Rollable display

Abstract

Disclosed is a rollable display that prevents slippage between a flexible display panel and a backplane attached to the flexible display panel for supporting the flexible display panel. The rollable display is characterized by a different pattern of the backplane for each region. Further, the rollable display is characterized in that the display unit can be folded and unfolded via the link unit so as not to be folded or rollable multiple times in the same direction.

Description

[0001] This application is a divisional application of the original invention patent application with application number 201811286009.8 (application date: October 31, 2018, invention name: rollable display). Technical Field

[0002] The present invention relates to a rollable display, and more particularly, to a rollable display that prevents slippage between a display panel and a back plate for supporting the display panel. Background Art

[0003] Image displays that reproduce various information on the screen are the core technology of the information and communication era, and are developing towards becoming thinner, lighter and having higher performance. Therefore, as an example of a flat panel display that can reduce the disadvantageous weight and volume of a cathode ray tube (CRT), an organic light emitting display that can achieve self-luminescence without a light source unit has become the focus of attention.

[0004] In such an organic light emitting display, a plurality of pixels are arranged in a matrix form to display an image, wherein each pixel includes a light emitting element and a pixel driving circuit composed of a plurality of transistors and driving the light emitting element independently of each other.

[0005] Recently, there is a growing demand for flexible displays that are easy to carry in a pocket or a small bag and can display images on a larger screen than when carried, with respect to various applications. Such flexible displays are folded or partially bent when carried or stored, but unfolded when displaying images, which can increase the image display area and can increase the user's visual perception and viewing reality perception.

[0006] In particular, among flexible display devices of various shapes, a rollable display has been extensively studied due to its advantages of excellent portability and increased area of ​​the display when unfolded compared to when rolled.

[0007] Figure 1 This is a diagram illustrating a general rollable display.

[0008] like Figure 1 As shown, the display panel 10 is attached to a plate 20 having a supporting force to constitute a display unit. Then, in a state where the display unit is rolled around a uniaxial roller (not shown), an end of the display unit is unwound from the roller to use the display unit for display.

[0009] Here, an adhesive layer (not shown) is provided between the display panel 10 and the board 20 to attach them to each other. Since the board 20 is wound along a circumference smaller than that of the display panel 10 on the inside, the greater the number of turns, the greater the path difference between the board 20 and the display panel 10 due to the circumference difference. Therefore, when wound around the roller two or more times, at the end of the display unit, the board 20 is pushed away to be a long distance from the display panel 10.

[0010] The display unit is wound around the roller in the storage or portable state of the rollable display, and is unwound from its end only when used for display. When the slippage between the plate 20 and the display panel 10 is serious in the state where the display unit is wound around the roller, the adhesive layer between the plate 20 and the display panel 10 is deformable, so that the two are fixed together in the state of slippage and deformation. As a result, when the display unit of the rollable display is unwound from the roller so that an image is displayed on the end of the display unit, a slippage defect occurs. Specifically, this slippage occurs not only between the plate 20 and the display panel 10, but also in turn between the various layers, adhesive layers and the plate 20 provided in the display panel 10. This is visible as a wavy uneven portion when displaying an image, which deteriorates visibility. Summary of the invention

[0011] Accordingly, the present invention is directed to a rollable display that substantially obviates one or more problems due to limitations and disadvantages of the related art.

[0012] The present invention is provided to solve the above-mentioned problems, and an object of the present invention is to provide a rollable display which prevents slippage between a display panel and a back plate by changing the shape of the back plate when the back plate is stored in a receiving case (housing).

[0013] Other advantages, purposes and features of the present invention will be partially described in the following description, and will become apparent to those skilled in the art after reviewing the following or may be learned from the practice of the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures specifically pointed out in the written description and its claims and the accompanying drawings.

[0014] To achieve these objects and other advantages, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention provides a rollable display in which a back panel for supporting a display panel is variable in shape so as to be stored in a containing housing in a folded state using the different characteristics of each area without the need for separate mechanical equipment.

[0015] According to one embodiment of the present invention, a rollable display includes: a flexible display panel, the flexible display panel including a first surface as a display surface and a second surface as a rear surface; a back plate, the back plate is configured to be in contact with the second surface and includes inner folding portions and outer folding portions arranged alternately, and a non-folding portion is located between the inner folding portions and the outer folding portions; and a accommodating shell, the accommodating shell is configured to accommodate the flexible display panel and the back plate folded integrally at the inner folding portions and the outer folding portions.

[0016] The accommodating shell may be provided with an opening through which the flexible display panel and the back plate are integrally introduced or led out. The accommodating shell may include a space having a height equal to or greater than the sum of the curvature of the inner folding portion, the curvature of the outer folding portion, and the length of the non-folding portion between the inner folding portion and the outer folding portion.

[0017] When folded inside the accommodating shell, in the inner folding portion, the back plate may be located on the inner side and the first surface of the flexible display panel may be located on the outer side, and in the outer folding portion, the back plate may be located on the outer side and the first surface of the flexible display panel may be located on the inner side.

[0018] The specific gravity of each of the inner folded portion and the outer folded portion of the back plate may be lower than that of the non-folded portion.

[0019] Each of the inner folded portion and the outer folded portion of the back plate may have a plurality of holes. Here, the depth of each hole may be greater than 1 / 2 of the thickness of the back plate.

[0020] The width of the outer folded portion of the back plate may be greater than the width of the inner folded portion.

[0021] The back plate may further include a step compensation layer on at least one of an upper surface and a lower surface of the back plate. The opening or hole may be filled with the step compensation layer.

[0022] The rollable display may further include: a cover member disposed on one side of the flexible display panel and the back plate.

[0023] The rollable display may further include: a pad member disposed on a side of the flexible display panel opposite to a side on which the cover member is disposed.

[0024] The rollable display may further include: a printed circuit board disposed in the receiving case to be electrically connected to the flexible film connected to the pad member.

[0025] The pad member may be electrically connected to the flexible printed circuit board.

[0026] The flexible printed circuit board may be attached and fixed within the accommodation case.

[0027] The rollable display may further include a supporting member disposed adjacent to the opening in the receiving case and configured to support the first surface of the display panel and a surface of the back plate that is not in contact with the second surface.

[0028] The back panel may include a plurality of inner folding portions and a plurality of outer folding portions, and adjacent inner folding portions that are separated from each other by an outer folding portion and non-folding portions located on opposite sides of the outer folding portion outside the accommodating shell may contact each other when the back panel is folded in the accommodating shell, and adjacent outer folding portions that are separated from each other by an inner folding portion and non-folding portions located on opposite sides of the inner folding portion outside the accommodating shell may contact each other when the back panel is folded in the accommodating shell.

[0029] In addition, the rollable display may include a display unit and a link unit such that the display unit may be folded and unfolded to alternately implement multiple inward folding and outward folding during folding of the link unit.

[0030] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

[0031] Note 1. A rollable display, comprising:

[0032] A flexible display panel, the flexible display panel comprising a first surface as a display surface and a second surface as a rear surface;

[0033] a back plate disposed in contact with the second surface and comprising inner folded portions and outer folded portions arranged alternately, with a non-folded portion being located between the inner folded portions and the outer folded portions; and

[0034] A receiving case is configured to receive the flexible display panel and the back plate integrally folded at the inner folding portion and the outer folding portion in the receiving case.

[0035] Note 2. The rollable display according to Note 1, wherein the accommodating shell is provided with an opening, through which the flexible display panel and the back plate are introduced or led out as a whole.

[0036] Note 3. A rollable display according to Note 1, wherein the accommodating shell includes a space, the height of the space is equal to or greater than the sum of the curvature of the inner folding portion, the curvature of the outer folding portion, and the length of the non-folding portion between the inner folding portion and the outer folding portion.

[0037] Note 4. The rollable display according to Note 1, wherein when the back plate is folded inside the accommodating shell, in the inner folding portion, the back plate is located inside and the first surface of the flexible display panel is located outside, and

[0038] In the outer folder, the back plate is located on the outside and the first surface of the flexible display panel is located on the inside.

[0039] Supplementary note 5. The rollable display according to Supplementary note 1, wherein a specific gravity of each of the inner folding portion and the outer folding portion of the back plate is lower than a specific gravity of the non-folding portion.

[0040] Supplementary note 6. The rollable display according to Supplementary note 5, wherein each of the inner folding portion and the outer folding portion of the back plate has a plurality of holes.

[0041] Note 7. The rollable display according to Note 6, wherein the size of each hole is greater than 1 / 2 of the thickness of the back plate.

[0042] Note 8. The rollable display according to Note 6, wherein the width of the outer folding portion of the back panel is greater than the width of the inner folding portion.

[0043] Note 9. The rollable display according to Note 6, wherein the back panel further comprises a step compensation layer located on at least one of the upper surface and the lower surface of the back panel.

[0044] Supplementary note 10. The rollable display according to Supplementary note 9, wherein the plurality of holes are filled with the step compensation layer.

[0045] Note 11. The rollable display according to Note 1 further comprises: a cover member, wherein the cover member is disposed on one side of the flexible display panel and the back plate.

[0046] Note 12. The rollable display according to Note 11 further comprises: a pad member located on a side of the flexible display panel opposite to a side where the cover member is disposed.

[0047] Supplementary note 13. The rollable display according to Supplementary note 12, further comprising: a printed circuit board disposed in the accommodating case to be electrically connected to the flexible film connected to the pad member.

[0048] Supplementary note 14. The rollable display according to Supplementary note 12, wherein the pad member is electrically connected to a flexible printed circuit board.

[0049] Note 15. The rollable display according to Note 14, wherein the flexible printed circuit board is attached and fixed within the accommodating shell.

[0050] Note 16. The rollable display according to Note 2 further comprises: a supporting member adjacent to the opening in the accommodating shell and supporting the first surface of the display panel and a surface of the back plate that is not in contact with the second surface.

[0051] Note 17. The rollable display according to Note 1, wherein the back panel comprises a plurality of inner folding portions and a plurality of outer folding portions,

[0052] wherein adjacent inner folding portions spaced apart from each other by an outer folding portion and non-folding portions located on opposite sides of the outer folding portion on the outside of the accommodating shell contact each other when the back plate is folded in the accommodating shell, and

[0053] Wherein, adjacent outer folding portions which are separated from each other by an inner folding portion and non-folding portions located on opposite sides of the inner folding portion outside the accommodating shell contact each other when the back plate is folded in the accommodating shell.

[0054] Note 18. A rollable display, comprising:

[0055] a display unit including a flexible display panel formed with an upper surface serving as a display surface of the flexible display panel and a back plate disposed in contact with a rear surface of the display panel and provided with a plurality of folding portions and non-folding portions arranged alternately; and

[0056] A link unit is coupled to a rear surface of the back plate to enable the folding portion of the display unit to be folded inwardly and folded outwardly alternately for a plurality of times.

[0057] Note 19. The rollable display according to Note 18, wherein the link unit comprises:

[0058] a plurality of shafts coupled to corresponding non-folding portions along a first direction on a rear surface of the display unit; and

[0059] a first link rod rotatably coupled to a corresponding shaft; and

[0060] A second link rod is coupled to the corresponding shaft outside the first link rod.

[0061] Supplement 20. The rollable display according to Supplement 19, wherein the plurality of axes include a first axis, a second axis disposed in front of the first axis along the first direction, and a third axis disposed behind the first axis along the first direction,

[0062] wherein one end of a first link rod corresponding to the first axis is connected to an upper end of a second link rod corresponding to the second axis, and the other end of the first link rod corresponding to the first axis is connected to a lower end of a second link rod corresponding to the third axis,

[0063] wherein one end of a second link rod corresponding to the first axis is connected to an upper end of a first link rod corresponding to the second axis, and the other end of the second link rod corresponding to the first axis is connected to a lower end of the first link rod corresponding to the third axis, and

[0064] The first link rod and the second link rod rotate in cooperation with each other.

[0065] Note 21. The rollable display according to Note 20, wherein when the first link rod rotates in a given direction around the rotation axis of the corresponding shaft and the second link rod rotates in a direction opposite to the given direction around the rotation axis of the corresponding shaft, the display unit is unfolded into a planar shape, and

[0066] Wherein, when the first link rod rotates in a direction opposite to the given direction and the second link rod rotates in the given direction, the display unit is folded to have a plurality of folding areas.

[0067] Note 22. A rollable display according to Note 21, wherein the display unit includes at least one hook-shaped member, which is arranged on the rear surface of each non-folding portion of the back plate and connected to a corresponding one of the first axis to the third axis to fix the display unit to the link unit.

[0068] Supplementary note 23. The rollable display according to Supplementary note 22, wherein the hook-shaped member is arranged so that a position where the hook-shaped member is coupled to the first axis does not interfere with a position where the hook-shaped member is coupled to the second axis or the third axis.

[0069] Note 24. According to the rollable display described in Note 21, the rollable display also includes: a side shaft, which is arranged parallel to the shaft to connect at least one of the two ends of the first link rod, and the rear surface of the display unit is supported by or connected to the side shaft.

[0070] Note 25. The rollable display according to Note 19 further comprises: a printed circuit board connected to one end of the display unit,

[0071] Wherein, the printed circuit board is formed to have a length equal to or smaller than a length of the first link bar or the second link bar.

[0072] Note 26. The rollable display according to Note 19, wherein the first link rod and the second link rod have the same length. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.

[0074] Figure 1 This is a diagram illustrating a general rollable display.

[0075] Figure 2 is a cross-sectional view illustrating a folded state of the rollable display according to the first embodiment of the present invention.

[0076] Figure 3 is an example Figure 2 A cross-sectional view of the unfolded state of the rollable display.

[0077] Figure 4 This is an example of the interior of the housing. Figure 2 A stereoscopic image of a rollable display.

[0078] Figure 5 Is a single example Figure 2 A plan view of a flexible display panel.

[0079] Figure 6 is a cross-sectional view illustrating a flexible display panel according to the present invention.

[0080] Fig. 7A and Figure 7B are examples Figure 2 The plan view of area B and area A.

[0081] Figure 8 is an example Figure 2 Plan view of the back panel.

[0082] 9A to 9F According to various embodiments Figure 2 A cross-sectional view of region A or region B of the back plate shown in FIG.

[0083] Fig.10 is a perspective view illustrating a rollable display according to a second embodiment of the present invention.

[0084] Figures 11 to 13 is an example Fig.10 Reference view of a rollable display gradually unfolding.

[0085] Fig.14A is an example Fig.12 A side view of the side surface.

[0086] Fig. 14B is an example Fig.13 A side view of the side surface.

[0087] Fig.15 is an example Fig.10 A reference view of a part of the interior. DETAILED DESCRIPTION

[0088] Hereinafter, an exemplary embodiment according to the present invention will be described in detail with reference to the accompanying drawings. Where possible, the same reference numerals will be used throughout the accompanying drawings to represent the same or similar components. In addition, in the following description of the embodiments, when the detailed description of the known functions and configurations incorporated herein may hinder the understanding of the embodiments, the detailed description thereof will be omitted. In addition, the names of the constituent elements used in the following description are selected in consideration of ease of writing the specification, and may be different from the names of the components of the actual product.

[0089] In addition, it should be understood that when an element or layer is referred to as being "on" another element, the element or layer may be directly on the other element or layer, or intervening elements or layers may also be present. On the other hand, it should be understood that when an element or layer is referred to as being "in contact with" another element, the element or layer is directly on the other element without intervening elements or layers therebetween.

[0090] In the drawings, the thickness or size of each constituent element is illustrated for clarity and convenience, and the present invention is not necessarily limited to the illustrated thickness or size of the constituent elements.

[0091] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

[0092] Figure 2 is a cross-sectional view illustrating a folded state of a rollable display according to a first embodiment of the present invention, and Figure 3 is an example Figure 2A cross-sectional view of the unfolded state of the rollable display. In addition, Figure 4 This is an example of the interior of the housing. Figure 2 A stereoscopic image of a rollable display.

[0093] like Figures 2 to 4 As shown, the rollable display (denoted by reference numeral 1000) according to the first embodiment of the present invention includes: a flexible display panel 100 including a first surface as a display surface and a second surface as a rear surface; a back plate 200, which contacts the second surface of the flexible display panel 100 and includes inner folding parts B and outer folding parts A arranged alternately and a non-folding part between the inner folding parts B and the outer folding parts A; and a receiving housing 400, which has an introduction / extraction opening 405 through which the display panel 100 and the back plate 200 are integrally introduced or led out, and contains the display panel 100 and the back plate 200 integrally folded at the inner folding parts B and the outer folding parts A. The flexible display panel 100 and the back plate 200 may form a display unit having inner folding parts B and outer folding parts A arranged alternately and a non-folding part UF between the inner folding parts B and the outer folding parts A.

[0094] The flexible display panel 100 is used to display an image. For example, like an organic light-emitting display panel, the flexible display panel 100 may use a self-luminous flexible display panel 100. In the rollable display of the present invention, Figure 2 and Figure 3 As shown, the flexible display panel 100 is repeatedly rolled and unwound together with the back plate 200, and displays an image in its unfolded state. Since the shape of each area is different, the back plate 200 can be folded when it is accommodated in the accommodating housing 400 without a separate component. The flexible display panel 100 can be thin enough, and its modulus can be lower than the modulus of the main material of the back plate 200, so as to be folded together with the back plate 200.

[0095] Considering the appearance of the rollable display, the following components are visible: a receiving case 400, a first surface of the flexible display panel 100 protruding from the receiving case 400 to display an image thereon, a rear surface (a surface opposite to the flexible display panel 100) of the back plate 200 attached to the second surface of the flexible display panel 100, and a cover member 600 provided on one side of the display panel 100 and the back plate 200 to perform a packaging function. The cover member 600 is formed of silicon, epoxy resin, acrylic resin, or other materials.

[0096] The flexible display panel 100 and the back plate 200 have a substantially rectangular shape when unfolded, but are not limited thereto. Alternatively, in addition to the rectangular shape, the flexible display panel 100 and the back plate 200 may be modified to have four rounded corners, or may be modified to have a polygonal or circular shape.

[0097] The back plate 200 is formed of a stainless steel plate, and one surface of the back plate 200 faces the lower surface of the flexible display panel 100. That is, the facing surfaces of the flexible display panel 100 and the back plate 200 are aligned with each other, so that the flexible display panel 100 and the back plate 200 are integrally folded inside the receiving housing 400 and are integrally unfolded outside the receiving housing 400. An adhesive layer (not shown) may be provided between the flexible display panel 100 and the back plate 200. Since the flexible display panel 100 and the back plate 200 integrally realize the winding inside the receiving housing 400 and the unwinding outside the receiving housing 400, the adhesive layer may be uniformly provided on the second surface of the flexible display panel 100.

[0098] Reference Figure 2 , the accommodating shell 400 may have a space whose height IH is equal to or greater than the sum of the curvature (1.5R) of the inner folding portion B, the curvature (1.5R) of the outer folding portion A, and the length (h) of the non-folding portion UF between the inner folding portion B and the outer folding portion A. Here, the height of the inner folding portion B or the outer folding portion A may be referred to as the radius of the outer curvature of the corresponding folding portion. If the radii of the outer curvatures of the inner folding portion B and the outer folding portion A are 1.5mm, respectively, and the height of the non-folding portion is 5.6mm, the minimum possible height IH of the accommodating shell 400 is 8.6mm. If R is the radius of the inner curvature of the inner folding portion B or the outer folding portion A, and if the radius of the outer curvature of the inner folding portion B or the outer folding portion A is 1.5R, the accommodating shell 400 has a height "3R+h" as the minimum internal thickness. In this case, the inner folding portion B and the outer folding portion A may be in contact with the inner surface of the accommodating shell 400. In addition, in order to reduce the longitudinal length (in the X direction) of the accommodating shell 400, the rollable display of the present invention is configured, for example, in such a manner that adjacent areas of the back panel 200 located at the outer folding portion A contact each other and adjacent areas of the flexible display panel 100 located at the inner folding portion B contact each other.

[0099] Figure 2 The curvature shown in FIG. 4 is an example and is not limited thereto. The curvature may be set to be greater than or less than the curvature and may be controlled according to the height of the receiving case 400.

[0100] The back plate 200 may include a plurality of inner folding portions B and a plurality of outer folding portions A. Adjacent inner folding portions B spaced apart from each other by one outer folding portion A and non-folding portions UF at opposite sides thereof outside the accommodating case 400 may contact each other when the back plate 200 is folded in the accommodating case 400. Adjacent outer folding portions A spaced apart from each other by one inner folding portion B and non-folding portions UF at opposite sides thereof outside the accommodating case 400 may contact each other when the back plate 200 is folded inside the accommodating case 400.

[0101] When folded inside the accommodating shell 400, in the inner folding portion B, the back plate 200 is located on the inside and the first surface of the flexible display panel 100 is located on the outside, while in the outer folding portion A, the back plate 200 is located on the outside and the first surface of the flexible display panel 100 is located on the inside.

[0102] Each of the inner folded portion B and the outer folded portion A of the back plate 200 may have a specific gravity lower than that of the non-folded portion UF.

[0103] To this end, the back plate 200 can be changed into any of various shapes, and the rollable display of the present invention is characterized in that, unlike the non-folding part UF, the inner folding part B or the outer folding part A has an opening or hole formed in a portion of the thickness of the back plate. It will be described below.

[0104] The flexible display panel 100 may include a pad member (not shown) located on a side of the flexible display panel 100 opposite to a side on which the cover member 600 is disposed (see Figure 5 in the .

[0105] Alternatively, the pad member PAD of the flexible display panel 100 may be connected to a flexible film such as COF, and the printed circuit board 500 may also be disposed inside the receiving case 400 so as to be electrically connected to the flexible film. Here, the printed circuit board 500 may be attached and fixed to the inner side portion or the inner lower surface of the receiving case 400. In this case, the printed circuit board 500 takes the form of a hard board, and an electrical signal is transmitted from the printed circuit board 500 to the pad member PAD via wiring disposed in the flexible film.

[0106] Alternatively, if Figure 2 As shown, the pad member PAD of the flexible display panel 100 and the flexible printed circuit board 500 may be directly connected to each other. Here, the other side portion of the flexible display panel 100 on which the flexible printed circuit board 500 is disposed may be fixed in the receiving case 400 using the fixing member 330.

[0107] As shown in the figure, the support members 310 and 320 may also be disposed adjacent to the introduction / extraction opening 405 in the receiving housing 400 to support the first surface of the flexible display panel 100 and the surface of the back plate 200 opposite to the second surface of the flexible display panel 100. The support members 310 and 320 may push the flexible display panel 100 and the back plate 200 so that the two are smoothly moved out through the introduction / extraction opening 405.

[0108] Figure 5 Is a single example Figure 2 A plan view of a flexible display panel, and Figure 6 is a cross-sectional view illustrating a flexible display panel according to the present invention.

[0109] exist Figure 5 In the embodiment, it is conceivable that the flexible display panel 100 is moved out through the introduction / extraction opening in the vertical direction. Here, the cover member 600 is provided on one side of the flexible display panel 100, and the pad member PAD is provided on the other side of the flexible display panel 100. The pad member PAD of the flexible display panel 100 may be directly connected to the printed circuit board 500, or may be connected to the printed circuit board 500 with a flexible film such as COF interposed therebetween as described above. Figure 2 As shown, the printed circuit board 500 is fixed to the back plate 200 and the flexible display panel 100 using the fixing member 330. In some cases, when the printed circuit board 500 is connected to the pad member PAD in a manner in which a flexible film is interposed therebetween, the printed circuit board 500 may be formed of a hard material so as to be fixed to the inner side portion or the inner lower surface of the receiving case 400, or may be constructed by a flexible printed circuit board using a flexible material.

[0110] The flexible display panel 100 independently realizes display, and in order to maintain flexibility, the flexible display panel 100, on which a flexible substrate material such as a thin film transistor array is disposed (see Figure 6 112 in the flexible substrate material 112 may be formed of a flexible plastic film or an organic material. The flexible substrate material 112 has a thickness in the range of about 3 μm to 100 μm, and even when the flexible display panel 100 includes an array formed on the flexible substrate material 112, the total thickness of the flexible display panel 100 is approximately in the range of 5 μm to 300 μm, so that the display panel 100 can be folded by folding or bending any area of ​​the display panel 100. However, in a rollable display as a finished product, the folding region FR of the rollable display may be set to a specific area according to the device requirements. The folding region FR may be specified as having different configurations for each region according to the requirements of any other component element (i.e., the backplane 200) other than the display panel 100. In some cases, in order to ensure sufficient flexibility and prevent damage to the array during the folding operation, the flexible display panel 100 may include a flexible substrate material 112 having different array shapes or different surface structures in the folding region FR and the unfolding region UFR.

[0111] like Figure 6 As shown, a buffer layer 120 is formed on a flexible substrate (eg, a flexible base material 112), and a thin film transistor Tr is formed on the buffer layer 120. The buffer layer 120 may be omitted.

[0112] The semiconductor layer 122 is formed on the buffer layer 120. The semiconductor layer 122 may be formed of an oxide semiconductor material or polysilicon.

[0113] When the semiconductor layer 122 is formed of an oxide semiconductor material, a light blocking pattern (not shown) may be formed under the semiconductor layer 122. The light blocking pattern prevents light from being incident on the semiconductor layer 122, thereby preventing the semiconductor layer 122 from being degraded by light. Different from this, the semiconductor layer 122 may be formed of polycrystalline silicon, in which case opposite edges of the semiconductor layer 122 may be doped with dopants.

[0114] The gate insulating layer 124 is formed using an insulating material on the semiconductor layer 122. The gate insulating layer 124 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride.

[0115] The gate 130 is formed on the gate insulating layer 124 using a conductive material such as metal to correspond to the center of the semiconductor layer 122 .

[0116] Although the gate insulating layer 124 is Figure 6 1 is shown as being formed over the entire surface of the flexible base material 112, but the gate insulating layer 124 may alternatively be patterned to have a shape corresponding to the shape of the gate 130. For example, the gate insulating layer 124 may have the same shape as the gate 130.

[0117] An interlayer insulating film 132 is formed using an insulating material on the gate electrode 130. The interlayer insulating film 132 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or may be formed of an organic insulating material such as benzocyclobutene or photo-acryl.

[0118] The interlayer insulating film 132 has therein a first contact hole 134 and a second contact hole 136 exposing opposite sides of the semiconductor layer 122. The first contact hole 134 and the second contact hole 136 are located at opposite sides of the gate 130 so as to be spaced apart from the gate 130.

[0119] Here, the first contact hole 134 and the second contact hole 136 are also formed in the gate insulating layer 124. Unlike this, when the gate insulating layer 124 is patterned to have the same shape as the gate 130, the first contact hole 134 and the second contact hole 136 may be formed only in the interlayer insulating film 132.

[0120] The source electrode 140 and the drain electrode 142 are formed on the interlayer insulating film 132 using a conductive material such as metal.

[0121] The source electrode 140 and the drain electrode 142 are disposed to be equally spaced apart from the gate electrode 130 , and contact opposite sides of the semiconductor layer 122 through the first contact hole 134 and the second contact hole 136 , respectively.

[0122] The semiconductor layer 122 , the gate electrode 130 , the source electrode 140 , and the drain electrode 142 constitute a thin film transistor Tr, and the thin film transistor Tr functions as a driving element.

[0123] The thin film transistor Tr may have a coplanar structure in which a gate electrode 130 , a source electrode 140 , and a drain electrode 142 are located on the semiconductor layer 122 .

[0124] Unlike this, the thin film transistor Tr may have an inverted staggered structure in which a gate electrode is located below a semiconductor layer and a source electrode and a drain electrode are located above the semiconductor layer. In this case, the semiconductor layer may be formed of amorphous silicon.

[0125] Although not shown, the gate line and the data line cross each other to define a pixel region, and a switching element is also formed so as to be connected to the gate line and the data line. The switching element is connected to the thin film transistor Tr serving as a driving element.

[0126] In addition, the power supply line may be spaced apart from and parallel to the gate line or the data line, and a storage capacitor may be further provided in order to maintain a constant voltage of the gate electrode of the thin film transistor Tr serving as a driving element during one frame.

[0127] A protective layer 145 having a drain contact hole 152 for exposing the drain electrode 142 of the thin film transistor Tr is formed to cover the thin film transistor Tr. The thin film transistor Tr having the same shape as described above is disposed in each pixel region, and the thin film transistors Tr disposed on the flexible base material 112 are collectively referred to as a thin film transistor array.

[0128] For each pixel region, a first electrode 160 is discretely formed on the protective layer 145 so as to be connected to the drain electrode 142 of the thin film transistor Tr through the drain contact hole 152. The first electrode 160 may be an anode and may be formed of a conductive material having a relatively large work function value. For example, the first electrode 160 may be formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), or may be configured using a multilayer electrode including at least one layer of a transparent conductive material.

[0129] In the case where the display panel 100 of the present invention is a top emission type, a reflective electrode or a reflective layer may be further formed under the first electrode 160. For example, the reflective electrode or the reflective layer may be formed of an aluminum-palladium-copper (APC) alloy. In some cases, a transparent conductive material may also be disposed under the reflective electrode.

[0130] In addition, a bank layer 166 is formed on the protective layer 145 so as to cover the edge of the first electrode 160. The bank layer 166 corresponds to the pixel region and exposes the center of the first electrode 160.

[0131] An organic light emitting layer 162 is formed on the first electrode 160. The organic light emitting layer 162 may be in the form of a single layer formed of a light emitting material. In addition, in order to improve light emitting efficiency, the organic light emitting layer 162 may have a multi-layer structure including a hole injection layer, a hole transport layer, a light emitting material layer, an electron transport layer, and an electron injection layer sequentially stacked on the first electrode 160.

[0132] The second electrode 164 is formed on the organic light emitting layer 162 above the flexible base material 112. The second electrode 164 may be located above the entire display area and may be a cathode formed of a conductive material having a relatively small work function value. For example, the second electrode 164 may be formed of any one of aluminum (Al), magnesium (Mg), silver (Ag), ytterbium (Yb), aluminum alloys (e.g., Al-Mg alloys), and silver alloys (e.g., Ag-Mg alloys).

[0133] The first electrode 160 , the organic light emitting layer 162 , and the second electrode 164 constitute an organic light emitting diode D. The organic light emitting diode D is provided in each pixel region so as to be connected to the thin film transistor Tr, and the organic light emitting diodes formed in all pixel regions are also collectively referred to as an organic light emitting diode array.

[0134] The encapsulation film 170 is formed on the second electrode 164 in order to prevent external moisture from entering the organic light emitting diode D. The encapsulation film 170 may take the form of a stacked body including a first inorganic insulating layer 172, an organic insulating layer 174, and a second inorganic insulating layer 176, but is not limited thereto as long as the encapsulation film 170 is formed by alternately stacking inorganic insulating layers and organic insulating layers so that the outermost layer is an inorganic insulating layer.

[0135] In addition, a touch electrode array including a first touch electrode 181 and a second touch electrode 182 may be provided on the packaging film 170 to detect touch. In the form shown, the bridge line 181a is provided on the second inorganic insulating layer 176 as the outermost layer, the touch insulating layer 183 is provided on the bridge line 181a, and the first touch pattern 181b and the second touch electrode 182 are spaced apart from each other on the touch insulating layer 183. Here, the first touch pattern 181b is electrically connected to the bridge line 181a through a contact hole in the touch insulating layer 183 to constitute the first touch electrode 181. In the figure, only a portion of the second touch electrode 182 is shown. The second touch electrode 182 is located on a portion of the touch insulating layer 183 where the first touch pattern 181b is not provided, and a mutual capacitance Cm is generated between the first touch pattern 181b and the second touch electrode 182 spaced apart from each other.

[0136] Whether a touch is present may be detected based on a change in the mutual capacitance Cm.

[0137] The touch electrode array shown is given as an example, and the present disclosure is not limited thereto. Although the touch electrode array can be formed directly on the packaging film 170 as shown in the figure, a separate material or insulating layer can be further provided so that the touch electrode array is provided thereon, or the touch electrode array can be provided in the cover film. In some cases, the packaging film 170 can be located on top of the display panel 100 without providing the touch electrode array.

[0138] A polarizer (not shown) may be attached to the touch electrode array to reduce reflection of external light. For example, the polarizer may be a circular polarizer. Alternatively, a cover layer such as a cover window may be further provided to protect the top of the touch electrode array.

[0139] The reference numeral "1100" not described above represents an array structure, which includes all components including an array of thin film transistors Tr formed on a flexible substrate material 112, an array of organic light emitting diodes D connected to the corresponding thin film transistors Tr, a packaging film 170 covering the above components, and a touch electrode array.

[0140] The above display panel is given as an example and is an organic light emitting display panel, but can be replaced by any other type of display panel as long as it is flexible. For example, the above organic light emitting display panel can be replaced by a flexible liquid crystal panel, a flexible quantum dot display panel or a flexible electrophoretic display panel.

[0141] In the rollable display of the present invention, as mentioned above with reference to Figures 2 to 4 As described above, the flexible display panel 100 and the back plate 200 are integrally rolled up inside the accommodating shell 400 in a state where they are bonded facing each other. Considering the shape of the rollable display, an inward folding structure in which the back plate 200 is rolled inward, a predetermined non-folding structure, an outward folding structure in which the back plate 200 is rolled outward, and another non-folding structure are repeatedly deployed. In this case, the flexible display panel 100 achieves inward folding and outward folding in a shape opposite to the inward folding and outward folding of the back plate 200. In this case, such inward folding and outward folding are obtained by the different shapes of the back plate 200 for each area without the need for a separate component. That is, as Figure 3 As shown, when the display unit having the flexible display panel 100 and the back plate 200 that are integrally unfolded is introduced into the limited space in the receiving housing 400, as shown in FIG. Figure 2 As shown, a specific area of ​​the back plate 200 is curled inward or outward due to the different patterns of the back plate 200 for each area, and the remaining area remains unfolded. In this case, the inward folding and the outward folding are repeated to compensate each other, so that no slip occurs between the flexible display panel 100 and the back plate 200.

[0142] Fig. 7A and Figure 7B are examples Figure 2 The plan view of area B and area A.

[0143] Fig. 7A There is illustrated an inner folded portion B. The non-folded portion 210 remains in a plate state, but a plurality of openings or holes 207 are formed in the inner folded portion B for inward folding.

[0144] Reference Fig. 7A , a single opening or hole is formed in a first pattern in odd-numbered columns, and two openings or holes are formed in a second pattern in even-numbered columns. However, the first pattern may include two or more openings or holes, and the second pattern may include three or more openings or holes.

[0145] Each of the first pattern and the second pattern is configured to extend in the column direction. That is, a major axis of each of the first pattern and the second pattern may be parallel to the column direction.

[0146] Therefore, the inner folded portion in which the opening 207 is formed acts as a spring to increase the elastic recovery energy of the back plate 200 during repeated folding and unfolding operations. Therefore, when the rollable display is changed to the unfolded state again so that the folding stress is eliminated, the time taken for the rollable display to return to its original state can be reduced.

[0147] The openings 207 in the pattern may be modified into a polygonal or elliptical shape elongated in the folding axis direction, or may be modified into a polygonal shape with corresponding rounded corners.

[0148] like Fig. 7A As shown, the opening pattern including the opening 207 may include a first pattern and a second pattern having the same shape in pairs, and may be repeated throughout the inner folding portion IF. Alternatively, the opening pattern having the same shape may be gradually densely or sparsely arranged from the center to the edge of the inner folding portion IF. In some cases, only a random opening pattern may be provided to distinguish the inner folding portion IF from the non-folding portion 210. The first pattern and the second pattern may be arranged so that their longitudinal directions coincide with the folding axis direction. That is, the opening 207 may be elongated in the folding axis direction.

[0149] The back plate 200 is located below the flexible display panel 100 and supports the display panel 100. The rigidity of the back plate 200 is greater than the rigidity of the flexible base material 112. That is, the Young's modulus of the back plate 200 may be greater than the Young's modulus of the flexible base material 112.

[0150] For example, the back plate 200 may be formed of a high-rigidity material such as stainless steel, and thus the back plate 200 may have a higher restoring force and greater rigidity than other materials, which may result in a reduction in the thickness of the back plate 200 .

[0151] That is, when the back plate 200 is formed of a high rigidity material such as stainless steel, even if the thickness of the back plate 200 is reduced, the back plate 200 can maintain a desired rigidity for supporting the flexible display panel 100. In addition, such a reduction in thickness can reduce plastic deformation of the back plate 200.

[0152] However, the back plate 200 formed of a high-rigidity material and having a small thickness is difficult to recover once deformed because of its narrow elastic deformation range. That is, the back plate 200 may not be unfolded after being folded, and the time to maintain the folded shape increases.

[0153] Although the shape that long rectangle and short rectangle are repeated alternately is shown, the shape of opening pattern is not limited to this, and the rectangle with the same shape can be repeated.In addition, the shape of opening or hole 207 is not limited to rectangle, and can be any shape in circle, other polygon, ellipse or its deformation.

[0154] Figure 7B An outer folding portion A (OF) is illustrated. The non-folding portion 210 (UF) remains in a plate shape, but a plurality of openings or holes 205 for folding outward are formed in the outer folding portion OF. The openings or holes 205 are shown to be formed to have a dumbbell shape in a plane, but are not limited thereto, and may be modified in various ways as in the above-mentioned inner folding portion B (IF).

[0155] It should be noted that the inner fold B and the outer fold A occupy different lengths of areas of the back plate 200, so that the area occupied by the opening or hole 205 in the outer fold OF is wider than the area occupied by the opening or hole 207 in the inner fold IF.

[0156] Here, the opening or hole 207 for inward folding serves to reduce the specific gravity of the region where the folding occurs, compared to the non-folding portion 210 having a relatively large modulus, so that the region acts as a spring. Although the back plate 200 used in the rollable display of the present invention may be formed of a high-rigidity material so as to support the flexible display panel 100 even with a small thickness ranging from 2 mm to 3 mm, when the back plate 200 is formed of only such a high-rigidity material, it may be difficult for the back plate 200 to return to its original state after an external force is applied. In order to prevent this, as Fig. 7A and Figure 7B As shown, openings or holes 207 and 205 are formed in the inner and outer folded portions in order to increase the restoring force of the back plate 200. That is, the back plate 200 having a small thickness and a high restoring force can be provided.

[0157] Fig. 7A and Figure 7BAn opening or hole 207 for inward folding and an opening or hole 205 for outward folding according to one example are illustrated, and the openings or holes 207 and 205 may have the same shape, but they may be formed in regions IF and OF having different widths due to an area (path) difference.

[0158] Figure 8 is an example Figure 2 A plan view of the back panel, and 9A to 9F According to various embodiments Figure 2 A cross-sectional view of region A or region B of the back plate shown in FIG.

[0159] The material of the back plate 200 in the rollable display of the present invention is a rigid iron alloy such as stainless steel, wherein the alloy elements other than steel are 50% or less and the content of chromium (Cr) in the iron alloy ranges from 7% to 32%. In addition to steel and chromium, the back plate 200 may also contain metals such as nickel and non-metallic materials such as silicon (Si).

[0160] like Figure 8 As shown, since the back plate 200 needs to repeatedly realize inward folding and outward folding, the inner folding part IF in which an opening or hole for inward folding is formed and the outer folding part OF in which an opening or hole for outward folding is formed are alternately repeated, and the non-folding part UF (which does not include an opening or hole and is formed of stainless steel) is interposed between the inner folding part IF and the outer folding part OF. The inner folding part IF may have a smaller length or width than the outer folding part OF.

[0161] Considering the detailed cross-sectional configuration, with the above Fig. 7A The different first and second patterns of planar shapes shown in FIG. 1 are denoted by 202a and 202b, respectively.

[0162] 9A to 9F 202 is a cross-sectional view illustrating an opening or a hole applicable to the inner folded portion IF or the outer folded portion OF of the back plate 200. The opening or the hole may have the same cross-sectional shape and thus is denoted by the same reference numeral '202'.

[0163] An opening 202 is formed including a first pattern 202a formed in a (2n-1)th column and a second pattern 202b formed in a (2n)th column (here, "n" is a positive integer).

[0164] Each of the first pattern 202a and the second pattern 202b may have a rectangular shape. In addition, a space between the second patterns 202b formed in the (2n)th column may correspond to the first pattern 202a formed in the (2n-1)th column.

[0165] In the back plate 200, as Fig.9A and FIG. 9C to FIG. 9F As shown, in order to prevent the region including the opening 202 from being stepped and to protect the back plate 200, a first step compensation layer 211 and a second step compensation layer 213 may be formed on the lower surface and the upper surface of the back plate 200. Here, the step compensation layers 211 and 213 are formed of a material having a lower rigidity than the body 200a of the back plate 200. For example, each of the first step compensation layer 211 and the second step compensation layer 213 may be formed of any one of polyurethane (PU), thermoplastic polyurethane (TPU), polyacrylate, rubber, and silicon (Si).

[0166] In this case, the first and second step compensation layers 211 and 213 cover the opening 202 to protect the opening 202 and eliminate any stepped portion. By providing the first and second step compensation layers 211 and 213, any display defects that may be caused by the opening 202 can be prevented.

[0167] Any one of the first step compensation layer 211 and the second step compensation layer 213 may be formed, and any one of the first step compensation layer 211 and the second step compensation layer 213 may be selectively formed only in the folding region FR.

[0168] In some cases, such as Fig.9D As shown, one of the first step compensation layer 211 and the second step compensation layer 213 may be formed to fill the opening 202. Here, the step compensation layer 211a filling the opening 202 in the inner folding part IF or the outer folding part OF may have lower rigidity than the back plate 200 formed of stainless steel, and thus reliability may be maintained even during repeated folding operations in the folding region FR.

[0169] here, Fig. 9B The most basic configuration of the back plate 200 is illustrated, which includes the inner folding part IF and the outer folding part OF, but does not include the step compensation layer, so that the openings 202 (202a and 202b) are exposed from the surface thereof. Fig. 9B When the back plate 200 of the cross-sectional structure shown in FIG. 1 is disposed to face the flexible display panel 100 , the adhesive layer therebetween may fill the opening 202 to perform attachment between the back plate 200 and the flexible display panel 100 .

[0170] The opening 202 may be Fig.9A As shown, the depth or length is equal to the partial thickness P1 of the body 200a, or it can be as shown. Fig. 9B or Fig. 9C As shown, the depth or length is equal to the entire thickness P2 of the body 200a. Fig.9EAs shown, the openings 202 having a length equal to the partial thickness P1 or P3 may be alternately disposed in the upper and lower surfaces of the body 200a. Fig.9F As shown, the openings 202 having a length equal to a partial thickness P1 of the body 200a and the openings 202 having a length equal to the entire thickness P2 of the body 200a may be alternately disposed.

[0171] when Fig.9E or Fig.9F When the opening 202 is formed to have a depth or length equal to the partial thickness P1, the thickness P1 needs to be greater than 1 / 2 of the thickness of the body 200 a, which is desirable in terms of expansion and contraction of the opening 202 .

[0172] As described above, the rollable display of the present invention includes a high-rigidity back plate 200 to support the display panel 100, and the back plate 200 is configured to have different patterns in the inner folding part, the outer folding part, and the non-folding part therebetween, which can make the outer folding part and the inner folding part compensate each other. Therefore, it is possible to prevent the slippage between the back plate and the flexible display panel, and thus improve visibility.

[0173] Specifically, the rollable display of the present invention is configured to repeatedly perform extension and compression, which can prevent slippage of the rollable display rolled in a given direction and waviness in the display caused thereby.

[0174] In the rollable display of the present invention, the inner folding part, the outer folding part and the non-folding part therebetween constitute a group, and a plurality of groups are arranged in the housing. With this configuration, the display surface of the rollable display can be expanded in its fully unfolded state, which results in a higher utilization efficiency of the display surface for a given area of ​​the housing.

[0175] Furthermore, due to the formation of different patterns of the back plate, the rollable display of the present invention enables the back plate to be automatically folded inwardly and outwardly inside the receiving case without requiring a specific mechanical member.

[0176] Fig.10 is a perspective view illustrating a rollable display according to a second embodiment of the present invention, Figures 11 to 13 is an example Fig.10 A reference view of a rollable display gradually unfolding, Fig.14A is an example Fig.12 A side view of a side surface of Fig. 14B is an example Fig.13 A side view of the side surface.

[0177] Reference Figures 10 to 13, the rollable display denoted by reference numeral 2000 according to the second embodiment of the present invention includes a display unit DP and a link unit 700. Here, because the display unit DP is folded multiple times, the rollable display 2000 according to the second embodiment of the present invention uses the name “rollable display”, but it can also be applied to the field of foldable displays.

[0178] The display unit DP includes a flexible display panel 100 and a back plate 200. Here, a detailed description of the display unit DP is the same as the above description of the flexible display panel 100 and the back plate 200, and thus a description thereof will be omitted below.

[0179] like Figure 8 As shown, the back plate 200 is composed of folding parts IF and OF and a non-folding part UF, and the folding part includes outer folding parts OF and inner folding parts IF arranged alternately, so that the display unit DP is rolled or folded in a zigzag pattern.

[0180] In the above-described display unit DP, the non-folding part UF is coupled to the link unit 700 so that the folding parts OF and IF are folded and unfolded according to the folding and unfolding of the link unit 700 .

[0181] Fig.11 The display unit DP is illustrated as follows: Fig.10 The state expands to about 30% of the state, Fig.12 The display unit DP is illustrated as follows: Fig.10 The state expands to about 50% of the state, and Fig.13 The state where the display unit DP is unfolded to 100% to become a plane is illustrated. Therefore, the greater the degree of unfolding of the link unit 700, the more the display unit DP is unfolded, and thus the display unit DP is closer to the shape of a flat panel display. When the link unit 700 is fully unfolded, the display unit DP is unfolded to 100% to form a plane.

[0182] Here, since the display unit DP includes the outer folding parts OF and the inner folding parts IF arranged alternately, the display unit DP is not folded multiple times in a single direction, which can prevent the separation between the flexible display panel 100 and the back plate 200.

[0183] The link unit 700 may have a retractable lattice grille and may include a plurality of shafts 710 , 720 , 730 , a plurality of first link joints 711 , 721 , 731 , and a plurality of second link joints 712 , 722 , 732 . The link unit 700 includes a first shaft 710 , a first link joint 711 , and a second link joint 712 .

[0184] Each end of the first shaft 710 is coupled to the center of the first link rod 711. In addition, the first shaft 710 may be rotatably coupled to the center of the first link rod 711. This serves to allow the display surface, which is the upper surface of the display unit DP, to be arranged in one plane while the link unit 700 is folded or unfolded in a state where the display unit DP is coupled to the first shaft 710. In addition, this serves to prevent deformation or damage of the display unit DP by uniformly distributing tensile stress or compressive stress to each of the folded portion and the non-folded portion while the display unit DP is folded or unfolded.

[0185] The second link bars 712 may be respectively disposed at outer sides of the first link bars 711. The second link bars 712 are coupled to the first shaft 710 as a rotation axis at the center thereof in the same manner as the first link bars 711. In addition, the first link bars 711 and the second link bars 712 may have the same length.

[0186] As such, a pair of first link bars 711 are disposed parallel to each other at both ends of the first shaft 710 , and a pair of second link bars 712 are disposed parallel to each other at both ends of the first shaft 710 , thereby providing a substantially “X” shaped link bar.

[0187] Here, the second shaft 720 and the third shaft 730 are respectively disposed in front of and behind the first shaft 710 so as to be parallel to the first shaft 710 in the first direction. Similarly, a pair of first link rods 721 and a pair of second link rods 722 are respectively disposed at both ends of the second shaft 720, and a pair of first link rods 731 and a pair of second link rods 732 are respectively disposed at both ends of the third shaft 730. Then, one end of the first link rod 711 corresponding to the first shaft 710 is connected to the upper end of the second link rod 722 corresponding to the second shaft 720, and the other end of the first link rod 711 corresponding to the first shaft 710 is connected to the lower end of the second link rod 732 corresponding to the third shaft 730. In addition, one end of the second link rod 712 corresponding to the first shaft 710 is connected to the lower end of the first link rod 731 corresponding to the third shaft 730, and the other end of the second link rod 712 corresponding to the first shaft 710 is connected to the upper end of the first link rod 721 corresponding to the second shaft 720. In this manner, the respective link bars may rotate in cooperation with each other, and the rotation angle thereof or the distance by which the display unit DP is deployed may be the same for each link bar.

[0188] The respective first link bars 711, 721, and 731 and the respective second link bars 712, 722, and 732 can rotate relative to each other in different directions around the rotation axis of the corresponding shafts 710, 720, and 730. For example, when the first link bar 711 rotates in a given direction around the rotation axis of the first shaft 710 and the second link bar 712 rotates in a direction opposite to the given direction, the link unit 700 and the display unit DP are unfolded. On the contrary, when the first link bar 711 rotates in the opposite direction around the rotation axis of the first shaft 710 and the second link bar 712 rotates in a given direction, the display unit DP is folded via a plurality of folding regions.

[0189] One end of the display unit DP is connected to the printed circuit board 500. Of course, the printed circuit board 500 may be a flexible printed circuit board, and although not shown in the figure, the printed circuit board 500 may include a drive unit (not shown). Here, the printed circuit board 500 is formed so that its length is equal to or less than the length of the non-folding portion UF of the unfolded display unit DP or the length of the first link rod 711 or the second link rod 712. Therefore, even in a state where the display unit DP is fully folded, the printed circuit board 500 is arranged between the non-folding portions UF so that the printed circuit board 500 or the drive unit is not exposed to the outside. Of course, when the printed circuit board 500 or the drive unit has a larger size, the printed circuit board 500 or the drive unit may be arranged on the lower side of the link unit 700 or the lower side of the display unit DP. So that it is not exposed to the outside during the operation of the display 2000.

[0190] Fig.15 is an example Fig.10 A reference view of a part of the interior.

[0191] Reference Fig.15 , the display unit DP is provided with a hook-shaped member 250 on its rear surface. In the display unit DP, at least one hook-shaped member 250 is provided in each non-folding portion UF on the rear surface of the back plate 200. The hook-shaped member 250 is coupled to the corresponding shaft and is used to fix the display unit DP to the link unit 700. The hook-shaped member 250 may be first coupled to the shaft so that an assembly of the hook-shaped member 250 and the shaft is coupled to the rear surface of the back plate 200. Alternatively, the hook-shaped member 250 separated from the shaft may be coupled to the rear surface of the back plate 200, and then may be interference-fitted with the shaft.

[0192] Here, in each non-folding portion UF of the back plate 200 , the hook member 250 coupled to the first shaft 710 and the hook member coupled to the second shaft or the third shaft may be disposed not to interfere with each other during folding of the display unit DP.

[0193] In addition, three or more hook members 250 may be provided on the back plate 200 at equal distances or at positions close to both ends of one axis.

[0194] The hook member 250 may be necessary for each shaft 710, 720 or 730 coupled to the center of the first link rod 711, 721 or 731, and a side shaft 713 may be provided to interconnect at least one of the two ends of the corresponding first link rod facing each other. More specifically, the side shaft 713 is provided at the lower end of the first link rod 711. Since the display unit DP can maintain a planar shape in its fully unfolded state only when the rear surface of the display unit DP is supported by the respective shafts, the side shaft 713 is provided at the lower end of the first link rod. Of course, the side shaft 713 can also be used to increase rigidity during the folding of the link unit.

[0195] As is apparent from the above description, the rollable display of the present invention has the following effects.

[0196] The back plate for supporting the flexible display panel is divided into a plurality of regions such that the inner folding portion and the outer folding portion are repeated alternately and the non-folding portion is located therebetween, which makes the length of the path along which the display panel and the back plate are folded equal so as to prevent slippage between the two. Thus, a rollable display in which no visibility defect is observed can be realized.

[0197] In addition, the display unit is coupled to the link unit so as to be folded by alternately repeating inward folding and outward folding. Therefore, a rollable display capable of preventing separation between the flexible display panel and the back plate and ensuring easy folding of the display unit can be provided.

[0198] Although the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, it is obvious to those skilled in the art that the present invention described above is not limited to the above embodiments, and various substitutions, modifications and variations can be conceived within the spirit and scope of the present invention. Therefore, it should be considered that these modifications will fall within the scope of the present invention, and the true technical scope of the present invention should be determined by the technical concept of the appended claims.

[0199] This application claims the benefit of Korean Patent Application No. 10-2017-0144082, filed on October 31, 2017, and Korean Patent Application No. 10-2018-0119836, filed on October 8, 2018, which are hereby incorporated by reference as if fully set forth herein.

Claims

1. A rollable display, comprising: A flexible display panel, the flexible display panel comprising a first surface as a display surface and a second surface as a rear surface; a back plate disposed in contact with the second surface and comprising a plurality of inner folded portions, a plurality of outer folded portions, and a plurality of non-folded portions, the inner folded portions and the outer folded portions being arranged overlappingly and the non-folded portions being located between the inner folded portions and the outer folded portions; a receiving case configured to receive the flexible display panel and the backplane in the receiving case, the flexible display panel and the backplane being integrally folded at the inner folding portion and the outer folding portion and integrally introduced or led out through an opening provided by the receiving case; a first supporting member and a second supporting member, the first supporting member and the second supporting member being adjacent to the opening in the accommodating case, the first supporting member supporting the first surface of the display panel and the second supporting member supporting a surface of the back plate that is not in contact with the second surface of the display panel; as well as a fixing member configured to fix the first end of the flexible display panel and the first end of the back plate in the accommodating housing, the fixing member being placed in the accommodating housing to be spaced apart from the first supporting member and the second supporting member, wherein the outer folded portion of the back plate has a width greater than a width of the inner folded portion, wherein adjacent areas of the flexible display panel at the inner folding portion, which are separated from each other by an outer folding portion and non-folding portions located on opposite sides of the outer folding portion, contact each other when the back plate is folded in the accommodating housing, wherein adjacent areas of the back plate at the outer folding portion, which are separated from each other by an inner folding portion and non-folding portions located on opposite sides of the inner folding portion, contact each other when the back plate is folded in the accommodating shell, wherein each of the inner folded portion and the outer folded portion of the back plate has a plurality of holes, wherein the area occupied by the holes in the outer fold is wider than the area occupied by the holes in the inner fold, wherein, when the back panel is folded in the accommodating shell, a space between two adjacent non-folding portions separated from each other by an outer folding portion outside the accommodating shell becomes larger as the two adjacent non-folding portions separated from each other by the outer folding portion get closer to the outer folding portion, and a space between two adjacent non-folding portions separated from each other by an inner folding portion outside the accommodating shell becomes larger as the two adjacent non-folding portions separated from each other by the inner folding portion get closer to the inner folding portion, and Wherein, when the back plate is folded in the accommodating shell, areas of the flexible display panel adjacent to the outer folding portion are spaced apart from each other, and areas of the back plate adjacent to the inner folding portion are spaced apart from each other.

2. The rollable display according to claim 1, further comprising a printed circuit board disposed in the receiving case to be electrically connected to a flexible film connected to the pad member on the first end of the flexible display panel.

3. The rollable display according to claim 1, wherein: The accommodating case includes a space having a height equal to or greater than a sum of a curvature of the inner folding portion, a curvature of the outer folding portion, and a length of the non-folding portion between the inner folding portion and the outer folding portion.

4. The rollable display according to claim 1, wherein: When the back plate is folded inside the accommodating housing, in the inner folding portion, the back plate is located inside and the first surface of the flexible display panel is located outside, and In the outer folder, the back plate is located on the outside and the first surface of the flexible display panel is located on the inside.

5. The rollable display according to claim 1, wherein: Each of the inner folded portion and the outer folded portion of the back plate has a specific gravity lower than that of the non-folded portion.

6. The rollable display according to claim 5, wherein: The size of each hole of the back plate is larger than 1 / 2 of the thickness of the back plate.

7. The rollable display according to claim 6, wherein: The plurality of holes include at least one of first holes having a first thickness and second holes having a second thickness greater than the first thickness.

8. The rollable display according to claim 7, wherein: The first holes are alternately located in the upper surface and the lower surface of the back plate.

9. The rollable display according to claim 7, wherein: The first holes and the second holes are alternately located in the back plate.

10. The rollable display according to claim 5, wherein: The back plate further includes a step compensation layer on at least one of the upper surface and the lower surface of the back plate.

11. The rollable display according to claim 10, wherein: The step compensation layer covers the plurality of holes of the back plate.

12. The rollable display according to claim 10, wherein: The step compensation layer is made of a material having lower rigidity than a main body of the back plate.

13. The rollable display according to claim 10, wherein: The plurality of holes of the back plate are filled with the step compensation layer.

14. The rollable display according to claim 1 further comprises a covering member, wherein the covering member is arranged on the second end of the flexible display panel and the second end of the back plate, and the second end of the flexible display panel and the second end of the back plate are located on opposite sides of the first end of the flexible display panel and the first end of the back plate.

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