CN112571693A

CN112571693A - Optical film using mark, and apparatus and method for manufacturing optical film

Info

Publication number: CN112571693A
Application number: CN202011020905.7A
Authority: CN
Inventors: 李文赞; 许殷奎; 朴正岵; 权铉喆
Original assignee: LG Chem Ltd
Current assignee: LG Chem Ltd
Priority date: 2019-09-27
Filing date: 2020-09-25
Publication date: 2021-03-30
Anticipated expiration: 2040-09-25
Also published as: CN112571693B; JP2022550538A; WO2021060739A1; JP7301452B2

Abstract

The present disclosure relates to an optical film, and an apparatus and method for manufacturing the same, in which an optimal mark may be formed and bending may be prevented during winding by considering that properties of the optical film vary according to an axial direction of a stretched optical film.

Description

Optical film using mark, and apparatus and method for manufacturing optical film

Technical Field

Embodiments of the present disclosure relate to an optical film using a mark, and an apparatus and method for manufacturing the optical film.

Background

The optical film is generally subjected to a manufacturing process of stretching treatment, surface treatment, slitting (slitting), and the like. Such optical film manufacturing processes are typically performed in a roll-to-roll (R2R) manner.

The surface treatment process of the optical film is performed in the order of unwinding, surface treatment, curing, and winding of the optical film. The winding process is the last step of the optical film production process, and when defects occur in the winding process, they are difficult to solve and become a factor of reducing the quality of products.

In order to properly wind the optical film after the R2R process, various factors, such as the distribution of winding tension applied to the film, the variation in film thickness, the anti-slip property of the film, the roughness of the film surface, and the density of the wound film, need to be considered.

Examples of poor winding of the film include bending of the film in the traveling direction and the vertical direction during winding, and a pressing defect caused by winding the core fixing tape. In order to suppress the bending defect, it is necessary to increase the winding tension or to increase the slip resistance of the film, and it is necessary to minimize the amount of air introduced between the films laminated during winding. In order to prevent the pressing defect, it is necessary to reduce the winding tension and to increase the amount of air introduced between the films during winding.

However, the prior art method of adjusting the winding tension of the film using only one kind has a problem in that it is difficult to solve the bending defect and the pressing defect in the winding process of the film.

In addition, in the art, when surface treatment is performed on the surface of the optical film, an additive is contained in the coating liquid. Therefore, the surface energy is low and the slip resistance is low as compared with a single optical film, which causes a problem that the film is bent in the traveling direction and the perpendicular direction.

Disclosure of Invention

Technical problem

The present disclosure has been made in view of the above circumstances, and aims to provide an optical film, and an apparatus and method for manufacturing the same, in which an optimum mark is formed and bending is prevented during winding by considering that properties of the optical film vary with an axial direction of a stretched optical film.

Technical scheme

An apparatus for manufacturing an optical film according to the present disclosure includes: a supply unit configured to supply an optical film in a first direction; a receiving unit disposed spaced apart from the supplying unit and configured to wind the optical film supplied from the supplying unit; and a marking unit disposed between the supplying unit and the receiving unit and configured to form a mark by irradiating a light source on the optical film.

The apparatus for manufacturing an optical film may further include a driving unit connected to the marking unit and configured to move the marking unit, and as the marking unit moves, a mark may be formed to form a preset angle with the first direction.

The optical film may include protrusions each formed along both sides of the mark.

Each of the protrusions formed on both sides of the mark may be formed to have a different height in a protrusion direction.

The optical film may include a mark region and an effective region, and the mark may be formed in a preset portion of the mark region.

The effective region may be formed in a central portion in a length direction of the optical film, and the mark region may be formed at an edge of the optical film so as to be disposed at both sides of the effective region.

A plurality of marking units may be disposed in the marking region.

The mark may form 0 ° to 180 ° with the first direction.

The apparatus for manufacturing an optical film may further include a coating unit configured to form a coating layer on one surface of the optical film between the supply unit and the receiving unit, and the marking unit may be disposed spaced apart from the coating unit with the optical film interposed therebetween, and the marking unit may form a mark on the other surface of the optical film.

The coating layer may be formed in a first region formed on one surface of the optical film, the mark may be formed in a second region formed on the other surface of the optical film opposite to the one surface on which the coating layer is formed, and the first region and the second region may not overlap in a direction perpendicular to the first direction.

The method for manufacturing an optical film according to the present disclosure includes: supplying an optical film in a first direction by a supply unit; determining a mark forming path by adjusting a marking unit disposed on an outer side of the optical film; forming a mark by irradiating a light source on the optical film by a marking unit; and winding the optical film on which the mark is formed by a receiving unit disposed apart from the supplying unit.

The mark may be formed to form a preset angle with the first direction.

Each of the protrusions formed on both sides of the mark may be formed to have a different height in the protrusion direction.

The method for manufacturing an optical film may further include: after the optical film is supplied in the first direction by the supply unit, a coating layer is formed on one surface of the optical film.

The mark may be formed on the other surface of the optical film on which the coating layer is formed on one surface.

The optical film according to the present disclosure may be manufactured using any one of the above-described manufacturing methods of the optical film.

The mark may be formed to have a groove shape, and when the total thickness of the optical film is denoted as 10, the groove depth of the mark may be formed at a ratio of 0.5 to 5.

When the total thickness of the optical film is taken as 10, the height of the protrusions formed on both sides of the mark may be formed at a ratio of 0.5 to 10.

Advantageous effects

The optical film using the mark and the apparatus and method for manufacturing the same according to the present disclosure provide an effect in that protrusions having different heights can be formed by forming a mark forming a preset angle with an axial direction of the optical film, and an optimal mark is formed in response to a property of the optical film, which varies with the axial direction of the stretched optical film.

In addition, the present disclosure provides an effect in that it is possible to increase surface energy, friction coefficient and slip resistance due to the protrusions formed on both sides of the mark, and prevent the occurrence of bending during winding.

In addition, the present disclosure provides an effect in that since air is introduced between the laminated films during winding, a pressing defect caused by winding the core fixing tape can be solved.

In addition, the present disclosure provides an effect in that, since a coating layer is formed on one surface of a film manufactured using the apparatus and method for manufacturing an optical film according to the present disclosure, and a mark is formed on the other surface opposite to the one surface, it is possible to increase surface energy, friction coefficient, and slip resistance, and prevent occurrence of bending during winding.

In addition, the present disclosure provides an effect in that since the coating layer and the mark do not overlap in a direction perpendicular to the length direction of the film, the possibility of the film breaking during winding can be reduced.

Obviously, the scope of the present disclosure is not limited by these effects.

Drawings

Fig. 1 is a perspective view schematically showing an apparatus for manufacturing an optical film according to a first embodiment of the present disclosure,

fig. 2 is a side view schematically showing an apparatus for manufacturing an optical film according to a first embodiment of the present disclosure,

fig. 3 and 4 are enlarged views illustrating a portion a of fig. 2.

Fig. 5 is a plan view partially showing an apparatus for manufacturing an optical film according to a first embodiment of the present disclosure,

figures 6a to 6c are diagrams each showing a mark formed at a predetermined angle to the first direction,

figure 7 is a graph showing the height of each protrusion angled according to the indicia,

fig. 8 is a flowchart illustrating a method for manufacturing an optical film according to a first embodiment of the present disclosure,

fig. 9 is a perspective view schematically illustrating an apparatus for manufacturing an optical film according to a second embodiment of the present disclosure.

Fig. 10 is a side view schematically illustrating an apparatus for manufacturing an optical film according to a second embodiment of the present disclosure.

Fig. 11 is an enlarged view showing a portion a of fig. 10.

Fig. 12 is a plan view illustrating an apparatus for manufacturing an optical film according to a second embodiment of the present disclosure,

figure 13 is a side view illustrating an optical film according to a second embodiment of the present disclosure,

fig. 14 is a flowchart illustrating a method for manufacturing an optical film according to a second embodiment of the present disclosure,

figure 15a is a graph showing water contact angle according to heat treatment temperature,

figure 15b is a graph showing the surface energy according to the heat treatment temperature,

fig. 16a is a graph showing a coefficient of friction (COF) according to a heat treatment temperature for an optical film according to a second embodiment of the present disclosure, an

Fig. 16b is a graph showing the coefficient of friction according to the heat treatment temperature for an optical film without surface treatment.

[ reference numerals ]

1: apparatus for manufacturing optical film

L: light source

10: optical film

11: effective area

15: marking area

16: marking

17: protrusion

100: supply unit

200: receiving unit

300: marking unit

400: drive unit

500: coating unit

Detailed Description

Hereinafter, the configuration and function of the specific embodiments of the present disclosure will be described in detail as follows with reference to the accompanying drawings.

Here, it is to be noted that, when reference numerals are added to component parts of each drawing, the same reference numerals are used to represent the same component parts as much as possible even if they are represented in different drawings.

Fig. 1 is a perspective view schematically illustrating an apparatus for manufacturing an optical film according to a first embodiment of the present disclosure. Fig. 2 is a side view schematically illustrating an apparatus for manufacturing an optical film according to a first embodiment of the present disclosure.

Referring to fig. 1 and 2, an apparatus 1 for manufacturing an optical film according to a first embodiment of the present disclosure may include a supply unit 100, a receiving unit 200, a marking unit 300, and a driving unit 400.

Specifically, the supply unit 100 according to the first embodiment of the present disclosure may supply the optical film 10 (hereinafter, referred to as "film") in a first direction (a direction from left to right based on fig. 2) and may rotate clockwise or counterclockwise by receiving power from the outside.

In this case, the supply unit 100 rotates clockwise (based on fig. 2), and when the wound film 10 is unwound, it moves toward the receiving unit 200 disposed at a distance from the supply unit 100.

When the receiving unit 200 rotates clockwise by receiving power from the outside, the film 10 moving from the supplying unit 100 to the receiving unit 200 may be wound.

The receiving unit 200 according to the first embodiment of the present disclosure may be disposed at a distance from the supplying unit 100, and may wind the film 10 supplied from the supplying unit 100.

The receiving unit 200 may rotate clockwise or counterclockwise by receiving power from the outside, and may wind the film 10 supplied from the supplying unit 100 while rotating clockwise based on fig. 2.

The film 10 may be moved from the supply unit 100 to the receiving unit 200 along the first direction, and the light source L may be irradiated on one surface (the upper surface based on fig. 2) of the film 10 by a marking unit 300 described later, and the mark 16 having a groove shape may be formed.

The marking unit 300 may be disposed between the supplying unit 100 and the receiving unit 200, and the mark 16 may be formed by irradiating the light source L on the film 10.

In the present disclosure, the light source L may be a laser, and when the light source L is irradiated on the film 10, the mark 16 having a groove shape may be formed in a preset portion, and in a portion in which the mark 16 is formed, the protrusion 17 may protrude in an outside direction (an upper side based on fig. 3) along both sides of the mark 16.

The height of the protrusion 17 may be relatively higher than the height of the bottom surface of the groove corresponding to the mark 16, and the protrusion may protrude upward from one surface (upper side based on fig. 3) of the film 10 before the mark 16 is formed.

Referring to fig. 3, the protrusion 17 may have a certain height based on the upper surface of the film 10 (based on fig. 3).

The protrusion 17 may function to guide the film 10 not to be inclined to one side when received in the receiving unit 200.

Although not shown in the drawings, the protrusion 17 is formed on the upper surface (based on fig. 2) of the film 10, and the film 10 is laminated in the distal direction based on the center of the receiving unit 200 while being wound by the receiving unit 200. Here, the protrusions 17 are in contact with the lower surface of the film 10 laminated on the outer side of the protrusions 17, and the anti-slip property increases as the surface pressure increases.

In addition, there is an effect that: due to the protrusions 17, the surface energy can be increased, thereby preventing the occurrence of bending due to slipping during winding.

In addition, the following effects are provided: when the film 10 is laminated on the receiving unit 200 while the layers are formed, a constant interval may be maintained between the layers 10.

In addition, there is an effect that when foreign matter is accidentally introduced during the manufacturing process of the film 10, the film 10 can be prevented from being damaged or broken due to the pressure of the film 10 disposed at the upper side. This has the effect that the surface pressure in the winding core direction can be increased as the projection 17 becomes higher.

The protrusions 17 are respectively formed on both sides of the mark 16 having a groove shape, and, as shown in fig. 3, the heights h1, h2 of the protrusions 17 formed on both sides may be the same.

On the other hand, as described later, the marker unit 300 may adjust the irradiation path and the irradiation angle of the light source L by receiving power from the driving unit 400, and here, the heights h1, h2 of the protrusions 17 formed on both sides of the marker 16 may be different. Which will be described in detail later.

Specifically, when the total thickness (t) of the optical film 10 is denoted as 10, the groove depth (d) of the mark 16 may be formed at a ratio of 0.5 to 5.

In other words, when the groove depth (d) of the mark 16 is formed at a ratio of 0.5 or less, there is a problem that the protrusion 17 cannot be formed at an appropriate height. In other words, the groove depth (d) and the height of the protrusion 17 are increased in proportion, and when the height of the protrusion 17 is low due to the low groove depth (d), the effect of increasing the slip resistance may not be significant.

In contrast, when the groove depth (d) of the mark 16 is formed at a rate of 5 or more, there is a problem in that the risk of cracking of the optical film 10 rapidly increases.

Further, when the total thickness (t) of the optical film 10 is denoted as 10, the height of the protrusions 17 formed on both sides of the mark 16 may be formed at a ratio of 0.5 to 10.

In other words, when the heights h1, h2 of the protrusions 17 are formed at a ratio of 0.5 or less, there is a problem in that the effect of increasing the grip performance may not be significant.

In contrast, when the heights h1, h2 of the protrusions 17 are formed at a ratio of 10 or more, the groove depth (d) is excessively increased, thereby causing a problem that the risk of cracking of the optical film 10 rapidly increases.

When the heights h1, h2 of the protrusions 17 and the groove depth (d) are increased by increasing the laser output or changing the pattern angle of the marks 16, the height of the protrusions 17 is no longer significantly increased and saturated when the height ratio of the protrusions 17 is 10 or more, but the groove depth (d) continues to increase. When the height ratio of the protrusions 17 is about 10, the ratio of the groove depths (d) is about 5, and thus, this value can be set as the basic ratio.

In this case, a coating layer (not shown) having a certain thickness may be laminated on either one of the front and back surfaces of the optical film 10 or both of the front and back surfaces of the optical film 10. When a coating layer is formed on the front surface of the optical film 10, the mark 16 may be formed on the coating layer of the optical film 10.

The coating layer has various functional effects such as antireflection, antiglare, anti-scattering, and optical film protection.

In this case, the coating used in the present disclosure is an anti-semi-glare (ASG) coating. The coating is typically formed of a harder material than the film, and therefore, the coating is sensitive to cracking and has a lower surface energy (45 mN/m for PET film > 30mN/m for ASG _ PET film). Due to the surface energy reduction, slipping easily occurs during the winding of the optical film 10. Therefore, the protrusion 17 is formed at the edge of the optical film 10 by laser marking. In this case, when the mark 16 is formed on the front surface of the optical film 10 on which the coating layer is formed by laser marking, the risk of cracking may increase. Thus, the laser mark 16 may be formed on the back surface of the uncoated optical film 10 by laser marking.

Referring to fig. 5, the marking unit 300 may form the mark 16 by irradiating the light source L on the mark region 15, the mark region 15 being each edge of both sides of the effective region 11 formed on the central portion based on the length direction of the film 10.

The film 10 includes an effective area 11 and a mark area 15, and the effective area 11 in this specification refers to an area of one surface of the film 10 attached to a display panel. The effective region 11 may be formed on the film 10 along a first direction (up-down direction based on fig. 5).

The effective region 11 may be formed to have a preset width based on the center of the length direction of the film 10. In other words, the effective region 11 is a region formed in the central portion in the width direction of the film 10.

In this specification, the "mark region 15" is a region of one surface of the film 10 other than the effective region 11 (the region attached to the display panel), and may be formed on the film 10 along the first direction (the up-down direction based on fig. 5).

The mark region 15 may be formed on both sides of the central effective region 11 based on the length direction of the film 10 (based on the up-down direction of fig. 5), i.e., at the edge of the film 10.

The marking unit 300 according to the first embodiment of the present disclosure may be disposed at an upper side of the marking region 15 (based on fig. 2), and a forming path of the mark 16 and an irradiation angle of the light source L may be adjusted by receiving power from a driving unit 400 described later.

In addition, a plurality of marking units 300 may be disposed and arranged on the marking regions 15 formed on both sides of the effective region 11.

Therefore, the mark 16 can be formed in each of the mark regions 15 formed at both side edges of the effective region 11 of the film 10. Further, the width of the effective area 11 may be determined according to the interval between the marks 16 formed on the mark area 15.

The driving unit 400 may be connected to the marking unit 300, and may move the marking unit 300. Such a driving unit 400 may transmit power to the marking unit 300 to move the marking unit 300, and as the marking unit 300 moves, the mark 16 may be formed while forming a preset angle with the first direction.

In this case, the driving unit 400 may be disposed between the supplying unit 100 and the receiving unit 200, and may be disposed at an upper side of the film 10 moving between the supplying unit 100 and the receiving unit 200. The driving unit 400 may be electrically connected to the marking unit 300, and may control the irradiation path and angle of the marking unit 300 by transmitting power to the marking unit 300.

In this case, the present disclosure shows and describes an example in which the marking unit 300 is moved by the driving unit 400 (gun type laser), but the present disclosure is not limited thereto. In other words, the method may be changed to a method in which the marking unit 300 itself irradiates a laser beam at a desired angle by an optical method (scanning type laser) to form the mark 16.

Referring to fig. 6a to 6c, the moving direction of the film 10 may be a first direction, i.e., a direction from a lower side to an upper side (based on fig. 6a), and the mark 16 formed by the light source L irradiated from the marking unit 300 may be formed while forming a preset angle with the first direction.

Specifically, in fig. 6a, the mark 16 is formed in the same direction as the moving direction (machine direction, MD) of the film 10, and the forming path of the mark 16 is formed at 0 ° from the first direction.

In this case, since the formation path of mark 16 and the first direction are formed to be 0 °, height h1 of left protrusion 17 and height h2 of right protrusion 17 may be the same, and left and right protrusions 17 may be formed on both sides of mark 16.

The mark 16 may be formed while forming an angle (θ 1), specifically, 15 ° with the moving direction of the film 10, the first direction (up-down direction based on fig. 6 b).

Referring to fig. 6b, when the formation path of the mark 16 and the first direction form 15 °, the height h2 of the right protrusion 17 may be relatively higher than the height h1 of the left protrusion 17, forming the left and right protrusions 17 at both sides of the mark 16.

In fig. 6c, the mark 16 may be formed while forming an angle (θ 2), specifically, 30 ° with the moving direction of the film 10, the first direction (up-down direction based on fig. 6 c).

In this case, since the formation path of mark 16 and the first direction form 30 °, height h2 of right protrusion 17 is relatively higher than height h1 of left protrusion 17, and left and right protrusions are formed on both sides of mark 16.

The height h2 of the right protrusion 17 in fig. 6c may be higher than the height h2 of the right protrusion 17 in fig. 6b, and the height h1 of the left protrusion 17 may be lower than the height of the left protrusion 17 in fig. 6 b.

The optical film 10 used as a display material is generally stretched at the time of use, and therefore, the degree of tensile strength, elongation, heat absorption/conduction, volume expansion, and the like thereof may vary depending on the axial direction thereof (specifically, the first direction).

Therefore, the height of the protrusion 17 needs to be adjusted according to the properties of the film 10, and the formation path of the mark 16 needs to form a preset angle with the first direction, i.e., the supply direction of the film 10.

The driving unit 400 may transmit power to the marking unit 300 such that the marking unit 300 forms a preset angle, specifically, 0 ° to 180 °, with the first direction.

The driving unit 400 may be connected to the marking unit 300, and as the marking unit 300 moves on the driving unit 400, an irradiation path and an angle of the light source L may be adjusted.

The marking unit 300 may be moved in the current direction (left-right direction based on fig. 2) on the driving unit 400. However, the present disclosure is not limited thereto, and various modifications may be made such that it can also move in the left-right direction based on fig. 5.

Although not shown in the drawings, the angle of the light source L irradiated from the marking unit 300 and incident on one surface (based on the upper surface of fig. 2) of the film 10 may also be adjusted.

Therefore, marking unit 300 forms mark 16 on mark region 15 of film 10 by irradiating light source L, where height h1 of left protrusion 17 and height h2 of right protrusion 17 (left and right protrusions 17 formed on both sides of mark 16) may be the same as each other (in the case of 0 ° and 180 °), or different from each other (greater than 0 ° and less than 180 °).

Fig. 7 is a diagram showing that the height of the protrusion 17 varies with the angle formed by the mark 16 and the first direction (up-down direction based on fig. 6a), and according to the angle, the height h1 of the left protrusion 17 and the height h2 of the right protrusion 17 may be the same as or different from each other.

Accordingly, the forming angle of the mark 16 having the optimal height of the protrusion 17 may vary according to the properties of the film 10 at the same output of the laser light source L, and thus, as the driving unit 400 controls the driving of the marking unit 300, the forming path of the mark 16 and the angle of the mark 16 from the first direction may be set.

As a result, the formation path of the marks 16 forming a preset angle with the first direction can be adjusted to correspond to the properties of the film 10, the surface pressure distribution caused by the thickness deviation of the film 10 can be increased when the protrusions 17 have an optimal height, and the anti-slip property can be increased since air is introduced by preventing the interfaces between the films 10 from being completely contacted with each other during winding.

There are effects that the occurrence of bending during winding can be prevented due to the increase of the slip resistance, and the occurrence of the press defect during winding can be suppressed due to the introduction of air between the interfaces of the film 10.

Hereinafter, an operation principle of an apparatus for manufacturing an optical film using a mark and a method for manufacturing an optical film according to a first embodiment of the present disclosure will be described. Fig. 8 is a flowchart illustrating a method for manufacturing an optical film according to a first embodiment of the present disclosure.

Referring to fig. 8, the method for manufacturing an optical film according to the first embodiment of the present disclosure may include: supplying the optical film S10; forming a path degree S20 by adjusting the angle determination mark; forming a mark S30 by irradiating a light source; and winding the optical film S40.

In supplying the optical film S10, the supply unit 100 supplies the optical film 10 in a first direction (a direction from left to right based on fig. 2).

The supply unit 100 may rotate clockwise or counterclockwise by receiving power from the outside, and referring to fig. 2, may rotate clockwise to move the film 10 in a right direction (based on fig. 2).

In determining the mark forming path S20, the forming path of the mark 16 may be determined by adjusting the mark unit 300 disposed on the upper side of the optical film 10.

The marking unit 300 may be disposed between the supplying unit 100 and the receiving unit 200, and may receive power from a driving unit 400 disposed at an upper side (based on fig. 2) of the film 10 to determine a forming path of the mark 16.

Here, the formation path of the mark 16 indicates not only the formation path of the mark 16 but also the formation path of the protrusion 17 formed along both sides of the mark 16 formed in the groove shape.

In other words, when forming mark 16, protrusions 17 having preset heights h1, h2 are formed on the left and right sides of mark 16 in the length direction of mark 16.

The driving unit 400 may determine a forming path of the mark 16 by moving and rotating the marking unit 300 (refer to fig. 1).

Specifically, referring to fig. 6a to 6c, the driving unit 400 may move and rotate the index unit 300 such that the first direction (up-down direction based on fig. 6a), i.e., the supply direction of the film 10 and the index 16 have a preset angle.

Although not shown in the drawings, a control unit (not shown) may be included, which is electrically connected to the driving unit 400 and the marking unit 300, receives an electric signal from the driving unit 400, and thus controls the driving of the marking unit 300.

Fig. 6a is a diagram showing that the first direction and the formation path of the mark 16 form 0 °. Fig. 6b is a diagram showing that the first direction and the formation path of the mark 16 form 15 °. Fig. 6c is a diagram showing that the first direction and the formation path of the mark 16 form 30 °.

However, the present disclosure is not limited thereto, and various modifications may be made such that the preset angle formed by the formation path of the mark 16 and the first direction (up-down direction based on fig. 6a) is in the range of 0 ° to 180 °.

In forming the mark S30, the mark unit 300 irradiates the light source L toward the optical film 10 to form the mark 16. In forming the mark S30, the light source L may irradiate along the path determined in the determination of the mark forming path S20.

Referring to fig. 6a to 6c, the mark 16 may be formed while forming a preset angle in the feeding direction of the film 10 (up-down direction based on fig. 6 a).

Referring to fig. 4, 6b and 6c, when the mark 16 is formed while forming a preset angle with the first direction, heights h1, h2 of the left and right protrusions 17 protruding at both sides of the mark 16 may be different.

Therefore, considering that the properties of the film 10, such as tensile strength, heat absorption/conduction or volume expansion, vary with the axial direction of the stretched film 10 (up-down direction based on fig. 5), and that the optimum height of the protrusions 17 for improving surface pressure and anti-slip property varies, there is an effect in that the protrusions 17 having different heights may be formed depending on the film 10.

In the winding S40 of the optical film, the receiving unit 200 disposed spaced apart from the supplying unit 100 is rotated clockwise (based on fig. 2) by receiving power from the outside, and the film 10 is wound with the mark 16 formed when forming a preset angle with the first direction (up-down direction based on fig. 6a), i.e., the supplying direction of the film 10.

In this case, there is an effect that surface energy, friction coefficient and anti-slip property can be increased and bending occurring when the film 10 is wound can be prevented due to the protrusions 17 formed on both sides of the mark 16 formed in the mark region 15 of the film 10.

In addition to this, there is an effect that since air is introduced between the laminated films 10 during winding, a pressing defect caused by winding the core fixing tape can be eliminated.

Besides, the following effects are achieved: when the mark 16 and the first direction, i.e., the supply direction of the film 10 form a preset angle, the heights of the protrusions 17 formed at both sides of the mark 16, specifically, the height h1 of the left protrusion 17 and the height h2 of the right protrusion 17 may be made different, and considering and reflecting that the properties of the film 10 generally vary with the axial direction of the stretched film 10 (the up-down direction based on fig. 5), the optimum mark 16 and the protrusion 17 may be formed.

Meanwhile, referring to fig. 9 and 10, an apparatus (1') for manufacturing an optical film according to a second embodiment of the present disclosure may include a supplying unit 100, a receiving unit 200, a coating unit 500, and a marking unit 300.

The configuration of the supply unit 100 and the receiving unit 200 according to the second embodiment of the present disclosure may be the same as that of the apparatus 1 for manufacturing an optical film according to the first embodiment.

The optical film 10 may be moved from the supply unit 100 to the receiving unit 200 along the first direction, and one surface of the film 10 (based on the upper surface of fig. 10) may be coated by a coating unit 500, which will be described below, or the marking unit 300 may form the mark 16 on the other surface (based on the lower surface of fig. 10) opposite to the coated one surface of the film 10.

The coating unit 500 may be disposed between the supply unit 100 and the receiving unit 200, and may form a coating layer CL on one surface (based on the upper surface of fig. 10) of the optical film 10.

Specifically, the coating unit 500 may form the coating layer CL on the upper surface of the optical film 10 by sequentially solution coating, curing, and drying while moving in the first direction.

The surface treatment is performed while the coating liquid flows out from the coating unit 500 onto the film 10. Specifically, the film 10 may be formed of polyethylene terephthalate (PET).

The coating CL may be an anti-half glare (ASG) coating CL and may be specifically formed of microparticles, UV curable resin or fluorine-based additive.

The coating layer CL may be formed on the film 10 by the coating unit 500, and the hardness of the film 10 on which the coating layer is formed is increased as compared to the film 10 on which the coating layer CL is not formed.

The coating unit 500 may be disposed in a direction perpendicular to the length direction of the film 10 (left-right direction based on fig. 12).

Referring to fig. 12, the film 10 is formed with an effective area 11 and a mark area 15, and "effective area 11" in this specification refers to an area of one surface of the film 10 attached to the display panel. The effective region 11 may be formed on the film 10 along a first direction (up-down direction based on fig. 12).

The effective region 11 may be formed to have a preset width based on the center of the length direction (up-down direction) of the film 10. In other words, it is a region formed in the central portion in the width direction of the film 10.

In this specification, the "mark region 15" is a region of one surface of the film 10 other than the effective region 11 (the region attached to the display panel), and may be formed on the film 10 along the first direction.

The mark regions 15 may be formed on both sides of the effective region 11, i.e., at the edges of the film 10, based on the center of the film 10 in the length direction (up-down direction).

A marking unit 300, which will be described later, may be disposed at a lower side of the film 10 (specifically, the marking region 15), and a coating unit 500 may be disposed at an upper side of the film 10. The coating unit 500 may form the coating layer CL in a preset region of the effective region 11 of the film 10.

The marking unit 300 may be disposed at the other side (the lower side based on fig. 9) opposite to the side (the upper side based on fig. 9) of the film 10 where the coating unit 500 is positioned, and the mark 16 may be formed by irradiating the light source L on the film 10.

Referring to fig. 12, the coating unit 500 may be disposed not to overlap the marking unit 300 in a direction perpendicular to the first direction.

In other words, in the preset portion of the film 10, the ASG coat layer CL is formed on one surface (the upper surface based on fig. 9) of the film 10, and the mark 16 is not formed on the other surface (the lower surface based on fig. 9) corresponding to the one surface in the vertical direction (the up-down direction based on fig. 10).

Since the ASG coating CL and the mark 16 are arranged so as not to overlap in the region of the film 10 in the direction perpendicular to the first direction, the breakage of the film 10 during winding can be prevented as compared with the case where they are arranged so as to overlap each other.

In other words, in the process of forming the ASG coating CL on the film 10, the film 10 has high hardness by UV curing, and the groove of the mark 16 is formed when the mark unit 300 irradiates the light source L onto the other surface corresponding to the surface on which the ASC coating CL is formed to form the mark 16.

The groove depth of the marks 16 increases the risk of cracking of the film 10, but the marks 16 do not overlap the coating CL in a direction perpendicular to the first direction, thereby reducing the risk of cracking.

In addition to this, there is an effect that, due to the protrusions 17 formed on both sides of the mark 16, it is possible to increase the increase of the surface energy and enhance the anti-slip property, thereby preventing the bending when the film 10 is wound.

The marking unit 300 may be disposed at a distance from the coating unit 500 with the optical film 10 interposed therebetween, and the mark 16 may be formed by irradiating the light source L on the other surface of the optical film 10 opposite to the one surface thereof on which the coating layer CL is formed.

In the present disclosure, the light source L may be a laser, and when the light source L is irradiated on the film 10, the mark 16 having a groove shape may be formed in a preset portion, and in a portion in which the mark 16 is formed, the protrusion 17 may be formed in an outside direction (based on a lower side of fig. 11) along both sides of the mark 16.

The protrusion 17 may protrude in a lower direction based on the lower surface of the film 10, and may have a certain height. Referring to fig. 11, the protrusion 17 may function to guide the film 10 not to be inclined to one side when received in the receiving unit 200.

Although not shown in the drawings, the protrusion 17 is formed on the lower surface of the film 10, and the film 10 is laminated in the centrifugal direction based on the center of the receiving unit 200 while being wound by the receiving unit 200. Here, the projection 17 is in contact with the upper surface of the film 10 that has been wound on the inner side of the projection 17, and the anti-slip property increases with the increase of the surface pressure.

In addition to this, there is an effect that when the film 10 is laminated on the receiving unit 200 while forming a layer, a constant interval between layers can be maintained.

In addition, there is an effect that when foreign substances are accidentally introduced during the manufacturing process of the optical film 10, the film 10 can be prevented from being damaged or broken due to the pressing pressure of the optical film 10 disposed on the upper side. This has the effect that the surface pressure in the winding core direction can be increased as the projection 17 becomes higher.

Referring to fig. 11 and 12, there are the following effects: due to the protrusions 17 formed on the film 10, specifically, on the marking regions 15 by the marking unit 300, it is possible to increase the surface energy and the slip resistance of the film 10 and to prevent the occurrence of bending due to slipping during winding.

The marking unit 300 may form the mark 16 in the mark region 15 at each of both sides of the effective region 11 on a central portion based on the length direction of the film 10.

The marks 16 may be formed on the other surface opposite to the upper surface of the film 10 on which the coating layer CL is formed, and they may be formed so as not to overlap in a direction perpendicular to the length direction of the film 10.

Therefore, even in the case where the mark 16 is formed in a groove shape, it does not correspond to the position of the coating layer CL, and therefore, it is possible to reduce the possibility of the film 10 breaking during winding, as compared with the case where the protrusion 17 is formed on the other surface corresponding to the region having increased hardness due to the UV-cured coating layer CL, and to reduce the occurrence of bending during winding due to the increased surface energy and the anti-slip property of the protrusion 17.

Referring to fig. 12, a plurality of marking units 300 may be provided and may be provided in the marking regions 15 formed on both sides of the effective region 11. Therefore, the mark 16 can be formed in each of the mark regions 15 formed at both side edges of the effective region 11 of the film 10.

The width of the effective region 11 may be determined according to the interval between the marks 16 formed on the mark region 15, and thus, the region where the coating layer CL is formed may also be increased.

Hereinafter, an operation principle of an apparatus for manufacturing an optical film and a method for manufacturing an optical film according to a second embodiment of the present disclosure will be described. Fig. 14 is a flowchart illustrating a method of manufacturing an optical film according to a second embodiment of the present disclosure.

Referring to fig. 9 to 14, the method for manufacturing an optical film according to the second embodiment of the present disclosure may include supplying an optical film S10, forming a coating layer S20, forming a mark S30, and winding the optical film S40.

In supplying the optical film S10, the supply unit 100 supplies the optical film 10 in a first direction (a direction from left to right based on fig. 10). The supply unit 100 may rotate clockwise or counterclockwise by receiving power from the outside, and may rotate clockwise to move the film 10 in a right direction (based on fig. 10).

In forming the coating layer S20, a coating layer CL may be formed on one surface of the optical film 10, and an ASG coating layer CL may be formed, but the present disclosure is not limited thereto, and various functional coating layers may be formed.

Referring to fig. 12 and 13, a coating layer CL may be formed on one surface (based on the upper surface of fig. 13) of the film 10, and the coating layer CL may be formed on the active area 11 of the film 10.

The coating layer CL may be formed in a region of the film 10 in a direction perpendicular to the first direction so as not to overlap with the mark 16 formed in the later-described forming mark S30.

In other words, the mark 16 is not formed on the lower surface of the film 10 corresponding to the upper surface of the film 10 on which the mark CL is formed, and the coat CL is not formed on the upper surface of the film 10 corresponding to the lower surface on which the mark 16 is formed.

Fig. 15a and 15b show results obtained by heat-treating the film with the coating layer CL formed and the film without the coating layer NCL formed around the glass transition temperature (Tg) and the melting temperature (Tm) and measuring the surface energy of the films, and it can be seen that the film with the coating layer CL formed has a very low surface energy at room temperature compared to the film without the coating layer NCL formed. After coating, there are problems that the slip resistance is reduced as the surface energy of the film 10 is reduced, and the possibility of occurrence of bending at the time of winding is increased.

On the other hand, after the heat treatment at a temperature near the melting point, the surface energy of the film without the coating layer NCL formed is increased as compared with the heat treatment at room temperature, and thus, when the surface of the film 10 is melted by the irradiation of the laser light source, the possibility of occurrence of bending can be suppressed due to the increased anti-slip property.

Fig. 16a and 16b show the results of heat-treating the film with the coating layer formed and the film without the coating layer formed in the vicinity of the glass transition temperature (Tg) and the melting temperature (Tm), and measuring the coefficient of friction (COF) of the films. Fig. 16a shows the result of measuring the friction coefficient of the film having the coating layer CL, and fig. 16b shows the result of measuring the friction coefficient of the film in which the coating layer NCL is not formed.

Referring specifically to fig. 16a and 16b, the interfacial friction force between the film surfaces was measured under loads of 200g (case 1) and 700g (case 2) using the apparatus for measuring the friction coefficient, and it can be seen that case 1 having a small load had a very low surface friction force even after heat treatment at a melting temperature (Tm) as compared to the film without the coating NCL.

Having a low surface friction means that it is susceptible to slip resistance and means that buckling is most likely to occur during winding.

In forming the mark S30, the mark unit 300 provided on the outer side (lower side based on fig. 10) of the optical film 10 may form the mark 16 by irradiating the light source L on the optical film 10.

The marking unit 300 may form the mark 16 by irradiating the light source L, i.e., laser, on the lower surface of the film 10 corresponding to the region of the upper surface of the film 10 where the coating layer CL is not formed, in a direction perpendicular to the first direction (the length direction of the film 10).

The effect is that since the mark 16 is formed in a groove shape, the protrusions 17 protrude at both sides of the mark 16, and due to the formation of the protrusions 17, it is possible to increase surface energy, friction coefficient, and anti-slip property, and prevent the occurrence of bending during winding.

In addition to this, since the coating layer CL is not formed on the upper side of the region where the mark 16 is formed, and the coating layer CL and the mark 16 do not overlap, it is possible to prevent an increase in the risk of cracking caused by the depth of the mark 16 having a groove shape, in addition to a decrease in surface energy due to UV curing in the process of forming the ASG coating layer CL.

In the wound optical film S40, when the receiving unit 200 disposed at a distance from the supplying unit 100 receives power from the outside and rotates clockwise, the coating layer CL is formed, and the film 10 on which the mark 16 is formed is wound.

The effect is that, in forming the mark S30, it is possible to increase the surface energy, the friction coefficient and the anti-slip property due to the protrusions 17 formed on both sides of the mark 16 formed in the mark region 15 of the film 10, and to prevent the occurrence of bending when the film 10 is wound.

The coating layer CL is formed on one surface of the film 10 manufactured using the apparatus for manufacturing an optical film 1 and the method for manufacturing an optical film according to the present disclosure, and the mark 16 is formed on the other surface opposite to the one surface, with the result that it is possible to increase surface energy, friction coefficient, and slip resistance and prevent occurrence of bending during winding.

In addition, there is an effect that since the coating layer CL and the mark 16 do not overlap in a direction perpendicular to the length direction of the film 10, the possibility of the film 10 breaking when the film 10 is wound can be reduced.

Above, the present disclosure has been shown and described with reference to the specific embodiments, but the present disclosure is not limited to the above-described embodiments, and various changes and modifications may be made within a scope not departing from the technical idea of the present disclosure.

Claims

1. An apparatus for manufacturing an optical film, the apparatus comprising:

a supply unit configured to supply an optical film in a first direction;

a receiving unit disposed spaced apart from the supplying unit and configured to wind the optical film supplied from the supplying unit; and

a marking unit disposed between the supplying unit and the receiving unit and configured to form a mark by irradiating a light source on the optical film.

2. The apparatus of claim 1, further comprising a drive unit connected to the marking unit and configured to move the marking unit,

wherein, as the marking unit moves, a mark forming a preset angle with the first direction is formed.

3. The apparatus of claim 2, wherein the optical film comprises protrusions each formed along two sides of the indicia.

4. The apparatus of claim 3, wherein each of the protrusions formed on both sides of the mark is formed to have a different height in a protrusion direction.

5. The apparatus of claim 2, wherein the optical film includes a mark region and an effective region, and the mark is formed in a preset portion of the mark region.

6. The apparatus of claim 5, wherein the effective area is formed in a central portion along a length direction of the optical film, and the mark area is formed at an edge of the optical film so as to be disposed on both sides of the effective area.

7. The apparatus of claim 6, wherein a plurality of marking units are disposed in the marking region.

8. The apparatus of claim 2, wherein the indicia forms 0 ° to 180 ° with the first direction.

9. The apparatus of claim 1, further comprising, between the supply unit and the receiving unit, a coating unit configured to form a coating layer on one surface of the optical film,

wherein the marking unit is disposed to be spaced apart from the coating unit with the optical film interposed therebetween, and the marking unit forms a mark on the other surface of the optical film.

10. The apparatus of claim 9, wherein the coating layer is formed in a first region formed on one surface of the optical film, the mark is formed in a second region formed on the other surface of the optical film opposite to the one surface of the optical film on which the coating layer is formed, and the first region and the second region do not overlap in a direction perpendicular to the first direction.

11. A method for manufacturing an optical film, the method comprising:

supplying an optical film in a first direction by a supply unit;

determining a mark forming path by adjusting a mark unit disposed on an outer side of the optical film;

forming a mark by irradiating a light source on the optical film by a marking unit; and

the optical film on which the mark is formed is wound by a receiving unit disposed spaced apart from the supplying unit.

12. The method of claim 11, wherein the mark is formed at a preset angle to the first direction.

13. The method of claim 11, wherein the optical film includes protrusions each formed along two sides of the indicia.

14. The method of claim 13, wherein each protrusion formed on both sides of the mark is formed to have a different height in a protrusion direction.

15. The method of claim 11, further comprising forming a coating layer on one surface of the optical film after the optical film is supplied in the first direction by the supply unit.

16. The method of claim 15, wherein the mark is formed on the other surface of the optical film on which the coating layer is formed on one surface.

17. The method of claim 16, wherein the coating layer is formed in a first region formed on one surface of the optical film, the mark is formed in a second region formed on the other surface of the optical film opposite to the one surface of the optical film on which the coating layer is formed, and the first region and the second region do not overlap in a direction perpendicular to the first direction.

18. An optical film produced using the method for producing an optical film according to any one of claims 11 to 17.

19. The optical film according to claim 18, wherein the mark is formed to have a groove shape, and when the total thickness of the optical film is denoted as 10, the groove depth of the mark is formed at a ratio of 0.5 to 5.

20. The optical film according to claim 18, wherein when the total thickness of the optical film is taken as 10, the height of the protrusions formed on both sides of the mark is formed at a ratio of 0.5 to 10.