14.

[0013] The present invention resides in the inkjet printing device A described above, in which the sheet body 13 is placed on the upper surface of the moisturizing body 12 so as to cover the entire moisturizing body 12, and the ends of the sheet body 13 are folded back and held down by the back surface of the receiving tray portion 11.

[0014] The present invention resides in the inkjet printing device A described above, in which a long hole 11a is formed at the end of the receiving tray portion 11 opposite the tank 14 side, and a sheet holding plate 11b is inserted into the long hole 11a via a sheet body 13.

[0015] The present invention resides in the inkjet printing device A described above, in which the moisturizing body 12 is a block-shaped sponge or a block-shaped felt, and the sheet body 13 is a sheet-shaped nonwoven fabric.

[0016] The present invention resides in the inkjet printing device A described above, which includes an ink head 6, a printing medium M on which an image is formed by ink ejected from the ink head 6, a plurality of transport rolls 7 for transporting the printing medium M, a stay 3 provided between adjacent transport rolls 7, and a frame 2 to which the stay 3 is attached via a bracket 4, and in which the bottom surface of the ink receiving section 1 is placed on the stay 3, and the position of the stay 3 is adjustable in the vertical direction.

[0017] The present invention resides in the inkjet printing device A described above, in which the end of the ink receiving part 1 opposite the tank 14 side is fixed to the stay 3 by a bolt 15e, a claw 15c is provided on the side of the ink receiving part 1 facing the tank 14, and a fixing device is provided on the bracket 4 opposite the claw 15c.

[0018] The present invention resides in the inkjet printing device A described above, which comprises an ink head 6, a printing medium M on which an image is formed by ink ejected from the ink head 6, a plurality of transport rolls 7 for transporting the printing medium M, stays 3 provided between adjacent transport rolls 7, and a frame 2 to which the stays 3 are attached via brackets 4, and in which the shortest distance L1 between the same plane of the printing surface of the printing medium M and the upper surface of the sheet 13 is 3 to 8 mm.

[0019] The present invention resides in the inkjet printing device A described above, in which preliminary ejection by an ink head 6 and image formation by an ink head 6 different from the ink head 6 that performs preliminary ejection are performed simultaneously.

[0020] The present invention may also be implemented by appropriately combining the above configurations. [Effects of the Invention]

[0021] The inkjet printing device A of the present invention is capable of reliably receiving the pre-ejected ink by having an ink receiving section 1 which comprises a receiving tray section 11, a moisturizing body 12 which is placed on the receiving tray section 11 and to which water or a water-based solvent is supplied, and a sheet body 13 which is placed on the upper surface of the moisturizing body 12. Furthermore, a sheet body 13 separate from the moisturizing body 12 is provided, and the sheet body 13 absorbs the ink that lands on the sheet body 13, so that the moisturizing body 12 does not directly receive the ink that has been temporarily ejected, and the moisturizing body 12 is prevented from being soiled. Furthermore, by supplying water or a water-based solvent to the moisturizer 12, the moisturizer 12 can maintain moisture during pre-ejection, preventing the ink ejected by pre-ejection from solidifying. Therefore, there is no need to interrupt pre-ejection to supply water or a water-based solvent, and inkjet printing can be performed continuously. For these reasons, the timing for replacing the moisturizer 12 can be extended as long as possible. Furthermore, when ink receiving section 1 receives a certain amount of ink or more from preliminary ejection, only sheet member 13 can be replaced to prevent moisture retention member 12 from becoming soiled, making maintenance easier.

[0022] In the inkjet printing device A of the present invention, the ink receiving unit 1 further comprises a tank 14, in which water or an aqueous solvent is stored, the end of the sheet member 13 on the tank 14 side is in contact with the water or aqueous solvent, and the water or aqueous solvent is supplied to the moisturizing body 12 via the sheet member 13, so that the water or aqueous solvent is constantly supplied from the sheet member 13 to the moisturizing body 12 during pre-ejection. This allows the moisturizing body 12 to maintain a more sufficient amount of moisture. Furthermore, since the tank 14 is disposed next to the receiving tray 11, there is no need to remove the moisturizing element 12 when supplying water or a water-based solvent, but rather, water or a water-based solvent can be added to the tank 14. This makes maintenance easy.

[0023] In the inkjet printing device A of the present invention, the inner bottom surface of the receiving tray portion 11 is positioned higher than the inner bottom surface of the tank 14, thereby improving the penetration efficiency of water or water-based solvent in the sheet body 13 due to capillary action and enabling an appropriate amount of water or water-based solvent to be supplied to the moisturizing body 12.

[0024] In the inkjet printing device A of the present invention, the sheet 13 is placed on the upper surface of the moisturizing body 12 so as to cover the entire moisturizing body 12, thereby preventing exposure of the surface of the moisturizing body 12. This allows moisture to be supplied evenly to the moisturizing body 12, preventing the moisturizing body 12 from drying out. Furthermore, the moisture retainer 12 can be prevented from being soiled by ink. Furthermore, the end of the sheet body 13 is folded back and held down by the back surface of the receiving tray portion 11, which prevents the sheet body 13 from being turned over by the accompanying flow caused by the transport of the printing medium M, and allows the sheet body 13 to maintain a state in which it covers the moisturizing body 12.

[0025] In the inkjet printing device A of the present invention, a long hole 11a is formed at the end of the receiving tray portion 11 opposite the tank 14 side, and a sheet holding plate 11b is inserted into the long hole 11a via the sheet body 13, thereby preventing the sheet body 13 from being turned over by the accompanying flow caused by the transport of the printing medium M, and enabling the sheet body 13 to maintain a state in which it covers the moisturizing body 12.

[0026] In the inkjet printing device A of the present invention, the moisturizing body 12 is a block-shaped sponge or a block-shaped felt, so that the moisturizing body 12 can maintain a sufficient amount of moisture. Furthermore, since the sheet body 13 is a sheet-like nonwoven fabric, the efficiency of penetration of water or water-based solvent into the sheet body 13 can be improved by capillary action, and an appropriate amount of water or water-based solvent can be supplied to the moisturizing body 12.

[0027] In the inkjet printing device A of the present invention, the bottom surface of the ink receiving unit 1 is placed on a stay 3, and the position of the stay 3 can be adjusted in the vertical direction, so that the ink receiving unit 1 can be positioned in the width direction and the vertical direction. This makes it possible to maintain an appropriate distance between the printing medium M and the ink receiving unit 1, and to suppress the effects of moisture from the ink receiving unit 1 on the printing medium M, such as bending of the printing medium M. In this case, it is preferable that the shortest distance L1 between the same plane of the printing surface of the printing medium M and the upper surface of the sheet member 13 is 3 to 8 mm. This makes it possible to minimize the influence of moisture from the ink receiving portion 1 on the printing medium M. Furthermore, since the position of the stay 3 can be adjusted in the vertical direction, even when the ink head 6 needs to be replaced, the position of the ink receiving part 1 can be adjusted, and the ink receiving part 1 can maintain an appropriate positional relationship with the ink head 6.

[0028] In the inkjet printing device A of the present invention, the end of the ink receiving part 1 opposite the tank 14 side is fixed to the stay 3 by a bolt 15e, so that the ink receiving part 1 can be attached and detached to the stay 3. In addition, a claw 15c is provided on the side of the ink receiving part 1 facing the tank 14, and a fixing device is provided on the bracket 4 opposite the claw 15c. Therefore, if the ink receiving part 1 tilts and one end rises up, the claw 15c will engage with the fixing device provided on the bracket 4, thereby suppressing the movement of the ink receiving part 1 and preventing it from rising up.

[0029] In the present invention, preliminary ejection by an ink head 6 and image formation by an ink head 6 other than the ink head 6 performing preliminary ejection are performed simultaneously, so that it is possible to prevent clogging in both the ink heads 6 in the print area Z and the ink heads 6 in the non-print area Z and maintain a state suitable for printing. Therefore, even when printing is performed successively on different print media M with different print area sizes, all of the ink heads 6 can maintain a state suitable for printing. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a top view showing the ink receiving section. [Figure 2] FIG. 2 is a partial cross-sectional side view showing the ink receiving portion. [Figure 3a] FIG. 3a is a side cross-sectional view showing the fastener and the claw. [Figure 3b] FIG. 3b is an enlarged view of the fastener and tab taken along line AA of FIG. 3a. [Figure 4] FIG. 4 is a top view showing the tray frame. [Figure 5] FIG. 5 is an enlarged partial cross-sectional side view showing the ink receiving portion. [Figure 6] FIG. 6 is a top view showing the tray portion. [Figure 7] FIG. 7 is an explanatory diagram showing the preliminary ejection. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, unless otherwise specified, the positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings. In this specification, the terms "transport direction" and "width direction" refer to the transport direction of the print medium M and the width direction perpendicular to this, respectively.

[0032] 1 is a top view showing the ink receiving unit 1. Note that portions where other components are present on the near side of the figure are indicated by dashed lines. The inkjet printing device A of the present invention comprises at least a frame 2, a printing unit 5 having a plurality of ink heads 6 attached to the frame 2, a printing medium M to be printed by the ink heads 6, a transport roll 7 for transporting the printing medium M, and an ink receiving unit 1 provided in a position opposite the ink heads 6 in the non-printing area Z. The inkjet printing device A is a device for printing by ejecting ink from an ink head 6 while conveying a long print medium M (see FIG. 7).

[0033] The frame 2 is a pillar- or beam-shaped frame that constitutes the inkjet printing device A. Each of the members described below is attached to the frame 2.

[0034] The transport rolls 7 are multiple guide rolls without a drive source, and are provided adjacent to each other on the upstream and downstream sides of the printing unit 5. The transport rolls 7 and a drive roll having a drive source (not shown) transport the print medium M by rotating in contact with the print medium M. Furthermore, the transport rolls 7 on the upstream side and downstream side of the printing unit 5 may both be drive rolls having a drive source, or either one of them may be a drive roll having a drive source. In other words, it is only necessary that the printing surface of the printing medium M on which printing is performed by the ink head 6 is formed by a plurality of adjacent transport rolls 7.

[0035] The printing unit 5 is a so-called line head type device in which a plurality of ink heads 6 are arranged in a staggered pattern so that the ink heads 6 are present across the entire printable width. The ink head 6 is in communication with an ink tank (not shown), and is supplied with ink from the ink tank. In this embodiment, the ink used for inkjet printing is water-based.

[0036] The printing unit 5 is attached to frames 2 located at both ends in the width direction. In addition, below the printing unit 5, stays 3 extending in the width direction are attached to the frames 2 via L-shaped brackets 4 (see Figure 2). The bracket 4 is fixed to the frame 2 by a bolt 4c through an elongated hole provided in the bracket 4, and the position of the stay 3 can be adjusted in the vertical direction by changing the mounting position of the bracket 4 relative to the frame 2 (see Figure 3). The stays 3 are provided downstream of the transport rolls 7 arranged upstream of the printing unit 5 described above, and upstream of the transport rolls 7 arranged downstream of the printing unit 5. That is, in the transport direction of the print medium M, the stays 3 are arranged on both ends of the printing unit 5, and further, transport rolls 7 are arranged on both outer ends thereof.

[0037] The ink receiving portion 1 is placed on the stay 3. The ink receiving unit 1 is provided at one end in the width direction of the inkjet printing device A. In this case, it is preferable that the ink receiving unit 1 is provided on the so-called operation side where printing operations and maintenance work are performed, rather than on the so-called drive side where the printing medium M is transported (see FIG. 7).

[0038] 2 is a partial cross-sectional side view showing the ink receiving portion 1. The same plane as the print medium M is indicated by a dashed line. The ink receiving section 1 comprises a flat dish-shaped receiving tray section 11, a block-shaped moisturizing body 12 placed on the receiving tray section 11, a sheet body 13 placed on the upper surface of the moisturizing body 12 so as to cover the moisturizing body 12, a tank 14 in which water is stored, and a receiving tray frame 15 that houses these. The tray portion 11 and the tank 14 are placed on a box-shaped tray frame 15 with an open top.

[0039] FIG. 3a is a side cross-sectional view showing the fastener and the claw. FIG. 3b is an enlarged view showing the fastener and the claws taken along line AA in FIG. 3a. In the ink receiving portion 1, a claw 15c is provided on the side surface of one end (operation side) of the receiving tray frame 15, protruding laterally. The bracket 4 on the operating side, which connects the frame 2 and the stay 3, is provided with a fixing device to prevent the tray frame 15 from floating up. The fixing device consists of multiple bolts 4a and a plate 4b that is screwed to the bracket 4 by the bolts 4a. A gap L2 exists between the claw 15c and the plate 4b. The gap L2 is preferably about 0.1 to 1.0 mm in the vertical direction. In this embodiment, the gap L2 is 0.5 mm. In this embodiment, as will be described later, the tray frame 15 is fixed to the stay 3 by the bolt 15e only on the other end side (drive side) of the ink receiving unit 1. When the tray frame 15 is fixed to the stay 3 by the bolt 15e only on one side in this way, the opposite end side (operation side) may be lifted up. In this embodiment, the gap L2 between the fixing device (plate 4b) and the claw 15c is 0.5 mm, so if one end (operation side) rises, the rise is kept to within 0.5 mm. This prevents the one end (operation side) of the tray frame 15 (ink receiving unit 1) from coming into contact with the print medium M. The plate 4b is screwed to the bracket 4 with a bolt 4a, and the bracket 4 is fixed to the frame 2 with a bolt 4c through a long hole. Therefore, by changing the mounting position of the bracket 4 relative to the frame 2, the stay 3 can be raised and lowered in the vertical direction. This allows the mounting position of the tray frame 15 to be changed. Therefore, even when the ink head 6 is replaced, the position of the ink receiving unit 1 can be adjusted, and the ink receiving unit 1 can maintain an appropriate positional relationship with the ink head 6.

[0040] FIG. 4 is a top view showing the tray frame 15. As shown in FIG. A protrusion 15b that protrudes upward in the conveyance direction is provided on the bottom surface of the receiving tray frame 15, and the receiving tray frame 15 is divided in the width direction into a side that houses the tank 14 and a side that houses the receiving tray portion 11. The tank 14 is positioned in the width direction by abutting the protrusion 15b (see FIG. 5). The length of the tank 14 in the conveying direction is set to approximately match the width of the inside of the receiving tray frame 15, and the tank 14 is positioned in the conveying direction by being housed in the receiving tray frame 15. In this way, the detachable tank 14 is housed in the receiving tray frame 15.

[0041] Stepped portions 15a are provided on both ends of the tray frame 15 in the conveying direction, and the tray portion 11 fits into the step portions 15a to be positioned in the conveying direction. The step portions 15a are provided only on the upstream and downstream sides in the conveying direction. Furthermore, the tray portion 11 is positioned in the width direction by abutting it against the inner side surface of the other end (drive side) of the tray frame 15 (see Figure 5). In this way, the removably provided tray portion 11 is housed within the tray frame 15. Because the step 15a is provided on the upper side of the tray frame 15, the inner bottom surface of the tray 11 is located higher than the inner bottom surface of the tank 14. This improves the efficiency of water penetration into the sheet 13 due to capillary action, which will be described later. This allows the sheet 13 to efficiently supply water to the moisturizing body 12.

[0042] In the ink receiving portion 1, a protrusion 15d that protrudes from the bottom surface of the tray frame 15 is provided on the side surface of the other end side (drive side) of the tray frame 15. A potbelly hole 15f, which is shaped like a circle with a large and a small diameter, is cut out in the protrusion 15d. The tray frame 15 is fixed to the stay 3 by a bolt 15e that passes through the small diameter hole in the potbelly hole 15f (see Figure 5). As mentioned above, the position of the stay 3 can be adjusted in the vertical direction, which allows the tray frame 15 to be positioned, and the ink receiving unit 1 to be positioned opposite the ink head 6 in the non-printing area Z. This ensures that the ink ejected by preliminary ejection is received by the ink receiving unit 1 (see Figure 7). Furthermore, because the screw holes for attachment are potbellied holes 15f, the tray frame 15 can be attached and detached without completely removing the bolts 15e from the stay 3. Specifically, with the bolts 15e loosened to a certain extent, the tray frame 15 is shifted from one end to the other (from left to right in FIG. 4) so ​​that the bolts 15e enter from the small-diameter holes into the large-diameter holes, and the tray frame 15 can be attached and detached to and from the stay 3 without the protrusions 15d interfering with the bolts 15e.

[0043] FIG. 5 is an enlarged partial cross-sectional side view showing the ink receiving portion 1. As shown in FIG. A moisturizing body 12, which is a block of felt, is placed on the receiving tray 11. The moisturizing body 12 is for retaining moisture supplied from a sheet body 13, which will be described later. The moisturizing body 12 can retain more moisture than the sheet body 13, and because it is covered by the sheet body 13 as described below, it loses less moisture due to evaporation than the sheet body 13. Therefore, when the sheet body 13 is unable to retain a sufficient amount of moisture due to conditions such as high temperature and low humidity, it can supply moisture to the sheet body 13. Therefore, the sheet body 13 that receives the provisional ejection can be maintained in a constantly moist state, and the ink ejected by the provisional ejection can be prevented from dissolving and solidifying.

[0044] The tray 11 is provided with a recess that corresponds to the shape of the moisturizer 12 in order to position and secure the moisturizer 12. By placing the moisturizer 12 in this recess, the moisturizer 12 can be reliably positioned opposite the ink head 6 where preliminary ejection is performed. This makes it possible for the sheet 13, which receives the ink ejected by preliminary ejection, to be constantly kept moist during the preliminary ejection.

[0045] The tank 14 is a box-shaped housing without a top surface, and stores water. One end of the sheet member 13 is immersed in the water in the tank 14, as will be described later. The tank 14 is detachably housed in the tray frame 15, positioned by the above-mentioned projections 15b. The water stored in the tank 14 is preferably purified water.

[0046] The tank 14 is disposed on the operation side of the tray frame 15. This allows water to be easily supplied to the tank 14 even during preliminary ejection (during printing).

[0047] The tank 14 has a plate-shaped lid 14a on its upper surface. The lid 14a is fixed in a predetermined position by the frame 2 on one end side and the shaft and bearing of the adjacent transport roll 7, and is sized to cover the tank 14, leaving a gap large enough for the sheet body 13 to come out. The lid 14a is fixed in a predetermined position relative to the tank 14 during pre-discharge. The lid 14a suppresses evaporation of water from the tank 14 and also suppresses movement of the sheet body 13 immersed in water in the tank 14. Furthermore, since the lid portion 14a is locked in a predetermined position on the tank 14, if there is a shortage of water in the tank 14 during preliminary ejection, water can be easily supplied to the tank 14 from the operating side of the inkjet printing device A (see Figure 7). The presence of the lid portion 14a can prevent the water stored in the tank 14 from being contaminated by ink mist, etc. Furthermore, by providing a cover made of paper or the like on the lid portion 14a, the lid portion 14a can be prevented from being contaminated by ink mist, etc.

[0048] The sheet body 13 is a sheet-like nonwoven fabric. A rag is preferably used as the sheet body 13. The sheet body 13, with one end immersed in the water in the tank 14, is placed on the top surface of the moisturizer 12 so as to cover the entire moisturizer 12 placed on the receiving tray 11 together with the receiving tray 11. This prevents the surface of the moisturizer 12 from being exposed. This allows moisture to be evenly supplied to the moisturizer 12, preventing it from drying out. The upstream and downstream ends of the sheet body 13 in the conveying direction are folded back and wrap around to the back surface of the receiving tray 11, which is then placed on the receiving tray frame 15 (step 15a). Therefore, the sheet body 13 is sandwiched and fixed between the receiving tray 11 and the receiving tray frame 15 (step 15a). Furthermore, it is preferable to attach both ends of the sheet body 13 that wrap around to the back surface of the receiving tray 11 to the back surface of the receiving tray 11 with paper tape or the like. This allows sheet body 13 to be securely fixed and held down on the back surface of receiving tray 11. This prevents sheet body 13 from being turned over by the accompanying flow caused by the transport of print medium M, and allows sheet body 13 to maintain a state in which it covers moisturizing body 12. As described above, the tank 14 and the receiving tray 11 are adjacent to each other, and the receiving tray 11 is located above, so that the sheet body 13 extends from one end immersed in the water stored in the tank 14 to cover the moisturizing body 12 and the receiving tray 11 located diagonally above. This improves the efficiency of permeation into the sheet body 13 by capillary action.

[0049] FIG. 6 is a top view showing the tray portion 11. As shown in FIG. The sheet body 13 is further fixed to the receiving tray 11 by a sheet retaining plate 11b. A long hole 11a is provided along the conveying direction at the end of the receiving tray 11 opposite to the tank 14 side. The sheet retaining plate 11b is an L-shaped member in a side view that is inserted into the long hole 11a (see FIGS. 5 and 7). As described above, with the sheet body 13 sandwiched and fixed between the tray 11 and the tray frame 15 (step 15a), the sheet retaining plate 11b is inserted into the slot 11a from above the sheet body 13. This fixes the sheet body 13 in place with the weight of the sheet retaining plate 11b. Furthermore, because the sheet body 13 is wet, a strong frictional force acts between the tray 11, the sheet body 13, and the sheet retaining plate 11b. At this time, the end of the sheet body 13 on the print medium M side is covered by the sheet retaining plate 11b (see FIG. 7). This prevents the sheet body 13 from moving during pre-ejection. This prevents the sheet body 13 from being turned over by the accompanying flow caused by the transport of the print medium M, and allows the sheet body 13 to maintain a state in which it covers the moisturizing body 12. This means that there is no need to interrupt pre-ejection to supply water, and inkjet printing can be performed continuously.

[0050] Sheet body 13 absorbs water from tank 14 and supplies it to moisturizer 12. In other words, sheet body 13 is always in a moist state. If the environment is one in which evaporation from sheet body 13 is active due to high temperature and low humidity, moisture is supplied from moisturizer 12 to sheet body 13 as described above, and sheet body 13 remains moist.

[0051] The sheet body 13 receives and absorbs the ink ejected by the preliminary ejection. As described above, the sheet body 13 is always in a moist state, so the ink ejected onto the sheet body 13 is dissolved by the moisture and spreads over the sheet body 13. This prevents the ink from scattering onto the print medium M or the like and soiling the surrounding area. At the same time, the moisture in the ink evaporates and solidifies, preventing the ink from building up. Furthermore, as described above, sheet member 13 completely covers moisturizer 12, so moisturizer 12 does not directly receive the temporarily ejected ink, and soiling of moisturizer 12 is prevented. For these reasons, the timing for replacing the moisturizer 12 can be extended as long as possible.

[0052] 2, the upper surface of the sheet 13 is preferably positioned so that the shortest distance L1 between the same plane of the printing surface of the print medium M and the upper surface of the sheet 13 is 3 to 8 mm. In this case, the sheet 13 is preferably positioned lower than the print medium M. This allows the distance between the print medium M and the ink receiving section 1 to be kept appropriate, and prevents moisture from the ink receiving section 1 from affecting the print medium M, such as bending the print medium. Furthermore, the ink ejected by the preliminary ejection can be reliably absorbed by the sheet member 13.

[0053] When a certain amount of ink or more has been absorbed into the sheet 13, it takes time for newly ejected ink to dissolve on the sheet 13. In this case, by replacing the sheet 13, the ink receiving section 1 can once again receive ink from a temporary ejection under suitable conditions while preventing soiling of the moisturizing body 12. Since the ink receiving section 1 is provided on the operation side, the sheet body 13 can be easily replaced. Furthermore, since the sheet body 13 is made of nonwoven fabric, it is easy to procure.

[0054] 7 is an explanatory diagram showing preliminary ejection, where parts of the configuration that are present on the front side of the drawing are indicated by dashed lines. The boundary of the non-printing area Z on the tank 14 side is indicated by a two-dot chain line. The boundary of the non-printing area Z on the printing medium M side is the edge of the printing medium M. Inkjet printing device A can freely set the printing range within the printable width. Therefore, when printing on print medium M narrower than the printable width, the nozzles of the ink head 6 are divided into those located in the area facing the print medium M and ejecting ink for printing (main ejection), and those located in the area not facing the print medium M (non-printing area Z) and not needing to eject ink for printing but only performing preliminary ejection to prevent clogging. Depending on the width of the print medium M, as mentioned above, a single ink head 6 may contain a mixture of nozzles that perform main ejection and nozzles that only perform preliminary ejection. The preliminary ejection by the ink head 6 and the image formation on the print medium M by an ink head 6 other than the ink head 6 that performs the preliminary ejection are performed simultaneously. This makes it possible to prevent clogging and maintain a state suitable for printing in both the ink heads 6 in the printing area and the ink heads 6 in the non-printing area Z. Therefore, even when printing is performed successively on different print media M with different print area sizes, all of the ink heads 6 can maintain a state suitable for printing. As described above, the ink receiving section 1 is provided in a position facing the ink head 6 in the non-printing area Z, and receives ink ejected by preliminary ejection. If the ink receiving section 1 were not to receive these inks, the nozzles of the ink head 6 in the non-printing area Z would be exposed to the air for a long time without ejecting ink, causing drying, clogging, etc., making the nozzles unsuitable for printing. Furthermore, if ink is ejected without anything to receive it, the ejected ink may soil the printing medium M or the inkjet printing device A, or may dry and form a buildup, thereby interfering with printing.

[0055] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

[0056] In the above embodiment, the moisturizing body 12 is a block of felt, but it may also be a sponge. Also, a combination of these may be used.

[0057] In the above embodiment, the water stored in the tank 14 is purified water, but it may also be tap water or a water-based solvent such as a cleaning liquid for water-based ink.

[0058] In the above embodiment, the sheet pressing plate 11b is provided along the conveying direction of the receiving tray 11, but this is not limitative. For example, it may be provided along the width direction.

[0059] In the above embodiment, the ink receiving section 1 is provided on the operation side of the inkjet printing device A, but it may be provided on the drive side depending on the position of the non-printing area Z, or on both the operation side and the drive side. [Industrial Applicability]

[0060] The inkjet printing device A of the present invention can be widely used in inkjet printing that uses aqueous ink to print including non-printed areas Z. This prevents clogging of the ink head 6 in the non-printing area Z, and makes it possible to maintain a state suitable for printing. [Explanation of symbols]

[0061] A···Inkjet printing device 1. Ink receiving part 11. Receptacle section 11a...long hole 11b Sheet retaining plate 12. Moisturizing body 13. Sheet body 14. Tank 14a...Lid part 15···Receptacle frame 15a...Stepped section 15b...protrusion 15c···claw 15d...Protrusion 15e volts 15f···Dharma hole 2. Frame 3. Stay 4. Bracket 4a bolt 4b Plate 4c bolt 5 Printing section 6. Ink head 7. Transport roll M...Print medium Z...Non-print area L1: The shortest distance between the flat surface of the printing surface and the top surface of the sheet L2: Gap

Claims

1. In an inkjet printing device having an ink receiving section for receiving ink temporarily ejected from an ink head at appropriate times to prevent clogging, The ink receiving portion is A saucer portion, a moisturizing body that is placed on the receiving tray and to which water or a water-based solvent is supplied; a sheet body placed on the upper surface of the moisture retaining body; Equipped with The sheet member absorbs the ink that lands on the inkjet printing device.

2. the ink receiving portion further includes a tank disposed adjacent to the receiving tray portion; The water or water-based solvent is stored in the tank, an end of the sheet body on the tank side contacts the water or the water-based solvent; 2. The ink jet printing device according to claim 1, wherein the water or water-based solvent is supplied to the moisturizing body through the sheet body.

3. 3. The ink jet printing device according to claim 2, wherein the inner bottom surface of the receiving tray is located higher than the inner bottom surface of the tank.

4. the sheet body is placed on the upper surface of the moisturizing body so as to cover the entire moisturizing body, 3. The ink jet printing device according to claim 2, wherein the edge of the sheet is folded back and held by the rear surface of the receiving tray.

5. An elongated hole is formed in the end of the receiving tray opposite to the tank side, 3. The ink jet printing device according to claim 2, wherein a sheet pressing plate is inserted into the slot through the sheet.

6. the moisturizing body is a block-shaped sponge or a block-shaped felt, 2. The ink jet printing apparatus according to claim 1, wherein the sheet body is a sheet-shaped nonwoven fabric.

7. the inkjet printing device comprises the ink head, a print medium on which an image is formed by ink ejected from the ink head, a plurality of transport rolls that transport the print medium, stays provided between adjacent transport rolls, and a frame to which the stays are attached via brackets; The bottom surface of the ink receiving portion is placed on the stay, 3. The ink jet printing apparatus according to claim 2, wherein the position of said stay is adjustable in the vertical direction.

8. an end of the ink receiving portion opposite to the tank side fixed to the stay by a bolt; a claw is provided on a side surface of the ink receiving portion on the tank side, 8. The ink jet printing device according to claim 7, wherein a fixing member is provided on the bracket opposite to the claw.

9. the inkjet printing device comprises the ink head, a print medium on which an image is formed by ink ejected from the ink head, a plurality of transport rolls that transport the print medium, stays provided between adjacent transport rolls, and a frame to which the stays are attached via brackets; 2. The ink jet printing device according to claim 1, wherein the shortest distance between the same plane of the printing surface of the printing medium and the upper surface of the sheet is 3 to 8 mm.

10. 2. The ink jet printing device according to claim 1, wherein preliminary ejection by the ink head and image formation by an ink head other than the ink head performing preliminary ejection are performed simultaneously.

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