KR102571794B1 - Ink circulation system and method - Google Patents

Abstract

The ink circulation system includes an ink reservoir in which ink is stored, an inkjet print head including at least one nozzle for discharging ink to a printing medium, an ink supply passage connecting the ink reservoir and the inkjet print head, and locations in the ink supply passage. and a first pump providing power for the ink stored in the ink reservoir to flow to the inkjet print head, coupled to at least one region of the inkjet printhead, and when coupled to the inkjet printhead, the at least one pump A cap protecting the nozzle, an ink recovery passage connecting the inner space of the cap and the ink reservoir, and the ink stored in the inkjet print head flowing in the direction toward the ink reservoir located in the ink recovery passage. It may include a second pump that provides power to do.

Description

Ink circulation system and method {INK CIRCULATION SYSTEM AND METHOD}

Embodiments relate to an ink circulation system and method, and more particularly, to an ink circulation system and method capable of preventing nozzle clogging of an inkjet printhead by recovering ink stored in a cap coupled to the inkjet printhead to an ink tank. It is about.

An inkjet printing apparatus is a device that prints an image having a predetermined color on the surface of a printing medium by ejecting droplets of a fine size of ink for printing onto a desired location on a printing medium using an inkjet print head.

The inkjet printing apparatus may include an ink reservoir in which ink is stored, and the ink stored in the ink reservoir may be supplied to the inkjet print head through an ink supply unit, and the supplied ink may be supplied to paper, film, and/or ink through nozzles of the inkjet print head. It can be ejected on a printing medium such as fabric to print an image.

Such an inkjet printing device may employ various printing/ejection methods, and may be classified into a piezoelectric type inkjet printing device, an electrostatic type inkjet printing device, or a thermal transfer type inkjet printing device according to the employed printing/ejection method.

The piezoelectric type inkjet printing device is a device capable of ejecting ink by using the deformation of a piezoelectric element. Since ink is ejected in a DOD (Drop On Demand) method, it is easy to control the printing operation. there is.

An electrostatic inkjet printing device is a device capable of ejecting ink using electrostatic force, and is suitable for precise printing because it is easy to implement fine droplets.

A thermal transfer type inkjet printing device is a device capable of ejecting ink using heat generated from microelectrodes, and can eject ink only with microelectrodes, so manufacturing costs are low and the printing device can be miniaturized.

Japanese Unexamined Patent Publication No. 2019-098737 (2019.06.24.)

In an inkjet printer, when there is no flow of ink for a long period of time due to the characteristics of printing ink, precipitation of printing ink particles may occur or aggregation between printing ink particles may occur.

Precipitates or agglomerates of ink particles for printing may block the nozzles of the inkjet print head through which ink is ejected, and as a result, the inkjet printing device may not be able to eject a desired amount of ink in a desired location, resulting in a problem of deterioration in print quality. there is.

In order to prevent precipitation or aggregation of ink particles for printing, an inkjet printer has been proposed that is located in the chamber of the inkjet print head and includes an agitator for mixing the ink located in the chamber. Since the agitating means must be arranged, the overall structure becomes complicated and the design of the inkjet print head becomes difficult.

As another method for preventing precipitation or aggregation of printing ink particles, an inkjet printer including an ink circulation system capable of circulating ink supplied from an ink reservoir to an inkjet print head back to the ink reservoir has also been proposed.

However, in the case of an inkjet printer including an ink circulation system, although the structure of the inkjet print head can be simplified, ink stored adjacent to the nozzle of the inkjet printhead cannot be circulated. There was a limitation that precipitation or aggregation of the ink particles to be prevented could not be prevented.

Accordingly, the present disclosure provides an ink circulation system and method capable of circulating ink stored adjacent to a nozzle of an inkjet printhead by forming an air circulation path between an ink reservoir and a cap coupled to the inkjet printhead. It is intended to overcome the above-mentioned limitations by providing.

The problems to be solved through the embodiments of the present disclosure are not limited to the above-mentioned problems, and problems not mentioned are clearly understood by those skilled in the art from this specification and the accompanying drawings to which the embodiments belong. It could be.

An ink circulation system according to an embodiment includes an ink reservoir in which ink is stored, an inkjet print head including at least one nozzle ejecting ink to a printing medium, and connecting the ink reservoir and the inkjet print head. an ink supply passage; a first pump positioned in the ink supply passage and providing power for the ink stored in the ink reservoir to flow to the inkjet print head; coupled to at least one area of the inkjet print head; When coupled to the print head, a cap protecting the at least one nozzle, an ink recovery path connecting the inner space of the cap and the ink reservoir, and located in the ink recovery path, stored in the inkjet print head A second pump providing power for ink to flow in a direction toward the ink reservoir may be included.

In one example, the inkjet printhead includes an ink chamber in which ink transferred from the ink reservoir to the inkjet printhead through the ink supply passage is stored, and an ink chamber for ejecting the ink stored in the ink chamber to the outside of the inkjet printhead. A piezoelectric element may be further included.

In one example, the ink circulation system may further include a remaining amount detection sensor for detecting a remaining amount of ink stored in the ink chamber and a processor electrically connected to the detection sensor, the first pump, and the second pump.

For example, the remaining amount detection sensor detects an indicator bar that is movable according to the amount of ink stored in the ink chamber and the position of the indicator bar, and detects the position of the indicator bar in the ink chamber based on the sensed position of the indicator bar. A sensor for determining the remaining amount of stored ink may be included.

In one example, the processor may be configured to control the operation of the first pump based on the remaining amount of ink detected by the remaining amount detection sensor.

In one example, the processor may control the operation of the second pump according to a designated time interval to discharge the ink stored in the ink chamber into the inner space of the cap, and then flow the discharged ink into the ink reservoir. .

At this time, the designated time interval may be variable.

In one example, the ink circulation system may further include a pressure regulating means for regulating the internal pressure of the ink chamber.

According to an embodiment, the ink circulation system is located in the ink recovery passage and further includes a first filter for removing foreign substances of ink flowing from the inner space of the cap toward the ink reservoir along the ink recovery passage. can do.

According to another embodiment, the ink circulation system may further include a second filter disposed in the ink supply passage and configured to remove foreign substances from ink flowing from the ink reservoir toward the inkjet print head along the ink supply passage. may be

An ink circulation method according to an embodiment includes an operation of supplying ink stored in an ink reservoir to an ink chamber of an inkjet print head using a first pump, and at least one area of the inkjet print head An operation of coupling a cap protecting the nozzle and an operation of recovering the ink stored in the ink chamber to the ink reservoir using a second pump may be included.

In one example, the operation of supplying the ink stored in the ink reservoir to the ink chamber may include an operation of measuring the remaining amount of ink stored in the ink chamber using a remaining amount detection sensor, and the first step based on the measured remaining amount of ink. It may include an operation to control the operation of the pump.

For example, in the operation of supplying the ink stored in the ink reservoir to the ink chamber, the first pump is operated to flow the ink stored in the ink reservoir into the ink chamber when the measured remaining amount of ink is equal to or less than a specified value. can

In another example, the operation of recovering the ink stored in the ink chamber to the ink reservoir may include discharging the ink stored in the ink chamber into the inner space of the cap using the second pump, and then discharging the discharged ink into the ink reservoir. can be moved by

The ink circulation system and method according to the above-described embodiments supply ink stored in the ink reservoir to the inkjet print head, recover the ink stored in the inkjet print head back to the ink reservoir, and circulate the ink. As a result, ink particles may be circulated. It is possible to reduce clogging that may occur around the nozzles of inkjet printheads due to precipitation or aggregation of .

The effects of the embodiments are not limited to the above-mentioned effects, and effects not mentioned will be clearly understood by those skilled in the art to which the embodiments belong from this specification and the accompanying drawings.

1 is a perspective view showing some configurations of an inkjet printing apparatus according to an embodiment.
FIG. 2 is a cross-sectional view illustrating a state in which an inkjet print head and a cap of the inkjet printing apparatus shown in FIG. 1 are coupled.
3 is a block diagram illustrating components of an ink circulation system for circulating ink of an inkjet printing apparatus according to an exemplary embodiment.
Fig. 4A is a perspective view of the ink circulation system shown in Fig. 3;
Fig. 4b is a front view of the ink circulation system shown in Fig. 3;
5 is a flowchart illustrating an ink circulation operation of an ink circulation system according to an exemplary embodiment.
6 is a diagram for explaining an ink supply operation of an ink circulation system according to an embodiment.
7A is a diagram for explaining an ink recovery operation of an ink circulation system according to an embodiment.
FIG. 7B is an enlarged cross-sectional view of area A of the ink circulation system shown in FIG. 7A.

The terms used in the embodiments have been selected from general terms that are currently widely used as much as possible while considering the functions in the present disclosure, but they may vary depending on the intention or precedent of a person skilled in the art, the emergence of new technologies, and the like. In addition, in a specific case, there is also a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the invention. Therefore, terms used in the present disclosure should be defined based on the meaning of the term and the general content of the present disclosure, not simply the name of the term.

In the present disclosure, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated. In addition, terms such as "-unit" and "-module" described in this disclosure refer to a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software. .

As used in this disclosure, when an expression such as “at least one of” precedes an array of components, it modifies the array of components as a whole and not each individual component. For example, the expression "at least one of a, b, and c" should be interpreted as including a, b, c, or a and b, a and c, b and c, or a and b and c. do.

In the present disclosure, an “inkjet printing device” may refer to a device capable of printing an image on a print medium by ejecting fine-sized ink particles to a desired location on the print medium.

Also, in the present disclosure, an “ink circulation system” may refer to a system for circulating ink between ink reservoirs (or “ink tanks”).

Hereinafter, with reference to the accompanying drawings, the embodiments of the present disclosure will be described in detail so that those skilled in the art can easily carry out the embodiments of the present disclosure. can be implemented and is not limited to the embodiments described herein.

FIG. 1 is a perspective view showing some configurations of an inkjet printing device according to an embodiment, and FIG. 2 is a cross-sectional view showing a state in which an inkjet print head and a cap are coupled to the inkjet printing device shown in FIG. 1 .

Referring to FIGS. 1 and 2 , an inkjet printing apparatus 10 according to an embodiment may include an inkjet print head 100 for ejecting ink for printing (hereinafter referred to as 'ink').

The inkjet print head 100 may print an image on the print medium P by discharging ink droplets having a fine size (eg, several tens of micrometers) at a desired location on the print medium P while moving along a designated path. . The print medium P may include, for example, at least one of paper, film, or fiber, but is not limited thereto.

In one embodiment, the print medium P may move along the first direction, and the inkjet print head 100 may eject ink droplets onto the moving print medium P at a fixed location. The method of discharging ink droplets of (100) is not limited thereto.

In another embodiment, the print medium P may move along a first direction to reach the inkjet print head 100, and the inkjet print head 100 may reach a second direction substantially perpendicular to the first direction. Ink droplets may be ejected onto the printing medium P that moves along the direction and reaches the inkjet print head 100 . In another embodiment, the inkjet print head 100 may eject ink droplets onto the printing medium P moving along the first direction while moving along the second direction.

In the present disclosure, "first direction" may mean the x direction of FIG. 1, and "second direction" may mean a y direction substantially perpendicular to the x direction, and the corresponding expressions will be used in the same meaning below. can

According to one embodiment, the inkjet print head 100 may include at least one nozzle 110 , at least one cartridge 120 and a piezoelectric element 140 .

The at least one nozzle 110 may be fluidly connected or communicated with the inside of the at least one cartridge 120, and serves to discharge droplets of ink stored in the at least one cartridge 120 to the printing medium P. can do. In one embodiment, at least one nozzle 110 may be located at the lower end of the inkjet print head 100 adjacent to the print medium P (eg, in the -z direction of FIG. 1 ), but is not limited thereto. In another embodiment, at least one nozzle 110 may be regularly arranged at designated intervals, but according to embodiments, at least one nozzle 110 may be arranged at irregular intervals.

The at least one cartridge 120 may include an ink chamber 130 in which ink of various colors is stored and an ink passage 131 connecting the ink chamber 130 and at least one nozzle 110 .

In one embodiment, the at least one cartridge 120 may be fluidly connected or communicated with an ink reservoir (not shown) located outside the inkjet print head 100 through an ink supply passage (not shown), and Ink supplied from the ink reservoir may be stored in the ink chamber 130 formed in the inner space of the cartridge 120 . For example, at least one cartridge 120 includes an ink inlet (not shown), and the ink stored in the ink reservoir reaches the ink inlet through the ink supply passage and then enters the ink chamber 130 through the ink inlet. can be infiltrated.

Ink stored in the ink chamber 130 may be discharged to the outside of the inkjet print head 100 in the form of droplets after moving in a direction toward the at least one nozzle 110 through the ink passage 131 .

According to one embodiment, the at least one cartridge 120 includes a first cartridge 121 storing black (key or black) ink, a second cartridge 122 storing cyan ink, and magenta ink. (Magenta) may include a third cartridge 123 for storing ink and a fourth cartridge 124 for storing yellow ink, but the number of cartridges 120 and the number of cartridges 120 The type of ink is not limited to the above-described embodiment.

The piezoelectric element 140 may provide a driving force for ink disposed in the ink passage 131 to be discharged to the outside of the inkjet print head 100 through at least one nozzle 110 .

According to an embodiment, the piezoelectric element 140 may be physically deformed (eg, stretched or expanded) by supplying an electrical signal. Due to the physical deformation of the piezoelectric element 140, a predetermined pressure may be applied to the ink passage 131 adjacent to the piezoelectric element 140, and the ink located in the ink passage 131 responds to the pressure applied from the piezoelectric element 140. may be discharged to the outside of the inkjet print head 100 through at least one nozzle 110.

The inkjet printing device 10 may include a cap 200 for protecting the inkjet print head 100 and preventing ink stored in the inkjet print head 100 from evaporating.

According to an embodiment, the cap 200 may be detachably coupled to one area of the inkjet print head 100 . For example, the cap 200 may be detachably coupled to an area where at least one nozzle 110 of the inkjet print head 100 is disposed, but is not limited thereto.

The cap 200 is coupled to the inkjet print head 100 by moving in a direction toward the inkjet print head 100 while being spaced apart from the inkjet print head 100, or coupled to one area of the inkjet print head 100. In this state, it can be detached from the inkjet print head 100 by moving in a direction away from the inkjet print head 100 .

Referring to FIG. 2 , the cap 200 may be located at the lower end of the inkjet print head 100 (eg, in the -z direction), and is moved in the z direction by the driving unit 210 to move the inkjet print head 100. It may be coupled to or moved in the -z direction to be separated from the inkjet print head 100 .

The driving means 210 may be, for example, a cam that contacts at least one region of the cap 200, and the cap 200 is moved in the z-direction or -z direction by clockwise or counterclockwise rotation of the cam. can move in either direction. For example, when the cam rotates counterclockwise, the cap 200 may move in the z direction and approach the inkjet print head 100 . As another example, when the cam rotates clockwise, the cap 200 may move in the -z direction and be separated from the inkjet print head 100 . However, the type of driving means 210 is not limited to the cam, and may include other types of components capable of moving the cap 200 in the z-direction or -z-direction.

The inkjet printing apparatus 10 may control the cap 200 to be coupled to the inkjet print head 100 only when the inkjet print head 100 is not operating through the above-described driving means 210 .

When coupled to the inkjet print head 100, the cap 200 is disposed to cover an area where at least one nozzle 110 of the inkjet print head 100 is disposed, thereby protecting the at least one nozzle 110 from external impact. can protect

In addition, when coupled to the inkjet print head 100, the cap 200 adheres to the at least one nozzle 110 to prevent the at least one nozzle 110 from being exposed to the outside of the inkjet print head 100. As a result, evaporation of the ink stored in the ink chamber 130 through the at least one nozzle 110 can be minimized.

The cap 200 may be fluidly connected to or communicated with the ink reservoir through an ink recovery passage (not shown), and at least a portion of the ink stored in the inkjet print head 100 is transferred to the cap 200 coupled to the inkjet print head 100. ), it can be recovered to the ink reservoir through the ink recovery passage. However, a detailed description of a process of recovering the ink stored in the inkjet print head 100 will be described later.

Although not shown in the drawings, the inkjet print head 100 according to an embodiment may further include a pressure adjusting means (not shown) for adjusting the internal pressure of the ink chamber 130 .

A phenomenon in which ink stored in the ink chamber 130 leaks through at least one nozzle 110 when the internal pressure (or 'negative pressure') of the ink chamber 130 is less than a predetermined value (hereinafter referred to as 'leak phenomenon'). this can happen In the inkjet print head 100 according to an exemplary embodiment, a leak occurring in the ink chamber 130 may be minimized by controlling the internal pressure or the negative pressure of the ink chamber 130 through a pressure control unit.

In one embodiment, the pressure control unit may include a pressure member (not shown) for pressurizing the ink chamber 130 and/or an elastic member (not shown) connected to the pressure member. The pressure control unit may adjust the degree to which the pressure member (eg, airbag) pressurizes the inner space of the ink chamber 130 by using the elastic force generated from the elastic member, and as a result, the pressure inside the ink chamber 130 is reduced to a predetermined level. can be maintained in the range of

However, components of the pressure adjusting unit are not limited to the above-described embodiments, and the pressure adjusting unit may include other components capable of adjusting the internal pressure or negative pressure of the ink chamber 130 in addition to the above-described components. .

Hereinafter, an ink circulation system for circulating ink between the inkjet print head 100 of the inkjet printing apparatus 10 and an ink reservoir will be described in detail with reference to FIGS. 3 and 4A to 4B.

3 is a block diagram illustrating components of an ink circulation system for circulating ink of an inkjet printing apparatus according to an embodiment, FIG. 4A is a perspective view of the ink circulation system shown in FIG. 3, and FIG. 4B is a view of FIG. It is a front view of the ink circulation system shown.

Referring to FIGS. 3, 4A and 4B, an ink circulation system 1000 according to an embodiment includes an inkjet print head 100 (eg, the inkjet print head 100 of FIGS. 1 and 2), a cap 200 ) (eg, the cap 200 of FIGS. 1 and 2), an ink reservoir 300, an ink supply passage S, an ink recovery passage R, a first pump 310 and a second pump ( 320) may be included.

At least one of the components of the ink circulation system 1000 according to an embodiment may be the same as or similar to at least one of the components of the inkjet printing apparatus 10 of FIGS. 1 and/or 2. Hereinafter, Redundant descriptions are omitted.

Ink may be stored inside the ink reservoir 300, and the ink reservoir 300 may be connected or communicated with the ink chamber 130 (eg, the ink chamber 130 of FIG. 2) of the inkjet print head 100. can

According to an embodiment, the ink reservoir 300 may be fluidly connected or communicated with the ink chamber 130 through an ink supply passage S, and the ink stored in the ink reservoir 300 may pass through the ink supply passage S. Accordingly, the ink may flow from the ink reservoir 300 toward the ink chamber 130 .

According to an embodiment, the first pump 310 may be disposed in the ink supply passage S, and the ink stored in the ink reservoir 300 is supplied to at least one of the inkjet print head 100 by the first pump 310. It may flow in a direction toward one cartridge 120 .

The first pump 310 may provide power for flowing the ink stored in the ink reservoir 300 in a direction toward the at least one cartridge 120, and the ink stored in the ink reservoir 300 may be supplied by the first pump ( It may flow in a direction toward at least one cartridge 120 by the power provided from 310 .

The ink that has reached the at least one cartridge 120 from the ink reservoir 300 flows into the ink chamber through an ink inlet (not shown) formed in the at least one cartridge 120, and then enters the ink chamber 130. can be stored

That is, the ink circulation system 1000 may supply the ink stored in the ink reservoir 300 to the ink chamber of the inkjet print head 100 through the ink supply passage S and the first pump 310 . The inkjet print head 100 moves from the ink reservoir 300 through at least one nozzle (eg, at least one nozzle 110 in FIG. 2 ) and/or a piezoelectric element (eg, piezoelectric element 140 in FIG. 2 ). An image may be printed on the print medium by discharging the ink supplied to the ink chamber 130 onto the print medium (eg, the print medium P of FIG. 1 ).

When the inkjet print head 100 is not used, the cap 200 may be coupled to at least one region of the inkjet print head 100 . When coupled to the inkjet print head 100, the cap 200 is disposed to cover an area where at least one nozzle of the inkjet print head 100 is disposed to protect the at least one nozzle of the inkjet print head 100 and , it is possible to prevent the ink stored in the ink chamber 130 from evaporating.

In the ink circulation system 1000 according to an embodiment, when the cap 200 is coupled to the inkjet print head 100, pressure is applied to the ink chamber 130 of the inkjet print head 100 to cool the ink inside the ink chamber 130. A purging operation may be performed to discharge existing bubbles to the outside of the inkjet print head 100 .

In the process of ink moving from the ink reservoir 300 into the ink chamber 130 , air bubbles may be generated in the ink and may exist in the ink chamber 130 . If bubbles exist in the ink chamber 130 of the inkjet print head 100, some areas of the nozzles of the inkjet print head 100 may be blocked by the bubbles, and ink may not be stably ejected. As a result, inkjet printing may not be performed. A defect may occur in an image printed by the head 100 .

The ink circulation system 1000 according to an embodiment performs a purging operation when the cap 200 is coupled to the inkjet print head 100 to remove air bubbles contained in the ink chamber 130 from the inkjet print head 100. By discharging to the outside, it is possible to minimize the occurrence of defective images in the printing process.

The ink circulation system 1000 may, for example, operate the first pump 310 in a state where the inkjet print head 100 and the cap 200 are coupled to provide pressure in the ink chamber 130 of the inkjet print head 100. As a result, air bubbles included in the ink chamber 130 together with a part of the ink stored in the ink chamber 130 may be discharged to the outside of the inkjet print head 100 .

According to an embodiment, when the inkjet print head 100 and the cap 200 are coupled, the inner space of the cap 200 formed between the inkjet print head 100 and the cap 200 is an ink recovery passage (R). ) It may be connected or communicated with the ink reservoir 300 through. At least a portion of the ink stored in the ink chamber 130 of the inkjet print head 100 may flow from the ink chamber 130 toward the ink reservoir 300 along the ink recovery passage R.

According to an embodiment, the second pump 320 may be disposed in the ink recovery passage R, and the ink stored in the ink chamber 130 is transferred to the inkjet print head 100 and the cap by the second pump 320. After being discharged into the space between the spaces 200 or the inner space of the cap 200, the ink may flow along the ink recovery passage R toward the ink reservoir 300.

The second pump 320 may provide power to flow the ink stored in the ink chamber 130 toward the ink reservoir 300, and the ink stored in the ink chamber 130 may be supplied by the second pump 320. After being discharged from the ink chamber 130 to the inner space of the cap 200 by the power provided therefrom, the ink may flow in a direction toward the ink reservoir 300 along the ink recovery passage R.

That is, the ink circulation system 1000 returns ink supplied from the ink reservoir 300 to the ink chamber 130 of the inkjet print head 100 through the ink recovery passage R and the second pump 320 back into the ink reservoir. It can be retrieved at (300). The ink recovered in the ink reservoir 300 is supplied to the ink chamber 130 again through the ink supply passage S and the first pump 310, so that it can be reused.

The ink circulation system 1000 according to an embodiment supplies ink from the ink reservoir 300 to the ink chamber 130 of the inkjet print head 100 and/or removes the ink stored in the ink chamber 130. Ink may be periodically circulated within the inkjet printing apparatus through an operation of recovering the ink back to the ink reservoir 300 .

Due to the nature of the ink, when there is no ink flow for a certain period of time or more, ink particles may be precipitated in the ink chamber 130 or aggregation may occur between the ink particles. When at least one nozzle of the inkjet print head 100 is clogged by sediments and/or aggregates (for example, TiO ₂ ) of generated ink particles, the inkjet print head 100 may eject a desired amount of ink to a desired location. As a result, print quality may deteriorate.

On the other hand, the ink circulation system 1000 according to an embodiment supplies ink from the ink reservoir 300 to the ink chamber 130 or recovers the ink stored in the ink chamber 130 back to the ink reservoir 300. By repeating the process according to a designated cycle, it is possible to prevent precipitation or aggregation of ink particles, and thus, it is possible to prevent deterioration in print quality due to clogging of nozzles.

Conventionally, an ink circulation system in which an ink recovery passage is formed between the inkjet printhead 100 and the ink reservoir 300 in order to prevent clogging of the nozzles of the inkjet printhead 100 due to precipitation and/or aggregation of ink particles. this has been proposed.

However, in the case of an ink circulation system in which an ink recovery path is formed between the inkjet print head 100 and the ink reservoir 300, the ink located upstream of the ink chamber 130 of the inkjet print head 100 can be effectively circulated. However, since the ink located downstream of the ink chamber 130 cannot be circulated, it is difficult to prevent sedimentation and/or aggregation of ink particles generated downstream of the ink chamber 130.

In the present disclosure, 'downstream of the ink chamber' refers to an area adjacent to a nozzle (eg, at least one nozzle 110 of FIG. 2 ) in the inner space of the ink chamber 130, and 'upstream of the ink chamber' refers to an area adjacent to the ink chamber 130 . It may mean an area located in the opposite direction to the downstream of the inner space of 130, and the corresponding expression may be used in the same meaning below.

On the other hand, the ink circulation system 1000 according to an embodiment, unlike the existing ink circulation system, has an ink recovery passage R between the cap 200 coupled to the lower end of the inkjet print head 100 and the ink reservoir 300. By forming the ink chamber 130, not only the ink located upstream of the ink chamber 130, but also the ink located downstream of the ink chamber 130 can be effectively circulated.

In addition, in the ink circulation system 1000 according to an embodiment, in the process of discharging the ink stored in the ink chamber 130 to the outside of the inkjet print head 100 (or 'inner space of the cap 200'), at least one Precipitates and/or agglomerates of ink particles formed at locations adjacent to the nozzles may also be discharged to the outside of the inkjet print head 100 .

That is, the ink circulation system 1000 according to an embodiment has at least one nozzle of the inkjet print head 100 and Precipitates and/or agglomerates of ink particles formed in adjacent positions can be effectively removed, and as a result, nozzle clogging can be more effectively prevented.

In addition, in the process of recovering at least a portion of the ink stored in the ink chamber 130 of the inkjet print head 100 to the ink reservoir 300, the ink circulation system 1000 according to an embodiment returns to the ink chamber 130. At least a portion of the included bubbles may also be discharged to the outside of the inkjet print head 100, and as a result, image defects caused by the bubbles may be minimized.

In other words, the ink circulation system 1000 can remove air bubbles included in the ink chamber 130 through not only the above-described purge operation but also the ink recovery operation, and through the above-described operations, ink can be stably ejected. there is.

The ink circulation system 1000 according to an embodiment may further include a remaining amount detection sensor 400 , a processor 510 and a memory 520 .

The remaining amount detection sensor 400 may serve to detect the remaining amount of ink stored in the ink chamber 130, and data on the remaining amount of ink stored in the ink chamber 130 detected by the remaining amount detection sensor 400 is may be transmitted to the processor 510 .

According to an embodiment, the remaining amount detection sensor 400 detects the position of the indicator bar 410 and the indicator bar 410 that can be moved according to the remaining amount of ink stored in the ink chamber 130, and detects the detected indicator bar A sensor 420 for determining the remaining amount of the ink chamber 130 based on the position of the ink chamber 410 may be included.

For example, the ink chamber 130 can be expanded or contracted according to the change in the amount of ink stored therein, and the indicator bar 410 is rotatably coupled to one area of the ink chamber 130 so that the ink chamber 130 ) may be rotated in response to expansion and/or contraction caused by a change in the remaining amount of ink.

As another example, the sensor 420 detects the position of the indicator bar 410 that rotates according to the change in the remaining amount of ink, and based on the detected position of the indicator bar 410, the remaining amount of ink stored in the ink chamber 130 can be judged or estimated. The sensor 420 may include, for example, an optical sensor for detecting the position of the indicator bar 410, but the type of sensor 420 is not limited thereto.

The processor 510 is electrically connected to the first pump 310, the second pump 320, the remaining amount detection sensor 400, and/or the memory 520 to control the overall operation of the ink circulation system 1000. can

According to an embodiment, the processor 510 may control the operation of the first pump 310 based on data on the remaining amount of ink stored in the ink chamber 130 received from the remaining amount detection sensor 400. can

For example, when the remaining amount of ink stored in the ink chamber 130 is less than a specified value, the processor 510 determines that the ink chamber 130 is short of ink, and operates the first pump 310 to fill the ink reservoir ( Ink stored in 300 may be supplied to the ink chamber 130 .

According to another embodiment, the processor 510 may recover the ink stored in the ink chamber 130 to the ink reservoir 300 by controlling the operation of the second pump 320 according to a specified time interval.

For example, the processor 510 may operate the second pump 320 at designated time intervals to cause the ink stored in the ink chamber 130 to flow toward the ink reservoir 300, and the processor 510 may As ink is periodically moved by the above-described operation, precipitation and/or aggregation of ink particles may be minimized. In the present disclosure, a 'designated time interval' may mean a preset time value, and the designated time interval may be varied by a user's manipulation.

Data necessary for the operation of the ink circulation system 1000 may be stored in the memory 520 . For example, the memory 520 stores data for a 'designated value' that is the basis for the operation of the first pump 310 and/or a 'designated time price' that is the basis for the operation of the second pump 320. It may be, but is not limited thereto.

According to one embodiment, the processor 510 and/or the memory 520 may be disposed on the printed circuit board 500, but the location of the processor 510 and/or the memory 520 may vary according to the above-described embodiment. It is not limited.

According to an embodiment, the ink circulation system 1000 may further include a first filter 610 disposed in the ink recovery passage R.

The first filter 610 may be located in the ink recovery passage R, and may remove or filter foreign substances included in the ink passing through the first filter 610 .

In the process of supplying or collecting ink and/or in the process of using the inkjet print head 100, a situation in which foreign substances are introduced into the ink may occur, and the foreign substances introduced into the ink may be transported together with the ink. For example, foreign substances introduced into the ink chamber 130 may flow from the ink chamber 130 into the ink reservoir 300 together with the ink during the ink recovery process.

When foreign substances are introduced into the ink reservoir 300, printing quality may deteriorate due to the foreign substances as the ink containing the foreign substances is supplied during the ink supply process. However, the ink circulation system 1000 according to an embodiment can block foreign substances from entering the ink reservoir 300 through the first filter 610, and as a result, it is possible to prevent deterioration in print quality caused by foreign substances. .

According to another embodiment, the ink circulation system 1000 may further include a second filter 620 disposed in the ink supply passage S.

Although foreign substances included in the ink passing through the ink recovery passage R are primarily filtered through the first filter 610, some foreign substances may flow into the ink reservoir 300 without being filtered.

In one embodiment, the ink circulation system 1000 secondarily filters foreign substances included in the ink passing through the ink supply passage S through the second filter 620, so that foreign substances introduced into the ink reservoir 300 are removed. Flow into the ink chamber 130 of the inkjet print head 100 may be prevented.

5 is a flowchart for explaining an ink circulation operation of an ink circulation system according to an embodiment, and FIG. 6 is a diagram illustrating an ink supply operation of the ink circulation system according to an embodiment.

Also, FIG. 7A is a diagram for explaining an ink recovery operation of the ink circulation system according to an embodiment, and FIG. 7B is an enlarged cross-sectional view of area A of the ink circulation system shown in FIG. 7A. At this time, area A of FIG. 7B is an enlarged cross-sectional view of the inkjet print head 100 of the ink circulation system 1000 and the cap 200 on the inkjet print head 100 .

Hereinafter, operations for circulating ink of the ink circulation system 1000 shown in FIG. 5 will be described with reference to components of the ink circulation system 1000 shown in FIGS. 6, 7, and 7B.

In operation 501, the ink circulation system 1000 according to an embodiment may supply ink stored in the ink reservoir 300 to the inkjet print head 100.

The processor (for example, the processor 510 of FIG. 3 ) of the ink circulation system 1000 operates the first pump 310 as shown in FIG. ) in a direction toward the inkjet print head 100. Ink reaching the inkjet print head 100 may flow into the ink chamber 130 of the inkjet print head 100 and then be stored in the ink chamber 130 .

According to an embodiment, the processor of the ink circulation system 1000 operates the first pump 310 based on the remaining amount of ink stored in the ink chamber 130 detected by the remaining amount detection sensor 400 so that the ink reservoir 300 ) can be controlled to supply the ink stored in the ink chamber 130 . For example, when the remaining amount of ink stored in the ink chamber 130 is equal to or less than a specified value, the processor determines that the ink stored in the ink chamber 130 is insufficient and operates the first pump 310 to return the ink to the ink chamber 130. Ink may be supplied, but is not limited thereto.

In operation 502, the ink circulation system 1000 according to an embodiment may couple the cap 200 to at least one region of the inkjet printhead 100 when the inkjet printhead 100 is not in use.

In one embodiment, the cap 200 may be approached or spaced apart from the inkjet print head 100 by a driving means (eg, the driving means 210 of FIG. 2 ), and the inkjet printing When the head 100 is not in use, it is coupled to one area of the inkjet print head 100 to protect the inkjet print head 100 and prevent ink stored in the ink chamber 130 from evaporating.

For example, when coupled with the inkjet print head 100, the cap 200 is disposed to surround a region where at least one nozzle 110 of the inkjet print head 100 is disposed, and the at least one nozzle 110 may be protected from external impact or inflow of foreign substances, but the coupling structure of the inkjet print head 100 and the cap 200 is not limited thereto.

In operation 503, the ink circulation system 1000 according to an embodiment returns ink supplied from the ink reservoir 300 to the ink chamber 130 in a state where the cap 200 is coupled to the inkjet print head 100. It can be recovered to the storage tank 300.

For example, the processor of the ink circulation system 1000 operates the second pump 320 while the cap 200 is coupled to the inkjet print head 100 so that the ink stored in the ink chamber 130 is transferred to the ink recovery passage. It may flow in a direction toward the ink reservoir 300 along (R).

7A and 7B , when the processor of the ink circulation system 1000 operates the second pump 320 while the cap 200 is coupled to the inkjet print head 100, the inkjet print head 100 A strong pressure may be applied to the inside of the ink chamber 130 of the ink chamber 130, and at least a portion of the ink stored in the ink chamber 130 may be discharged to the outside of the inkjet print head 100 by the pressure applied to the ink chamber 130. can

In one embodiment, at least a portion of the ink stored in the ink chamber 130 is transferred between the inkjet print head 100 and the cap 200 through the at least one nozzle 110 by the pressure applied to the ink chamber 130 . The ink may be discharged into the space (or 'the inner space of the cap 200') (v), and the discharged ink may flow along the air recovery passage R and be recovered into the ink reservoir 300.

The processor of the ink circulation system 1000 may operate the second pump 320 at designated time intervals to recover the ink stored in the ink chamber 130 to the ink reservoir 300, and as a result, the ink periodically moves. Therefore, it is possible to minimize the precipitation of ink particles stored in the ink chamber 130 or the occurrence of aggregation between ink particles.

The ink circulation system 1000 may again perform operation 501 to resupply the ink recovered from the ink chamber 130 to the ink reservoir 300 to the ink chamber 130 of the inkjet print head 100, and the inkjet printing device (eg, the inkjet printing apparatus 10 of FIGS. 1 and 2 ) may print an image on a print medium using ink resupplied into the ink chamber 130 . As described above, the ink circulation system 1000 allows the recovered ink to be reused, thereby increasing the replacement cycle of the inkjet print head 100 (for example, the cartridge 120 of FIGS. 1 and 2 ).

Also, when the inkjet print head 100 is not used, the ink circulation system 1000 may recover the ink resupplied through operations 502 to 503 into the ink reservoir 300 again.

That is, the ink circulation system 1000 according to the above-described embodiments may periodically circulate ink by repeatedly performing operations 501 to 503 described above, and as a result, inkjet by precipitation and/or aggregation of ink particles. Printing defects and damage of the print head 100 can be minimized.

The method for circulating ink of the ink circulation system according to the above-described embodiments may be implemented in the form of a recording medium including instructions executable by a computer, such as program modules executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. Also, computer readable media may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, other data in a modulated data signal such as program modules, or other transport mechanism, and includes any information delivery media.

Those skilled in the art related to the present embodiment will be able to understand that it may be implemented in a modified form within a range that does not deviate from the essential characteristics of the above description. Therefore, the disclosed methods are to be considered in an illustrative rather than a limiting sense. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the equivalent range should be construed as being included in the present invention.

10: inkjet printing device 100: inkjet print head
110: nozzle 120: cartridge
130: ink chamber 131: ink flow path
140: piezoelectric element 200: cap
300: ink reservoir 310: first pump
320: second pump 400: remaining amount detection sensor
500: printed circuit board 510: processor
520: memory 610: first filter
620: second filter 1000: ink circulation system
S: ink supply flow path R: ink return flow path

Claims (15)

an ink reservoir in which ink is stored;
an inkjet print head including an ink chamber in which the ink transported from the ink reservoir is stored, at least one nozzle for discharging ink to a printing medium, and a piezoelectric element for discharging the ink stored in the ink chamber to the outside;
an ink supply passage connecting the ink reservoir and the ink chamber;
a first pump positioned in the ink supply passage and providing power for the ink stored in the ink reservoir to flow toward the inkjet print head;
a cap coupled to at least one region of the inkjet print head and protecting the at least one nozzle when coupled to the inkjet print head;
an ink recovery passage connecting the inner space of the cap and the ink reservoir;
a second pump positioned in the ink recovery passage and providing power for the ink stored in the inkjet print head to flow toward the ink reservoir;
a remaining amount detection sensor for detecting a remaining amount of ink stored in the ink chamber; and
A processor electrically connected to the remaining amount detection sensor, the first pump, and the second pump; includes,
The processor controls the operation of the second pump according to a designated time interval to discharge the ink stored in the ink chamber into the inner space of the cap, and then flows the discharged ink into the ink reservoir;
ink may be circulated between the ink chamber, the inner space of the cap, and the ink reservoir through the ink supply passage and the ink recovery passage;
The remaining amount detection sensor,
an indicator bar rotatably coupled to one area of the ink chamber and rotationally moving in response to expansion or contraction of the ink chamber according to a change in the amount of ink stored in the ink chamber; and
and a sensor for detecting the position of the indicator bar and determining the remaining amount of ink stored in the ink chamber based on the detected position of the indicator bar. According to claim 1,
Wherein the processor is configured to control the operation of the first pump based on the remaining amount of ink detected by the remaining amount detection sensor. According to claim 1,
wherein the specified time interval is variable. According to claim 1,
The ink circulation system further comprising: a pressure adjusting means for adjusting the internal pressure of the ink chamber. According to claim 1,
The ink circulation system further includes a first filter disposed in the ink recovery passage and configured to remove foreign substances of the ink flowing from the inner space of the cap toward the ink reservoir along the ink recovery passage. According to claim 5,
The ink circulation system further includes a second filter disposed in the ink supply passage and configured to remove foreign substances from the ink flowing from the ink reservoir toward the inkjet print head along the ink supply passage. delete delete delete delete delete delete delete delete delete

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