JP2021146688A - Ink jet printer - Google Patents

Abstract

To provide an ink jet printer capable of maintaining constant suction force, for preventing contamination due to mist of ink droplets regardless of a width of a printing medium.SOLUTION: On a facing position of a mist suction part 19 sandwiching a continuous sheet WP therebetween, a leak suppressing member 21 is arranged, so that, even when transporting the continuous sheet WP having a small width by a transport roller 11A, air resistance among the mist suction part 19, the continuous sheet WP and the leak suppression member 21, can be set to almost equal to that when the continuous sheet WP having a maximum width Pwm is transported. Therefore, since suction force can be maintained to constant force, even when a sheet width Pw1 of the continuous sheet WP is small, regardless of the width of the continuous sheet WP, contamination due to mist of ink droplets can be prevented.SELECTED DRAWING: Figure 3

Description

The present invention relates to an inkjet printing apparatus that ejects ink droplets to print on a printing medium, and particularly relates to a technique for collecting mist of ink droplets.

Conventionally, as a device of this type, there is a device including a transport mechanism, an inkjet head, a switching unit, and a mist suction unit (see, for example, Patent Document 1). The transport mechanism transports the printing paper in a predetermined transport direction. In the inkjet head, the nozzle surface on which a plurality of nozzles are formed is arranged above the printing surface of the printing paper, and ink droplets are ejected from the plurality of nozzles toward the printing surface of the printing paper. The switching unit bends the transport direction of the printing paper in the direction opposite to the printing surface on the downstream side of the inkjet head. The mist suction unit sucks a gas containing a mist of ink droplets from the vicinity of the printing surface of the printing paper passing through the switching unit.

In the inkjet printing apparatus, printing is performed by adhering ink droplets ejected from the inkjet head to the printing surface of the printing paper. The ink droplets ejected from the inkjet head at high speed become finer ink droplets due to air resistance before a part of the ink droplets reaches the printing surface of the printing paper. Then, this becomes a mist-like mist and floats on the printing surface of the printing paper. The floating ink droplet mist causes a problem of contaminating the nozzle surface of the inkjet head, the control board of the inkjet head, the transport mechanism, and the like. This problem is solved by the mist suction unit sucking the gas containing the mist.

JP-A-2015-112829

However, in the case of the conventional example having such a configuration, there are the following problems.
That is, since printing paper of various widths is conveyed in the conventional apparatus, the width of the suction opening of the mist suction portion is formed according to the maximum width of the printing paper that can be conveyed by the conveying mechanism. Therefore, when printing on printing paper with a width narrower than the maximum width, the air resistance decreases at the suction openings located outside both ends of the printing paper in the mist suction part, and due to this effect, the printing paper The suction force at the suction opening located above is weakened. Therefore, the mist of ink droplets cannot be sufficiently sucked and contamination occurs. Therefore, in order to deal with this problem, it is conceivable to set a large suction force in the mist suction part, but the cost of the suction source such as a fan, a blower or a vacuum pump that generates the suction force in the mist suction part becomes high. Another problem arises.

The present invention has been made in view of such circumstances, and provides an inkjet printing apparatus capable of preventing contamination by mist of ink droplets regardless of the width of the printing medium by keeping the suction force constant. With the goal.

The present invention has the following configuration in order to achieve such an object.
That is, the invention according to claim 1 is an inkjet printing apparatus that ejects ink droplets onto a long printing medium to print, and conveys the printing medium in a conveying direction along the longitudinal direction thereof. , A transport mechanism capable of transporting various sizes in the width direction orthogonal to the longitudinal direction of the print medium, and an inkjet that ejects ink droplets onto the print surface of the print medium conveyed by the transport mechanism. A mist suction portion arranged on the downstream side of the head and the inkjet head in the transport direction and sucking a gas containing the mist of ink droplets from the vicinity of the print surface, and the opposite side of the print surface. A leak suppressing member which is arranged so as to face the mist suction portion across the print medium and has a length in the width direction corresponding to the maximum width of the print medium which can be conveyed by the transfer mechanism. It is characterized by being present.

[Action / Effect] According to the invention of claim 1, ink droplets are ejected from an inkjet head onto a printing surface of a printing medium conveyed by a conveying mechanism to perform printing. At that time, a mist of ink droplets is generated, and a gas containing the mist flows along the printing surface of the printing medium to the downstream side of the inkjet head. The gas is sucked by the mist suction part. Since the leak suppressing member is arranged at the position opposite to the print medium of the mist suction part, the mist suction part, the printing medium, and the leak suppressing member are arranged even when the transport mechanism conveys a print medium having a small width. The air resistance between the and the print medium can be made almost the same as when the print medium having the maximum width is conveyed. Therefore, since the suction force can be kept constant even if the width of the print medium is reduced, contamination by the mist of ink droplets can be prevented regardless of the width of the print medium.

Further, in the present invention, the leak suppressing member is preferably a plate-shaped member having a short side in the transport direction and a long side in the width direction (claim 2).

It is only necessary to arrange a plate-shaped member having a short side in the transport direction and a long side in the width direction as a leak suppressing member. Therefore, it is possible to prevent contamination of ink droplets by mist while suppressing an increase in device cost.

Further, in the present invention, it is preferable that the leak suppressing member is arranged so as to be separated from the opposite surface of the printing surface of the printing medium (claim 3).

Wrinkles or the like may occur on the print medium, but by arranging the leak suppressing members apart from each other, it is possible to prevent such rubbing against the print medium. Therefore, it is possible to prevent the leak suppressing member from damaging the print medium.

Further, in the present invention, it is preferable that the leak suppressing member is connected to the mist suction portion at both ends (claim 4).

The leak suppressing member can be integrally configured with the mist suction portion. Therefore, even if the mounting position of the mist suction portion fluctuates slightly, the distance between the leak suppressing member and the mist suction portion can be maintained constant. Therefore, since the suction force of the gas containing the mist of the ink droplets can be made constant, contamination by the mist of the ink droplets can be reliably prevented even if the attachment position of the mist suction portion is slightly changed.

Further, in the present invention, the leak suppressing member is composed of two members extending from both end sides in the width direction toward the center portion, and the center portion in the width direction is open in a plan view. Is preferable (claim 5).

The leak suppressing member is composed of two members, and the central portion in the width direction in a plan view is open. Therefore, the weight of the leak suppressing member can be reduced.

Further, in the present invention, it is preferable that the length of the leak suppressing member is set in the width direction in consideration of the maximum amount of blurring of the print medium conveyed by the transfer mechanism in the width direction (). Claim 6).

When the printing medium is conveyed by the conveying mechanism, skewing or meandering generally occurs. Therefore, even if the print medium has the maximum width, both ends move in the width direction. Therefore, by setting the length of the leak suppressing member in the width direction in consideration of the amount of blurring, even if skewing or meandering occurs, the air resistance between the mist suction portion and the printing medium and the leak suppressing member can be increased. , It can be almost the same as when the maximum width print medium is conveyed.

Further, in the present invention, it is preferable that the leak suppressing member is arranged between the frames in which the transport rollers of the transport mechanism are supported (claim 7).

The transport mechanism includes a frame that rotatably supports both ends of the transport roller. Therefore, by arranging the leak suppressing member between the frames, the leak suppressing member can be easily attached.

Further, in the present invention, the transfer destination is changed from the first direction to the second by bending the print medium in the direction opposite to the print surface on the downstream side of the ink head in the print medium. It is preferable that the mist suction section is further provided with a switching section for switching in the direction of the above, and the mist suction section is located on an extension line of the first direction (claim 8).

Since the transfer destination of the print medium is switched from the first direction to the second direction by the switching unit, the gas containing the mist of ink droplets can be separated from the print surface of the print medium by utilizing the inertial force. Therefore, the mist of the ink droplets together with the separated gas can be efficiently sucked by the mist suction unit.

The invention according to claim 9 is a method for suppressing leakage of ink droplet mist in an inkjet printing apparatus that ejects ink droplets onto a long printing medium to print, and is orthogonal to the longitudinal direction of the printing medium. With respect to the transport process of transporting the print medium in the transport direction along the longitudinal direction by a transport mechanism capable of transporting various sizes in the width direction and the printing surface of the print medium conveyed by the transport mechanism. Ink droplets are ejected by a mist suction unit that is arranged downstream of the inkjet head in the transport direction and sucks a gas containing the mist of the ink droplets from the vicinity of the printing surface. A suction process for sucking a gas containing the mist of the above is provided. It is characterized in that a leak suppressing member having a length in the width direction corresponding to the maximum width of the print medium that can be conveyed is arranged.

[Action / Effect] According to the invention of claim 9, the print medium conveyed by the transfer mechanism in the transfer process is printed by ejecting ink droplets from the inkjet head onto the printing surface in the ejection process. Will be done. At that time, a mist of ink droplets is generated, and a gas containing the mist flows along the printing surface of the printing medium to the downstream side of the inkjet head. The gas is sucked by the mist suction part in the suction process. In the suction process, since the leak suppressing member is arranged at the position opposite to the print medium of the mist suction part, the mist suction part, the print medium, and the print medium are arranged even when the transfer mechanism conveys the print medium having a small width. The air resistance with the leak suppressing member can be made substantially the same as when the maximum width printing medium is conveyed. Therefore, since the suction force can be kept constant even if the width of the print medium is reduced, contamination by the mist of ink droplets can be prevented regardless of the width of the print medium.

According to the inkjet printing apparatus according to the present invention, ink droplets are ejected from the inkjet head onto the printing surface of the printing medium conveyed by the conveying mechanism to perform printing. At that time, a mist of ink droplets is generated, and a gas containing the mist flows along the printing surface of the printing medium to the downstream side of the inkjet head. The gas is sucked by the mist suction part. Since the leak suppressing member is arranged at the position opposite to the print medium of the mist suction part, the mist suction part, the printing medium, and the leak suppressing member are arranged even when the transport mechanism conveys a print medium having a small width. The air resistance between the and the print medium can be made almost the same as when the print medium having the maximum width is conveyed. Therefore, since the suction force can be kept constant even if the width of the print medium is reduced, contamination by the mist of ink droplets can be prevented regardless of the width of the print medium.

It is a schematic block diagram which shows the whole of the inkjet printing system which concerns on Example. It is a side view which enlarged the main part. It is the figure which looked at the main part from the downstream side. It is a figure which provides the explanation of the problem which occurs in the conventional example. It is the figure which looked at the main part which concerns on the 1st modification from the downstream side. It is the figure which looked at the main part which concerns on the 2nd modification from the downstream side. It is the figure which looked at the main part which concerns on the 3rd modification from the downstream side.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing the entire inkjet printing system according to the embodiment.

The inkjet printing system 1 according to this embodiment includes a paper feeding unit 3, an inkjet printing device 5, and a paper discharging unit 7.

The paper feed unit 3 rotatably holds the roll of the continuous paper WP around the horizontal axis, unwinds the continuous paper WP from the roll of the continuous paper WP, and supplies the continuous paper WP to the inkjet printing apparatus 5. The inkjet printing apparatus 5 prints on a long continuous paper WP. The paper ejection unit 7 winds up the continuous paper WP printed by the inkjet printing device 5 around the horizontal axis. Assuming that the supply side of the continuous paper WP is upstream and the discharge side of the continuous paper WP is downstream, the paper feed unit 3 is arranged on the upstream side of the inkjet printing device 5, and the paper discharge unit 7 is located on the downstream side of the inkjet printing device 5. Is located in.

The continuous paper WP corresponds to the "printing medium" in the present invention.

The inkjet printing apparatus 5 includes a first drive roller M1 for taking in continuous paper WP from the paper feed unit 3 on the upstream side. The continuous paper WP unwound from the paper feed unit 3 by the first drive roller M1 is conveyed along the rotatable transfer roller 11 and the like, and is conveyed toward the paper discharge unit 7 on the downstream side.

An edge position control unit 13 is arranged on the downstream side of the first drive roller M1. The edge position control unit 13 automatically adjusts when the continuous paper WP meanders in the width direction Y orthogonal to the conveying direction X, and controls so that the continuous paper WP is conveyed to the correct position.

A second drive roller M2 is arranged on the downstream side of the edge position control unit 13. The continuous paper WP sent to the downstream side by the second drive roller M2 is a transfer roller 11 arranged on the downstream side of the second drive roller M2 in the printing area PA for printing along the transfer path. The destination can be changed depending on. A rotary encoder 15 is attached to the transfer roller 11. A plurality of transport rollers 11 are arranged in the print area PA along the transport path of the continuous paper WP, and these transport rollers 11 guide the continuous paper WP along the transport direction X. A printing unit 17 is arranged above the printing area PA.

The printing unit 17 is composed of, for example, four inkjet heads 17a to 17d. For example, the most upstream inkjet head 17a ejects black (K) ink droplets, the next inkjet head 17b ejects cyan (C) ink droplets, and the next inkjet head 17c ejects magenta (M). Inkjet head 17d ejects yellow (Y) ink droplets. The inkjet heads 17a to 17d are arranged apart from each other by a predetermined interval in the transport direction.

Examples of the ink droplets ejected by the printing unit 17 described above include water-based inks and ultraviolet curable inks. In this embodiment, the type of ink droplets will be described without being specified, but any type of ink droplets may be used.

The transfer destination of the continuous paper WP printed in the print area PA is changed by the transfer roller 11 arranged immediately after the print area PA. Here, the transfer roller 11 is referred to as a transfer roller 11A in order to distinguish it from other transfer rollers 11. The transport roller 11A bends the transport destination in the direction opposite to the printing surface of the continuous paper WP. Specifically, the transport roller 11A switches the transport destination from the horizontal direction (convey direction X), which is the first direction, to the diagonally lower left, which is the second direction in FIG. A mist suction portion 19 is arranged on an extension line in the first direction of the transport roller 11A. A leak suppressing member 21 is arranged on the side opposite to the printing surface of the continuous paper WP and at a position facing the mist suction portion 19 sandwiching the continuous paper WP.

The plurality of transport rollers 11 described above correspond to the "convey mechanism" in the present invention, and the transport rollers 11A correspond to the "switching unit" in the present invention.

The transfer destination of the continuous paper WP is changed downward by the transfer roller 11 downstream of the transfer roller 11A. A third drive roller M3 is arranged at that position. The third drive roller M3 winds the continuous paper WP with a large winding angle and abuts on the continuous paper WP to dry the ink droplets of the continuous paper WP. The third drive roller M3 has a built-in heater and is also called a heat drum.

The continuous paper WP dried by the third drive roller M3 is sent to the paper ejection unit 7 by the fourth drive roller M4 while the transfer destination is changed by the plurality of transfer rollers 11. An inspection unit 23 is arranged on the upstream side of the fourth drive roller M4. The inspection unit 23 inspects the continuous paper WP printed by the printing unit 17. The paper ejection unit 7 winds up the continuous paper WP inspected by the inspection unit 23 in a roll shape.

The nip roller 25 is rotatably attached to the first drive roller M1, the second drive roller M2, and the fourth drive roller M4 described above. The conveying force to the continuous paper WP is given by the nip roller 25 sandwiching the continuous paper WP with each drive roller. The pressing force by the nip roller 25 is applied by, for example, an air cylinder (not shown). The nip roller 25 is made of an elastic body such as rubber.

Here, the mist suction unit 19 and the leak suppressing member 21 described above will be described in detail with reference to FIGS. 2 and 3. Note that FIG. 2 is an enlarged side view of the main part, and FIG. 3 is a view of the main part viewed from the downstream side.

The inkjet printing apparatus 5 includes a pair of frames 31. Each frame 31 has a plate shape when viewed from the transport direction X. The frames 31 are erected so as to be substantially parallel to each other with a predetermined width. A plurality of transfer rollers 11 are attached to the frame 31 via bearings 33, and each transfer roller 11 is rotatable around a horizontal axis.

The outer peripheral surface of the transport roller 11A comes into contact with the opposite side of the printing surface of the continuous paper WP, and the length of the outer peripheral surface in the width direction Y is defined as the roller width RW. The roller width RW is determined according to the maximum dimension in the width direction Y of the continuous paper WPs that can be printed by the inkjet printing system 1. For example, assuming that the maximum width of the paper width Pw1 in the width direction Y is Pwm, the roller width RW is set to be slightly larger than the maximum width Pwm. This is because the continuous paper WP to be conveyed is meandered or skewed so that the continuous paper WP can be normally conveyed even if the end face position in the width direction Y is deviated in the width direction Y.

The mist suction unit 19 is located on the downstream side of the transfer roller 11A and is arranged on an extension line in the first direction of the transfer roller 11A. The mist suction portion 19 has a suction opening 19a formed on a surface facing the continuous paper WP. In the mist suction unit 19, the suction opening 19a is communicated with a suction source (fan, blower, vacuum pump, etc.) (not shown). The mist suction unit 19 sucks gas from the suction opening 19a at least while the printing process is being performed by the printing unit 17. In the mist suction unit 19, the suction opening 19a is arranged on an extension line in the first direction in which the transfer destination of the continuous paper WP is directed from the first direction to the second direction by the transfer roller 11A. Therefore, the gas containing the mist of the ink droplets ejected from the printing unit 17 moves while drifting near the printing surface of the continuous paper WP, but the gas is carried by inertia in the first direction. Since the mist suction unit 19 sucks the gas, it is possible to prevent the printing unit 17, the transport roller 11, and the like from being contaminated by the mist of ink droplets contained in the gas.

The leak suppressing member 21 has, for example, a plate shape. More specifically, it is composed of a plate-shaped member having a short side in the transport direction X and a long side in the width direction Y. The leak suppressing member 21 is arranged so that its upper surface is substantially parallel to the surface of the mist suction portion 19 facing the continuous paper WP. Both ends of the leak suppressing member 21 in the width direction Y are arranged between the frames 31. More specifically, a locking groove 35 is formed on the inner surface of the frame 31. Both ends of the leak suppressing member 21 are fitted into these locking grooves 35, and the leak suppressing member 21 is attached. The leak suppressing member 21 is provided between the frames 31 so that the surface facing the continuous paper WP does not come into contact with the continuous paper WP. The separated distance is preferably such that the continuous paper WP does not come into contact with each other even if it sags due to fluctuations in the transport tension. The distance is preferably, for example, about 0.5 to 2 mm, and more preferably about 1 mm. The continuous paper WP may have wrinkles or the like due to the influence during transportation. By arranging the leak suppressing member 21 at a distance from the continuous paper WP, it is possible to prevent the continuous paper WP and the leak suppressing member 21 from rubbing against each other. Therefore, it is possible to prevent the leak suppressing member 21 from rubbing against the continuous paper WP and damaging the continuous paper WP.

Since the leak suppressing member 21 is arranged between the frames 31, it is preferable that the leak suppressing member 21 is made of a material having a certain degree of rigidity. Examples of the material include stainless steel, aluminum and plastic.

Here, the dimension of the inkjet head 17d in the width direction Y that contributes to printing is defined as the effective width HW. The execution width HW that contributes to printing is the width between both ends of the nozzles used for printing in the width direction Y among the nozzle groups (not shown). Further, in the mist suction portion 19, the dimension of the suction opening 19a in the width direction Y is defined as the nozzle width NW. Further, of the paper width Pw1 of the continuous paper WP, the dimension in the width direction Y set as the print area is defined as the effective print width Pw2. Further, among the leak suppressing members 21, the dimension between the inner side surfaces of the frame 31 is defined as the member effective width LW.

The dimensions of the above-mentioned parts in this embodiment have the following magnitude relations.
Member effective width LW> Roller width RW> Nozzle width NW> Effective printing width Pw2

The effective member width LW is larger than the roller width RW because the leak suppressing member 21 is attached to each other of the frames 31. However, in terms of the action of the leak suppressing member 21, the effective width LW of the member of the leak suppressing member 21 may be sufficient so that the roller width RW> the effective member width LW = the nozzle width NW> the effective printing width Pw2.

See FIG. 4 here. Note that FIG. 4 is a diagram provided for explaining the problems that occur in the conventional example.

FIG. 4 is a configuration corresponding to a conventional example in which the leak suppressing member 21 is removed in the configuration shown in FIG. Further, the continuous paper WP shows a state when the width Pw1 is narrower than the maximum width Pwm. In this state, since the continuous paper WP does not exist at the opposite position in the suction opening 19a located outside the width Pw1 of the continuous paper WP, a large amount of gas is sucked from below between the frames 31. Therefore, the air resistance is extremely reduced compared to the central part. Therefore, it affects the suction in the suction opening 19a located above the continuous paper WP, and the suction force is weakened. Therefore, the mist suction unit 19 cannot sufficiently suck the mist of ink droplets, which may cause contamination.

However, according to the present embodiment having the above-described configuration, as shown in FIG. 3, the leak suppressing member 21 is arranged at the opposite position of the mist suction unit 19 across the continuous paper WP. Therefore, even when the continuous paper WP whose paper width Pw1 is smaller than the maximum width Pwm is conveyed, the air resistance between the mist suction unit 19, the continuous paper WP, and the leak suppressing member 21 is increased so that the paper width Pw1 has the maximum width Pwm. It can be almost the same as when the continuous paper WP is conveyed. Therefore, since the suction force can be made constant even if the paper width Pw1 of the continuous paper WP becomes small, contamination by the mist of ink droplets can be prevented regardless of the width of the continuous paper WP.

<First modification>

Here, a modified example of the present invention will be described with reference to FIG. Note that FIG. 5 is a view of the main part according to the first modification as viewed from the downstream side.

The leak suppressing member 21A is composed of a leak suppressing member main body 41, a connecting member 43, and a mounting member 45.

The leak suppressing member main body 41 has a plate shape similar to the leak suppressing member 21 in the above-described embodiment. The connecting member 43 connects the leak suppressing member main body 41 to the mounting member 45. The mounting member 45 fixes the leak suppressing member main body 41 to the side surface of the inkjet head 17d together with the connecting member 43.

Even the leak suppressing member 21A in the first modification has the same effect as that in the above-described embodiment. Moreover, even if the mounting position of the mist suction unit 19 fluctuates slightly, the distance between the leak suppressing member 21A and the mist suction unit 19 can be maintained constant. Therefore, since the suction force of the gas containing the mist of the ink droplets can be made constant, contamination by the mist of the ink droplets can be reliably prevented even if the attachment position of the mist suction portion 19 is slightly changed.

<Second modification>

Here, a modified example of the present invention will be described with reference to FIG. Note that FIG. 6 is a view of the main part according to the second modification as viewed from the downstream side.

The leak suppressing member 21B is composed of a pair of leak suppressing pieces 51, a connecting member 53, and a mounting member 55.

The pair of leak suppression pieces 51 have a plate shape similar to the leak suppression member main body 41 in the first modification described above, but are separated into two members. Further, each leak suppressing piece 51 extends from the connecting member 53 to the central portion in the width direction Y. The combined length of the two leak suppressing pieces 51 is shorter than that of the leak suppressing member main body 41 described above, and the central portion in the width direction Y is open. The interval at the center is set to be larger than the minimum of the paper width Pw1 of the continuous paper WP.

Even the leak suppressing member 21B in the second modification has the same effect as that of the above-described embodiment. In addition, two leak suppression pieces 51 are provided, and the central portion in the width direction Y is open. Therefore, the leak suppressing member 21B can be made lighter than the leak suppressing member 21A of the first modification. Further, since the interval at the center is set to be larger than the minimum of the paper width Pw1 of the continuous paper WP, the same effect can be obtained regardless of the paper width Pw1 of the continuous paper WP while reducing the weight of the leak suppressing member 21B. Play.

<Third modification example>

Here, a modified example of the present invention will be described with reference to FIG. 7. Note that FIG. 7 is a view of the main part according to the third modification as viewed from the downstream side.

The leak suppressing member 21C is composed of a pair of leak suppressing pieces 61, a bent portion 63, and a screw 65.

The pair of leak suppression pieces 61 have a plate shape similar to the leak suppression member main body 41 in the first modification described above, but are separated into two members. Each of the pair of leak suppression pieces 61 forms a bent portion 63 that is bent according to the inner side surface and the upper surface of the frame 31. Each of the pair of leak suppression pieces 61 has a bent portion 63 attached to the upper portion of the frame 31, and is fixed to the frame 31 by a screw 65 at the bent portion 63.

Even the leak suppressing member 21C in the third modification has the same effect as that of the above-described embodiment. Further, since the pair of leak suppressing pieces 61 can be easily attached and detached by the screws 65, maintenance such as cleaning and replacement of the leak suppressing member 21C can be easily performed.

The present invention is not limited to the above embodiment, and can be modified and implemented as follows.

(1) In the above-described Examples and Modifications, the continuous paper WP has been described as an example as the printing medium, but the present invention is not limited to the continuous paper WP as the printing medium. As another printing medium, for example, a plastic film used for packaging food and drink can be applied.

(2) In the above-described examples and modifications, the leak suppressing members 21 and 21A to 21C have a plate shape, but the present invention is not limited to such a form. Any member may be used as a resistance so that the air resistance in the suction opening 19a is constant regardless of the paper width Pw1 of the continuous paper WP. Therefore, for example, a configuration in which a plurality of rod-shaped members are bundled may be adopted as the leak suppressing member 21.

(3) In the above-described examples and modifications, the mist suction unit 19 is arranged on the upper surface of the continuous paper WP, and the mist suppressing member 21 is arranged on the lower surface of the continuous paper WP. However, the present invention is not limited to such a configuration. When the printing surface of the continuous paper WP is the lower surface, the mist suction unit 19 may be arranged on the lower surface of the continuous paper WP, and the mist suppressing member 21 may be arranged on the upper surface of the continuous paper WP.

(4) Although the switching unit 11A is provided in the above-described examples and modifications, the present invention does not require the switching unit 11A.

(5) In the above-described examples and modifications, the printing unit 17 is composed of four inkjet heads 17a to 17d, but the present invention is not limited to such a configuration. That is, the present invention can be applied as long as there is at least one inkjet head.

As described above, the present invention is suitable for an inkjet printing apparatus having a configuration for sucking a gas containing a mist of ink droplets.

1… Inkjet printing system 3… Feeding unit 5… Inkjet printing device 7… Paper ejection unit 11 (11A)… Conveying roller X… Conveying direction Y… Width direction PA… Printing area 17… Printing unit 17a to 17d… Inkjet head 19 … Mist suction part 19a… Suction opening 21… Leak suppression member RW… Roller width Pw1… Paper width Pwm… Maximum width HW2… Effective width NW… Nozzle width Pw2… Effective printing width LW… Member effective width

Claims (9)

In an inkjet printing device that prints by ejecting ink droplets onto a long printing medium.
A transport mechanism for transporting the print medium in a transport direction along the longitudinal direction thereof, and capable of transporting various sizes of the print medium in the width direction orthogonal to the longitudinal direction.
An inkjet head that ejects ink droplets onto the printing surface of the printing medium conveyed by the conveying mechanism, and
A mist suction unit arranged on the downstream side of the inkjet head in the transport direction and sucking a gas containing a mist of ink droplets from the vicinity of the printing surface.
The length in the width direction corresponding to the maximum width of the print medium that is on the opposite side of the print surface and is arranged so as to face the mist suction portion across the print medium and can be conveyed by the transfer mechanism. Leak suppression member and
An inkjet printing device characterized by being equipped with. In the inkjet printing apparatus according to claim 1,
The leak suppressing member is an inkjet printing apparatus having a short side in the transport direction and a long side in the width direction. In the inkjet printing apparatus according to claim 1 or 2.
An inkjet printing apparatus characterized in that the leak suppressing member is arranged apart from the opposite surface of the printing surface of the printing medium. In the inkjet printing apparatus according to any one of claims 1 to 3.
An inkjet printing apparatus characterized in that the leak suppressing member is connected to the mist suction portion. In the inkjet printing apparatus according to any one of claims 1 to 4.
The leak suppressing member is composed of two members extending from both end sides in the width direction toward the center portion, and the central portion in the width direction is open in a plan view. Device. In the inkjet printing apparatus according to any one of claims 1 to 5.
The leak suppressing member is an inkjet printing apparatus whose length in the width direction is set in consideration of the maximum amount of blurring of the print medium conveyed by the transfer mechanism in the width direction. In the inkjet printing apparatus according to any one of claims 1 to 6.
An inkjet printing apparatus characterized in that the leak suppressing member is arranged between frames in which a transport roller of the transport mechanism is supported. In the inkjet printing apparatus according to any one of claims 1 to 7.
A switching unit that switches the transport destination from the first direction to the second direction by bending the print medium in the direction opposite to the print surface on the downstream side of the ink head in the print medium. With more
The mist suction unit is an inkjet printing apparatus characterized in that it is located on an extension line in the first direction. In a method for suppressing leakage of ink droplet mist in an inkjet printing apparatus that ejects ink droplets onto a long printing medium for printing.
A transport process in which the print medium is transported in a transport direction along the longitudinal direction by a transport mechanism capable of transporting various sizes in the width direction orthogonal to the longitudinal direction of the print medium.
The ejection process of ejecting ink droplets onto the printing surface of the printing medium conveyed by the conveying mechanism, and
A suction process in which a gas containing a mist of ink droplets is sucked from the vicinity of the printing surface by a mist suction unit arranged on the downstream side of the inkjet head in the transport direction and sucking the gas containing the mist of the ink droplets. When,
With
In the suction process, the width corresponding to the maximum width of the print medium that is on the opposite side of the print surface, is arranged so as to face the mist suction portion with the print medium sandwiched between them, and can be conveyed by the transfer mechanism. A method for suppressing leakage of ink droplet mist in an inkjet printing apparatus, which comprises arranging a leak suppressing member having a length in a direction.

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