KR102320160B1 - Precise tension control method and system using infeeder and outfeeder unit for Roll-to-Roll printing system - Google Patents

Abstract

A technology disclosed herein is a precision tension control method of a roll-to-roll printing system using infeeder and outfeeder units, the method comprising: unwinding, by the infeeder, a web so that constant tension is applied to the web; measuring a tension value of the web using a first load cell; rotating the outfeeder at the same speed as a rotational speed of the infeeder and applying pressure to the web passing through the outfeeder to break the tension; discreetly controlling the outfeeder using the measured web tension value; and rewinding the web using a rewinder, wherein the rewinding of the web may further include controlling the rewinder based on a tension value measured from a third load cell.

Description

Precise tension control method and system using infeeder and outfeeder unit for Roll-to-Roll printing system

The technology disclosed herein relates to a precision tension control method and system of a roll-to-roll printing system using an infeeder and an outfeeder unit, and more particularly, the tension applied to the web of the roll-to-roll printing apparatus. The present invention relates to a control method and system capable of more precisely controlling and improving the printing accuracy of a pattern.

In the field of roll-to-roll printing technology, when a pattern is printed overlaid on a film, there are various obstacles to precision printing, such as inaccuracy of overlay and deformation of the film. Specifically, when an external factor such as heat is applied to a film called 'web', deformation such as lengthening or bending of the web may occur. When printing of a pattern is performed overlappingly, since printing is performed a plurality of times at the same position, it becomes difficult to obtain a result in which an accurate pattern is formed even if there is only slight deformation on the web.

Therefore, in the field of roll-to-roll technology for printing overlapping patterns, it is essential to precisely control the tension caused by using a roll. In particular, since severe deformation of the web is caused when a large tension is applied while the web moves along the roll in the moving direction, it is essential in the art to implement a printing system with low-tension.

In the case of the prior art, methods such as speed control, dancer control, or torque control have been used to control the tension, but it is difficult to implement a precise storage force printing system by simply applying them. The need to implement a roll-to-roll printing system capable of extremely precise tension control by feeding back the necessary changes to the web by measuring the

US 10-1629728 B1

SUMMARY OF THE INVENTION The present invention aims to solve the above problems and other problems related thereto.

An exemplary object of the present specification is to provide a high-accuracy precision tension control method and system using an infeeder and an outfeeder unit in a roll-to-roll printing system.

The technical task to be achieved by the precision tension control method and system of a roll-to-roll printing system using an infeeder and an outfeeder unit according to the technical idea of the technology disclosed in the present specification is to solve the above-mentioned problems It is not limited to the task for, and another task not mentioned will be clearly understood by those skilled in the art from the following description.

The precision tension control method of a roll-to-roll printing system using an infeeder and an outfeeder unit according to an embodiment of the technology disclosed herein is such that the infeeder applies the same tension to the web. unraveling; measuring the tension value of the web using a first load cell; rotating the outfeeder at the same speed as the rotational speed of the infeeder, and breaking the tension by applying pressure to the web passing through the outfeeder; discretely controlling the outer feeder using the measured web tension value; and rewinding the web using a rewinder, wherein the rewinding of the web may further include controlling the rewinder based on a tension value measured from a third load cell.

In addition, the method may further comprise the step of meandering the web.

In addition, the method may further include monitoring the tension of the web using a second load cell.

The discretely controlling the outer feeder may include temporarily changing the rotation speed of the outer feeder according to a tension value measured from the first load cell.

In the controlling of the rewinder, the power of the motor is reduced by using a clutch mounted on a motor that provides power to the rewinder, and the clutch is operated by the clutch based on the tension value measured from the third load cell. It may be one that is controlled to adjust the output.

A precision tension control system for roll-to-roll printing according to an embodiment of the technology disclosed herein, the system comprising: an unwinder for unwinding a web; an infeeder configured to unwind the web at a constant speed; an outfeeder configured to control the tension applied to the web; a first load cell formed between the infeeder and the outfeeder along the traveling direction of the web; and a tension control unit for performing precise tension control of the system, wherein the first load cell measures the tension of the web and provides it to the tension control unit, and the tension is precisely measured using the infeeder and the outfeeder It may be characterized in that it is controlled.

The infeeder is configured to simultaneously rewind and unwind the web unwound from the unwinder to maintain a constant radius of the web wound around the infeed, and the infeeder may perform an operation of rotating at a constant speed.

The outer feeder may be operable to perform speed-based tension control based on a tension value measured using the first load cell, and independently control the tension applied to both ends based on the outer feeder.

The outer feeder may further perform discrete control through feedback provided from the first load cell.

The operation of independently controlling the tension may be applying pressure to the web in a vertical direction.

The discretely controlling the outer feeder may include temporarily changing the rotation speed of the outer feeder according to a tension value measured from the first load cell.

A roll-to-roll printing apparatus using precise tension control and a system using the same according to an embodiment of the technology disclosed in the present specification have the following effects.

The present invention can maintain the minimum tension required by the printing system by measuring the tension applied to the web in real time and feeding it back to the control system.

In addition, it is possible to provide a more precise printing control system by using a speed and torque control method that replaces the dancer control method, which has poor control stability and is difficult to control the storage force.

In addition, it is configured to independently control each part of the system, so that the tension of each operating part can be precisely maintained without the influence of external factors, and it has the effect of variously expanding the configuration of the system.

However, the effects according to an embodiment of the technology disclosed in the present specification are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

In order to more fully understand the drawings cited herein, a brief description of each drawing is provided.
1 shows a roll-to-roll printing apparatus using precise control according to an embodiment of the technology disclosed herein.
2 shows a detailed structure for tension control of the roll-to-roll printing apparatus disclosed herein.
3 shows a detailed structure of the printing unit disclosed in the present specification.
4 shows a control flow diagram of the roll-to-roll printing system disclosed herein.
5 and 6 show the detailed structure of the rewinder unit disclosed herein.

Since the technology disclosed in this specification can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings, and this will be described in detail through the detailed description. However, this is not intended to limit the technology disclosed herein to specific embodiments, and it is understood that the technology disclosed herein includes all modifications, equivalents and substitutions included in the spirit and scope of the technology disclosed herein. should be

In describing the technology disclosed in the present specification, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the technology disclosed herein, the detailed description thereof will be omitted. In addition, numbers (eg, first, second, etc.) used in the description process of the present specification are only identifiers for distinguishing one component from other components.

In addition, in this specification, when a component is referred to as "connected" or "coupled" to another component, the component may be directly connected or coupled to the other component, but the opposite is particularly true. Unless there is a description, it should be understood that other elements may be interposed or connected or combined therebetween.

In addition, in the present specification, two or more components may be combined into one component, or one component may be divided into two or more for each more subdivided function. In addition, each of the components to be described below may additionally perform some or all of the functions of other components in addition to the main functions that each component is responsible for, and some of the main functions of each of the components are different It goes without saying that it may be performed exclusively by the component.

Expressions such as "first", "second", "first", or "second" used in various embodiments may modify various elements regardless of order and/or importance, do not limit For example, without departing from the scope of the technology disclosed herein, a first component may be referred to as a second component, and similarly, a second component may also be renamed to a first component.

Hereinafter, a roll-to-roll printing apparatus and system using precise tension control according to a preferred embodiment will be described in detail.

1 illustrates a cross-section of a roll-to-roll printing apparatus 10 using precise tension control according to an embodiment of the present invention.

In FIG. 1 , it can be seen from the left side that a film called a 'web' 100 wound around the unwinder 110 for printing a pattern is unwound. The web 100 unwound from the unwinder 110 passes through the infeeder 120 to go to the printing unit 130 while maintaining a uniform tension. The infeeder 120 operates so that one layer of the web 100 can be wound on the roll in order to constantly maintain the tension varying according to the radius of the web wound on the roll. Accordingly, the tension applied to the web 100 passing through the infeeder 120 may be maintained constant regardless of the thickness or radius of the web 100 wound around the unwinder 110 .

Thereafter, the web 100 proceeds to the printing unit 130 , and a printing operation in which a predetermined pattern is printed is performed by the printing unit 130 . After the printing operation, it passes through a heating furnace for curing the pattern, and external factors such as heat, normal drag, and frictional force generated from these sequential operations cause deformation in the web 100 . Therefore, in order to maintain the tension applied to the web 100 at low-tension, the first load cell 210 located between the infeeder 120 and the outfeeder 140 is located in the portion of the web 100 . ) to monitor the tension applied to it.

The outfeeder 140 may perform speed control in consideration of the rotational speed of the infeeder 120 and simultaneously perform discrete control based on the tension measured from the first load cell 210 . That is, the feeder 140 operates to more precisely control the tension applied to the web 100 by utilizing the feedback through the first load cell 210 , and detailed operations based thereon will be described later.

The illustrated second load cell 220 may be used for monitoring the tension of the corresponding roll-to-roll printing system, and the third load cell 230 may be configured to monitor the tension of the rewinder 150 . The rewinder 150 may perform the operation of rewinding the web 100 after the pattern has been printed, and at the same time perform more precise tension control through feedback based on the data received from the third load cell 230 .

2 schematically shows a detailed structure for tension control of a roll-to-roll printing apparatus according to an embodiment of the present invention.

Referring to FIG. 2 , the infeeder 120 and the outfeeder 140 operate to maintain the tension of the web 100 by maintaining a constant speed with each other. This speed-based tension control method is superior to the dancer-based control method in terms of stability of the control operation or the simplification of the structure, and also enables storage force control. In the case of the dancer-based control method, unlike the speed or torque-based tension control method, the use of a dancer increases friction and normal force, which may be disadvantageous in terms of utilization and accuracy in the control system.

According to the traveling direction of the web 100 , a predetermined pattern is printed on the web 100 that has reached the printing unit 130 . After the printing operation is performed, there may be a heating furnace for curing it, and deformation may occur in the web 100 due to external factors such as heat generated in the printing operation itself or heat generated by the heating furnace. Therefore, maintaining a low tension applied to the web 100 passing through a plurality of rolls, and also maintaining a low deviation in a plurality of sections is a very important task for the implementation of a high-precision roll-to-roll printing system. As a means of solving this problem, the present invention discloses an apparatus and system for performing precise tension control by performing feedback through the monitoring of tension through the first to third load cells (210, 220, 230).

For the implementation of the apparatus and system described above, the first load cell 210 may be configured to measure the tension applied to the web 100 passing through the printing unit 130 . The feeder 140 may further perform discrete control in addition to the speed-based tension control described above. In this case, the feeder 140 performs discrete control through a control signal fed back based on the measured tension data of the web 100 received from the first load cell 210 . That is, when the outer feeder 140 rapidly adjusts the rotation speed to control the tension, the tension is not kept constant but gradually increases, so the outer feeder 140 temporarily increases the rotation speed and then decreases again. The tension can be kept constant through discrete control.

In addition, the outer feeder 140 may be configured to independently control the tension in both directions around the outer feeder 140 by applying pressure in the vertical direction to the passing web 100 . When a pressure is applied to the web 100, the tension of the web 100 at both ends of the outfeeder 140 is cut off from each other, and therefore more precise tension control is possible independently based on this structure, and additionally, Since the respective tensions are not related to each other, it further includes the advantage of securing scalability to introduce additional control elements.

Along the traveling direction of the web 100, the second load cell 220 may be included to perform tension monitoring of the present system, and may further include units for meandering control.

Subsequently, the third load cell 230 is configured to measure the tension applied to the web 100 passing through the rewinder 150 . The rewinder 150 performs torque-based tension control through a control signal fed back based on the tension data measured from the third load cell 230 . The tension control operation of the rewinder 150 will be described in detail with reference to FIGS. 5 and 6 to be described later.

3 shows a specific structure of the printing unit 130 according to an embodiment of the present invention.

3 shows a mask 131 for printing a predetermined pattern on the web 100, and the mask 131 may adjust a tilting angle or perform centering adjustment according to the position of the illustrated alignment mark 132. have. Specifically, a sensor such as the CCD camera 133 confirms the position of the alignment mark 132 on the web 100, and moves the mask 131 at the current position in a manner to adjust the tilting angle or adjust the centering. After that, a printing operation may be performed. Specific features performed by the printing unit 130 are described in more detail in (Patent Document 1) Patent Publication KR 10-1629728 B1, the entirety of which is referenced herein.

4 is a flowchart showing a control flow of a roll-to-roll printing system according to an embodiment of the present invention.

Referring to the upper part of FIG. 4 , a reference speed is given, which is input to the controller to perform a comparison operation with the speed measured from a sensor measuring the speed of the infeed. The feeder is continuously controlled close to the reference speed based on the fed back control signal.

Thereafter, the speed value for synchronizing with the speed of the infeed is transmitted to the outfeeder. The outfeeder rotates at the same speed as the infeeder, and is fed back based on the tension measured from the tension sensor 1 and controlled to match the reference tension.

Referring to the lower part, when the tension is controlled by the outfeeder, unlike the input of the speed value of the infeeder, the tension control of the rewinder is independently controlled by the outfeeder from the infeeder, so it is necessary to input the speed of the infeeder. there is no Accordingly, the rewinder performs torque-based tension control based on the tension measured from the tension sensor 2, and is similarly controlled to match the reference tension through feedback based on the measured tension.

5 and 6 show a detailed structure of a rewinder unit according to an embodiment of the present invention.

The illustrated rewinder 150 may include a motor 151 providing power and a clutch 152 . The clutch 152 serves to reduce and transmit the power of the motor 151 that continuously operates without interruption. The rewinder 150 may further include one or more wedges 153 for being fixed to the paper tube 154 on which the web 100 is wound. In FIG. 6 , the wedges 153 are briefly illustrated as four, but generally consist of six or more.

Specifically, as the web 100 is wound on the rewinder 150, the radius of the roll on which the web 100 is wound gradually increases. Therefore, when the rotation angular velocity is constant, the speed at which the web 100 is wound on the roll also gradually increases. will do In order to obtain a roll of uniform quality, since it is necessary to make the speed at which the web 100 is wound on the roll constant, the angular speed of rotation should be reduced as the radius of the roll increases. Since the motor 151 generally controls the rotational angular speed, the power of the motor 151 is reduced using the clutch 152, and the applied tension is measured from the third load cell 230 and a control signal based thereon. By feeding back the to the clutch 152, it is possible to obtain a roll on which the web 100 is wound at a constant speed.

As described above, when the power of the clutch 152 is fed back based on the data measured by the third load cell 230 , the speed at which the web 100 is wound is the previous roll, that is, the speed of the outer feeder 140 . is followed as it is, and the tension of the web 100 wound around the rewinder 150 can be constantly maintained through precise tension control.

The above-described apparatus and its control may be implemented by a hardware component, a software component, and/or a combination of the hardware component and the software component. For example, the devices and components described in the embodiments may include a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), and a programmable logic unit (PLU). It may be implemented using one or more general purpose or special purpose computers, such as a logic unit, microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For convenience of understanding, although one processing device is sometimes described as being used, one of ordinary skill in the art will recognize that the processing device may include a plurality of processing elements and/or multiple types of processing elements. it can be seen that there is For example, the processing device may include a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as parallel processors.

Software may include a computer program, code, instructions, or a combination of one or more thereof, which configures the processing device to operate as desired, or independently or in combination instructs the processing device to operate as desired. can do. The software and/or data may be permanently or temporarily on any machine, component, physical device, virtual device, computer storage medium or device of any type to be interpreted by or to provide instructions or data to the processing device. can be materialized. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored in one or more computer-readable recording media.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and available to those skilled in the art of computer software. Examples of the computer readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

As described above, although the embodiments have been described with reference to the limited embodiments and drawings, various modifications and variations are possible by those skilled in the art from the above description. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

10: roll-to-roll printing device
100: web
110: unwinder
120: Infeeder
130: printing unit
131: mask
132: alignment mark
133: CCD camera
140: outfeeder
150: rewinder
151: motor
152: clutch
153: wedge
154: branch
210: first load cell
220: second load cell
230: third load cell

Claims (11)

As a precision tension control method of a roll-to-roll printing system using an infeeder and an outfeeder unit,
unwinding the web so that the infeeder applies the same tension to the web;
measuring the tension value of the web using a first load cell;
rotating the outfeeder at the same speed as the rotational speed of the infeeder, and breaking the tension by applying pressure to the web passing through the outfeeder;
discretely controlling the outer feeder using the measured web tension value; and
Rewinding the web using a rewinder;
Rewinding the web further comprises controlling the rewinder based on a tension value measured from a third load cell.
A precision tension control method for a roll-to-roll printing system. The method of claim 1,
Further comprising the step of meandering control of the web,
A precision tension control method for a roll-to-roll printing system. The method of claim 1,
Further comprising the step of monitoring the tension of the web using a second load cell,
A precision tension control method for a roll-to-roll printing system. The method of claim 1,
The step of discretely controlling the feeder,
Temporarily changing the rotation speed of the outer feeder according to the tension value measured from the first load cell,
A precision tension control method for a roll-to-roll printing system. The method of claim 1,
The step of controlling the rewinder comprises:
reducing the power of the motor by using a clutch mounted on the motor that provides power to the rewinder;
wherein the clutch is controlled to adjust the output of the clutch based on a tension value measured from the third load cell.
A precision tension control method for a roll-to-roll printing system. As a precision tension control system for roll-to-roll printing,
The system is:
Unwinder to unwind the web;
an infeeder configured to unwind the web at a constant speed;
an outfeeder configured to control the tension applied to the web;
a first load cell formed between the infeeder and the outfeeder along the traveling direction of the web; and
A tension control unit for performing precise tension control of the system,
The first load cell measures the tension of the web and provides it to the tension control unit,
The tension is precisely controlled using the infeeder and the outfeeder,
The outer feeder performs speed-based tension control based on the tension value measured using the first load cell,
Characterized in that it operates to independently control the tension applied to both ends based on the outer feeder,
Precision tension control system for roll-to-roll printing. 7. The method of claim 6,
The infeeder is configured to simultaneously rewind and unwind the web unwound from the unwinder to maintain a constant radius of the web wound around the infeed,
The infeed performs an operation of rotating at a constant speed,
Precision tension control system for roll-to-roll printing. delete 7. The method of claim 6,
The outer feeder further performs discrete control through the feedback provided from the first load cell,
Precision tension control system for roll-to-roll printing. 7. The method of claim 6,
The operation of independently controlling the tension is,
applying pressure in a vertical direction to the web,
Precision tension control system for roll-to-roll printing. 10. The method of claim 9,
The operation of discretely controlling the feeder is,
Temporarily changing the rotation speed of the outer feeder according to the tension value measured from the first load cell,
Precision tension control system for roll-to-roll printing.

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