KR20230060910A - Electronic device including flexible display - Google Patents

Abstract

The present invention relates to an electronic device comprising: a housing; a flexible display capable of being inserted into an inner space of the housing and withdrawn from the inner space of the housing; and a driving part for insertion and withdrawal of the flexible display, wherein the housing is equipped with an uneven pattern on at least some areas of the inside. Therefore, the present invention is capable of minimizing a surface damage of the flexible display.

Description

Electronic device including a flexible display {ELECTRONIC DEVICE INCLUDING FLEXIBLE DISPLAY}

The present invention relates to an electronic device including a flexible display.

BACKGROUND ART With the development of digital technology, electronic devices are provided in various forms such as a smart phone, a tablet personal computer (PC), or a personal digital assistant (PDA). Electronic devices tend to be designed to provide a larger screen while having a portable size that does not cause inconvenience to a user's hand.

In accordance with this trend, recently, a flexible display implemented to be bendable using a flexible substrate instead of an inflexible flat panel display panel has been included, thereby contributing to a large display area while occupying less space. Advantageous electronic devices are being developed. For example, an electronic device implemented so that all or part of the flexible display can be wound around or unfolded from a roller, or all or part of the flexible display is pulled out from the internal space of the electronic device in a sliding manner to slide There are electronic devices implemented to expand the screen in this way.

Korean Patent Publication No. 10-2018-0006533 also discloses an electronic device implemented such that a flexible display can be wound around a roller or unfolded from a roller.

However, electronic devices including various types of conventional flexible displays, including those disclosed in the Patent Publication, in the process of being driven in such a way that the flexible display is drawn into and drawn from the inner space of the housing, the flexible display, in particular, the flexible display Contact occurs between the screen of the display and the inner surface of the housing and/or other members such as a film provided inside the housing. At this time, when the friction coefficient between the screen of the flexible display and other members such as the inner surface of the housing and/or a film provided inside the housing in contact with the screen is high, an excessive operating load is applied during the process of retracting and withdrawing the flexible display. The driving of the electronic device may not be smooth, and furthermore, damage such as scratches may occur on the screen of the flexible display.

Therefore, it is necessary to develop an electronic device capable of minimizing operating load and surface damage of the flexible display generated during the process of pulling in and out of the flexible display.

Republic of Korea Patent Publication No. 10-2018-0006533

An object of the present invention is to provide an electronic device including a flexible display in which an operating load generated in the process of pulling in and out of the flexible display is minimized.

Another object of the present invention is to provide an electronic device including a flexible display in which damage to the surface of the flexible display is minimized during the process of pulling in and pulling out the flexible display.

However, the problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

The present invention, the housing; a flexible display capable of being drawn into and drawn out of the inner space of the housing; and a driving unit for pulling in and out of the flexible display, wherein the housing has a concavo-convex pattern on at least a portion of the inside of the housing.

In the first aspect of the present invention, the concavo-convex pattern may be provided in at least a part of the friction area.

In the second aspect of the present invention, the concavo-convex pattern may contact at least one surface of the inserted flexible display.

In the third aspect of the present invention, one side of the flexible display that comes into contact with the concavo-convex pattern may be a viewing side surface.

In the fourth aspect of the present invention, a coefficient of friction between a surface of the flexible display contacting the concave-convex pattern and the concave-convex pattern may be 0.5 or less.

In the fifth aspect of the present invention, a coefficient of friction between a surface of the flexible display contacting the concave-convex pattern and the concave-convex pattern may be 0.2 or less.

In the sixth aspect of the present invention, the average roughness (Ra) of the concavo-convex pattern may be 0.1 to 1.0 μm.

In the seventh aspect of the present invention, the average roughness (Ra) of the concavo-convex pattern may be 0.2 to 0.5 μm.

In the eighth aspect of the present invention, the concavo-convex pattern may be attached in the form of a film.

In the ninth aspect of the present invention, the flexible display may be drawn in by being wound into the inner space of the housing by the drive unit, and drawn out by being unwound in the inner space of the housing.

In the tenth aspect of the present invention, the flexible display can be drawn in by being slid in to the inner space of the housing by the driving unit, and can be drawn out by being slid out of the inner space of the housing.

According to the electronic device including the flexible display according to the present invention, by minimizing the coefficient of friction between the surface of the flexible display and the inner surface of the housing in contact therewith and/or other members such as films provided inside the housing, the conventional flexible display can be achieved. Compared to the included electronic device, an operating load generated during the process of pulling in and out of the flexible display may be minimized.

In addition, according to the electronic device including the flexible display according to the present invention, by minimizing the coefficient of friction between the flexible display surface and the inner surface of the housing in contact therewith and/or other members such as a film provided inside the housing, the conventional flexible Compared to an electronic device including a display, damage to the surface of the flexible display may be minimized during the process of pulling in and out of the flexible display.

1A is a cross-sectional view of a driving unit of an electronic device in a closed state according to an embodiment of the present invention.
1B is a cross-sectional view of a driving unit of an electronic device in an open state according to an embodiment of the present invention.
2A is a cross-sectional view of a driving unit of an electronic device in a closed state according to another embodiment of the present invention.
2B is a cross-sectional view of a driving unit of an electronic device in an open state according to another embodiment of the present disclosure.

The present invention relates to an electronic device having a concavo-convex pattern, and more particularly, by providing the concavo-convex pattern in a partial area inside a housing, operating load and display surface damage generated during the process of pulling in and out of a flexible display can be minimized. It's about electronic devices.

More specifically, a housing; a flexible display capable of being drawn into and drawn out of the inner space of the housing; and a driving unit for pulling in and out of the flexible display, wherein the housing has a concavo-convex pattern on at least a portion of the inside of the housing.

Hereinafter, with reference to the drawings, an embodiment of the present invention will be described in more detail. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the contents of the above-described invention, so the present invention is described in such drawings should not be construed as limited to

Terms used herein are for describing the embodiments, and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase.

As used herein, "comprises" and/or "comprising" means the presence or addition of one or more other elements, steps, operations and/or elements other than the mentioned elements, steps, operations and/or elements. is used in the sense of not excluding. Like reference numerals designate like elements throughout the specification.

The spatially relative terms “below”, “bottom”, “lower”, “above”, “upper”, “upper”, etc. refer to one element or component and another element or component as shown in the drawings. It can be used to easily describe the correlation with Spatially relative terms should be understood as encompassing different orientations of elements in use or operation in addition to the orientations shown in the figures. For example, when an element shown in the drawing is turned over, an element described as "below" or "below" another element may be placed "above" or "above" the other element. Accordingly, the exemplary term “below” may include directions of both down and up. Elements may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

1A is a cross-sectional view of a driving unit of an electronic device in a closed state according to an embodiment of the present invention, and FIG. 1B is a view showing a cross section of an electronic device in an open state according to an embodiment of the present invention. It is a diagram showing a cross section of a drive unit related to an electronic device.

Referring to FIGS. 1A and 1B , an electronic device 100 according to an embodiment of the present invention may include a housing 200, a flexible display 300, a driving unit 400, and a concavo-convex pattern 500. .

In one embodiment, the housing 200 (or housing structure) may be formed of a transparent material and / or a translucent material, for example, coated or colored glass, ceramics, polymers, It may be formed by aluminum, stainless steel (STS), or a combination of at least two or more of the foregoing materials.

In one embodiment, the housing 200 may be formed by combining a plurality of housing parts, or may be formed as a single member integrally formed.

In one embodiment, the electronic device 100 may be driven in a slide in-out method. For example, the viewer-side surface 310 of the flexible display 300 is a display area that is visible to the outside of the flexible display 300, and is visually exposed to an active area of the flexible display 300 capable of outputting an image. It may include an active region, and the rear-side surface 320 may be a region that faces the viewer-side surface 310 and is not visible to the outside.

1A shows the electronic device 100 in a state in which the viewer-side surface 310 of the flexible display 300 is not expanded, and FIG. 1B shows a state in which the viewer-side surface 310 of the flexible display 300 is expanded. represents the electronic device 100 of A state in which the viewer-side surface 310 is not expanded is a state in which the flexible display 300 is not moved in the first direction (eg, the +x-axis direction) with respect to the housing 200, and the electronic device 100 is closed. It can be referred to as a closed state. The state in which the viewer-side surface 310 is expanded is a state in which the flexible display 300 is moved to a maximum in which the flexible display 300 is no longer moved in the first direction with respect to the housing 200, and the open state (open state) of the electronic device 100 state) can be referred to as In some embodiments, the open state may include a fully open state as well as an intermediate state between a fully open state and a closed state.

In one embodiment, when the flexible display 300 moves at least partially in the first direction with respect to the housing 200 and is withdrawn from the housing 200, the flexible display 300 is “slide out”. can be referred to. When the flexible display 300 moves at least partially in a second direction (eg, -x axis direction) opposite to the first direction with respect to the housing 200 and is drawn into the housing 200, the " It may be referred to as "slide in". That is, the first direction may be referred to as a slide-out direction, and the second direction may be referred to as a slide-in direction.

In one embodiment, when the electronic device 100 is switched from a closed state to an open state, a portion of the flexible display 300 located inside the housing 200 slides, and the electronic device It is drawn out from the inner space of 100, and as a result, the viewer-side surface 310 of the flexible display 300 may be expanded. When the electronic device 100 is switched from an open state to a closed state, a portion of the flexible display 300 located outside the housing 200 slides to the inside of the electronic device 100 As a result, the viewer-side surface 310 of the flexible display 300 may be reduced.

In an embodiment, the flexible display 300 of the electronic device 100 may be drawn out from and drawn into the inner space of the electronic device 100 by the driving unit 400 . For example, the driving unit 400 may include a driving roller (or pulley) and/or a driving gear, and in the electronic device 100, a partial area of the flexible display 300 is driven by the driving roller. rotation of the drive roller (or pulley and/or drive gear) in transition between a closed state and an open state in driving connection with the (or pulley) and/or drive gear Through this, the movement of the flexible display 300 and its movement direction may be guided. For example, when the driving unit 400 rotates counterclockwise, the flexible display 300 driven by driving A part of the area of the electronic device 100 slides into the inside of the electronic device 100, the electronic device 100 can be switched to a closed state, and when the driving unit 400 rotates clockwise, the driving unit A partial area of the flexible display 300 driven by 400 may slide out of the inside of the electronic device 100, and the electronic device 100 may be converted into an open state. At this time, the area of the flexible display 300 drivingly connected to the driving roller (or pulley) and/or driving gear is a curved surface corresponding to the driving roller (or pulley) and/or driving gear. It may have an area bent to have a bending radius, which may be referred to as a bendable area or a bendable section In some embodiments, the driving unit may be in an open state and a closed state. It may be connected to a motor or an elastic member for automatic or semi-automatic implementation of a closed state, and in another embodiment, it may be connected to a pressure sensor or motion sensor capable of sensing pressure or motion.

In one embodiment, the electronic device 100 may have a concave-convex pattern 500 on at least a partial region inside the housing 200 . For example, the electronic device 100 may have a concave-convex pattern 500 on the inner surface of the housing 200 . In this case, in order for the electronic device 100 to switch between a closed state and an open state, a partial area of the flexible display 300 is drawn into and removed from the internal space of the electronic device 100. Friction between the viewer-side surface 310 of the flexible display 300 and the inner surface of the housing 200 that occurs during the drawing process can be minimized.

」 형태를 갖는 것일 수 있다. 전자 장치(100)가 마찰 영역(FR)에 대응되는 하우징(200)의 내측면 상에 요철 패턴(500)을 구비할 경우, 전자 장치(100)가 닫힌 상태(closed state)에서 열린 상태(open state)로 전환될 때, 하우징(200) 내부에 위치한 플렉서블 디스플레이(300)의 일부 영역이 전자 장치(100)의 내부 공간으로부터 인출되는 과정에서 플렉서블 디스플레이(300)의 시인측 표면(310)과 하우징(200)의 내측면 사이의 마찰을 최소화할 수 있다. 또한, 전자 장치(100)가 열린 상태(open state)에서 닫힌 상태(closed state)로 전환될 때, 하우징(200) 외부에 위치한 플렉서블 디스플레이(300)의 일부 영역이 전자 장치(100)의 내부 공간으로 인입되는 과정에서 플렉서블 디스플레이(300)의 시인측 표면(310)과 하우징(200)의 내측면 사이의 마찰을 최소화할 수 있다. 일부 실시 예에 있어서 전자 장치는, 마찰 영역에 대응되는 하우징의 내측면 중 일부 영역에만 요철 패턴을 구비할 수 있다.When the electronic device 100 is in a closed state, the area between the viewer-side surface 310 of the flexible display 300 drawn into the electronic device 100 and the inner surface of the housing 200 is It may be referred to as a friction region FR, for example, a form having a bent portion as shown in FIGS. 1A and 1B, for example, "

」 It may have a form. When the electronic device 100 has the concavo-convex pattern 500 on the inner surface of the housing 200 corresponding to the friction region FR, the electronic device 100 moves from a closed state to an open state. state), the viewer side surface 310 and the housing Friction between the inner surfaces of (200) can be minimized. In addition, when the electronic device 100 is switched from an open state to a closed state, a partial area of the flexible display 300 located outside the housing 200 is the internal space of the electronic device 100. Friction between the viewer-side surface 310 of the flexible display 300 and the inner surface of the housing 200 may be minimized during the process of being drawn into the flexible display 300 . In some embodiments, the electronic device may have a concavo-convex pattern only on a portion of an inner surface of the housing corresponding to the friction area.

In one embodiment, the coefficient of friction between the viewer-side surface 310 of the flexible display 300 and the concave-convex pattern 500 is preferably 0.5 or less, for example, 0.01 to 0.5, more preferably. It may be 0.2 or less, for example, it may be 0.05 to 0.2. When the friction coefficient between the viewer-side surface 310 of the flexible display 300 and the concave-convex pattern 500 satisfies the above range, the electronic device 100 is between a closed state and an open state When switching from , smooth driving is possible, and damage to the viewer-side surface 310 due to friction with the concave-convex pattern 500 itself can be prevented. In one embodiment, the electronic device 100 may include a hard coating layer (not shown) on the viewer-side surface 310 of the flexible display 300. In this case, the friction coefficient is It may refer to a coefficient of friction between the hard coating layer (not shown) of 310 and the concavo-convex pattern 500.

In one embodiment, the average roughness (Ra) of the concave-convex pattern 500 is preferably 0.1 to 1.0 μm, more preferably 0.2 to 0.5 μm. The average roughness (Ra) may be measured by a measurement method commonly used in the art. Specifically, with respect to the reference length L in the center line direction of the surface roughness curve, the center line direction is the x-axis, and the height It may be a value (μm) calculated according to Equation 1 below when the roughness curve is a function y = f(x) with the direction as the y-axis.

[Equation 1]

When the average roughness (Ra) of the concavo-convex pattern 500 is less than 0.1 μm, the anti-adhesive function between the viewer-side surface 310 of the flexible display 300 and the concavo-convex pattern 500 deteriorates, and the friction coefficient between the two contact surfaces increases If the average roughness (Ra) exceeds 1.0 μm, the viewer-side surface 310 may be damaged by the concavo-convex pattern 500 itself during the repetitive pulling-in/out process of the flexible display 300. .

In one embodiment, the concave-convex pattern 500 may be manufactured in the form of a film having a concave-convex pattern and attached to the inner surface of the housing 200 . For example, the film having the concavo-convex pattern is silica particles, silicone resin particles, melamine resin particles, acrylic resin particles, styrene resin particles, acrylic-styrene resin particles, polycarbonate resin particles, polyethylene resin particles , It may be produced by applying a composition for forming a concave-convex pattern including particles capable of forming a concave-convex pattern, such as vinyl chloride-based resin particles, to a transparent adhesive substrate. In some embodiments, commercially available products may be used as the film having the concavo-convex pattern, and for example, 3M AG Protection Filter from 3M, AGS1 from Nitto, and the like may be used.

In the electronic device 100 according to an embodiment of the present invention described above, the concavo-convex pattern 500 is directly formed on the inner surface of the housing 200, but the content of the present invention is not necessarily limited thereto. For example, in an electronic device according to some embodiments of the present disclosure, a surface in contact with a viewer-side surface of a flexible display in a closed state may be another member such as a film provided inside a housing. In this case, The concavo-convex pattern may be provided on an upper surface of the other member. In an electronic device according to another embodiment of the present invention, in a closed state, a part of the viewer-side surface of the flexible display is in contact with the inner surface of the housing, and the other part is a film provided inside the housing. It may be in contact with another member, and in this case, the concave-convex pattern may be provided on the inner surface of the housing and/or the upper surface of the other member.

2A is a cross-sectional view of a driving unit of an electronic device in a closed state according to another embodiment of the present invention, and FIG. 2B is a cross-sectional view of a driving unit of an electronic device in an open state according to another embodiment of the present invention. is the diagram shown.

Referring to FIGS. 2A and 2B , an electronic device 100 according to another embodiment of the present invention may include a housing 200, a flexible display 300, a driving unit 400, and a concavo-convex pattern 500. .

In another embodiment of the present invention, the electronic device 100 may be driven in a rollable manner. For example, the viewer-side surface 310 of the flexible display 300 is a display area that is visible to the outside of the flexible display 300, and is visually exposed to an active area of the flexible display 300 capable of outputting an image. It may include an active region, and the rear-side surface 320 may be a display area that faces the viewer-side surface 310 and is not visible to the outside.

FIG. 2A shows the electronic device 100 in a state in which the viewer-side surface 310 of the flexible display 300 is not expanded, and FIG. 2B shows a state in which the viewer-side surface 310 of the flexible display 300 is expanded. represents the electronic device 100 of The state in which the viewer-side surface 310 is not expanded is when a portion of the flexible display 300 is wound around the driving unit 400 and is not moved in the first direction (eg, the +x-axis direction) with respect to the housing 200. As a state, it may be referred to as a closed state of the electronic device 100 . In the state in which the viewer-side surface 310 is expanded, a portion of the flexible display 300 wound around the driving unit 400 is unwound from the driving unit 400 and is no longer moved in the first direction with respect to the housing 200. This state in which the electronic device 100 is moved to the maximum value may be referred to as an open state of the electronic device 100 . In some embodiments, the open state may include a fully open state as well as an intermediate state between a fully open state and a closed state. In some other embodiments, in a closed state of the electronic device, the entirety of the flexible display may be wound around the driving unit so that the flexible display may not be viewed from the outside of the housing.

In another embodiment of the present invention, when the electronic device 100 is switched from a closed state to an open state, a portion of the flexible display 300 located inside the housing 200 is moved by the driving unit 400. The electronic device 100 is unwound and drawn out from the internal space of the electronic device 100, and as a result, the viewer-side surface 310 of the flexible display 300 may be expanded. When the electronic device 100 is switched from an open state to a closed state, a partial area of the flexible display 300 located outside the housing 200 is wound around the driving unit 400, and the electronic device ( 100), and as a result, the viewer-side surface 310 of the flexible display 300 may be reduced.

In an embodiment, the flexible display 300 of the electronic device 100 may be drawn out from and drawn into the inner space of the electronic device 100 by the driving unit 400 . For example, in the electronic device 100, a partial region of the flexible display 300 is drivingly connected to the driving unit 400 to switch between a closed state and an open state. The movement of the flexible display 300 and its movement direction may be guided through rotation of ). For example, when the driving unit 400 rotates in a counterclockwise direction, a portion of the flexible display 300 drivingly connected to the driving unit 400 is wound around the driving unit 400, thereby forming the flexible display 300. is drawn into the electronic device 100, the electronic device 100 can be switched to a closed state, and when the driving unit 400 rotates clockwise, As a partial area of the flexible display 300 is unwound around the driving unit 400, the flexible display 300 is unwound from the inside of the electronic device 100 and the electronic device 100 is converted into an open state. can

」 형태를 갖는 것일 수 있다. 전자 장치(100)가 마찰 영역(FR)에 대응되는 하우징(200)의 내측면 상에 요철 패턴(500)을 구비할 경우, 전자 장치(100)가 닫힌 상태(closed state)에서 열린 상태(open state)로 전환될 때, 하우징(200) 내부에 위치한 플렉서블 디스플레이(300)의 일부 영역이 전자 장치(100)의 내부 공간으로부터 인출되는 과정에서 플렉서블 디스플레이(300)의 시인측 표면(310)과 하우징(200)의 내측면 사이의 마찰을 최소화할 수 있다. 또한, 전자 장치(100)가 열린 상태(open state)에서 닫힌 상태(closed state)로 전환될 때, 하우징(200) 외부에 위치한 플렉서블 디스플레이(300)의 일부 영역이 전자 장치(100)의 내부 공간으로 인입되는 과정에서 플렉서블 디스플레이(300)의 시인측 표면(310)과 하우징(200)의 내측면 사이의 마찰을 최소화할 수 있다. 일부 실시 예에 있어서 전자 장치는, 마찰 영역에 대응되는 하우징의 내측면 중 일부 영역에만 요철 패턴을 구비할 수 있다.In another embodiment of the present invention, when the electronic device 100 is in a closed state, the viewer side surface 310 of the flexible display 300 drawn into the electronic device 100 and the housing ( 200) may be referred to as a friction region FR, and, for example, a semicircular shape as shown in FIGS. 2A and 2B, for example, "

」 It may have a form. When the electronic device 100 has the concavo-convex pattern 500 on the inner surface of the housing 200 corresponding to the friction region FR, the electronic device 100 moves from a closed state to an open state. state), the viewer side surface 310 and the housing Friction between the inner surfaces of (200) can be minimized. In addition, when the electronic device 100 is switched from an open state to a closed state, a partial area of the flexible display 300 located outside the housing 200 is the internal space of the electronic device 100. Friction between the viewer-side surface 310 of the flexible display 300 and the inner surface of the housing 200 may be minimized during the process of being drawn into the housing 200 . In some embodiments, the electronic device may have a concavo-convex pattern only on a portion of an inner surface of the housing corresponding to the friction area.

The electronic device 100 according to another embodiment of the present invention shown in FIGS. 2A and 2B is, except for the above description, the electronic device 100 according to an embodiment of the present invention shown in FIGS. 1A and 1B Substantially the same content as described in can be applied.

」 형태를 가질 수 있고, 이에 대응하여 요철 패턴이 구비되는 영역 또한 확대될 수 있다. 또한, 도 2에 도시된 전자 장치에서 하우징이 플렉서블 디스플레이가 인입 및 인출될 수 있는 슬릿을 구비한 채, 구동부를 모두 덮는 형태로도 제작될 수 있다. 이 경우, 플렉서블 디스플레이의 시인측 표면과 하우징의 내측면(또는, 하우징 내부에 구비된 필름 등의 다른 부재) 사이의 마찰 영역은 「

」 형태를 가질 수 있고, 이에 대응하여 요철 패턴이 구비되는 영역 또한 확대될 수 있다.The electronic device of the present invention may be manufactured in various forms other than the forms shown in FIGS. 1 and 2 described above. For example, in the electronic device shown in FIG. 1 , the housing may be manufactured to cover all of the left semicircular portion of the driving unit (ie, the edge of the electronic device). In this case, the friction area between the viewer-side surface of the flexible display and the inner surface of the housing (or other members such as films provided inside the housing) is

」 shape, and correspondingly, the area provided with the concavo-convex pattern may also be enlarged. In addition, in the electronic device shown in FIG. 2 , the housing may be manufactured in a form covering the entire driving unit while having a slit through which the flexible display can be drawn in and out. In this case, the friction area between the viewer-side surface of the flexible display and the inner surface of the housing (or other members such as films provided inside the housing) is

」 shape, and correspondingly, the area provided with the concavo-convex pattern may also be enlarged.

Hereinafter, in order to evaluate driving stability of an electronic device and prevention of surface damage of a flexible display according to one or more embodiments of the present invention, the following experiments were performed on Samples 1 to 3 and Comparative Samples 1 to 2.

Preparation Example 1: Preparation of Sample 1

40 wt% pentaerythritol triacrylate (Miwon Corporation, M340), 2 wt% amorphous silica particles (Xylophobic 200, average particle diameter 3.9㎛, Fuji Silysia Co.), 55 wt% propylene glycol monomethyl ether, 2.7 wt% photoinitiator (Chiba Co., I-184) and 0.3% by weight fluorine-based leveling agent (KY-1203, Shin-Etsu Co.) were mixed using a stirrer to prepare a composition for forming a concave-convex pattern.

Thereafter, the composition for forming the concave-convex pattern was applied on a 60 μm TAC film using a wire bar #9, and then the solvent was dried at a temperature of 80° C. for 2 minutes. Thereafter, the dried film was irradiated with UV at a cumulative light amount of 400 mJ/cm ² to prepare a film having a concavo-convex pattern.

Thereafter, Sample 1 was prepared by fixing the film having the concavo-convex pattern to a glass substrate with an adhesive so that the concavo-convex pattern faces the upper surface.

Preparation Example 2: Preparation of Sample 2

40 wt% pentaerythritol triacrylate (Miwon Corporation, M340), 2 wt% amorphous silica particles (Xylophobic 200, average particle diameter 3.9㎛, Fuji Silysia Co.), 55 wt% propylene glycol monomethyl ether, 2.7 wt% photoinitiator (Ciba, I-184) and 0.3% by weight of a silicone-based leveling agent (BYK-333, BYK) were mixed using a stirrer to prepare a composition for forming a concavo-convex pattern.

Thereafter, the composition for forming the concavo-convex pattern was applied on a 60 μm TAC film using wire bar #7, and then the solvent was dried at 80° C. for 2 minutes. Thereafter, the dried film was irradiated with UV at a cumulative light amount of 400 mJ/cm ² to prepare a film having a concavo-convex pattern.

Thereafter, Sample 2 was prepared by fixing the film having the concavo-convex pattern to a glass substrate with an adhesive so that the concavo-convex pattern faces the upper surface.

Preparation Example 3: Preparation of Sample 3

38 wt% pentaerythritol triacrylate (Miwon Corporation, M340), 4 wt% amorphous silica particles (Xylophobic 200, average particle diameter 3.9㎛, Fuji Silysia Co.), 55 wt% propylene glycol monomethyl ether, 2.7 wt% photoinitiator (Ciba, I-184) and 0.3% by weight of a silicone-based leveling agent (BYK-333, BYK) were mixed using a stirrer to prepare a composition for forming a concavo-convex pattern.

Thereafter, the composition for forming the concave-convex pattern was applied on a 60 μm TAC film using a wire bar #8, and then the solvent was dried at 80° C. for 2 minutes. Thereafter, the dried film was irradiated with UV at a cumulative light amount of 400 mJ/cm ² to prepare a film having a concavo-convex pattern.

Thereafter, Sample 3 was prepared by fixing the film having the concavo-convex pattern to a glass substrate with an adhesive so that the concavo-convex pattern faces the upper surface.

Preparation Example 4: Preparation of Comparative Sample 1

42 wt% pentaerythritol triacrylate (Miwon Corporation, M340), 55 wt% propylene glycol monomethyl ether, 2.7 wt% photoinitiator (Ciba, I-184) and 0.3 wt% silicone-based leveling agent (BYK-UV3570, BYK) ) was mixed using a stirrer to prepare a composition for forming a hard coating.

Thereafter, the composition for forming the hard coating was applied on a 60 μm TAC film using a wire bar #10, and then the solvent was dried at 80° C. for 2 minutes. Thereafter, the dried film was irradiated with UV at a cumulative light amount of 400 mJ/cm ² to prepare a hard coating film.

Thereafter, the hard coating film was fixed to a glass substrate with an adhesive to prepare Comparative Sample 1.

Preparation Example 5: Preparation of Comparative Sample 2

42 wt% pentaerythritol triacrylate (Miwon Corporation, M340), 55 wt% propylene glycol monomethyl ether, 2.7 wt% photoinitiator (Ciba, I-184) and 0.3 wt% fluorine-based leveling agent (KY-1203, Shin-Etsu Co., Ltd. ) was mixed using a stirrer to prepare a composition for forming a hard coating.

Thereafter, the composition for forming the hard coating was applied on a 60 μm TAC film using a wire bar #10, and then the solvent was dried at 80° C. for 2 minutes. Thereafter, the dried film was irradiated with UV at a cumulative light amount of 400 mJ/cm ² to prepare a hard coating film.

Then, comparative sample 2 was prepared by fixing the hard coating film to a glass substrate with an adhesive.

Evaluation item (1): average roughness (Ra) measurement

The center line average roughness (Ra) values measured at 1,000x magnification using a confocal microscope (Keynes Co.) for the films having concavo-convex patterns of Samples 1 to 3 and the hard coating films of Comparative Samples 1 to 2 are shown in Table 1 below. was described in.

Evaluation item (2): haze measurement

The haze values measured using a haze meter (Murakami, HM-150) for the films having concavo-convex patterns of Samples 1 to 3 and the hard coating films of Comparative Samples 1 to 2 are shown in Table 1 below.

Evaluation item (3): contact angle measurement

The surface water contact angles measured for the films having concavo-convex patterns of Samples 1 to 3 and the hard coating films of Comparative Samples 1 to 2 are shown in Table 1 below.

Evaluation item (4): friction coefficient measurement

For each of Samples 1 to 3 and Comparative Samples 1 to 2, the hard coat surface of the hard coating film for flexible display is in contact with the concave-convex pattern of Samples 1 to 3 or the hard coating film of Comparative Samples 1 to 2, 25 ° C. And it was left for 24 hours under 50% RH conditions.

Then, the friction coefficient measured when the hard coating film for a flexible display provided on the upper surface of each of Samples 1 to 3 and Comparative Samples 1 to 2 was rubbed 10 times with a load of 200g was shown in Table 1 below.

Evaluation item (5): evaluation of adhesion prevention

For each of Samples 1 to 3 and Comparative Samples 1 to 2, the hard coat surface of the hard coating film for flexible display is in contact with the concave-convex pattern of Samples 1 to 3 or the hard coating film of Comparative Samples 1 to 2, 25 ° C. And it was left for 24 hours under 50% RH conditions.

Thereafter, the hard coating film for a flexible display provided on the upper surface of each of Samples 1 to 3 and Comparative Samples 1 to 2 was pulled in a direction parallel to the glass substrate to evaluate anti-adhesiveness between the two films, and the results are shown in the table below. 1.

<Evaluation Criteria for Anti-Adherence>

○: In terms of appearance, the two films do not adhere at all and move naturally.

△: Although the two films are adhered to each other in appearance, they move without difficulty in pulling.

Χ : The two films are attached to each other, and the adhesive surface falls off when pulled and moves unnaturally.

Average roughness (μm) Haze (%) Contact angle (°) friction coefficient anti-adherence sample 1 0.20 13.2 111 0.06 ○ sample 2 0.38 15.3 87 0.12 ○ sample 3 0.44 25.4 94 0.15 ○ Comparison Sample 1 0.04 0.5 105 0.93 Χ Comparison Sample 2 0.04 0.3 115 0.54 Χ

Referring to Table 1, samples 1 to 3 having a concave-convex pattern having an average roughness in the range of 0.1 to 1.0 μm and a friction coefficient of 0.5 or less have excellent anti-adhesion performance between the two films, and slide in-out (slide When applied to an electronic device driven in an in-out or rollable manner, it can be seen that there is no difficulty in driving the device and damage to the viewer-side surface of the flexible display can be prevented.

On the other hand, Comparative Samples 1 and 2 having an average roughness of less than 0.1 μm and a friction coefficient of more than 0.5 had poor anti-adhesive performance between the two films, so that the slide in-out method or rollable It can be seen that when applied to an electronic device driven in this manner, an excessive load may cause the device to drive poorly and damage the viewer-side surface of the flexible display.

Claims (11)

housing;
a flexible display capable of being drawn into and drawn out of the inner space of the housing; and
A driving unit for retracting and withdrawing the flexible display;
The electronic device, wherein the housing has a concave-convex pattern on at least a partial region therein.
The electronic device according to claim 1, wherein the concavo-convex pattern is provided in at least a portion of the friction area.
The electronic device of claim 1, wherein the concavo-convex pattern contacts at least one surface of the inserted flexible display.
The electronic device of claim 3 , wherein one surface of the flexible display contacting the concavo-convex pattern is a viewer-side surface.
The electronic device of claim 3, wherein a coefficient of friction between a surface of the flexible display contacting the concave-convex pattern and the concave-convex pattern is 0.5 or less.
The electronic device of claim 5 , wherein a coefficient of friction between a surface of the flexible display contacting the concave-convex pattern and the concave-convex pattern is 0.2 or less.
The electronic device of claim 1 , wherein an average roughness (Ra) of the concavo-convex pattern is 0.1 to 1.0 μm.
The electronic device of claim 7 , wherein an average roughness (Ra) of the concavo-convex pattern is 0.2 to 0.5 μm.
The electronic device of claim 1 , wherein the concavo-convex pattern is attached in the form of a film.
The electronic device of claim 1 , wherein the flexible display is drawn in by being wound around the housing interior space by the driving unit, and drawn out by being unwound in the housing interior space.
The electronic device of claim 1 , wherein the flexible display is drawn in by being slid into the housing inner space by the driving unit and drawn out by being slid out of the housing inner space.

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