Foldable display device

Abstract

This disclosure relates to foldable display devices. One embodiment of the foldable display device includes: a display panel, wherein at least a portion of the display panel comprises a transparent display panel; and a floating screen connected to the display panel and reflecting an image displayed on the display panel. Thus, a foldable display device utilizes a floating screen and a display panel to display images with enhanced three-dimensional effects.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2021-0192382, filed with the Korean Intellectual Property Office on December 30, 2021, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to foldable display devices, and more specifically, to foldable display devices capable of displaying stereoscopic images. Background Technology

[0004] In recent years, as society has entered a fully information-based era, the field of display devices that process and display large amounts of information has developed rapidly. As display devices used as monitors for computers, televisions, or cellular phones, there are organic light-emitting display devices (OLEDs) that are self-emissive and liquid crystal display devices (LCDs) that require a separate light source.

[0005] The applications of display devices have diversified to personal digital assistants and monitors for computers and televisions, and research is underway on display devices with large display areas and reduced size and weight.

[0006] Specifically, recently, flexible display devices, which are manufactured to display images even when bent or folded like paper, have attracted attention as a next-generation display device. Flexible display devices, utilizing plastic thin-film transistor substrates instead of glass, are classified into highly durable, unbreakable display devices; bendable display devices that can be bent without breaking; rollable display devices that can be rolled up; and foldable display devices that can be folded. Such flexible display devices offer advantages in space utilization, interior design, and overall aesthetics, and have diverse application areas. Summary of the Invention

[0007] The purpose of this disclosure is to provide a foldable display device that uses a floating screen and display panel to display images with more three-dimensional effects.

[0008] Another objective of this disclosure is to provide a foldable display device that increases the mounting angle of the floating screen to increase the usable area of ​​the display panel and enhance the three-dimensional effect of the image.

[0009] Another objective, according to the publicly available information, is to improve the visibility of the transparent display panel.

[0010] The purpose of this disclosure is not limited to the purposes mentioned above, but rather other purposes not mentioned above will be clearly understood by those skilled in the art from the following description.

[0011] According to one aspect of this disclosure, a foldable display device includes: a display panel, wherein at least a portion of the display panel includes a transparent display panel; and a floating screen connected to the display panel and reflecting an image displayed on the display panel.

[0012] Further details of the exemplary embodiments are included in the detailed embodiments and the accompanying drawings.

[0013] According to this disclosure, a foldable display device capable of displaying stereoscopic images can be provided.

[0014] According to this disclosure, the usable area of ​​the display panel is increased and the three-dimensional effect of the image is enhanced.

[0015] According to this disclosure, visibility and brightness in transparent display panels are improved, and the brightness difference between transparent and non-transparent display panels is also reduced.

[0016] The effects of this disclosure are not limited to those exemplified above, and this specification includes a variety of other effects. Attached Figure Description

[0017] Figure 1 This is a schematic plan view of a foldable display device according to an exemplary embodiment of the present disclosure;

[0018] Figure 2 It is along Figure 1 A schematic cross-sectional view of line II-II';

[0019] Figures 3A to 3D This is a schematic diagram illustrating the state of a foldable display device according to an exemplary embodiment of the present disclosure;

[0020] Figures 4A to 4D This is a schematic diagram illustrating a floating screen of a foldable display device according to an exemplary embodiment of the present disclosure;

[0021] Figure 5 This is a schematic plan view of a foldable display device according to another exemplary embodiment of the present disclosure;

[0022] Figure 6 It is along Figure 5 A schematic cross-sectional view of line VI-VI';

[0023] Figures 7A to 7C This is a schematic diagram illustrating the state of a foldable display device according to another exemplary embodiment of the present disclosure;

[0024] Figure 8This is a schematic plan view of a foldable display device according to yet another exemplary embodiment of the present disclosure;

[0025] Figure 9 It is along Figure 8 A schematic cross-sectional view of the line IX-IX'; and

[0026] Figure 10A and Figure 10B This is a schematic diagram illustrating the state of a foldable display device according to another exemplary embodiment of the present disclosure. Detailed Implementation

[0027] The advantages and features of this disclosure, as well as methods for achieving these advantages and features, will become clear from the exemplary embodiments described in detail below with reference to the accompanying drawings. However, this disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. These exemplary embodiments are provided by way of example only so that those skilled in the art can fully understand the disclosure and scope of this disclosure. Therefore, this disclosure will be limited only by the scope of the appended claims.

[0028] The shapes, dimensions, ratios, angles, numbers, etc., shown in the accompanying drawings to describe exemplary embodiments of this disclosure are merely examples, and this disclosure is not limited thereto. Throughout this specification, the same reference numerals generally denote the same elements. Furthermore, in the following description of this disclosure, detailed descriptions of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of this disclosure. Terms such as “comprising,” “having,” and “consisting of” as used herein are generally intended to allow for the addition of additional components, unless these terms are used in conjunction with the term “only.” Unless otherwise expressly stated, any reference to the singular may include the plural.

[0029] Even without explicit explanation, components are interpreted as including the normal tolerance range.

[0030] When using terms such as “above,” “over,” “below,” and “adjacent” to describe the positional relationship between two parts, one or more parts may be located between the two parts, unless these terms are used in conjunction with the terms “immediately following” or “directly.”

[0031] When one element or layer is placed "on" another element or layer, the other layer or element can be directly inserted on or between the other elements.

[0032] Although the terms "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from others. Therefore, the first component referred to below may be the second component in the technical concept of this disclosure.

[0033] Throughout this specification, the same reference numerals generally denote the same elements.

[0034] The dimensions and thicknesses of each component shown in the accompanying drawings are for illustrative purposes only, and this disclosure is not limited to the dimensions and thicknesses of the components shown.

[0035] Features of various embodiments of this disclosure may be partially or wholly dependent on or combined with each other and may be technically interlocked and operated in various ways, and these embodiments may be performed independently or in association with each other.

[0036] In the following, a display device according to an exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0037] Figure 1 This is a schematic plan view of a foldable display device according to an exemplary embodiment of the present disclosure. Figure 2 It is along Figure 1 A schematic cross-sectional view taken from line II-II'.

[0038] A foldable display device 100 according to an exemplary embodiment of the present disclosure includes a display panel 110, a polarizing film 120, a cover window 130, a top plate 140, a bottom plate 150, a back plate 180, and a gap holding unit G.

[0039] Reference Figure 1 and Figure 2 According to an exemplary embodiment of the present disclosure, the foldable display device 100 includes a first non-foldable region NFA1, a first foldable region FA1, and a second non-foldable region NFA2. The first foldable region FA1 is the region that is folded when the foldable display device 100 is folded.

[0040] The first folding region FA1 is the region that is folded when the foldable display device 100 is folded, such that the first folding region FA1 can be folded along the folding direction—that is, relative to the folding direction. Figure 1 A specific radius of curvature in the X-axis direction is folded. When the first folded region FA1 is folded relative to the folding direction (X-axis direction), the first folded region FA1 can form part of a circle or ellipse. In this case, the radius of curvature of the first folded region FA1 can refer to the radius of the circle or ellipse formed by the first folded region FA1.

[0041] When the foldable display device 100 is folded, the first non-foldable region NFA1 and the second non-foldable region NFA2 are not folded. That is, when the foldable display device 100 is folded, the first non-foldable region NFA1 and the second non-foldable region NFA2 remain flat. When the first foldable region FA is folded relative to the folding direction, the first non-foldable region NFA1 and the second non-foldable region NFA2 can overlap each other. At this time, the upper surfaces of the first non-foldable region NFA1 and the second non-foldable region NFA2 become the display surface, and the first foldable region can be folded inward, so that the first non-foldable region NFA1 and the second non-foldable region NFA2 are folded so that they face each other.

[0042] Reference Figure 2 The display panel 110 is a panel for displaying images. Display elements for displaying images and circuit units for driving the display elements can be disposed in the display panel. For example, when the foldable display device 100 is an organic light-emitting display device, the display elements may include organic light-emitting diodes. In the following description, for ease of description, it is assumed that the foldable display device 100 according to various exemplary embodiments of the present disclosure is a foldable display device including organic light-emitting diodes, but the present disclosure is not limited thereto.

[0043] The circuit unit may include various thin-film transistors, capacitors, wiring, and driver ICs for driving organic light-emitting diodes. For example, the circuit unit may include, but is not limited to, various configurations such as driving thin-film transistors, switching thin-film transistors, storage capacitors, gate lines, data lines, gate driver ICs, and data driver ICs.

[0044] In the display panel 110, a flexible substrate on which driving thin-film transistors and light-emitting diodes are formed is packaged by a packaging unit, such that in order to achieve flexibility, the display panel 110 includes a flexible substrate having a very thin thickness and display elements disposed on the flexible substrate.

[0045] The flexible substrate can be formed from a flexible insulating material, such as an insulating plastic substrate selected from polyimide, polyethersulfone, polyethylene terephthalate and polycarbonate.

[0046] The display panel 110 includes a first display panel 111 disposed in a first non-folding region NFA1 and a second display panel 112 disposed in a second non-folding region NFA2. The first display panel 111 can be a transparent display panel, and the second display panel 112 can be a non-transparent display panel. That is, light emitted from the first display panel 111, which is a transparent display panel, is visible from both the upper and lower surfaces, while light emitted from the second display panel 112, which is a non-transparent display panel, is visible only from the upper surface. Therefore, the second display panel 112 can be a commonly used display panel. The first display panel 111 is a transparent display panel, such that the plurality of pixels of the first display panel 111 include a transmissive unit and a light-emitting unit. In this case, the display element can be disposed only in the light-emitting unit, or it can be disposed in both the light-emitting unit and the transmissive unit. Furthermore, the circuit unit for driving the display element can be disposed only in the light-emitting unit. However, it is not limited to this, and the display element of the first display panel 111 can be disposed in various forms.

[0047] Reference Figure 1 and Figure 2 The gap retaining unit G is disposed between the first display panel 111 and the second display panel 112. That is, the gap retaining unit G is disposed between the first display panel 111, which is a transparent display panel, and the second display panel 112, which is a non-transparent display panel. The gap retaining unit G can be made of a material with a high compressibility, such as silicon-based pads. The compressive strain of the gap retaining unit G can be from 10% to 50%, but is not limited thereto.

[0048] A polarizing film 120 is disposed on the display panel 110. The polarizing film 120 polarizes light emitted from the display panel 110 by a polarization angle. The polarizing film 120 emits light polarized by the polarization angle to the outside. The polarizing film 120 may include the function of blocking the reflection of external light other than light polarized by the polarization angle.

[0049] To protect the display panel 110 from external impacts and to prevent damage such as scratches, a cover window 130 is provided above the display panel 110. The cover window 130 can be made of a foldable, soft plastic-based cover to ensure the thinness and flexibility of the foldable display device 100.

[0050] In addition, the touch panel forming the touch sensor can be optionally positioned between the display panel 110 and the cover window 130 as needed.

[0051] A base plate 150 for supporting the display panel 110 is provided on the rear surface of the display panel 110 and the gap holding unit G. The base plate 150 supports a flexible substrate that configures the display panel 110 to prevent sagging and protects the components mounted on the flexible substrate from external moisture, heat, and impact. In addition, the base plate 150 supports the display panel 110 and reduces the overall thickness of the foldable display device 100 to reduce the radius of curvature of the first folding region FA1.

[0052] The base plate 150 can be formed of a transparent material. For example, the base plate 150 can be formed of glass and have a thickness of about 100 μm, but is not limited thereto.

[0053] The base plate 150 may include multiple patterns in the area corresponding to the first folding area FA1. Here, the multiple patterns may have, for example... Figure 2 The recessed or hole shapes shown are illustrated. Because the base plate 150 includes multiple patterns, the base plate 150 facilitates the easy folding of the foldable display device 100 and its easy unfolding after folding, thereby improving the folding performance of the foldable display device 100.

[0054] Furthermore, according to an exemplary embodiment of this disclosure, a top plate 140 may be included between the display panel 110 and the base plate 150, supporting the display panel 110 together with the base plate 150. When the foldable display device 100 is folded, the top plate 140 maintains a constant curvature of the display panel 110 and suppresses creases generated on the upper surface of the display panel 110.

[0055] The top plate 140 can be formed of a transparent material. For example, the top plate 140 can be formed of glass and have a thickness of about 30 μm, but is not limited thereto.

[0056] The cover window 130, polarizing film 120, display panel 110, top plate 140, and bottom plate 150 described above are attached by means of an adhesive layer 160. For example, a first adhesive layer 160a is provided between the cover window 130 and the polarizing film 120 to bond the cover window 130 and the polarizing film 120 to each other. A second adhesive layer 160b is provided between the display panel 110 and the top plate 140 to bond the display panel 110 and the top plate 140 to each other. A third adhesive layer 160c is provided between the top plate 140 and the bottom plate 150 to bond the top plate 140 and the bottom plate 150 to each other.

[0057] A back panel 180 is disposed below the base plate 150. The back panel 180 may be disposed below the display panel 110, the top plate 140, and the base plate 150. The back panel 180 may overlap with either the first display panel 111 or the second display panel 112. That is, the size of the back panel 180 is equal to that of the first display panel 111 and the second display panel 112. When the back panel 180 is disposed below the first display panel 111, the back panel overlaps with the first display panel 111; and when the back panel 180 is disposed below the second display panel 112, the back panel overlaps with the second display panel 112.

[0058] The back panel 180 may be formed of an opaque material. The back panel 180 is configured to improve the visibility of the first display panel 111, which is a transparent display panel and is disposed below the display panel 110. The back panel 180 may be an SUS board or a colored film, but is not limited to these.

[0059] The back panel 180 is slidably configured below the display panel 110. For example, the back panel 180 can slide below the display panel 110 by means of a tool such as a guide rail. Thus, the back panel 180 can be moved to overlap with either the first display panel 111 or the second display panel 112.

[0060] In the following text, reference will be made to Figures 3A to 3D The various display states of the foldable display device 100 according to exemplary embodiments of the present disclosure are described in more detail.

[0061] Figures 3A to 3D This is a schematic diagram illustrating the state of a foldable display device according to an exemplary embodiment of the present disclosure. Figure 3A This is a view showing the first display panel 111 and the second display panel 112 folded into a first state facing each other, and Figure 3B This is a view showing a second state in which the first display panel 111 is folded to be perpendicular to the second display panel 112. Furthermore, Figure 3C and Figure 3D This is a view showing a third state in which the first display panel 111 and the second display panel 112 are fully extended. Figures 3A to 3D For ease of description, only the display panel 110, the gap holding unit G, the back plate 180, the floating screen 170, and the first hinge unit H1 are shown.

[0062] First, refer to Figure 3AIn a first state where the first display panel 111 and the second display panel 112 are folded to face each other, the display panel 110 can display images facing the lower surface of the first display panel 111 and the upper surface of the second display panel 111. That is, a first image IM1 from the first display panel 111 is displayed on the lower surface of the first display panel 111, and a second image IM2 from the second display panel 112 is displayed on the upper surface of the second display panel 112. In other words, the first display panel 111 is a transparent display panel, such that both the first image IM1 from the first display panel 111 and the second image IM2 from the second display panel 112 are visible to the user. Alternatively, the first display panel 111 is not driven to remain transparent, and only the second image IM2 from the second display panel 112 is displayed.

[0063] Next, refer to Figure 3B In the second state where the first display panel 111 is folded to be perpendicular to the second display panel 112, the display panel 110 can use the floating screen 170 to display stereoscopic images.

[0064] In the following text, reference will be made to Figures 4A to 4D A more detailed description of the stereoscopic image display using the floating screen 170.

[0065] Figures 4A to 4D This is a schematic diagram illustrating a floating screen of a foldable display device according to an exemplary embodiment of the present disclosure. Figure 4B This is a schematic perspective view of the floating screen 170, and Figure 4C and Figure 4D This is an enlarged cross-sectional view used to illustrate the floating screen 170 in more detail.

[0066] Reference Figure 4A In the second state, where the first display panel 111 is folded perpendicular to the second display panel 112, the floating screen 170 can be connected to the first display panel 111 via the first hinge unit H1. In the folded state of the first hinge unit H1, the floating screen 170 can be positioned adjacent to the first display panel 111. However, as described above, in the second state where the first display panel 111 is folded perpendicular to the second display panel 112, the first hinge unit H1 is extended to its maximum extent, such that the floating screen 170 is supported by the first hinge unit H1.

[0067] The floating screen 170 is connected to the display panel 110 and reflects the image displayed on the display panel 110. Specifically, the floating screen 170 is connected to the first display panel 111 and reflects the image displayed on the second display panel 112. Therefore, the floating screen 170 includes a base member 171, a first layer 172, and a second layer 173.

[0068] The base member 171 of the floating screen 170 is configured to support the floating screen 170. The base member 171 may have a rigid plate shape formed of a material such as glass, PMMA, or PBMA, or it may have a soft film shape formed of a material such as PET or PC. In this case, the floating screen 170 needs to transmit the first image IM1 displayed on the first display panel 111, such that the transmittance of the base member 171 is 90% or higher.

[0069] The first layer 172 and the second layer 173 can be formed from different resins. The first layer 172 and the second layer 173 can be formed from thermosetting or UV-curing resins. In this case, the floating screen 170 needs to reflect the second image IM2 displayed on the second display panel 112, such that the refractive index of the second layer 173 is higher than the refractive index of the first layer 172.

[0070] At this time, in order for the floating screen 170 to reflect the second image IM2 displayed on the second display panel 112, the first layer 172 includes a plurality of recesses and the second layer 173 fills the plurality of recesses. At this time, as... Figure 4B As shown, each of the plurality of recesses has a shape that extends in the horizontal direction. In order to transmit and display the first image IM1 on the first display panel 111 through the floating screen 170 and to suppress distortion of the first image IM1, the width of the plurality of recesses in the width direction can be 5 μm or less.

[0071] In order for the floating screen 170 to reflect the second image IM2 displayed on the second display panel 112 and to maximize the usability of the first display panel 111's usable area, the plurality of recesses in the first layer 172 may have an asymmetrical shape. For example, when the plurality of recesses are not provided on the first layer 172 and the interface between the first layer 172 and the second layer 173 is flat, the angle θ formed by the second display panel 112 and the floating screen 170 needs to be 45 degrees in order to reflect the second image IM2 displayed on the second display panel 111 to the front. However, when the angle formed by the second display panel 112 and the floating screen 170 is 45 degrees, the visible display area of ​​the floating screen 170 is about 50%, making the actual usable area of ​​the first display panel 111 about 50%. Therefore, in the foldable display device 100 of the exemplary embodiment of the present disclosure, the plurality of recesses in the first layer 172 have an asymmetrical shape in the width direction. Therefore, the installation angle of the floating screen 170, that is, the angle θ formed by the second display panel 112 and the floating screen 170, can be increased to more than 45 degrees.

[0072] For example, such as Figure 4CAs shown, when the surfaces of the multiple recesses are formed as curved and flat surfaces, the flat surface is located above and the curved surface is located below. In this case, the width of the curved surface is greater than the width of the upper surface, and the point where the flat surface and the curved surface meet is set close to the upper end. Therefore, even at a large mounting angle of the floating screen 170, the second image IM2 of the second display panel 112 can be reflected by the floating screen 170 in the forward direction.

[0073] In addition, for example, such as Figure 4D As shown, when the surfaces of the multiple recesses are formed by multiple flat surfaces, the slope of the surface of the recess at the upper end can be steeper than the slope of the surface of the recess at the lower end. Therefore, even at a large mounting angle of the floating screen 170, the second image IM2 of the second display panel 112 can be reflected by the floating screen 170 in the forward direction.

[0074] Therefore, even when the installation angle of the floating screen 170 is increased by using the floating screen 170, the second image IM2 of the second display panel 112 can still be reflected in the front direction, such as... Figures 4A to 4D As shown. Therefore, the usable area is increased and the sense of unity between the first image IM1 on the first display panel 111 and the second image IM2 on the second display panel 112 is enhanced.

[0075] Refer again Figure 3B In the second state where the first display panel 111 is folded to be perpendicular to the second display panel 112, the display panel 110 can use the floating screen 170 disposed between the first display panel 111 and the second display panel 112 to display stereoscopic images.

[0076] Specifically, the first image IM1 of the first display panel 111 is transmitted through the floating screen 170 as is so that it is visible to the user, and the second image IM2 of the second display panel 112 is reflected by the floating screen 170 so that it is visible to the user. At this time, the first display panel 111 is a transparent display panel, so that when the user views the first display panel 111, the first display panel can be identified as transparent.

[0077] At this time, in order to display a stereoscopic image, the first image IM1 displayed on the first display panel 111 and the second image IM2 displayed on the second display panel 112 can be images obtained by photographing the same object at different focal points. That is, when the first image IM1 and the second image IM2, photographed at different focal points, float, the two images appear to overlap in the air, making it possible to achieve a pseudo-hologram with greater depth and three-dimensional effect.

[0078] At this time, in order to display a stereoscopic image, the first image IM1 displayed on the first display panel 111 can be a background image within an image, and the second image IM2 displayed on the second display panel 112 can be an object image within a background image within an image. That is, in an image, the image used as the background is displayed by the first display panel 111, and the image used as the object is displayed by the second display panel 112. Therefore, when the first image IM1 and the second image IM2 float, the background image and the object image appear to overlap in the air, making it possible to achieve a pseudo-hologram with greater depth and a three-dimensional effect.

[0079] However, the method of displaying stereoscopic images by means of display panel 110 can be achieved by combining various images other than those described above, but is not limited to the examples described above.

[0080] Next, refer to Figure 3C and Figure 3D In the third state, with the first display panel 111 and the second display panel 112 fully extended, the display panel 110 can display a flat image. In this third state, the floating screen 170 is disposed within the first display panel 111, but the floating screen 170 is highly transmissive, allowing the first image IM1 of the first display panel 111 to be transmitted as is. Therefore, the floating screen does not... Figure 3C and Figure 3D As shown in the image.

[0081] Reference Figure 3C With the display panel 110 in a flat state, the back panel 180 is located below the second display panel 112. At this time, the first display panel 111 is a transparent display panel, allowing the transmittance of the first display panel 112 and the second display panel 112 to differ. Therefore, when the first image IM1 and the second image IM2 are displayed on the first display panel 111 and the second display panel 112, a brightness difference may occur.

[0082] Therefore, refer to Figure 3D With the display panel 110 in a flat state, the back panel 180 slides to be positioned below the first display panel 111. As described above, the back panel 180 is opaque, which allows the brightness difference between the first display panel 111 and the second display panel 112 to be minimized by positioning the back panel 180 below the first display panel 111.

[0083] Furthermore, the brightness and resolution of the first display panel 111, which is a transparent display panel that needs to ensure the transmission unit, can be lower than the brightness and resolution of the second display panel 112, which is a non-transparent display panel. Therefore, when the display panel is driven in the third state, the second display panel 112 can be driven by reducing its brightness and resolution.

[0084] In the foldable display device 100 of the exemplary embodiment of the present disclosure, the bottom plate 150 and the top plate 140 of the foldable display device 100 are made of transparent material, so that a transparent foldable display device can be realized.

[0085] Furthermore, in the foldable display device 100 according to an exemplary embodiment of this disclosure, the floating screen 170 and the display panel 110 are used to display images with more three-dimensional effects. That is, in the foldable display device 100, a first display panel 111 as a transparent display panel and a second display panel 112 as a non-transparent display panel and a floating screen 170 are used. In addition, the shape of the plurality of recesses of the floating screen 170 and the refractive index difference between the first layer 172 and the second layer 173 are used to realize a pseudo-hologram with a sense of depth and three-dimensional effect.

[0086] Furthermore, in the foldable display device 100 according to an exemplary embodiment of this disclosure, the mounting angle of the floating screen 170 is increased due to the shape of the plurality of recesses of the floating screen 170. Therefore, the usable area is increased, and the unity of the first image IM1 on the first display panel 111 and the second image IM2 on the second display panel 112 is enhanced.

[0087] Furthermore, in the foldable display device 100 according to an exemplary embodiment of the present disclosure, the brightness difference between the first display panel 111, which is a transparent display panel, and the second display panel 112, which is a non-transparent display panel, can be minimized by using the sliding back panel 180.

[0088] Figure 5 This is a schematic plan view of a foldable display device according to another exemplary embodiment of the present disclosure. Figure 6 It is along Figure 5 A schematic cross-sectional view taken from line VI-VI'. Except for the differences between the display panel 210 and the back panel 280, and the omission of the gap-holding unit G, Figure 5 and Figure 6 Foldable display device 200 and Figures 1 to 4D The foldable display device 100 is basically the same as the foldable display device 100, so redundant descriptions will be omitted.

[0089] Reference Figure 5The display panel 210 can be a single transparent display panel. The display panel 210 may include signal transparent display panels disposed in the first non-folded region NFA1, the first folded region FA1, and the second non-folded region NFA2. Therefore, light emitted from the display panel 210, which is a transparent display panel, can be seen from both the upper and lower surfaces. The display panel 210 is a transparent display panel such that its multiple pixels include both transmission units and light-emitting units. In this case, the display element may be disposed only in the light-emitting unit, or it may be disposed in both the light-emitting and transmission units. Furthermore, the circuit unit for driving the display element may be disposed only in the light-emitting unit. However, the display panel is not limited to this, and the pixel configuration of the display panel 210 can be set in various forms.

[0090] A back plate 280 is disposed below the base plate 150. The back plate 280 may be disposed below the display panel 210, the top plate 140, and the base plate 150. The back plate 280 may overlap with the entire display panel 210. That is, the size of the back plate 280 may be equal to the size of the display panel 210.

[0091] The back panel 280 may be formed of an opaque material. The back panel 280 is a configuration used to improve the visibility of the display panel 210, which is a transparent display panel and is disposed below the display panel 210. The back panel 280 may be an SUS board or a colored film, but is not limited to these.

[0092] In the following text, reference will be made to Figures 7A to 7C The various display states of a foldable display device 200 according to another exemplary embodiment of the present disclosure are described in more detail.

[0093] Figures 7A to 7C This is a schematic diagram illustrating the state of a foldable display device according to another exemplary embodiment of the present disclosure. Figure 7A This is a view of the first state in which the display panel 210 is fully extended. Figure 7B This is a view showing the process of folding the display panel 210, and Figure 7C This is a view showing the second state in which the display panel 210 is vertically folded. Figures 7A to 7C For ease of description, only the display panel 210, back panel 180, floating screen 170, and second hinge unit H2 are shown.

[0094] First, refer to Figure 7A In its first state, when the display panel 210 is fully extended, the display panel 210 can perform flat image display. Therefore, the image IM can be realized through flat image display.

[0095] Specifically, the back panel 280 can be positioned below the display panel 210, which is a transparent display panel, to improve visibility. Since the display panel 210 is transparent, its brightness may be reduced. Therefore, the back panel 280 is positioned below the display panel 210 to improve its brightness.

[0096] The floating screen 170 can be connected to one end of the display panel 210 by means of a second hinge unit H2. The second hinge unit H2 allows the floating screen 170 to rotate at one end of the display panel 210. That is, the floating screen 170 can be configured to rotate at one end of the display panel 210 by means of the second hinge unit H2. In the first state, the floating screen 170 can be disposed below the back panel 280.

[0097] like Figure 7B As shown, in order to switch to Figure 7C In the second state shown, the display panel 210 is folded and the floating screen 270 rotates by means of the second hinge unit H2. For example, the display panel 210 is folded such that the flat portion provided on the back plate 280 and the folded portion are perpendicular to each other, and the second hinge unit H2 can rotate along one end of the display panel 210.

[0098] Therefore, refer to Figure 7C In the second state where the display panel 210 is vertically folded, the display panel 210 can use the floating screen 170 to display stereoscopic images.

[0099] Specifically, the first image IM1 of the horizontal portion of the display panel 210 is reflected from and transmitted through the floating screen 170 to the vertical portion of the display panel 210 for the user to see, and the second image IM2 of the vertical portion of the display panel 210 is directly seen by the user. At this time, the first display panel 210 is a transparent display panel, so when the user views the vertical portion of the display panel 210, the vertical portion can be perceived as transparent.

[0100] In this case, for stereoscopic image display, the first image IM1 and the second image IM2 can be images obtained by photographing the same object at different focal points. That is, when the first image IM1 and the second image IM2, photographed at different focal points, float, the two images appear to overlap in the air, making it possible to achieve a holographic-like effect with greater depth and three-dimensionality.

[0101] Furthermore, for stereoscopic image display, the second image IM2 is a background image within an image, and the first image IM1 is an object image displayed within the background image of an image. That is, in an image, the image used for the background is displayed by the vertical portion of the display panel 210, and the image used for the object is displayed by the horizontal portion of the display panel 210. Therefore, when the first image IM1 and the second image IM2 float, the background image and the object image appear to overlap in the air, making it possible to achieve a holographic-like effect with greater depth and three-dimensionality.

[0102] However, the method of displaying stereoscopic images by means of display panel 210 can be achieved by combining various images other than those described above, but is not limited to the examples described above.

[0103] In another exemplary embodiment of the foldable display device 200 according to the present disclosure, the bottom plate 150 and the top plate 140 of the foldable display device 200 are made of transparent material, so that a transparent foldable display device can be realized.

[0104] Furthermore, in another exemplary embodiment of the foldable display device 200 according to this disclosure, the floating screen 170 and the display panel 210 are used to display images with more three-dimensional effects. That is, in the foldable display device 200, the display panel 210, which is a transparent display panel, and the floating screen 170 are used. In addition, the shape of the plurality of recesses of the floating screen 170 and the refractive index difference between the first layer 172 and the second layer 173 are used to realize a pseudo-hologram with a sense of depth and three-dimensional effect.

[0105] Furthermore, in another exemplary embodiment of the foldable display device 200 according to this disclosure, the mounting angle of the floating screen 170 is increased due to the shape of the plurality of recesses of the floating screen 170. Therefore, the usable area is increased and the unity of the first image IM1 and the second image IM2 is enhanced.

[0106] Furthermore, in another exemplary embodiment of the foldable display device 200 according to this disclosure, the visibility of the display panel 210, which is a transparent display panel, can be improved by the back plate 280.

[0107] Figure 8 This is a schematic plan view of a foldable display device according to yet another exemplary embodiment of the present disclosure. Figure 9 It is along Figure 8 A schematic cross-sectional view taken from line IX-IX'. Besides the display panel 310, the gap-holding unit G, and the base plate 350, Figure 8 and Figure 9 Foldable display device 300 and Figures 1 to 4DThe foldable display device 100 is basically the same as the foldable display device 100, so redundant descriptions will be omitted.

[0108] Reference Figure 8 and Figure 9 According to another exemplary embodiment of the present disclosure, the foldable display device 300 includes a first non-foldable region NFA1, a first foldable region FA1, a second non-foldable region NFA2, a second foldable region FA2, and a third non-foldable region NFA3, which are sequentially positioned along the folding direction (X-axis direction). The first foldable region FA1 and the second foldable region FA2 are regions that are folded when the foldable display device 300 is folded.

[0109] The first folding region FA1 and the second folding region FA2 are the regions that are folded when the foldable display device 300 is folded, such that the first folding region FA1 and the second folding region FA2 can be folded along the folding direction—that is, relative to the folding direction. Figure 1 A specific radius of curvature in the X-axis direction is folded. When the first folded region FA1 and the second folded region FA2 are folded relative to the folding direction (X-axis direction), the first folded region FA1 and the second folded region FA2 can form part of a circle or an ellipse. At this time, the radius of curvature of each of the first folded region FA1 and the second folded region FA2 refers to the radius of the circle or ellipse formed by the first folded region FA1 and the second folded region FA2, respectively.

[0110] When the foldable display device 300 is folded, the first non-foldable region NFA1, the second non-foldable region NFA2, and the third non-foldable region NFA3 remain unfolded. That is, when the foldable display device 300 is folded, the first non-foldable region NFA1, the second non-foldable region NFA2, and the third non-foldable region NFA3 remain flat. At this time, the first foldable region FA1 can be folded inwards, causing the first non-foldable region NFA1 and the second non-foldable region NFA2 to be folded opposite each other. The second foldable region FA2 can be folded inwards, causing the second non-foldable region NFA2 and the third non-foldable region NFA3 to be folded opposite each other.

[0111] Reference Figure 8The display panel 310 includes a first display panel 311 disposed in a first non-folding region NFA1, a second display panel 312 disposed in a second non-folding region NFA2, and a third display panel 313 disposed in a third non-folding region NFA3. The third display panel 313 can be a transparent display panel, while the first display panel 311 and the second display panel 312 can be opaque display panels. That is, light emitted from the third display panel 313, which is a transparent display panel, is visible from both the upper and lower surfaces, while light emitted from the first display panel 311 and the second display panel 312, which are opaque display panels, is visible only from the upper surface. Therefore, the first display panel 311 and the second display panel 312 can be a commonly used display panel 310. The third display panel 313 is a transparent display panel, such that the plurality of pixels of the third display panel 313 include a transmissive unit and a light-emitting unit. In this case, the display element can be disposed only in the light-emitting unit, or it can be disposed in both the light-emitting unit and the transmissive unit. Furthermore, the circuit unit for driving the display element may be provided only in the light-emitting unit; however, it is not limited to this, and the display element of the third display panel 313 may be provided in various forms.

[0112] Reference Figure 8 and Figure 9 A gap retaining unit G is provided between the first display panel 311 and the second display panel 312, and between the second display panel 312 and the third display panel 313. Specifically, the gap retaining unit G is provided between the first display panel 311 and the second display panel 312 in the first folding region FA1, and between the second display panel 312 and the third display panel 313 in the second folding region FA2. The gap retaining unit G can be made of a material with a high compressibility, such as silicon-based pads. The compressive strain of the gap retaining unit G can be from 10% to 50%, but is not limited to this.

[0113] A base plate 350 for supporting the display panel 310 is provided on the rear surface of the display panel 310 and the gap holding unit G. The base plate 350 supports the flexible substrate in which the display panel 310 is configured to not sag and protects the components mounted on the flexible substrate from external moisture, heat and impact. Therefore, the base plate 350 reduces the overall thickness of the foldable display device 300 while supporting the display panel 310, thereby reducing the radius of curvature of the first folding region FA1 and the second folding region FA2.

[0114] The base plate 350 can be formed of a transparent material. For example, the base plate 350 can be formed of glass and have a thickness of about 300 μm, but is not limited thereto.

[0115] The base plate 350 may include multiple patterns in areas corresponding to the first folding area FA1 and the second folding area FA2. Here, the multiple patterns may have, for example... Figure 9 The recessed or hole shapes shown are illustrated. Because the base plate 350 includes multiple patterns, it facilitates easy folding of the foldable display device 300 and subsequent easy unfolding after folding, thereby improving the folding performance of the foldable display device 300.

[0116] In the following text, reference will be made to Figure 10A and Figure 10B The various display states of the foldable display device 300 according to yet another exemplary embodiment of the present disclosure are described in more detail.

[0117] Figure 10A and Figure 10B This is a schematic diagram illustrating the state of a foldable display device according to another exemplary embodiment of the present disclosure. Figure 10A This is a view showing a first state in which the first display panel 311 and the second display panel 312 are not folded at all, and the third display panel 313 is folded toward the lower surface of the second display panel 312. Figure 10B This is a view showing a second state in which the first display panel 311 is folded perpendicular to the second display panel 312 and the third display panel 313 is folded perpendicular to the second display panel 312. Figure 10A and Figure 10B For ease of description, only the display panel 310, the gap holding unit G, the floating screen 170, and the third hinge unit H2 are shown.

[0118] First, refer to Figure 10A In a first state where the first display panel 311 and the second display panel 312 are not folded at all and the third display panel 313 is folded toward the lower surface of the second display panel 312, the display panel 310 can perform flat image display.

[0119] The first display panel 311 and the second display panel 312 are opaque, making the floating screen 170 and the third display panel 313 located below the first display panel 311 and the second display panel 312 invisible to the user. Therefore, the user can regard the first image IM1 of the first display panel 311 and the second image IM2 of the second display panel 312 as flat images.

[0120] Next, refer to Figure 10B In a second state where the first display panel 311 is folded perpendicular to the second display panel 312 and the third display panel 313 is folded perpendicular to the second display panel 312, the display panel 310 can perform stereoscopic image display.

[0121] At this time, as Figure 10B As shown, in order to switch to the second state, the display panel 310 is folded and the floating screen 270 is rotated by means of the third hinge unit H3. That is, the first display panel 311 is folded to be perpendicular to the second display panel 312, the third display panel 313 is folded to be perpendicular to the second display panel 312, and the third hinge unit H3 rotates along one end of the third display panel 313.

[0122] Therefore, the first image IM1 of the first display panel 311, which is a non-transparent display panel, penetrates the floating screen 170 and the third display panel 313, which is a transparent display panel, to be visible to the user. Furthermore, the second image IM2 of the second display panel 312, which is also a non-transparent display panel, is reflected by the floating screen 170 to penetrate the third display panel 313 and become visible to the user. The third image IM3 of the third display panel 313, which is a transparent display panel, is visible to the user from the front.

[0123] At this time, in order to display a stereoscopic image, the first image IM1 displayed on the first display panel 311, the second image IM2 displayed on the second display panel 312, and the third image IM3 displayed on the third display panel 313 can be images obtained by photographing the same object at different focal points. That is, when the first image IM1, the second image IM2, and the third image IM3, photographed at different focal points, float, the three images appear to overlap in the air, making it possible to achieve a pseudo-hologram with greater depth and three-dimensional effect.

[0124] Furthermore, to display a stereoscopic image, the first image IM1 displayed on the first display panel 311 can be a background image within an image, and the second image IM2 and the third image IM3 displayed on the second display panel 312 and the third display panel 313 can be object images within a background image displayed in an image. That is, in an image, the image used as the background is displayed by the first display panel 311, and the image used as the object is displayed by the second display panel 312 and the third display panel 313. Therefore, when the first image IM1, the second image IM2, and the third image IM3 float, the background image and the object image appear to overlap in the air, making it possible to achieve a holographic-like effect with greater depth and three-dimensionality.

[0125] However, the method of displaying stereoscopic images by means of display panel 310 can be achieved by combining various images other than those described above, but is not limited to the examples described above.

[0126] In another exemplary embodiment of the foldable display device 300 according to the present disclosure, the bottom plate 350 and the top plate 140 of the foldable display device 300 are made of transparent material, so that a transparent foldable display device can be realized.

[0127] Furthermore, in another exemplary embodiment of the foldable display device 300 according to this disclosure, the floating screen 170 and the display panel 310 are used to display images with more three-dimensional effects. That is, in the foldable display device 300, a third display panel 313 as a transparent display panel and a first display panel 311, a second display panel 312 as non-transparent display panels, and the floating screen 170 are used. In addition, the shape of the plurality of recesses of the floating screen 170 and the refractive index difference between the first layer 172 and the second layer 173 are used to realize a pseudo-hologram with a sense of depth and three-dimensional effect.

[0128] Furthermore, in another exemplary embodiment of the foldable display device 300 according to this disclosure, the mounting angle of the floating screen 170 is increased due to the shape of the plurality of recesses of the floating screen 170. Therefore, the usable area is increased and the sense of unity among the first image IM1, the second image IM2, and the third image IM3 is enhanced.

[0129] Exemplary embodiments of this disclosure can also be described as follows:

[0130] According to one aspect of this disclosure, a foldable display device is provided. The foldable display device includes: a display panel, wherein at least a portion of the display panel comprises a transparent display panel; and a floating screen connected to the display panel and reflecting an image displayed on the display panel.

[0131] The foldable display device may further include a first non-foldable region, a second non-foldable region, and a first foldable region between the first non-foldable region and the second non-foldable region. The display panel may include a transparent display panel disposed in the first non-foldable region and a non-transparent display panel disposed in the second non-foldable region, and a floating screen may be disposed between the transparent display panel and the non-transparent display panel.

[0132] The foldable display device may further include a hinge unit that connects the transparent display panel and the floating screen, and the hinge unit is configured to support the floating screen when the first folding area is folded.

[0133] When the transparent display panel and the non-transparent display panel are perpendicular to each other, the angle formed by the floating screen and the non-transparent display panel can be 45 degrees or greater.

[0134] A floating screen can reflect images displayed on a non-transparent display panel.

[0135] Images displayed on a transparent display panel and images displayed on a non-transparent display panel can be obtained by photographing the same object at different focal points.

[0136] The image displayed on the transparent display panel can be a background image, and the image displayed on the non-transparent display panel can be an object image to be displayed in the background image.

[0137] The foldable display device may further include a gap-holding unit disposed between the transparent display panel and the non-transparent display panel in the first folding area.

[0138] The foldable display device may further include: a base plate disposed below the display panel and the gap retention unit and including a plurality of patterns in an area corresponding to the first folding area.

[0139] The base plate can be made of glass.

[0140] The foldable display device may also include an opaque back panel configured to slide beneath the display panel to overlap with either the transparent display panel or the opaque display panel.

[0141] The foldable display device may further include a first non-foldable region, a second non-foldable region, and a first foldable region between the first non-foldable region and the second non-foldable region. The display panel may include a single transparent display panel disposed in the first non-foldable region, the first foldable region, and the second non-foldable region, and the floating screen may be configured to rotate at one end of the transparent display panel.

[0142] The foldable display device may also include an opaque back panel disposed below the display panel to overlap with the entire display panel.

[0143] The foldable display device may further include a first non-foldable region, a second non-foldable region, a third non-foldable region, a first foldable region between the first non-foldable region and the second non-foldable region, and a second foldable region between the second non-foldable region and the third non-foldable region. The display panel may include a first opaque display panel disposed in the first non-foldable region, a second opaque display panel disposed in the second non-foldable region, and a transparent display panel disposed in the third non-foldable region, and the floating screen may be configured to rotate at one end of the transparent display panel.

[0144] The foldable display device may further include: a first gap retaining unit disposed between a first opaque display panel and a second opaque display panel in the first folding region, and a second gap retaining unit disposed between a second opaque display panel and a transparent display panel in the second folding region.

[0145] The floating screen may include: a base member; a first layer disposed on the base member and including a plurality of recesses; and a second layer filling the plurality of recesses of the first layer and having a refractive index higher than that of the first layer.

[0146] Each of the multiple recesses can have an asymmetrical shape in the width direction.

[0147] The surface with multiple recesses can be formed by multiple flat surfaces.

[0148] Multiple recesses can be formed by curved surfaces and flat surfaces, with the width of the curved surface being greater than the width of the flat surface.

[0149] Although exemplary embodiments of the present disclosure have been described in detail with reference to the accompanying drawings, the present disclosure is not limited thereto and can be implemented in many different forms without departing from the technical concept of the present disclosure. Therefore, the exemplary embodiments of the present disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of the present disclosure. The scope of the technical concept of the present disclosure is not limited thereto. Therefore, it should be understood that the exemplary embodiments described above are illustrative in all respects and do not limit the present disclosure. The scope of protection of the present disclosure should be interpreted based on the appended claims, and all technical concepts within the equivalent scope thereof should be interpreted as falling within the scope of the present disclosure.

Claims

1. A foldable display device, comprising: The display panel includes a transparent display panel for displaying a first image, which has multiple pixels with light-emitting units arranged thereon, and a non-transparent display panel connected to the transparent display panel; as well as A floating screen includes a first end connected to the display panel and a second end opposite to the first end that is not attached to the display panel, and the floating screen is configured to reflect a second image displayed on the non-transparent display panel.

2. The foldable display device according to claim 1, further comprising: A first non-folded region, a second non-folded region, and a first folded region between the first non-folded region and the second non-folded region. The display panel includes a transparent display panel disposed in the first non-folding area and a non-transparent display panel disposed in the second non-folding area, and the floating screen is disposed between the transparent display panel and the non-transparent display panel.

3. The foldable display device according to claim 2, further comprising: A hinge unit connects the transparent display panel to the floating screen, and the hinge unit is configured to support the floating screen when the first folding area is folded. 4.The foldable display apparatus of claim 3, wherein, When the transparent display panel and the non-transparent display panel are perpendicular to each other, the angle formed by the floating screen and the non-transparent display panel is 45 degrees or greater. 5.The foldable display apparatus of claim 2, wherein, The floating screen is configured to transmit light from the light-emitting units of multiple pixels of the transparent display panel.

6. The foldable display device according to claim 5, wherein, The first image displayed on the transparent display panel and the second image displayed on the non-transparent display panel are images obtained by photographing the same object at different focal points.

7. The foldable display device according to claim 5, wherein, The first image displayed on the transparent display panel is a background image, and the second image displayed on the non-transparent display panel is an object image to be displayed in the background image.

8. The foldable display device according to claim 2, further comprising: A gap-maintaining unit is disposed between the transparent display panel and the non-transparent display panel in the first folding area.

9. The foldable display device according to claim 8, further comprising: A base plate, which is disposed below the display panel and the gap holding unit and includes a plurality of patterns in a region corresponding to the first folding region.

10. The foldable display device according to claim 9, wherein, The base plate is made of glass.

11. The foldable display device according to claim 2, further comprising: An opaque back panel is configured to slide beneath the display panel to overlap with either the transparent display panel or the opaque display panel.

12. The foldable display device according to claim 1, further comprising: A first non-folded region, a second non-folded region, and a first folded region between the first non-folded region and the second non-folded region. The display panel includes a single transparent display panel disposed in the first non-folding area, the first folding area, and the second non-folding area, and the floating screen is configured to be able to rotate at one end of the transparent display panel.

13. The foldable display device according to claim 12, further comprising: An opaque back panel is disposed below the display panel to overlap with the entire display panel.

14. The foldable display device according to claim 1, further comprising: A first non-foldable region, a second non-foldable region, a third non-foldable region, a first foldable region between the first non-foldable region and the second non-foldable region, and a second foldable region between the second non-foldable region and the third non-foldable region. The display panel includes a first non-transparent display panel disposed in the first non-folding area, a second non-transparent display panel disposed in the second non-folding area, and a transparent display panel disposed in the third non-folding area, and the floating screen is configured to be able to rotate at one end of the transparent display panel.

15. The foldable display device according to claim 14, further comprising: A first gap retaining unit is disposed between the first opaque display panel and the second opaque display panel in the first folding area; as well as The second gap retaining unit is disposed between the second non-transparent display panel and the transparent display panel in the second folding area.

16. The foldable display device according to claim 1, wherein, The floating screen includes: Base components; The first layer, which is disposed on the base member and includes a plurality of recesses; and The second layer fills the plurality of recesses of the first layer and has a higher refractive index than the first layer.

17. The foldable display device according to claim 16, wherein, Each of the plurality of recesses has an asymmetrical shape in the width direction.

18. The foldable display device according to claim 16, wherein, The surfaces of the plurality of recesses are formed by a plurality of flat surfaces.

19. The foldable display device according to claim 16, wherein, The plurality of recesses are formed by curved surfaces and flat surfaces, wherein the width of the curved surfaces is greater than the width of the flat surfaces.

Images