KR20210043029A - Substrate for flexible display device and flexible display device - Google Patents

Abstract

Disclosed is a support substrate for a flexible display device to prevent a wrinkle of a flexible display device. The support substrate for a flexible display device comprises: an elastic member disposed on the rear surface of a flexible display panel; a first rigid support member disposed on the rear surface of the elastic member and disposed on a left or right side of a folded region in the middle of the elastic member; and a second rigid support member disposed symmetrically with the first rigid support member with respect to the folded region.

Description

Support substrate for flexible display device and flexible display device {SUBSTRATE FOR FLEXIBLE DISPLAY DEVICE AND FLEXIBLE DISPLAY DEVICE}

The present invention relates to a support substrate for a flexible display device and a flexible display device, and more particularly, to a support substrate for a flexible display device and a flexible display device having improved elasticity during folding.

In recent years, as society enters the era of full-scale information, the field of display processing and displaying a large amount of information has rapidly developed, and in response to this, various flat display devices have been developed. Be in the spotlight.

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescent display. Devices (Electroluminescence Display device: ELD), organic light emitting diodes (OLED), etc. can be mentioned. These flat panel display devices show excellent performance of thinner, lighter, and low power consumption. : CRT) is rapidly being replaced.

Meanwhile, since such a flat panel display device uses a glass substrate to withstand high heat generated during a manufacturing process, there is a limit to providing light weight, thinness, and flexibility.

Therefore, a flexible display device manufactured to maintain display performance even if it is bent like paper by using a flexible material such as plastic instead of the existing glass substrate is rapidly emerging as a next-generation flat panel display device.

The flexible display device uses a plastic thin film transistor substrate instead of glass, which is highly durable, unbreakable, bendable without breaking, rollable, and foldable folders. It can be classified into foldable, etc., and such a flexible display device has advantages of space utilization, interior design, and design, and can have various application fields.

In particular, in recent years, in order to realize a large area along with ultra-thin, lightweight, and compact, research on a foldable flexible display device that can be carried in a folded state and displays an image in an unfolded state has been actively conducted.

The flexible display device can be applied not only to mobile devices such as mobile phones, ultra mobile PCs, e-books, and electronic newspapers, but also to various fields such as TVs and monitors.

Such a flexible display device includes a display panel for largely realizing an image, a back plate positioned below the display panel to support the display panel, and a cover window positioned in front of the display panel to protect the display panel. cover window).

Since such a flexible display device must be able to be folded and unfolded, both a back plate including a display panel and a cover window are formed in a very thin film form, and such a flexible display device has a problem of very weak impact resistance.

In addition, in the case of a flexible display device, in the conventional case, the substrate constituting the back plate is made of a plastic material or a metal material. In the case of a plastic material, there is a problem of insufficient elasticity and rigidity, and in the case of a metal material, there is a problem that the bending radius is large and durability against folding is weak.

Therefore, the problem to be solved by the present invention is to improve the resilience of the flexible display device during folding, give rigidity to the rest of the area except for the folded area, and prevent wrinkles in the flexible display device due to the folding operation. It is to provide a device support substrate and a flexible display device.

A support substrate for a flexible display device according to an embodiment of the present invention includes an elastic member disposed on a rear surface of the flexible display panel; A first rigid support member disposed on the rear surface of the elastic member and disposed to the left or right of the folded region in the center of the elastic member; And a second rigid support member disposed symmetrically with the first rigid support member based on the folded region.

In one embodiment, the elastic member may be formed of a metal thin film foil.

In one embodiment, the metal thin film foil may be made of stainless steel.

In one embodiment, the metal thin film foil may be made of stainless steel, may have a thickness of 30 μm or less, a Vickers hardness value of 490 or more, a yield strength of 1200 N/mm 2 or more, and a tensile strength of 1500 N/mm 2 or more.

In one embodiment, the elastic member is adhered to the rear surface of the flexible display panel by an adhesive, the first rigid support member and the second rigid support member are adhered to the rear surface of the elastic member by the adhesive, and the The adhesive may have an adhesive force maintained between the flexible display panel and the elastic member, between the elastic member and each of the rigid support members of 500 gf/cm 2 or more.

In one embodiment, it may further include an elastic reinforcing layer disposed on the folded region.

In one embodiment, the elastic reinforcing layer may be a thermoplastic polyurethane elastomer containing carbon fiber or glass fiber.

In one embodiment, the elastic reinforcing layer may be disposed to have a step difference of 10 μm or less from the first rigid support member and the second rigid support member.

A flexible display device according to an embodiment of the present invention includes a flexible display panel on which an image is implemented; And a support substrate supporting the flexible display panel, wherein the support substrate comprises: an elastic member disposed on a rear surface of the flexible display panel; A first rigid support member disposed on the rear surface of the elastic member and disposed to the left or right of the folded region in the center of the elastic member; And a second rigid support member disposed symmetrically with the first rigid support member based on the folded region.

In one embodiment, it may further include an elastic reinforcing layer disposed on the folded region.

In one embodiment, the elastic reinforcing layer may be a thermoplastic polyurethane elastomer containing carbon fiber or glass fiber.

In one embodiment, the elastic reinforcing layer may be disposed to have a gap of 10 μm or less, respectively, from the first and second rigid support members.

In one embodiment, the elastic member may be made of a metal thin film foil, and the metal thin film foil may be made of stainless steel.

The support substrate for a flexible display device according to the present invention may have the following advantages.

First, since an elastic member composed of a metal thin film foil and an elastic reinforcing layer disposed in the folded region of the elastic member are provided, if the support substrate supports the flexible display panel, there is an advantage of improving the resilience that is restored after the flexible display panel is folded. .

Second, since the first rigid support member and the second rigid support member are provided in the remaining areas except for the folded area of the elastic member, that is, the non-folding area, when the support substrate supports the flexible display panel, rigidity is imparted to the remaining areas except the folded area. Therefore, when the flexible display panel is folded, the torsion of the support substrate is minimized, and there is an advantage of stably supporting the flexible display panel.

Third, since the elastic reinforcing layer is disposed only in the folded area, the division between the folded area and the non-folded area becomes clear, and according to this clear division, there is an advantage that the folding operation based on the folded area can be accurately performed.

Fourth, since the elastic member is disposed on the rear surface of the flexible display panel, there is an advantage in that wrinkles of the flexible display panel due to the folding operation of the flexible display panel can be prevented.

1 is a cross-sectional view for explaining the configuration of a support substrate for a flexible display device according to an embodiment of the present invention.
2 is a view showing a state in which a support substrate is folded by supporting a flexible display panel according to an embodiment of the present invention.

Hereinafter, a support substrate for a flexible display device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the present invention, various modifications may be made and various forms may be applied, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals have been used for similar elements. In the accompanying drawings, the dimensions of the structures are shown to be enlarged than the actual size for clarity of the present invention.

Terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility of the presence or addition.

Unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

1 is a cross-sectional view for explaining the configuration of a support substrate for a flexible display device according to an embodiment of the present invention.

Referring to FIG. 1, a support substrate according to an embodiment of the present invention may include an elastic member 110, a first rigid support member 121, a second rigid support member 122, and an elastic reinforcing layer 140. have.

The elastic member 110 may be disposed on the rear surface of the flexible display panel 150. In this case, the elastic member 110 may be adhered to the rear surface of the flexible display panel 150 through the adhesive 130. The adhesive 130 may be provided so that the adhesive force maintained between the flexible display panel 150 and the elastic member 110 is 500 gf/cm 2 or more. When the adhesive force is less than 500 gf/cm 2, the elastic member 110 may be peeled off or lifted when the flexible display panel 150 is folded. When the flexible display panel 150 is folded to a half size, the elastic member 110 may be folded based on the center area, and in this case, a predetermined width in the center of the elastic member 110 may be the folded area 111.

In one embodiment, the elastic member 110 may be formed of a metal thin film foil. For example, the metal thin film foil may be made of stainless steel. The metal thin film foil may be provided to have elasticity. For example, the metal thin film foil may have a thickness of 30 μm or less, a Vickers hardness value of 490 or more, a yield strength of 1200 N/mm 2 or more, and a tensile strength of 1500 N/mm 2 or more.

The first rigid support member 121 and the second rigid support member 122 may be disposed on the rear surface of the elastic member 110. In this case, the first rigid support member 121 and the second rigid support member 122 may be adhered to the rear surface of the elastic member 110 through the adhesive 130. The adhesive 130 may be provided so that the adhesive force maintained between the elastic member 110 and each of the rigid support members 121 and 122 is 500 gf/cm 2 or more. The first rigid support member 121 and the second rigid support member 122 may be formed of a metal material.

The first rigid support member 121 may be disposed on the left or right side of the folded region 111 of the elastic member 110. For example, the first rigid support member 121 may be disposed on the left side of the folded region 111.

The second rigid support member 122 may be disposed symmetrically with the first rigid support member 121 based on the folded region 111 of the elastic member 110.

These first rigid support member 121 and the second rigid support member 122 are disposed on the left and right sides of the folded region 111 of the elastic member 110 so that the elastic member 110 other than the folded region 111 cannot be folded. It can be placed in an area that does not. In addition, there is no particular limitation on the thickness of the first rigid support member 121 and the second rigid support member 122, and the non-folding area of the flexible display panel 150 and the elastic member 110 is not bent or bent. It can have a thickness.

The elastic reinforcing layer 140 is disposed on the folded region 111 and is positioned between the first rigid support member 121 and the second rigid support member 122. In this case, the elastic reinforcing layer 140 may be disposed to have a step difference of 10 μm or less from the first and second rigid support members 121 and 122. When the interval exceeds 10 μm, visibility as if the elastic reinforcing layer 140 is recessed may occur. The elastic reinforcing layer 140 may be made of a material having elasticity. For example, the elastic reinforcing layer 140 may be composed of a thermoplastic polyurethane elastomer containing carbon fiber or glass fiber.

Such a support substrate according to an embodiment of the present invention may be disposed on the rear surface of the flexible display panel 150 to constitute a flexible display device.

2 is a view showing a state in which a support substrate is folded by supporting a flexible display panel according to an embodiment of the present invention.

In the support substrate according to an embodiment of the present invention, the flexible display panel 150 may be folded in half with respect to the folded region 111 of the elastic member 110. In this case, the elastic reinforcing layer 140 disposed in the folded region 111 may be expanded and folded.

When attempting to unfold the folded support substrate again, spaced apart both sides of the support substrate facing each other, the expanded elastic reinforcing layer 140 is restored and the support substrate can be unfolded.

Such a support substrate according to an embodiment of the present invention may have the following advantages.

First, since an elastic member 110 made of a metal thin film foil and an elastic reinforcing layer 140 disposed in the folded region 111 of the elastic member 110 are provided, a flexible display when the supporting substrate supports the flexible display panel 150 There is an advantage of improving the resilience that is restored after the panel 150 is folded.

Second, since the first rigid support member 121 and the second rigid support member 122 are provided in the remaining areas except for the folded area 111 of the elastic member 110, that is, the non-folding area, the supporting substrate is a flexible display panel ( When supporting 150), rigidity is given to the remaining areas except for the folded area 111, thereby minimizing the torsion of the supporting substrate when folding the flexible display panel 150, and stably supporting the flexible display panel 150 There is this.

Third, since the elastic reinforcing layer 140 is disposed only in the folded area 111, the division between the folded area 111 and the non-folding area becomes clear, and the folding operation based on the folded area 111 is accurately performed according to this clear division. There is an advantage to be able to.

Fourth, since the elastic member 110 is disposed on the rear surface of the flexible display panel 150, there is an advantage that wrinkles of the flexible display panel 150 due to the folding operation of the flexible display panel 150 can be prevented.

The description of the presented embodiments is provided to enable any person skilled in the art to use or practice the present invention. Various modifications to these embodiments will be apparent to those of ordinary skill in the art, and general principles defined herein can be applied to other embodiments without departing from the scope of the present invention. Thus, the present invention is not to be limited to the embodiments presented herein, but is to be construed in the widest scope consistent with the principles and novel features presented herein.

Claims (13)

An elastic member disposed on the rear surface of the flexible display panel;
A first rigid support member disposed on the rear surface of the elastic member and disposed to the left or right of the folded region in the center of the elastic member; And
It characterized in that it comprises a second rigid support member disposed symmetrically with the first rigid support member based on the folded region,
Support substrate for flexible display devices. The method of claim 1,
The elastic member is characterized in that consisting of a metal thin film foil,
Support substrate for flexible display devices. The method of claim 2,
The metal thin film foil is characterized in that the stainless material,
Support substrate for flexible display devices. The method of claim 2,
The metal thin film foil is made of stainless steel,
The thickness is less than 30㎛,
Vickers hardness value is more than 490,
Yield strength is 1200N/㎟ or more,
Characterized in that the tensile strength is 1500N/mm2 or more,
Support substrate for flexible display devices. The method of claim 1,
The elastic member is adhered to the rear surface of the flexible display panel by an adhesive,
The first rigid support member and the second rigid support member are adhered to the rear surface of the elastic member by the adhesive,
The pressure-sensitive adhesive is characterized in that the adhesive force maintained between each of the flexible display panel and the elastic member, between the elastic member and each rigid support member is 500 gf/cm 2 or more,
Support substrate for flexible display devices. The method of claim 1,
It characterized in that it further comprises an elastic reinforcing layer disposed on the folded region,
Support substrate for flexible display devices. The method of claim 1,
The elastic reinforcing layer is characterized in that the thermoplastic polyurethane elastic body containing carbon fiber or glass fiber,
Support substrate for flexible display devices. The method of claim 7,
The elastic reinforcing layer is characterized in that it is disposed to have a step difference of 10 μm or less with the first rigid support member and the second rigid support member,
Support substrate for flexible display devices. A flexible display panel on which an image is implemented; And
Including a support substrate for supporting the flexible display panel,
The support substrate,
An elastic member disposed on the rear surface of the flexible display panel;
A first rigid support member disposed on the rear surface of the elastic member and disposed to the left or right of the folded region in the center of the elastic member; And
It characterized in that it comprises a second rigid support member disposed symmetrically with the first rigid support member based on the folded region,
Flexible display device. The method of claim 9,
It characterized in that it further comprises an elastic reinforcing layer disposed on the folded region,
Flexible display device. The method of claim 10,
The elastic reinforcing layer is characterized in that the thermoplastic polyurethane elastic body containing carbon fiber or glass fiber,
Flexible display device. The method of claim 10,
The elastic reinforcing layer is characterized in that the first rigid support member and the second rigid support member and are arranged to each have a spacing of 10 μm or less,
Flexible display device. The method of claim 9,
The elastic member is composed of a metal thin film foil,
The metal thin film foil is characterized in that the stainless material,
Flexible display device.

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