wiper mechanism

Abstract

To provide a wiper mechanism, which can suppress ink from remaining on a side surface of an inkjet head after wiping the surface.SOLUTION: A wiper mechanism 1 comprises a first wiper 11 and a second wiper 12 that wipe a head surface 111a provided with a nozzle row 111b of an inkjet head 111, in a wiping direction D1. The first wiper 11 wipes the head surface 111a, at a place closer to a downstream side in the wiping direction D1 than the second wiper 12. A tip 11a of the first wiper 11 has notched portions 11b at both ends in a width direction D2 of the head surface 111a which is orthogonal to the wiping direction D1, which is smaller in width in the width direction D2 than the tip 12a of the second wiper 12.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a wiper mechanism that wipes a head surface on which nozzle rows of an inkjet head are provided. [Background technology]

[0002] Conventionally, inkjet printing devices equipped with a wiper mechanism that wipes the head surface (e.g., the bottom surface) on which the nozzle rows of the inkjet head are provided have been known. Among such inkjet printing devices, an inkjet printing device has been proposed in which a first wiper is disposed with a gap between it and the head surface, which allows ink to be adsorbed by surface tension, and a second wiper is disposed without a gap between it and the head surface so as to wipe off ink droplets and the like (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-224975 Summary of the Invention [Problem to be solved by the invention]

[0004] In the wiper mechanism, when the head surface is wiped with only a single wiper made of, for example, a rubber blade, if the contact pressure on the head surface is strong, the cleaning performance of the head surface improves but the durability of the head surface decreases.

[0005] Therefore, it is conceivable to improve cleaning performance and maintain durability at the same time by using multiple wipers as described above. However, it is difficult to arrange the first wiper with a small gap between it and the head surface of the inkjet head, which allows ink droplets to be adsorbed by surface tension, and the effect (adsorption performance, etc.) varies greatly due to variations in the size of the gap.

[0006] Whether a single wiper or multiple wipers are used, ink spreads (expands) from the top of the wiper that extends beyond both ends of the inkjet head onto the side of the inkjet head, resulting in ink adhering to the side of the inkjet head. The greater the amount of ink wiped, the greater the amount of ink adhering to the side of the inkjet head. Furthermore, when the wiper passes through the inkjet head after wiping, ink accumulated between the wiper and the inkjet head disperses as droplets, resulting in ink adhering to the side of the inkjet head (the surface downstream in the wiping direction). If ink remains on the side of the inkjet head, air currents and vibrations during paper transport can cause ink to flow onto the head surface, resulting in ink ejection problems or ink adhering to the paper being transported.

[0007] SUMMARY OF THE INVENTION An object of the present invention is to provide a wiper mechanism that can prevent ink from remaining on the side surface of an inkjet head after wiping. [Means for solving the problem]

[0008] In one embodiment, the wiper mechanism includes a first wiper and a second wiper that wipe the head surface on which the nozzle row of the inkjet head is provided in a wiping direction, the first wiper wipes the head surface downstream in the wiping direction from the second wiper, and the tip of the first wiper has notched portions on both ends in the width direction of the head surface perpendicular to the wiping direction, and is narrower in the width direction than the tip of the second wiper. [Effects of the Invention]

[0009] According to this aspect, it is possible to prevent ink from remaining on the side surface of the inkjet head after wiping. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a front view showing the internal structure of an inkjet printing apparatus according to an embodiment; [Figure 2] FIG. 2 is a diagram illustrating a main control configuration of an inkjet printing apparatus according to an embodiment. [Figure 3] FIG. 1 is a front view of a wiper mechanism in a wiping position according to one embodiment. [Figure 4] FIG. 2 is a plan view showing a wiper mechanism according to an embodiment. [Figure 5] FIG. 5 is a cross-sectional view of FIG. 4 . [Figure 6] FIG. 2 is a front view showing a first wiper and a second wiper in the embodiment. [Figure 7] FIG. 3 is a bottom view of the inkjet head for explaining the positional relationship between the first wiper and the second wiper according to the embodiment. [Figure 8] FIG. 4 is a right side view of the wiper unit for explaining a wiping operation in the embodiment. [Figure 9] FIG. 2 is a perspective view of a wiper unit for explaining a wiping operation in the embodiment. [Figure 10] FIG. 10 is a front view showing a first wiper and a second wiper in a first modified example of the embodiment. [Figure 11] FIG. 10 is a front view showing a first wiper and a second wiper in a second modified example of the embodiment. [Figure 12] FIG. 10 is a front view showing a first wiper and a second wiper in a third modified example of the embodiment. [Figure 13] FIG. 10 is a right side view of the wiper unit for explaining a wiping operation in another embodiment. [Figure 14] FIG. 10 is an enlarged right side view of the first wiper and the second wiper during wiping in another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wiper mechanism according to an embodiment of the present invention will now be described with reference to the drawings.

[0012] FIG. 1 is a front view showing the internal structure of an inkjet printing apparatus 100 according to one embodiment.

[0013] FIG. 2 is a diagram showing the main control configuration of the inkjet printing apparatus 100.

[0014] Note that the front-to-back, up-down, and left-to-right directions shown in Figure 1 and Figures 3 to 14 described below are merely examples in which the transport direction of paper P, which is an example of a medium, during printing is the right direction, and the wiping direction D1 of the first wiper 11 and the second wiper 12 is the forward direction, but for example, the front-to-back and left-to-right directions are horizontal directions, and the up-to-down direction is vertical directions.

[0015] As shown in Fig. 1, inkjet printing apparatus 100 includes a wiper mechanism 1, a printing unit 110, a suction conveying unit 120, an external paper feed unit 130, internal paper feed units 141-143, conveying roller pairs 151-155, and a registration roller pair 156. As shown in Fig. 2, inkjet printing apparatus 100 further includes a control unit 161, a storage unit 162, an operation panel unit 163, a scanner 164, and a paper discharge unit 165. In Fig. 1, the conveying paths extending from external paper feed unit 130 and internal paper feed units 141-143 to printing unit 110 are indicated by thick solid lines.

[0016] The printing unit 110 shown in FIG. 1 has a plurality of inkjet heads 111. As shown in FIG. 4, two sets of six inkjet heads 111 are arranged in a staggered pattern along the main scanning direction (front-rear direction) perpendicular to the transport direction (rightward) of the paper P, for a total of 12 inkjet heads. That is, the six inkjet heads 111 in one set arranged along the front-rear direction are arranged with their positions shifted alternately in the left-right direction. As an example, the six inkjet heads 111 in one set eject ink of two colors (for example, black (K) and cyan (C)), and the six inkjet heads 111 in the other set eject ink of two colors different from those in the one set (for example, magenta (M) and yellow (Y)).

[0017] As shown in FIG. 1, the suction transport unit 120 is disposed opposite the printing unit 110. The suction transport unit 120 transports the paper P by a transport belt while, for example, suctioning the paper P. The suction transport unit 120 is preferably movable between the printing position shown in FIG. 1, a wiping position shown in FIG. 3 below the printing position, and a standby position (not shown) below the wiping position. The wiper mechanism 1 is located below the printing unit 110 during wiping as shown in FIG. 3, and is located in a position retracted from below the printing unit 110 during printing as shown in FIG. 1.

[0018] The external paper feed unit 130 and the internal paper feed units 141 to 143 each include paper feed trays 131, 141a, 142a, and 143a, scraper rollers 132, 141b, 142b, and 143b, and pickup rollers 133, 141c, 142c, and 143c.

[0019] A plurality of sheets of paper P are stacked on the paper feed trays 131, 141a, 142a, and 143a.

[0020] The scraper rollers 132, 141b, 142b, and 143b are feed rollers that feed and transport the uppermost sheet P among the plurality of sheets P stacked on the sheet feed trays 131, 141a, 142a, and 143a.

[0021] The pickup rollers 133, 141c, 142c, and 143c transport the paper P fed out by the scraper rollers 132, 141b, 142b, and 143b.

[0022] The conveying roller pairs 151 to 155 are arranged on the conveying path between the internal paper feed units 141 to 143 and the registration roller pair 156.

[0023] The sheet P conveyed from the external sheet feeding unit 130 and the internal sheet feeding units 141 to 143 abuts against the pair of registration rollers 156. As a result, skew of the sheet P is corrected.

[0024] The control unit 161 shown in Figure 2 has a processor (e.g., a CPU: Central Processing Unit) that functions as an arithmetic processing device that controls the operation of the entire inkjet printing device 100, and controls the operation of each part of the inkjet printing device 100, such as the wiper drive unit 40, the printing unit 110, and the suction conveying unit 120.

[0025] The memory unit 162 is, for example, a ROM (Read Only Memory), which is a read-only semiconductor memory in which a predetermined control program is pre-recorded, a RAM (Random Access Memory), which is a semiconductor memory that can be written and read at any time and is used as a working memory area as needed when the processor executes various control programs, or a hard disk device.

[0026] The operation panel unit 163 functions as an example of an input unit and a display unit of the inkjet printing apparatus 100 by having, for example, operation keys for performing various operations, a touch panel, a display for displaying various information, and the like.

[0027] The scanner 164 reads image data from an original.

[0028] Although not shown in FIG. 1, the paper discharge unit 165 has a paper discharge tray on which paper sheets P printed by the printing unit 110 are stacked, and discharge rollers that discharge the paper sheets P onto this paper discharge tray.

[0029] FIG. 3 is a front view showing the wiper mechanism 1 in the wiping position.

[0030] FIG. 4 is a plan view showing the wiper mechanism 1. As shown in FIG.

[0031] FIG. 5 is a cross-sectional view taken along line VV of FIG.

[0032] FIG. 6 is a front view showing the first wiper 11 and the second wiper 12. As shown in FIG.

[0033] FIG. 7 is a bottom view of the inkjet head 111 for explaining the positional relationship between the first wiper 11 and the second wiper 12. As shown in FIG.

[0034] The front-rear, up-down, and left-right directions shown in FIGS. 3 to 7 and FIGS. 8 to 14 described later are directions when the wiper mechanism 1 is located between the printing unit 110 and the suction transport unit 120 as shown in FIG.

[0035] As shown in FIG. 4, the wiper mechanism 1 includes a wiper unit 10, two guide portions 20, an ink receiving portion 30, and a wiper driving portion 40.

[0036] The wiper unit 10 has, for example, four first wipers 11, for example, four second wipers 12, and a single wiper support member 13 that supports the first wipers 11 and the second wipers 12.

[0037] 5 are wiper blades made of, for example, an elastic material such as rubber. The first wiper 11 is provided downstream of the second wiper 12 in the wiping direction D1. That is, the first wiper 11 wipes the head surface 111a before the second wiper 12. As shown in FIG. 8, which will be described later, the first wiper 11 is provided at a height that does not allow it to come into contact with the head surface 111a, but it can be said to wipe the head surface 111a because it can scrape off the purged ink PI from the head surface 111a.

[0038] The first wiper 11 and the second wiper 12 wipe a head surface 111a (for example, a bottom surface) on which a nozzle row 111b that ejects ink of the inkjet head 111 shown in Fig. 7 is provided, in a wiping direction D1 (forward direction) that is perpendicular to the transport direction (rightward) of the paper P. In Fig. 7, the first wiper 11 and the second wiper 12 are indicated by two-dot chain lines (imaginary lines).

[0039] For example, although not shown, the head surface 111a includes a nozzle surface formed of polyimide resin and provided with the nozzle rows 111b, and the bottom surface of a protection plate that protects this nozzle surface. The head surface 111a is preferably coated with an ink-repellent film.

[0040] As described above, two sets of six inkjet heads 111 are arranged in a staggered pattern, so that the inkjet heads 111 are arranged in a total of four rows in the left-right direction as shown in Fig. 4. Therefore, four first wipers 11 and four second wipers 12 are arranged to wipe the head surfaces 111a of one row (three inkjet heads) of the inkjet heads 111 shown in Fig. 7.

[0041] As shown in FIG. 5, the first wiper 11 and the second wiper 12 are spaced apart by a wiper spacing L3 in the wiping direction D1 before wiping, and extend from the wiper support member 13 upward in a direction perpendicular to the head surface 111a. Before wiping, the tip 11a (see FIG. 6), which is the upper end of the first wiper 11, is located below the head surface 111a. Therefore, the first wiper 11 is provided with a length that does not allow it to contact the head surface 111a during wiping, and is not in contact with the head surface 111a (see FIG. 8). On the other hand, the tip 12a (which is the upper end of the second wiper 12) is located above the head surface 111a. As a result, the second wiper 12 wipes the head surface 111a in a curved state (see FIG. 8) during wiping.

[0042] As shown in FIG. 6, the tip 11a of the first wiper 11 has cutout portions 11b at both ends of the head surface 111a in a width direction D2 perpendicular to the wiping direction D1. The cutout portions 11b are formed, for example, by obliquely cutting the corner between the tip 11a and the side surface of the first wiper 11. The cutout portions 11b have a width L1 and a height L2. Note that the width of the first wiper 11 at the cutout portions 11b in the width direction D2 is narrower than that of the lower portion of the cutout portions 11b.

[0043] The width of the tip 11a of the first wiper 11 in the width direction D is narrower than the width of the tip 12a of the second wiper 12 in the width direction D2. In Fig. 6, the width of the first wiper 11 below the cutout portion 11b in the width direction D2 is the same as the width of the second wiper 12 in the width direction D, but may be different.

[0044] 7, when wiping the head surface 111a, the tip 11a of the first wiper 11 is positioned at a distance G inward from both ends in the width direction D2 and wipes only a portion of the head surface 111a, including the nozzle row 111b. Meanwhile, the portion below the cutout portion 11b of the first wiper 11 and the second wiper 12 are larger in the width direction D2 than the head surface 111a, and the second wiper 12 wipes the entire head surface 111a in the width direction D2. Note that when wiping the head surface 111a, the tip 11a of the first wiper 11 may be positioned at a distance G inward from only one end of the head surface 111a in the width direction D2 and wipe one end of the head surface 111a, but as described above, it is preferable that the tip 11a be positioned at a distance G inward from both ends in the width direction D2 of the head surface 111a. Furthermore, the second wiper 12 does not have to wipe the entire head surface 111a in the width direction D2, but it is preferable that the second wiper 12 wipes the entire head surface 111a in the width direction D2.

[0045] 6 is preferably set so that the tip 11a of the first wiper 11 is narrower than the tip 12a of the second wiper 12, as described above. However, if the cutout width L1 is too long, the area of ​​the head surface 111a that can be wiped by the first wiper 11 will be narrow. In this case, the amount of ink used when the head surface 111a is wiped by the second wiper 12 will increase.

[0046] Next, the cutout height L2 shown in Figure 6 above is effective if it is greater than 0, but it is preferable that the dimension is not too long so that ink can be held between the cutout portion 11b of the first wiper 11 and the second wiper 12 by the surface tension of the ink acting between the cutout portion 11b and the second wiper 12, as will be described later.

[0047] 5 described above is effective if it is greater than 0, but the larger this dimension is, the more likely it is that the ink will collapse due to the surface tension of the ink and will not be able to be held between the notched portion 11b and the second wiper 12. Therefore, it is preferable that the wiper interval L3 be a distance that can withstand the wiping speed and vibration of the first wiper 11 and the second wiper 12 and hold the ink.

[0048] 4, the four first wipers 11 and four second wipers 12 are integrally provided on the wiper support member 13. Note that the first wipers 11 and the second wipers 12 may be provided separately from the wiper support member 13 and attached to the wiper support member 13.

[0049] As shown in FIGS. 4 and 5, the wiper support member 13 is provided with, for example, a pair of left and right screw holes 13a, 13a that penetrate in the front-rear direction.

[0050] Each of the two guide portions 20 is, for example, a screw shaft extending in the front-rear direction and is arranged to pass through the screw holes 13a, 13a of the wiper support member 13. Therefore, by rotating the guide portions 20, the wiper unit 10 can move in the wiping direction D1, which is the front-rear direction.

[0051] The ink receiving section 30 receives the purged ink PI shown in FIG. 8 that falls from the inkjet head 111 together with paper powder, dust, and the like.

[0052] When the wiper mechanism 1 is tilted in the retracted position shown in FIG. 1, the ink in the ink receiving unit 30 flows from the discharge portion 30b of the ink receiving unit 30 shown in FIG. 4 through a waste liquid path (not shown) to the waste liquid storage unit. The ink receiving unit 30 has, for example, a rectangular parallelepiped shape that opens upward. Therefore, the inner bottom surface of the ink receiving unit 30 becomes the ink receiving surface 30a. The ink receiving unit 30 rotatably supports the front end of the guide unit 20.

[0053] The wiper drive unit 40 has, for example, two motors 41.

[0054] The motor 41 is an example of a driving means (actuator) that drives the wiper unit 10 (first wiper 11 and second wiper 12), and is bonded to the guide portion 20, for example, by adhesive. The motor 41 rotates the guide portion 20, thereby moving the wiper unit 10 forward and backward as described above. Note that a single motor 41 may rotate a drive belt, for example, to rotate the two guide portions 20 via pulleys within the drive belt. Alternatively, only a single motor 41 and a single guide portion 20 may be provided, and this single guide portion 20 may move the wiper unit 10 forward and backward.

[0055] Next, we will explain the wiping operation using the first wiper 11 and the second wiper 12. This wiping operation may be performed, for example, after a predetermined number of prints or after an elapsed time, or based on a user operation on the operation panel unit 163 shown in FIG.

[0056] 8 and 9 are a right side view and a perspective view of the wiper unit 10 for explaining the wiping operation.

[0057] First, before the first wiper 11 and the second wiper 12 wipe the head surface 111a of the inkjet head 111, as shown in Fig. 3, the suction transport unit 120 moves downward from the printing position shown in Fig. 1, and the wiper mechanism 1 moves between the printing unit 110 and the suction transport unit 120. Furthermore, the inkjet head 111 ejects purged ink PI from the nozzle row 111b as shown in Fig. 8. As a result, the purged ink PI ejected from the nozzle row 111b gathers and is scattered in multiple locations.

[0058] Thereafter, the first wiper 11 and the second wiper 12 move in the wiping direction D1. As a result, the purged ink PI and the like (for example, the purged ink PI, the ink originally adhering to the head surface 111a, and paper powder and dust contained in the ink) wiped by the first wiper 11 and the second wiper 12 flows down the first wiper 11 and the second wiper 12 and falls in the direction of gravity onto the ink receiving surface 30a of the ink receiving unit 30 shown in Figures 4 and 5 described above. Note that the purged ink PI after being wiped by the first wiper 11 is not shown in Figures 8 and 9.

[0059] The first wiper 11 and the second wiper 12 do not come into contact with each other during wiping. However, it is desirable that the first wiper 11 and the second wiper 12 be close to each other during wiping so that the surface tension of the purged ink PI acts between the cutout portion 11b of the first wiper 11 and the end of the second wiper 12 in the width direction D2 to hold the purged ink PI, as shown in FIG.

[0060] Here, by providing the cutout portion 11b, the purged ink PI wiped by both end portions in the width direction D2 of the second wiper 12 is pulled (moves slightly) by surface tension toward the cutout portion 11b in a direction inclined from the wiping direction D1 toward the center and downward in the width direction D2 of the first wiper 11. This reduces the amount of purged ink PI near both end portions in the width direction D2 of the second wiper 12.

[0061] When the purged ink PI wiped by the second wiper 12 comes into contact with the first wiper 11, the purged ink PI moves to a point where the force trying to spread onto the first wiper 11 (the force in the direction of movement from the second wiper 12 to the first wiper 11 (wiping direction D1)) and the force trying to remain on the second wiper 12 (the force in the direction of movement from the first wiper 11 to the second wiper 12) are balanced (the center of gravity moves and the shape changes).

[0062] As described above, the purged ink PI moves from the second wiper 12 toward the first wiper 11 due to the surface tension of the purged ink PI. This surface tension is a force generated at the interface between the liquid and the atmosphere, and acts in a direction that tries to reduce the surface area of ​​the liquid, that is, in a direction that tries to make the liquid a perfect sphere. This is because the purged ink PI near the end of the second wiper 12 in the width direction D2 moves slightly toward the first wiper 11 to try to become as close to a perfect sphere as possible.

[0063] 7, when wiping the head surface 111a, the tip 11a of the first wiper 11 is positioned at a distance G inward from both ends of the head surface 111a in the width direction D2. Therefore, the purged ink PI wiped by the first wiper 11 is less likely to adhere to the side surface of the inkjet head 111, as shown in FIG. 9. In particular, when surface tension of the purged ink PI acts between the cutout portion 11b of the first wiper 11 and the end of the second wiper 12 in the width direction D2, the purged ink PI is even less likely to adhere to the side surface of the inkjet head 111.

[0064] As described above, the first wiper 11 is provided with a length that prevents it from coming into contact with the head surface 111a during wiping. Therefore, after being wiped by the first wiper 11, the purged ink PI remains as a thin liquid film on the head surface 111a.

[0065] The purged ink PI, which has become a thin liquid film, is then wiped away by the second wiper 12. The second wiper 12 wipes the entire head surface 111a in the width direction D2, but because some of the purged ink PI has already been wiped by the first wiper 11, the purged ink PI is less likely to adhere to the side surfaces of the inkjet head 111. Note that the second wiper 12 wipes the purged ink PI and other materials remaining at the ends of the head surface 111a in the width direction D2 that have not been wiped by the first wiper 11, at the ends of the second wiper 12 in the width direction D2. Therefore, the purged ink PI and other materials tend to fall in the direction of gravity along the side surfaces of the ends of the second wiper 12 in the width direction D2 onto the ink receiving surface 30a of the ink receiving unit 30.

[0066] After the first wiper 11 and the second wiper 12 have wiped the head surfaces 111a of all the inkjet heads 111, the inkjet heads 111 perform a flushing operation in which the piezoelectric elements are driven to eject ink from each nozzle row 111b, thereby preventing ink from mixing in the nozzle rows 111b. The suction and transport unit 120 shown in FIG. 3 then moves downward, and the wiper mechanism 1 moves to the retracted position shown in FIG. 1. The suction and transport unit 120 also moves upward to a position close to the printing unit 110 when printing is being performed, and moves downward to a standby position when printing is not being performed. It is desirable that the wiper unit 10 (the first wiper 11 and the second wiper 12) return to the upstream side in the wiping direction D1 in preparation for the next wiping operation when the wiper mechanism 1 is in the retracted position shown in FIG. 1.

[0067] 10 to 12 are front views showing the first wipers 51, 61, 71 and the second wiper 12 in first to third modified examples of the present embodiment.

[0068] The first wipers 51, 61, and 71 shown in FIGS. 10 to 12 differ from the first wiper 11 shown in FIG. 6 in the shapes of the cutout portions 51b, 61b, and 71b.

[0069] 10 has a notched portion 51b at both ends in the width direction D2 of the tip 51a of the first wiper 51. The notched portion 51b is formed by cutting a corner between the tip 51a and the side surface of the first wiper 51 in a rectangular shape.

[0070] The notched portion 61b of the tip 61a of the first wiper 61 shown in FIG. 11 is formed by cutting the corner between the tip 61a of the first wiper 61 and the side surface into a recessed R-shape (arc shape).

[0071] The notched portion 71b of the tip 71a of the first wiper 71 shown in FIG. 12 is formed by cutting the corner between the tip 71a of the first wiper 71 and the side surface into a bulging R-shape (arc-shape).

[0072] Like the first wipers 51, 61, and 71 in the first to third modified examples shown in FIGS. 10 to 12, the shapes of the cutout portions 51b, 61b, and 71b are not particularly limited.

[0073] In the present embodiment described above, the wiper mechanism 1 includes a first wiper 11 and a second wiper 12 that wipe a head surface 111a, on which a nozzle row 111b of an inkjet head 111 is provided, in a wiping direction D1. The first wiper 11 wipes the head surface 111a downstream in the wiping direction D1 from the second wiper 12. The tip 11a of the first wiper 11 has notched portions 11b on both ends in a width direction D2 of the head surface 111a that is perpendicular to the wiping direction D1, and is narrower in the width direction D2 than the tip 12a of the second wiper 12.

[0074] In this way, the tip 11a of the first wiper 11 has the cutout portion 11b and is narrower than the tip 12a of the second wiper 12, so that the purged ink PI is prevented from being wiped by the first wiper 11 and from flowing around the side surfaces of the inkjet head 111 from both ends in the width direction D2 of the first wiper 11. Furthermore, since the cutout portion 11b is provided in the first wiper 11, the width (cutout width L1) of the tip 11a of the first wiper 11 is narrowed and the height (cutout height L2) of the tip 11a is reduced. Therefore, when the surface tension of the purged ink PI acts between the cutout portion 11b and the second wiper 12 and the purged ink PI is held between the cutout portion 11b and the second wiper 12, it is possible to prevent the purged ink PI from spreading or bulging outward from the upper part of the second wiper 12 from increasing in volume. This also prevents the purged ink PI from wrapping around the side surfaces of the inkjet head 111. Therefore, according to this embodiment, it is possible to prevent ink from remaining on the side surfaces of the inkjet head 111 after wiping. This prevents the purged ink PI remaining on the side surfaces of the inkjet head 111 from flowing into the head surface 111a due to air currents or vibrations caused by the transport of a medium such as paper P, which could result in ejection failure or ink adhering to the medium being transported. Furthermore, the tip 12a of the second wiper 12 is wider than the tip 11a of the first wiper 11, and therefore can wipe away the purged ink PI that is not wiped away by the first wiper 11. Furthermore, when the surface tension of the purged ink PI acts between the cutout portion 11b and the second wiper 12, the purged ink PI is retained between the first wiper 11 and the second wiper 12 even after the first wiper 11 and the second wiper 12 wipe the inkjet head 111, thereby preventing the purged ink PI from remaining on the front side (the downstream side in the wiping direction D1), which is the side of the inkjet head 111, immediately after wiping.

[0075] In this embodiment, the tip 11a of the first wiper 11 has a width in the width direction D2 that is narrower than the head surface 111a, and wipes a part of the head surface 111a that includes the nozzle row 111b.

[0076] In this way, the first wiper 11, which wipes the head surface 111a before the second wiper 12, wipes only a portion of the head surface 111a including the nozzle row 111b, and therefore it is possible to prevent the purged ink PI wiped by the first wiper 11 from overflowing from above the first wiper 11 and wrapping around to the side surface of the inkjet head 111. This makes it possible to further prevent ink from remaining on the side surface of the inkjet head 111 after wiping.

[0077] In addition, in this embodiment, the first wiper and the second wiper do not come into contact with each other during wiping.

[0078] As a result, the purged ink PI accumulates between the first wiper 11 and the second wiper 12, making it possible to prevent the purged ink PI from flowing from the second wiper 12 to the side surfaces of the inkjet head 111. Furthermore, if the surface tension of the purged ink PI can be exerted between the cutout portion 11b and the second wiper 12, it is possible to more reliably prevent the purged ink PI from flowing from the second wiper 12 to the side surfaces of the inkjet head 111. Furthermore, the purged ink PI, which has become a thin liquid film after being wiped by the first wiper 11, is wiped away by the second wiper 12 before it aggregates in part of the head surface 111a due to the ink-repellent properties of the head surface 111a. Therefore, it is possible to prevent a decrease in cleaning performance and deterioration of the head surface 111a caused by the second wiper 12 wiping an area of ​​the head surface 111a where there is no purged ink PI (empty wipe). Furthermore, since the first wiper 11 and the second wiper 12 do not come into contact with each other, it is possible to prevent a decrease in cleaning performance caused by the rigidity of the contact portion between the first wiper 11 and the second wiper 12 being increased only in a part of the width direction D2, and the second wiper 12 can reliably wipe away purged ink PI, etc. between the first wiper 11 and the second wiper 12.

[0079] In this embodiment, the first wiper 11 is provided with a length that prevents it from coming into contact with the head surface 111a during wiping.

[0080] As a result, the purged ink PI after being wiped by the first wiper 11 spreads uniformly as a thin liquid film (liquid residue) on the head surface 111a. Therefore, the purged ink PI can be reliably wiped by the second wiper 12. Also, the durability of the head surface 111a can be maintained.

[0081] FIG. 13 is a right side view of a wiper unit 210 for explaining a wiping operation in another embodiment.

[0082] FIG. 14 is an enlarged right side view of the first wiper 211 and the second wiper 212 during wiping in another embodiment.

[0083] 4, the wiper unit 210 shown in Fig. 13 has, for example, four first wipers 211, for example, four second wipers 212, and a wiper support member 213 that supports the first wipers 211 and the second wipers 212. The wiper unit 210 shown in Fig. 13 differs from the wiper unit 10 shown in Fig. 4 mainly in the first wipers 211, but can be otherwise similar. Therefore, detailed descriptions of other embodiments will be omitted.

[0084] The first wiper 211 extends from the wiper support member 213 at an angle opposite to the wiping direction D1 (rearward) with respect to the upward direction perpendicular to the head surface 111a in both the wiping state shown in FIG. 13 and the pre-wiping state (not shown). On the other hand, the second wiper 212 extends from the wiper support member 213 at an angle opposite to the wiping direction D1 (rearward) with respect to the upward direction perpendicular to the head surface 111a in the wiping state shown in FIG. 13, but extends from the wiper support member 213 in the upward direction perpendicular to the head surface 111a in the pre-wiping state (not shown). Before wiping, the tip 211a of the first wiper 211 and the tip 212a of the second wiper 212 are positioned above the head surface 111a. As a result, the second wiper 212 also wipes the head surface 111a in a curved state during wiping, similar to the first wiper 211. Furthermore, because the first wiper 211 extends at an angle before wiping, the contact pressure of the first wiper 211 against the head surface 111a is weaker than that of the second wiper 212. In this way, in order to make the contact pressure of the first wiper 211 weaker than that of the second wiper 212, in addition to changing the angles before wiping between the first wiper 211 and the second wiper 212, it is also possible to, for example, make the length in the up-down direction before wiping (free length) of the first wiper 211 longer than that of the second wiper 212, make the thickness (wiping direction D1) of the first wiper 211 thinner than that of the second wiper 212, or use different materials for the first wiper 211 and the second wiper 212.

[0085] As in the above-described embodiment, the tip 211a of the first wiper 211 has a notched portion 211b. Although not shown, the width of the tip 211a of the first wiper 211 in the width direction D2 (see FIG. 4) is narrower than the width of the tip 212a of the second wiper 212, for example, narrower than the width of the head surface 111a.

[0086] During wiping, the first wiper 211 and the second wiper 212 move in the wiping direction D1. As a result, the purged ink PI and the like (for example, the purged ink PI, the ink originally adhering to the head surface 111a, and paper powder and dust contained in the ink) wiped away by the first wiper 211 and the second wiper 212 flows down the first wiper 211 and the second wiper 212 and falls in the direction of gravity onto the ink receiving surface 30a of the ink receiving unit 30 shown in FIGS. 4 and 5 described above. Note that FIG. 13 does not illustrate the purged ink PI after it has been wiped by the first wiper 211. Also, FIG. 14 illustrates the first wiper 211 and the second wiper 212 in FIG. 13, without illustrating the purged ink PI.

[0087] 14, the first wiper 211 and the second wiper 212 do not come into contact with each other during elastic deformation associated with wiping of the head surface 111a. Furthermore, during elastic deformation associated with wiping of the head surface 111a, at least the tip 211a of the first wiper 211 is preferably located in the same position as the second wiper 212-1 (shown by an imaginary two-dot chain line) before elastic deformation associated with wiping, or between this position and the second wiper 212 (deformation region 212b) when elastically deformed associated with wiping. In this way, it is desirable that the first wiper 211 and the second wiper 212 are close to each other during wiping.

[0088] On the other hand, before wiping the head surface 111a, the tip 211a of the first wiper 211 is located downstream in the wiping direction D1 of the deformation region 212b of the second wiper 212. The deformation region 212b of the second wiper 212 is a part including the tip of the second wiper 212, and since the second wiper 212 extends in an upward direction perpendicular to the head surface 111a from the wiper support member 213 before wiping, a root region 212c of the second wiper 212 closer to the wiper support member 213 than the deformation region 212b extends in an upward direction perpendicular to the head surface 111a. When wiping the head surface 111a, the tip 211a of the first wiper 211 is located at the same position in the wiping direction D1 as the root region 212c of the second wiper 212 (or the intersection of the direction in which the root region 212c extends and the head surface 111a) or is located upstream of the wiping direction D1.

[0089] As described above, the first wiper 211 has a weaker contact pressure with the head surface 111a than the second wiper 212. Therefore, after being wiped by the first wiper 211, the purged ink PI remains as a thin liquid film on the head surface 111a.

[0090] The purged ink PI, which has become a thin liquid film, is then wiped away by the second wiper 212. The second wiper 212 wipes the entire head surface 111a in the width direction D2, but because some of the purged ink PI has already been wiped away by the first wiper 211, the purged ink PI is less likely to adhere to the side surface of the inkjet head 111.

[0091] In the other embodiments described above, the same effects as those of the above-described embodiment can be obtained, namely, the effect of preventing ink from remaining on the side of the inkjet head 111 after wiping.

[0092] In addition, in this embodiment, the first wiper 211 exerts a weaker contact pressure on the head surface 111a than the second wiper 212 during wiping.

[0093] As a result, the purged ink PI after being wiped by the first wiper 211 spreads evenly as a thin liquid film (liquid residue) on the head surface 111a. Therefore, the purged ink PI can be reliably wiped by the second wiper 212. Furthermore, the durability of the head surface 111a can be maintained by the first wiper 211 not abutting against the head surface 111a, separating the thin liquid film of purged ink PI.

[0094] Furthermore, in this embodiment, when the head surface 111a is elastically deformed in association with wiping, the first wiper 211 and the second wiper 212 do not come into contact with each other, and at least the tip 211a of the first wiper 211 is located at the same position as the second wiper 212 before elastic deformation in association with wiping, or between this position and the second wiper 212 (deformation area 212b) when elastically deformed in association with wiping.

[0095] In this way, by the tip 211a of the first wiper 211 approaching the second wiper 212 (deformation region 212b) during wiping, it is possible to make the surface tension of the purged ink PI more easily work between the cutout portion 211b of the first wiper 211 and the second wiper 212. Therefore, it is possible to more reliably prevent the purged ink PI from flowing from the second wiper 212 onto the side surface of the inkjet head 111. Furthermore, the purged ink PI, which has become a thin liquid film after being wiped by the first wiper 211, is wiped by the second wiper 212 before it aggregates in a part of the head surface 111a due to the ink-repellent properties of the head surface 111a. Therefore, it is possible to prevent a decrease in cleaning performance and deterioration of the head surface 111a caused by the second wiper 212 wiping an area of ​​the head surface 111a where there is no purged ink PI (empty wiping). Furthermore, since the first wiper 211 and the second wiper 212 do not come into contact with each other, it is possible to prevent a decrease in cleaning performance caused by the rigidity of the contact portion between the first wiper 211 and the second wiper 212 being increased only in a part of the width direction D2, and the second wiper 212 can reliably wipe away purged ink PI and the like between the first wiper 211 and the second wiper 212.

[0096] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiments. For example, all of the components shown in the embodiments can be appropriately combined. Naturally, various modifications and applications are possible without departing from the spirit of the invention. The invention as originally claimed in the present application is described below.

[0097] [Appendix 1] a first wiper and a second wiper for wiping a head surface on which a nozzle row of the inkjet head is provided in a wiping direction; the first wiper wipes the head surface downstream of the second wiper in the wiping direction; The tip of the first wiper has notched portions at both ends in a width direction of the head surface perpendicular to the wiping direction, and is narrower in the width direction than the tip of the second wiper. A wiper mechanism characterized by:

[0098] [Appendix 2] The tip of the first wiper has a width in the width direction narrower than the head surface, and wipes a part of the head surface including the nozzle row. 2. The wiper mechanism according to claim 1.

[0099] [Appendix 3] The first wiper and the second wiper do not come into contact with each other during wiping. 2. The wiper mechanism according to claim 1.

[0100] [Appendix 4] The first wiper is provided with a length that prevents it from contacting the head surface during wiping, or the contact pressure of the first wiper with respect to the head surface is weaker than that of the second wiper. 2. The wiper mechanism according to claim 1.

[0101] [Appendix 5] During elastic deformation accompanying wiping of the head surface, The first wiper and the second wiper do not come into contact with each other, and at least the tip of the first wiper is located at the same position as the second wiper before elastic deformation due to wiping, or between that position and the second wiper when elastic deformation due to wiping occurs. 2. The wiper mechanism according to claim 1. [Explanation of symbols]

[0102] 1 Wiper mechanism 10. Wiper unit 11 First wiper 11a tip 11b Cutout part 12 Second wiper 12a tip 13 Wiper support member 13a screw hole 20 Guide section 30 Ink receiver 30a Ink receiving surface 30b Discharge section 40 Wiper drive unit 41 Motor 51, 61, 71 First wiper 51a, 61a, 71a tip 51b, 61b, 71b Notch 100 Inkjet printing device 110 Printing Department 111 Inkjet head 111a head surface 111b Nozzle row 120 Suction conveying section 130 External paper feed section 131 Paper tray 132 Scraper roller 133 Pickup roller 141,142,143 Internal paper feed section 141a, 142a, 143a Paper tray 141b, 142b, 143b scraper rollers 141c, 142c, 143c Pickup roller 151~155 Conveyor roller pair 156 Registration roller pair 161 Control Unit 162 Storage section 163 Operation panel 164 Scanner 165 Paper output section 210 Wiper unit 211 First wiper 211a tip 211b Notch 212 Second wiper 212-1 Second wiper before elastic deformation 212a Tip 212b Deformation area 212c Root region 213 Wiper support member D1 Wipe Direction D2 width direction G interval L1 Notch width L2 Notch height L3 Wiper Interval P paper PI Purge Ink

Claims

1. a first wiper and a second wiper for wiping a head surface on which a nozzle row of the inkjet head is provided in a wiping direction; the first wiper wipes the head surface downstream of the second wiper in the wiping direction; a tip end of the first wiper has notched portions at both ends in a width direction of the head surface perpendicular to the wiping direction, and is narrower in the width direction than a tip end of the second wiper; the tip of the first wiper is positioned at an interval from both ends of the head surface inward in the width direction when wiping the head surface, and wipes a part of the head surface including the nozzle row; The first wiper and the second wiper are arranged such that, when wiping the head surface, ink is held between the notched portion of the first wiper and both end portions of the second wiper in the width direction by surface tension. A wiper mechanism characterized by:

2. The first wiper and the second wiper do not come into contact with each other during wiping.

2. The wiper mechanism according to claim 1.

3. The first wiper is provided with a length that prevents it from contacting the head surface during wiping, or the contact pressure of the first wiper with respect to the head surface is weaker than that of the second wiper.

2. The wiper mechanism according to claim 1.

4. During elastic deformation accompanying wiping of the head surface, The first wiper and the second wiper do not come into contact with each other, and at least the tip of the first wiper is located at the same position as the second wiper before elastic deformation due to wiping, or between that position and the second wiper when elastic deformation due to wiping occurs.

2. The wiper mechanism according to claim 1.

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