JP7828234B2 - wiper mechanism - Google Patents

Description

The present invention relates to a wiper mechanism that wipes the head surface on which the nozzle rows of an inkjet head are provided.

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 located are known. One such inkjet printing device has been proposed in which a first wiper is positioned with a gap between it and the head surface that allows ink to be adsorbed by surface tension, and a second wiper is positioned 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).

Japanese Patent Application Laid-Open No. 2005-224975

In a wiper mechanism, if the head surface is wiped using only a single wiper, such as a rubber blade, a strong contact pressure on the head surface will improve the cleaning performance of the head surface but will reduce the durability of the head surface.

As such, it is conceivable to achieve both improved cleaning performance and maintained durability by using multiple wipers as described above. However, as described above, it is difficult to position the first wiper with a small gap between it and the inkjet head surface, allowing surface tension to adsorb ink droplets, etc., and there is also significant variation in effectiveness (adsorption performance, etc.) due to variations in the size of the gap.

Whether a single wiper or multiple wipers are used, ink spreads (swells) 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 more ink is wiped, the more ink that adheres to the side of the inkjet head. Furthermore, when the wiper passes through the inkjet head after wiping, ink that has accumulated between the wiper and the inkjet head breaks down into droplets and scatters, causing ink to adhere 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 caused by paper transport can cause ink to flow onto the head surface, resulting in ejection problems or ink adhering to the paper as it is transported.

The object of the present invention is to provide a wiper mechanism that can prevent ink from remaining on the sides of an inkjet head after wiping.

In one aspect, the wiper mechanism includes a first wiper and a second wiper that wipe a head surface on which a nozzle row of an 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 on 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.

This aspect makes it possible to prevent ink from remaining on the side of the inkjet head after wiping.

1 is a front view showing the internal structure of an inkjet printing apparatus according to an embodiment; FIG. 2 is a diagram illustrating a main control configuration of an inkjet printing apparatus according to an embodiment. FIG. 1 is a front view of a wiper mechanism in a wiping position according to one embodiment. FIG. 2 is a plan view showing a wiper mechanism according to an embodiment. 5 is a cross-sectional view taken along the line VV in FIG. 4. FIG. 2 is a front view showing a first wiper and a second wiper according to the embodiment. FIG. 4 is a bottom view of the inkjet head for explaining the positional relationship between the first wiper and the second wiper in the embodiment. FIG. 4 is a right side view of the wiper unit for explaining a wiping operation in the embodiment. FIG. 2 is a perspective view of a wiper unit for explaining a wiping operation in the embodiment. FIG. 10 is a front view showing a first wiper and a second wiper according to a first modified example of the embodiment. FIG. 10 is a front view showing a first wiper and a second wiper according to a second modified example of the embodiment. FIG. 11 is a front view showing a first wiper and a second wiper according to a third modified example of the embodiment. FIG. 10 is a right side view of the wiper unit for explaining a wiping operation in another embodiment. FIG. 10 is an enlarged right side view of the first wiper and the second wiper during wiping in another embodiment.

The following describes a wiper mechanism according to an embodiment of the present invention, with reference to the drawings.

Figure 1 is a front view showing the internal structure of an inkjet printing device 100 in one embodiment.

Figure 2 shows the main control configuration of the inkjet printing device 100.

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, an example of a medium, during printing is the right direction, and the wiping direction D1 of the first wiper 11 and second wiper 12 is the forward direction. However, for example, the front-to-back and left-to-right directions are horizontal directions, and the up-to-down direction is vertical.

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

The printing unit 110 shown in FIG. 1 has multiple 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-to-back 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-to-back direction are arranged with their positions shifted alternately in the left-to-right direction. As an example, the six inkjet heads 111 in one set eject ink of two colors (e.g., 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 first set (e.g., magenta (M) and yellow (Y)).

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, the wiping position shown in FIG. 3 which is below the printing position, and a standby position (not shown) which is below the wiping position. The wiper mechanism 1 is positioned below the printing unit 110 during wiping as shown in FIG. 3, and is positioned retracted from below the printing unit 110 during printing as shown in FIG. 1.

The external paper feed unit 130 and internal paper feed units 141-143 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.

Multiple sheets of paper P are loaded in paper feed trays 131, 141a, 142a, and 143a.

Scraper rollers 132, 141b, 142b, and 143b are feed rollers that feed and transport the uppermost sheet P among the multiple sheets P stacked in paper feed trays 131, 141a, 142a, and 143a.

Pickup rollers 133, 141c, 142c, and 143c transport paper P fed by scraper rollers 132, 141b, 142b, and 143b.

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

The pair of registration rollers 156 abuts against the paper P transported from the external paper feed unit 130 and the internal paper feed units 141-143. This corrects any skew in the paper P.

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, printing unit 110, and suction transport unit 120.

The storage unit 162 may be, for example, a ROM (Read Only Memory), which is a read-only semiconductor memory in which predetermined control programs are pre-recorded; a RAM (Random Access Memory), which is semiconductor memory that can be written to 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 drive.

The operation panel unit 163 has, for example, operation keys for performing various operations, a touch panel, a display for displaying various information, and the like, and functions as an example of an input unit and display unit for the inkjet printing device 100.

Scanner 164 reads image data from the original.

Although not shown in Figure 1, the paper discharge unit 165 has a paper discharge tray on which paper P printed by the printing unit 110 is stacked, and discharge rollers that discharge paper P onto this paper discharge tray.

Figure 3 is a front view showing the wiper mechanism 1 in the wiping position.

Figure 4 is a plan view showing the wiper mechanism 1.

Figure 5 is a cross-sectional view taken along line V-V in Figure 4.

Figure 6 is a front view showing the first wiper 11 and the second wiper 12.

Figure 7 is a bottom view of the inkjet head 111 to explain the positional relationship between the first wiper 11 and the second wiper 12.

The front-to-back, up-down, and left-to-right directions shown in Figures 3 to 7 and Figures 8 to 14 described below refer to directions when the wiper mechanism 1 is located between the printing unit 110 and the suction transport unit 120, as shown in Figure 3.

As shown in Figure 4, the wiper mechanism 1 includes a wiper unit 10, two guide sections 20, an ink receiving section 30, and a wiper drive section 40.

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 these first wipers 11 and second wipers 12.

The first wiper 11 and second wiper 12 shown in Figure 5 are wiper blades made of, for example, an elastic material such as rubber. The first wiper 11 is located downstream of the second wiper 12 in the wiping direction D1. In other words, the first wiper 11 wipes the head surface 111a before the second wiper 12. As shown in Figure 8, which will be described later, the first wiper 11 is located at a height that does not contact the head surface 111a, but it can still be said to wipe the head surface 111a because it can scrape off purged ink PI from the head surface 111a.

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

For example, although not shown, the head surface 111a includes a nozzle surface formed from polyimide resin and provided with the nozzle row 111b, and the bottom surface of a protective plate that protects this nozzle surface. It is preferable that the head surface 111a be coated with an ink-repellent film.

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 Figure 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 Figure 7.

As shown in FIG. 5, before wiping, the first wiper 11 and the second wiper 12 are spaced apart by a wiper spacing L3 in the wiping direction D1, and extend upward from the wiper support member 13 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 located at 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.

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

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 Figure 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 they may be different.

As shown in FIG. 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 only one end of the head surface 111a. However, 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 desirable to wipe the entire head surface 111a in the width direction D2.

Here, the notch width L1 shown in Figure 6 above should be 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 notch width L1 is too long, the area that can be wiped on the head surface 111a by the first wiper 11 will be narrow. In this case, the amount of ink used when wiping the head surface 111a with the second wiper 12 will increase.

Next, the cutout height L2 shown in Figure 6 above is effective if it is greater than 0, but it should not be too long so that the 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.

Next, the wiper spacing L3 shown in Figure 5 above is effective if it is greater than 0, but the larger this dimension, the more likely it is that the ink will not be retained between the cutout portion 11b and the second wiper 12 due to the surface tension of the ink, and will collapse. Therefore, it is desirable for the wiper spacing L3 to be a spacing that can withstand the wiping speed and vibration of the first wiper 11 and second wiper 12 and retain ink.

As shown in FIG. 4, the wiper support member 13 is integrally provided with the four first wipers 11 and four second wipers 12. Note that the first wipers 11 and second wipers 12 may be provided separately from the wiper support member 13 and attached to the wiper support member 13.

As shown in Figures 4 and 5, the wiper support member 13 has, for example, a pair of left and right screw holes 13a, 13a that penetrate in the front-to-rear direction.

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

The ink receiver 30 receives the purged ink PI shown in Figure 8 that falls from the inkjet head 111 along with paper powder, dust, etc.

When the wiper mechanism 1 is tilted in the retracted position shown in Figure 1, the ink in the ink receiving unit 30 flows from the discharge section 30b of the ink receiving unit 30 shown in Figure 4 to the waste liquid storage section via a waste liquid path (not shown). 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 section 20.

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

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, for example, adhesively attached to the guide portion 20. The motor 41 rotates the guide portion 20, thereby moving the wiper unit 10 back and forth as described above. Note that a single motor 41 may also rotate the two guide portions 20 via pulleys within the drive belt, for example, by rotating 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 back and forth.

Next, we will explain the wiping operation using the first wiper 11 and the second wiper 12. Note that this wiping operation may be performed, for example, after a predetermined number of printed sheets or after a certain amount of time has elapsed, or based on user operation on the operation panel unit 163 shown in Figure 2.

Figures 8 and 9 are right side and perspective views of the wiper unit 10 to explain the wiping operation.

First, before the first wiper 11 and 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. The inkjet head 111 also 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.

Then, the first wiper 11 and the second wiper 12 move in the wiping direction D1. As a result, the purged ink PI and other materials wiped away by the first wiper 11 and the second wiper 12 (for example, the purged ink PI, the ink originally adhering to the head surface 111a, and paper powder and dust contained in the ink) travel down the first wiper 11 and the second wiper 12 and fall in the direction of gravity onto the ink receiving surface 30a of the ink receiving section 30 shown in Figures 4 and 5 above. Note that Figures 8 and 9 omit illustration of the purged ink PI after being wiped by the first wiper 11.

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 Figure 9.

Here, by providing the cutout portion 11b, the purged ink PI wiped by both ends of the second wiper 12 in the width direction D2 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 ends of the second wiper 12 in the width direction D2.

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).

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 reduces the surface area of the liquid, i.e., causes the liquid to become spherical. 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 in order to become as close to a spherical shape as possible.

As described above, as shown in FIG. 7, when wiping the head surface 111a, the tip 11a of the first wiper 11 is positioned at a distance G inward in the width direction D2 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 of the inkjet head 111, as shown in FIG. 9. In particular, when 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, the purged ink PI is even less likely to adhere to the side of the inkjet head 111.

As mentioned 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.

The thin liquid film of purged ink PI 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 away by the first wiper 11, the purged ink PI is less likely to adhere to the side of the inkjet head 111. Note that the second wiper 12 wipes away purged ink PI and other materials remaining at the end of the head surface 111a in the width direction D2 that were not wiped by the first wiper 11, using the end of the second wiper 12 in the width direction D2. This means that the purged ink PI and other materials tend to fall along the side of the end of the second wiper 12 in the width direction D2 onto the ink receiving surface 30a of the ink receiving unit 30 in the direction of gravity.

After the first wiper 11 and second wiper 12 have wiped the head surfaces 111a of all 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 improving ink color 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 further downward to a standby position when printing is not being performed. It is desirable that the wiper unit 10 (first wiper 11 and second wiper 12) return to the upstream side of 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.

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

The first wipers 51, 61, and 71 shown in Figures 10 to 12 differ from the first wiper 11 shown in Figure 6 in the shape of the cutout portions 51b, 61b, and 71b.

The tip 51a of the first wiper 51 shown in Figure 10 has cutout portions 51b on both ends in the width direction D2. These cutout portions 51b are formed by cutting a rectangular shape into the corner between the tip 51a and the side surface of the first wiper 51.

The notch 61b on the tip 61a of the first wiper 61 shown in Figure 11 is formed by cutting a recessed R-shape (arc-shaped) at the corner between the tip 61a and the side of the first wiper 61.

The notch 71b on the tip 71a of the first wiper 71 shown in Figure 12 is formed by cutting the corner between the tip 71a of the first wiper 71 and the side surface into a curved R-shape (arc-like).

As with the first wipers 51, 61, and 71 in the first to third modified examples shown in Figures 10 to 12, the shapes of the cutout portions 51b, 61b, and 71b are not particularly limited.

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

In this way, because 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, the purged ink PI is prevented from being wiped by the first wiper 11 and wrapping around the sides of the inkjet head 111 from both ends of the first wiper 11 in the width direction D2. Furthermore, the provision of the cutout portion 11b in the first wiper 11 narrows the width (cutout width L1) and reduces the height (cutout height L2) of the tip 11a of the first wiper 11. 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, an increase in the volume of the purged ink PI caused by spreading or bulging outward from the top of the second wiper 12 beyond the head surface 111a can be prevented. 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 defects or ink adhering to the medium being transported. Furthermore, because the tip 12a of the second wiper 12 is wider than the tip 11a of the first wiper 11, it can wipe away the purged ink PI that is not wiped away by the first wiper 11. Furthermore, if 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 have wiped the inkjet head 111, which prevents 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.

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

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, which prevents the purged ink PI wiped by the first wiper 11 from overflowing from the top of the first wiper 11 and wrapping around the side of the inkjet head 111. This further prevents ink from remaining on the side of the inkjet head 111 after wiping.

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

This allows the purged ink PI to accumulate between the first wiper 11 and the second wiper 12, preventing the purged ink PI from flowing from the second wiper 12 to the side 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 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. This prevents a decrease in cleaning performance and deterioration of the head surface 111a caused by the second wiper 12 wiping areas of the head surface 111a that are free of purged ink PI (empty wipe). Furthermore, by preventing contact between the first wiper 11 and the second wiper 12, it is possible to prevent a decrease in cleaning performance caused by the rigidity of the contact area between the first wiper 11 and the second wiper 12 being increased only in a portion of the width direction D2, and the second wiper 12 can reliably wipe away purged ink PI and the like between the first wiper 11 and the second wiper 12.

In addition, 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.

As a result, the purged ink PI after being wiped by the first wiper 11 spreads evenly as a thin liquid film (liquid residue) on the head surface 111a. This allows the purged ink PI to be reliably wiped away by the second wiper 12. Furthermore, the durability of the head surface 111a can be maintained.

Figure 13 is a right side view of the wiper unit 210 to explain the wiping operation in another embodiment.

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

The wiper unit 210 shown in FIG. 13, like the wiper unit 10 shown in FIG. 4, has, for example, four first wipers 211, for example, four second wipers 212, and a wiper support member 213 that supports these first wipers 211 and second wipers 212. Note that 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.

13 and a pre-wiping state (not shown), 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. Meanwhile, 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 (not shown), but extends from the wiper support member 213 in an 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, like the first wiper 211, also wipes the head surface 111a in a curved state during wiping. 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 pre-wiping angles of the first wiper 211 and the second wiper 212, it is also possible to, for example, make the vertical length (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.

The tip 211a of the first wiper 211 has a notch portion 211b, as described in the above embodiment. Furthermore, 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.

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 other particles wiped away by the first wiper 211 and the second wiper 212 (for example, the purged ink PI, the ink originally adhering to the head surface 111a, and paper powder and dust contained in the ink) travel down the first wiper 211 and the second wiper 212 and fall in the direction of gravity onto the ink receiving surface 30a of the ink receiving unit 30 shown in Figures 4 and 5 above. Note that Figure 13 does not show the purged ink PI after it has been wiped by the first wiper 211. Also, Figure 14 shows the first wiper 211 and the second wiper 212 from Figure 13, without showing the purged ink PI.

As shown in Figure 14, the first wiper 211 and the second wiper 212 do not come into contact with each other during elastic deformation associated with wiping the head surface 111a. Furthermore, during elastic deformation associated with wiping 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 the 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 for the first wiper 211 and the second wiper 212 to be close to each other during wiping.

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. Note that the deformation region 212b of the second wiper 212 is a part that includes the tip of the second wiper 212, and since the second wiper 212 extends upward from the wiper support member 213 perpendicular to the head surface 111a before wiping, the root region 212c of the second wiper 212 closer to the wiper support member 213 than the deformation region 212b extends upward 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 extension direction of the root region 212c and the head surface 111a), or is located upstream of the wiping direction D1.

As mentioned 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.

The purged ink PI, which has now 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 of the inkjet head 111.

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.

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

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. This allows the second wiper 212 to reliably wipe the purged ink PI. Furthermore, by preventing the first wiper 211 from coming into contact with the head surface 111a, separating it from the thin liquid film of purged ink PI, the durability of the head surface 111a can be maintained.

In addition, in this embodiment, when the first wiper 211 elastically deforms in association with wiping the head surface 111a, 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 in 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 region 212b) when elastically deformed in association with wiping.

In this way, by having the tip 211a of the first wiper 211 approach the second wiper 212 (deformation region 212b) during wiping, the surface tension of the purged ink PI can be more easily exerted between the cutout portion 211b of the first wiper 211 and the second wiper 212. This more reliably prevents the purged ink PI from seeping from the second wiper 212 onto the side 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 away by the second wiper 212 before it aggregates on a portion of the head surface 111a due to the ink-repellent properties of the head surface 111a. This prevents 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 that is free of purged ink PI (empty wipe). Furthermore, by preventing contact between the first wiper 211 and the second wiper 212, it is possible to prevent a decrease in cleaning performance caused by the rigidity of the contact area between the first wiper 211 and the second wiper 212 being increased only in a portion 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.

The present invention is not limited to the above-described embodiments, and can be embodied by modifying the components within the scope of the spirit of the invention. Furthermore, various inventions can be created by appropriately combining the multiple components disclosed in the above-described embodiments. For example, all of the components shown in the embodiments can be combined as appropriate. Naturally, various modifications and applications are possible within the scope of the spirit of the invention. The following is an appendix to the invention as set forth in the claims of this application as originally filed.

[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;
a tip of the first wiper having notched portions at both ends in a width direction of the head surface perpendicular to the wiping direction, and having a width in the width direction narrower than that of the tip of the second wiper;

[Appendix 2]
2. The wiper mechanism according to claim 1, wherein a 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 that includes the nozzle row.

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

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

[Appendix 5]
During elastic deformation accompanying wiping of the head surface,
2. The wiper mechanism according to claim 1, wherein 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 elastically deformed due to wiping.

REFERENCE SIGNS LIST 1 wiper mechanism 10 wiper unit 11 first wiper 11a tip 11b cutout portion 12 second wiper 12a tip 13 wiper support member 13a screw hole 20 guide portion 30 ink receiving portion 30a ink receiving surface 30b discharge portion 40 wiper drive portion 41 motor 51, 61, 71 first wiper 51a, 61a, 71a tip 51b, 61b, 71b cutout portion 100 inkjet printing device 110 printing portion 111 inkjet head 111a head surface 111b nozzle row 120 suction transport portion 130 external paper feed portion 131 paper feed tray 132 scraper roller 133 pickup roller 141, 142, 143 internal paper feed portion 141a, 142a, 143a Paper feed tray 141b, 142b, 143b Scraper rollers 141c, 142c, 143c Pickup rollers 151 to 155 Pair of conveying rollers 156 Pair of registration rollers 161 Control unit 162 Storage unit 163 Operation panel unit 164 Scanner 165 Paper discharge unit 210 Wiper unit 211 First wiper 211a Tip 211b Notch portion 212 Second wiper 212-1 Second wiper before elastic deformation 212a Tip 212b Deformation area 212c Base area 213 Wiper support member D1 Wiping direction D2 Width direction G Spacing L1 Notch width L2 Notch height L3 Wiper spacing P Paper PI Purge Ink

Claims (4)

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: The wiper mechanism according to claim 1 , wherein the first wiper and the second wiper do not come into contact with each other during wiping. The wiper mechanism according to claim 1, wherein the first wiper is provided with a length that prevents the first wiper from contacting the head surface during wiping, or the first wiper has a weaker contact pressure with the head surface than the second wiper. During elastic deformation accompanying wiping of the head surface,
2. The wiper mechanism according to claim 1, wherein the first wiper and the second wiper do not contact 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 elastically deformed due to wiping.