JP2023144201A - liquid discharge device - Google Patents

Abstract

To provide a liquid discharge device that can eliminate bubbles in a cap part without polluting a discharge head.SOLUTION: A liquid discharge device includes a head unit 10 with first to fifth head parts 11 to 15 (discharge head) for discharging ink. First to fifth bubble crushing members 17a to 17e for crushing bubbles formed in first to fifth cap parts 21 to 25 for sealing discharge ports of the first to fifth head parts 11 to 15 are provided at a surface of the head unit 10 opposite to the first to fifth cap parts 21 to 25.SELECTED DRAWING: Figure 3

Description

The present invention relates to a liquid ejecting device equipped with an ejecting head that ejects liquid.

2. Description of the Related Art Conventionally, inkjet printing apparatuses have been proposed that print on print media such as paper and film by ejecting ink from an inkjet head.

In an inkjet printing apparatus, when performing head cleaning, initial ink introduction processing, etc., purging accompanied by ink discharge is performed with the ink ejection openings of the inkjet head being capped by a cap section.

During this purging, the ink is discharged at a high flow rate through tiny nozzle holes. may remain on the cap.

After purging, the inkjet head moves to the wiping unit to perform the wiping process, and is then capped again by the cap section. However, as mentioned above, if the cap section is capped with air bubbles remaining in the cap section, the air bubbles may be removed. It adheres to the ink ejection surface of the inkjet head and becomes contaminated with ink again, causing ink ejection failure.

In Patent Document 1, in order to eliminate the air bubbles remaining in the cap part as described above, after the wiping process is performed, the air bubbles in the cap part are brought into contact with the ink ejection surface of the inkjet head. A method has been proposed in which air bubbles are extinguished by bringing the ink into contact with the ink ejection surface.

Japanese Patent Application Publication No. 2020-121471

However, as described in Patent Document 1, if the air bubbles in the cap portion are brought into contact with the ink ejection surface to eliminate them, the ink ejection surface will be contaminated with ink again, causing ink ejection failure, and as described above. can't solve the problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejection device that can eliminate air bubbles in a cap portion without contaminating an ejection head.

The liquid ejection device of the present invention includes an ejection section having an ejection head that ejects liquid, and a bubble-destroying member that destroys air bubbles formed in a cap portion that seals an ejection port of the ejection head. provided on the surface of the section.

According to the liquid ejection device of the present invention, since the bubble destroying member is provided on the surface of the ejection portion facing the cap portion, air bubbles in the cap portion can be extinguished without contaminating the ejection head.

A diagram showing a schematic configuration of an inkjet printing device using an embodiment of a liquid ejection device of the present invention. A diagram of the inkjet printing device shown in FIG. 1 viewed from the direction of arrow A. A diagram showing a schematic configuration of an example of a head unit Diagram showing an example of a bubble-busting member A perspective view showing a schematic configuration of a capping unit Top view showing the structure of the cap part Block diagram showing the configuration of the control system of the inkjet printing device Explanatory diagram for explaining the operation of extinguishing bubbles formed in the first to fifth cap parts Explanatory diagram for explaining the operation of extinguishing bubbles formed in the first to fifth cap parts Flowchart for explaining the operation of eliminating air bubbles formed in the first to fifth cap parts

DESCRIPTION OF THE PREFERRED EMBODIMENTS An inkjet printing apparatus using an embodiment of a liquid ejection apparatus of the present invention will be described in detail below with reference to the drawings. The inkjet printing apparatus of this embodiment is characterized by the configuration of a head unit corresponding to the liquid ejection apparatus of the present invention, but first, the overall configuration of the inkjet printing apparatus will be described. FIG. 1 is a schematic configuration diagram of an inkjet printing apparatus 1 of this embodiment. Moreover, FIG. 2 is a diagram of the inkjet printing apparatus 1 shown in FIG. 1 viewed from the direction of arrow A. In the following description of the embodiment, the up, down, left, right, front and back directions indicated by arrows in FIG.

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

The base 2 is a columnar member extending in the front-rear direction, and is arranged in parallel at intervals in the left-right direction. Two wheels 2a are provided on the bottom surfaces of the two bases 2, respectively.

A leg stand 3 is erected on each base 2. A platen 4 is supported on the upper surfaces of two leg stands 3 facing each other.

A front paper guide 4a and a rear paper guide 4b, which are formed in an arc shape, extend in front and behind the platen 4. Furthermore, a vacuum chamber 4c in which a fan 4d is installed is provided below the platen 4, as shown in FIG. In addition, in FIG. 1, the vacuum chamber 4c is not shown.

As the fan 4d of the vacuum chamber 4c rotates, the inside of the vacuum chamber 4c becomes negative pressure, and a suction force is generated in a suction hole (not shown) formed in the platen 4. The printing medium P is attracted onto the platen 4 by the suction force generated in the suction holes of the platen 4 .

Further, behind the platen 4, as shown in FIG. 2, a drive roller 6 and a pressure roller 7 are provided facing each other. In addition, in FIG. 1, the drive roller 6 and the pressure roller 7 are not shown.

The drive roller 6 is a long roller extending in the extending direction of the platen 4, and is rotated by a conveyance drive motor 61 (see FIG. 7), which will be described later.

Like the drive roller 6, the pressure roller 7 is an elongated roller extending in the extending direction of the platen 4, and is supported so as to be movable up and down by an elevating mechanism (not shown).

Then, the print medium P on the rear paper guide 4b is held between the drive roller 6 and the pressure roller 7, and the drive roller 6 rotates with the print medium P being pressed by the pressure roller 7. P is sent forward.

On the front side of the base 2 of the inkjet printing apparatus 1, a winding-side core holding section 8 that removably holds a core 8a for winding up the printing medium P is provided. The take-up side core holding part 8 is linked to a take-up drive motor 81 (see FIG. 7) via a torque limiter (not shown), and the take-up side core holding part 8 is controlled by the take-up drive motor 81. It is configured to rotate.

Further, on the back side of the base 2 of the inkjet printing apparatus 1, a supply-side core holding unit 9 is provided that removably holds a roll paper core 9a on which the printing medium P is wound into a roll. . The supply side core holder 9 is linked to a supply drive motor 91 (see FIG. 7) via a torque limiter (not shown), and is configured such that the supply drive motor 91 rotates the supply side core holder 9. has been done.

Then, as shown in FIG. 2, the roll paper (print medium P) held by the supply-side core holder 9 is pulled out, and is placed between the rear paper guide 4b, the drive roller 6 and the pressure roller 7, and the platen 4. The sheet is configured to be wound onto a core 8a held by a winding-side core holder 8 via the upper and front paper guides 4a.

A rail portion 5 is installed above the two leg stands 3 via a support member (not shown). The rail section 5 includes a rail (not shown) extending in the left-right direction and a main scanning drive motor 54 (see FIG. 7) that reciprocates the head unit 10 in the left-right direction on the rail.

Further, a capping unit 20 is fixedly disposed on the lower front side of one end of the rail section 5 with respect to the leg base 3 by means of support means (not shown). By moving the head unit 10 onto the capping unit 20, capping is performed by the capping unit 20.

3A and 3B are diagrams showing a schematic configuration of the head unit 10. FIG. 3A is a diagram of the head unit 10 viewed from the front side, and FIG. 3B is a diagram of the head unit 10 viewed from the bottom side. be.

As shown in FIGS. 3A and 3B, the head unit 10 of this embodiment is provided with five heads, a first head 11 to a fifth head 15. The second head 12, the third head 13, and the fourth head 14 are inkjet heads each having a plurality of nozzles that eject ink of different colors, such as C (cyan), M (magenta), and Y ( (yellow) ink is ejected.

The fifth head 15 has the same configuration as the second head 12 to the fourth head 14, but the liquid it ejects is not ink but a pretreatment liquid. The pretreatment liquid is a liquid that is applied for pretreatment before ejecting ink onto the print medium P and performing a printing process. As the pretreatment liquid, for example, a liquid for improving the coloring properties and uniform coating properties of the ink is used, and any known pretreatment liquid can be used.

The first head 11 is an inkjet head that ejects ink like the second to fourth heads 12 to 14. For example, when printing a pattern on a black base, the first head 11 discharges white ink onto the black base so that the black base does not show through.

The first to fifth heads 11 to 15 are arranged side by side in the moving direction (horizontal direction) of the head unit 10, and as shown in FIG. 3B, the first head 11 and the second to fourth heads The heads 12 to 14 are arranged in a staggered arrangement, and the fifth head 15 and the second to fourth heads 12 to 14 are also arranged in a staggered arrangement.

That is, the second to fourth heads 12 to 14 and the first and fifth heads 11 and 15 are arranged at different positions in the direction (front-back direction) orthogonal to the moving direction of the head unit 10. The first head 11 and the fifth head 15 are arranged at the same position in a direction (front-back direction) orthogonal to the moving direction of the head unit 10. Further, the second to fourth heads 12 to 14 are arranged at the same position in a direction (front-back direction) orthogonal to the moving direction of the head unit 10.

The first to fifth heads 11 to 15 are installed on the head holder 10a. Through holes are formed in the lower surface 10b of the head holder 10a, in which the first to fifth heads 11 to 15 are installed. As shown in FIG. 3A, the first to fifth heads 11 to 15 are installed through through holes formed in the lower surface 10b of the head holder 10a, and the first to fifth heads 11 to 15 are installed through the through holes formed in the lower surface 10b of the head holder 10a. No. 15 ejection surfaces are installed so as to be exposed from the head holder 10a. The ejection surfaces of the first to fifth heads 11 to 15 are surfaces on which ejection ports of nozzles that eject ink or pretreatment liquid are arranged.

Furthermore, first to fifth bubble breaking members 17a to 17e are provided on the lower surface 10b of the head holder 10a facing the capping unit 20. The first to fifth bubble destroying members 17a to 17e are members that physically destroy the bubbles formed in the first to fifth cap portions 21 to 25 of the capping unit 20.

The first to fifth bubble breaking members 17a to 17e are provided for the first to fifth heads 11 to 15, respectively, as shown in FIG. 3B. 15.

Further, the first bubble-destroying member 17a is provided adjacent to the right side of the first head 11, and the second bubble-destroying member 17b is provided between the first head 11 and the second head 12 in the left-right direction. The third bubble-destroying member 17c is provided between the second head 12 and the third head 13 in the left-right direction, and the fourth bubble-destroying member 15d is provided between the second head 12 and the third head 13 in the left-right direction. The fifth bubble destroying member 17e is provided between the third head 13 and the fourth head 14, and the fifth bubble breaking member 17e is provided between the fourth head 14 and the fifth head 15 in the left-right direction.

The first to fifth bubble breaking members 17a to 17e extend in the front-rear direction and have the same length as the first to fifth cap portions 21 to 25. 4A is a diagram of the first bubble-destroying member 17a seen from the front side, and FIG. 4B is a diagram of the first bubble-destroying member 17a shown in FIG. 4A seen from the right side. As shown in FIGS. 4A and 4B, the first bubble-destroying member 17a has a large number of needle-like protrusions 18, and by piercing the protrusions 18 into the bubbles formed in the first cap part 21, the bubbles are destroyed. destroy and make it disappear. In this way, by destroying the bubbles with the needle-like protrusions 18 of the first bubble-destroying member 17a, it is possible to make it difficult for dirt caused by the destruction of the bubbles to remain on the first bubble-destroying member 17a.

In the present embodiment, the first bubble-destroying member 17a has the needle-shaped protrusion 18 as described above, but the first bubble-destroying member 17a is not limited to this, and may have any structure as long as it can destroy bubbles. Furthermore, the second to fifth bubble-destroying members 17b to 17e have the same structure as the first bubble-destroying member 17a shown in FIGS. 4A and 4B.

The operation of destroying the bubbles formed in the first to fifth cap portions 21 to 25 by the first to fifth bubble destroying members 17a to 17e will be described in detail later.

Next, the capping unit 20 of this embodiment will be explained. 5A is a diagram of the capping unit 20 viewed from above, and FIG. 5B is a diagram of the capping unit 20 shown in FIG. 5A viewed from the right side.

The capping unit 20 is configured to prevent the ejection surfaces (ejection ports) of the first to fifth heads 11 to 15 from drying out while the inkjet printing apparatus 1 is on standby and does not perform printing processing. ~15 discharge surfaces (discharge ports) are sealed. Further, the capping unit 20 seals the ejection surfaces (ejection ports) of the first to fifth heads 11 to 15 when purging is performed in the head unit 10.

Specifically, the capping unit 20 includes first to fifth cap parts 21 to 25. The first to fifth cap parts 21 to 25 are cap parts corresponding to the first to fifth heads 11 to 15, respectively.

FIG. 6 is a top view showing the configuration of the first cap part 21, and the configurations and functions of the second to fifth cap parts 22 to 25 are the same as those of the first cap part 21.

As shown in FIG. 6, the first cap portion 21 includes a capping member 21a. The capping member 21a includes a bottom portion 21b and a peripheral wall 21c erected on the periphery of the bottom portion 21b. Two discharge holes 21d are formed in the bottom portion 21b.

The length of the capping member 21a in the front-rear direction is equivalent to the length of the first head 11 in the front-rear direction. The peripheral wall 21c of the capping member 21a is made of resin such as rubber, and seals the ejection surface of the first head 11 by coming into close contact with the first head 11.

Furthermore, when the first head 11 is purged, the liquid discharged from the first head 11 is received by the capping member 21a and discharged from the discharge hole 21d formed in the bottom portion 21b.

A discharge path (not shown), a suction pump (not shown), etc. are provided in the casing 20a of the capping unit 20. The processing liquid is sucked by a suction pump and discharged to a waste liquid tank (not shown) via a discharge path.

Next, FIG. 7 is a block diagram showing the configuration of the control system of the inkjet printing apparatus 1 of this embodiment. The inkjet printing device 1 operates each part to be controlled shown in FIG. 7 in response to a control signal from the print control device 16.

The printing control device 16 and the inkjet printing device 1 are connected via a USB (Universal Serial Bus). However, they may be connected via a communication line such as a LAN (Local Area Network) or the Internet line.

The print control device 16 is composed of a computer including a CPU (Central Processing Unit), a semiconductor memory, a hard disk, and the like. The print control device 16 executes a print control program stored in advance in a storage medium such as a semiconductor memory or a hard disk based on an input print job, and operates each unit shown in FIG. 7 by operating an electric circuit. Control.

Next, in the inkjet printing apparatus 1 of this embodiment, the operation of extinguishing air bubbles formed in the first to fifth cap parts 21 to 25 after purging is explained in the explanatory diagrams of FIGS. 8 and 9 and This will be explained with reference to the flowchart shown in FIG.

First, the capping unit 20 rises toward the head unit 10, and as shown in FIG. 8A, the first to fifth cap parts 21 to 25 contact and cap the first to fifth heads 11 to 15. (S10).

Next, purging is performed in the first to fifth heads 11 to 15, and a suction pump (not shown) is operated to perform ink suction processing through the discharge holes 21d of the first to fifth cap parts 21 to 25. is performed (S12).

After the ink suction process, the capping unit 20 is lowered, and the first to fifth cap parts 21 to 25 are separated from the first to fifth head parts 11 to 15, as shown in FIG. 8B. (Cap open) (S14).

Then, the suction pump (not shown) operates again, and the ink discharge process is performed through the discharge holes 21d of the first to fifth cap parts 21 to 25 (S16).

Next, with the cap open, the head unit 10 moves to the left by a predetermined distance (S18), and as shown in FIG. ~Fifth bubble destroying members 17a to 17e are arranged.

Then, the capping unit 20 rises again toward the head unit 10, and as shown in FIG. 9B, the first to fifth cap parts 21 to 25 and the first to fifth bubble breaking members 17a to 17e come into contact with each other, As a result, the bubbles formed in the first to fifth cap portions 21 to 25 are destroyed and disappear (S20). At this time, the needle-like protrusions 18 of the first to fifth bubble-destroying members 17a to 17e enter the capping members 21a of the first to fifth cap parts 21 to 25, thereby destroying the bubbles. Ru.

As described above, the bubbles formed in the first to fifth cap portions 21 to 25 are destroyed by the first to fifth bubble destroying members 17a to 17e provided on the lower surface 10b of the head unit 10. Therefore, the air bubbles in the first to fifth cap parts 21 to 25 can be eliminated without contaminating the first to fifth head parts 11 to 15.

Further, the first to fifth bubble breaking members 17a to 17e are provided adjacent to the first to fifth head parts 11 to 15, and after the head unit 10 is moved, the first to fifth bubble breaking members Since the bubbles are destroyed by bringing the caps 17a to 17e into contact with the first to fifth cap portions 21 to 25, the bubbles can be efficiently extinguished.

Furthermore, since the first to fifth bubble destroying members 17b to 17e are provided between the first to fifth head parts 11 to 15, respectively, the moving distance of the head unit 10 when extinguishing bubbles is shortened. Therefore, the moving time of the head unit 10 can be shortened.

Then, in the state shown in FIG. 9B, the suction pump (not shown) operates again, and the ink discharge process is performed through the discharge holes 21d of the first to fifth cap parts 21 to 25 (S22). By this ink discharge process, ink adhering to the first to fifth bubble breaking members 17a to 17e can be removed.

Subsequently, the capping unit 20 is lowered, and the first to fifth cap parts 21 to 25 are separated from the first to fifth head parts 11 to 15 (cap open) (S24).

Then, the head unit 10 moves to the position of a wiping unit (not shown), and the first to fifth head sections 11 to 15 are wiped by the wiping unit (S26).

Subsequently, the head unit 10 moves again to a position above the capping unit 20 (S28), and the first to fifth heads 11 to 15 are placed in positions facing the first to fifth cap parts 21 to 25. Placed.

Then, the capping unit 20 rises again toward the head unit 10, and as shown in FIG. 8A, the first to fifth cap parts 21 to 25 abut against the first to fifth heads 11 to 15 and cap. (cap close) (S30).

When the user inputs a print start instruction in the print control device 16, the inkjet printing device 1 releases the capping of the head unit 10 by the capping unit 20 and starts printing processing. The operation of the inkjet printing apparatus 1 during printing processing will be described in detail later.

After the printing process is completed, the inkjet printing apparatus 1 moves the head unit 10 to a position directly above the capping unit 20 to perform capping.

Next, the operation during printing processing in the inkjet printing apparatus 1 of this embodiment will be described. Note that here, the first head 11 is not used, the pretreatment liquid is ejected from the fifth head 15 and applied to the print medium P, and then ink is applied from the second to fourth heads 12 to 14. A case will be described in which a printing process is performed on a printing medium P coated with a pretreatment liquid by ejection.

First, as shown in FIG. 2, a roll of paper is installed in the supply side core holder 9, the roll of paper (printing paper P) is pulled out, and the rear paper guide 4b, drive roller 6, and pressure roller 7 are connected to each other. During this time, the paper passes over the platen 4 and through the front paper guide 4a, and is wound around the core 8a held by the winding-side core holder 8.

Then, the printing control device 16 feeds out the printing paper P by rotating the supply side core holding unit 9, the winding side core holding unit 8, and the drive roller 6, and when the printing paper P reaches the initial printing position, the printing paper The sending of P is temporarily stopped.

Next, the print control device 16 operates the main scanning drive motor 54 to move the head unit 10 on the rail portion 5 in the first direction (either the left or right direction). Then, as the head unit 10 moves, the print control device 16 operates the fifth head 15 of the head unit 10 to apply the pretreatment liquid to the first scanning line. Note that during the initial scanning of the first scanning line, ink is not ejected from the second to fourth heads 12 to 14.

Next, the print control device 16 sends out the print medium P by one scanning line so that the first scanning line coated with the pretreatment liquid is placed directly below the second to fourth heads 12 to 14. .

Then, the printing control device 16 moves the head unit 10 in a second direction opposite to the first direction on the rail section 5, and as the head unit 10 moves, ink is discharged from the second to fourth heads 12 to 14. The liquid is ejected to print on the first scanning line. Further, the print control device 16 performs printing on the first scanning line, and operates the fifth head 15 to apply the pretreatment liquid to the second scanning line following the first scanning line.

Subsequently, the print control device 16 feeds out the print medium P by one scanning line, arranges the second scanning line directly below the second to fourth heads 12 to 14, and arranges the second scanning line directly below the fifth head 15. , a third scan line is placed next to the second scan line.

Then, the printing control device 16 moves the head unit 10 in the first direction on the rail section 5, and operates the second to fourth heads 12 to 14 and the fifth head 15 along with the movement. , a pretreatment liquid is applied to the third scanning line, and printing is performed to the second scanning line.

Thereafter, the print control device 16 alternately sends out the print medium P for one scanning line and moves the head unit 10 on the rail section 5 in the first direction or the second direction, as described above. While repeating, applying the pretreatment liquid to the (n+1)th scanning line and printing to the nth scanning line are sequentially performed.

In addition, in the above description, the operation in the case where the pretreatment liquid is applied by the fifth head 15 without using the first head 11 was explained. 11 may be used to print the base. The ink ejection timing from the first head 11 in this case is the same as the ejection timing from the fifth head 15 in the above description.

It should be noted that the present invention is not limited to the above-described embodiments, and can be embodied by modifying the constituent elements within the scope of the invention at the implementation stage. Moreover, various inventions can be formed by appropriately combining the plurality of components disclosed in the above embodiments. For example, all the components shown in the embodiments may be combined as appropriate. It goes without saying that various modifications and applications can be made without departing from the spirit of the invention.

Regarding the present invention, the following additional notes are further disclosed.
(Additional note)

In the liquid ejection device of the present invention, the bubble-destroying member is provided adjacent to the ejection head on the surface of the ejection portion facing the cap portion, and the ejection portion is configured to destroy bubbles in the direction in which the bubble-destroying member and the ejection head are adjacent to each other. After the member and the cap portion relatively move to a position where they face each other, the bubble-destroying member comes into contact with the cap portion, thereby destroying the bubbles formed in the cap portion.

In the liquid ejection device of the present invention, after the bubble destroying member comes into contact with the cap portion to destroy the bubbles formed in the cap portion, a suction operation can be performed in the cap portion.

Furthermore, in the liquid ejection device of the present invention, the ejection section may include a plurality of ejection heads, and a bubble-destroying member may be provided between the ejection heads.

Further, in the liquid ejection device of the present invention, the bubble breaking member can have a plurality of protrusions.

1 Inkjet printing device 2 Base 2a Wheels 3 Legs 4 Platen 4a Front paper guide 4b Rear paper guide 4c Vacuum chamber 4d Fan 5 Rail section 6 Drive roller 7 Pressure roller 8 Winding side core holding section 8a Core 9 Supply Side mandrel holding part 9a Mandrel 10 Head unit 10a Head holder 10b Lower surfaces 11 to 15 First to fifth heads 16 Printing control device 17a First bubble breaking member 17b Second bubble breaking member 17c Third Bubble-destroying member 17d Fourth bubble-destroying member 17e Fifth bubble-destroying member 18 Protrusion 20 Capping unit 20a Housings 21 to 25 First to fifth cap portions 21a Capping member 21b Bottom portion 21c Peripheral wall 21d Discharge hole 54 Main scanning Drive motor 61 Conveyance drive motor 81 Take-up drive motor 91 Supply drive motor P Print medium

Claims (5)

comprising a discharge section having a discharge head for discharging liquid;
A liquid ejection device, wherein a bubble destroying member for destroying air bubbles formed in a cap portion that seals an ejection port of the ejection head is provided on a surface of the ejection portion facing the cap portion. The bubble breaking member is provided adjacent to the ejection head on a surface of the ejection portion facing the cap portion,
After the discharge part relatively moves in the direction in which the bubble-destroying member and the discharge head are adjacent to each other to a position where the bubble-destroying member and the cap part face each other, the bubble-destroying member abuts the cap part. 2. The liquid ejecting device according to claim 1, wherein air bubbles formed in the cap portion are destroyed by the following steps. 3. The liquid ejecting device according to claim 2, wherein the bubble destroying member contacts the cap part to destroy the bubbles formed in the cap part, and then performs a suction operation in the cap part. 4. The liquid ejecting device according to claim 1, wherein the ejecting section has a plurality of ejecting heads, and the bubble breaking member is provided between the ejecting heads. The liquid ejecting device according to any one of claims 1 to 3, wherein the bubble destroying member has a plurality of protrusions.