Display device and electronic device including the same

Abstract

The invention relates to a display device and an electronic device including the same. The display device includes: a display panel including a foldable area having flexibility and a non-foldable area adjacent to the foldable area; a cover window on a first side of the display panel; and an isolation layer on a second side of the display panel opposite to the first side and including an elastic body. The release layer has a tensile modulus at-20 DEG C in a range of about 0.7 Gpa to about 1.5 Gpa.

Description

TECHNICAL FIELD

[0001] Embodiments disclosed herein relate generally to display apparatuses. More particularly, embodiments relate to foldable display apparatuses. BACKGROUND

[0002] Display apparatuses have become essential for many technologies as a medium for information exchange with users. Accordingly, the use of display apparatuses, such as liquid crystal display apparatuses, organic light emitting display apparatuses, and plasma display apparatuses, is increasing.

[0003] Flexible display apparatuses that can be converted into various shapes have been developed. Unlike flat panel displays, flexible display apparatuses can be folded, bent, or rolled like paper. Such flexible display apparatuses are easy to carry and are more convenient for users. Recently, foldable display apparatuses have received much attention in flexible display apparatuses. Foldable display apparatuses can be repeatedly folded and unfolded. SUMMARY

[0004] Embodiments disclosed herein can provide display apparatuses with improved reliability.

[0005] A display apparatus according to an embodiment of the disclosure can include a display panel including a foldable area having flexibility and a non-foldable area adjacent to the foldable area, a cover window at a first side of the display panel, and a spacer layer at a second side of the display panel opposite the first side and including an elastomer. The spacer layer can have a tensile modulus at -20℃ in a range of about 0.7 Gpa to about 1.5 Gpa.

[0006] In an embodiment, the spacer layer can have a tensile modulus at room temperature in a range of about 0.4 Gpa to about 1 Gpa.

[0007] In an embodiment, the spacer layer can have a tensile modulus at room temperature in a range of about 25% to about 60% of a tensile modulus at -20℃.

[0008] In an embodiment, the elastomer can include at least one material selected from the group consisting of thermoplastic polyurethane (TPU), thermosetting polyurethane (PU), polyether block amide (PEBA), nitrile rubber (NBR), ethylene-propylene rubber (EPDM), silicone rubber, epoxy material, and polyester block copolymer.

[0009] In an embodiment, the spacer layer can include polyether block amide (PEBA).

[0010] In an embodiment, the spacer layer can have a thickness in a range of about 25 micrometers (μm) to about 150 micrometers (μm).

[0011] In an embodiment, the display device can further include a support plate under the isolation layer and facing the second side of the display panel.

[0012] In an embodiment, the support plate can include a metal or an alloy.

[0013] In an embodiment, the support plate can include a carbon fiber reinforced plastic (CFRP) or a glass fiber reinforced plastic (GFRP).

[0014] In an embodiment, the support plate can include a stretchable portion overlapping the foldable area.

[0015] In an embodiment, a plurality of openings spaced apart from each other can be defined in the stretchable portion.

[0016] In an embodiment, each of the plurality of openings can have an elongated shape extending in a first direction, and the openings can be arranged along the first direction and a second direction crossing the first direction.

[0017] In an embodiment, the display device can further include a panel protection film between the display panel and the isolation layer, the panel protection film including a flexible plastic material, a first adhesive member attaching the panel protection film and the isolation layer, and a second adhesive member attaching the isolation layer and the support plate.

[0018] In an embodiment, the second adhesive member can overlap the foldable area and the non-foldable area.

[0019] In an embodiment, the second adhesive member can not overlap the foldable area and can overlap the non-foldable area.

[0020] A display device according to an embodiment of the disclosure can include a display panel including a foldable area having flexibility and a non-foldable area adjacent to the foldable area, a cover window at a first side of the display panel, an isolation layer at a second side of the display panel opposite the first side and including an elastomer, and a support plate under the isolation layer, facing the second side of the display panel, and including a stretchable portion overlapping the foldable area. A tensile modulus of the isolation layer at -20℃ can be in a range of about 0.7 Gpa to about 1.5 Gpa, and a tensile modulus of the isolation layer at room temperature can be in a range of about 0.4 Gpa to about 1 Gpa.

[0021] In an embodiment, the elastomer can include at least one material selected from the group consisting of a thermoplastic polyurethane (TPU), a thermosetting polyurethane (PU), a polyether block amide (PEBA), a nitrile rubber (NBR), an ethylene-propylene rubber (EPDM), a silicone rubber, an epoxy material, and a polyester block copolymer.

[0022] In an embodiment, the thickness of the isolation layer can be in a range of about 25 micrometers (µm) to about 150 micrometers (µm).

[0023] In an embodiment, the support plate can include a metal or an alloy.

[0024] In an embodiment, the display device can further include a panel protection film disposed between the display panel and the isolation layer, the panel protection film including a flexible plastic material, a first adhesive member attaching the panel protection film and the isolation layer, and a second adhesive member attaching the isolation layer and the support plate.

[0025] An electronic device according to an embodiment of the disclosure can include a display device including a display panel including a foldable area having flexibility and a non-foldable area adjacent to the foldable area, a cover window at a first side of the display panel, and an isolation layer at a second side of the display panel opposite the first side and including an elastomer, and a processor controlling the display device. A tensile modulus of the isolation layer at -20℃ can be in a range of about 0.7 Gpa to about 1.5 Gpa.

[0026] A display device according to an embodiment of the disclosure can include a display panel including a foldable area having flexibility and a non-foldable area adjacent to the foldable area, and an isolation layer disposed under the display panel and including an elastomer. A tensile modulus of the isolation layer at a low temperature (-20℃) can be in a first predetermined range, and a tensile modulus of the isolation layer at room temperature can be in a second predetermined range. Accordingly, reliability of the display device can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] The illustrative, non-limiting embodiments will be better understood from the following detailed description with reference to the appended drawings.

[0028] Figure 1 FIG. 1 is a plan view to illustrate a display device according to an embodiment of the disclosure.

[0029] Figure 2 and Figure 3 FIG. 2 is a cross-sectional view to illustrate the display device of FIG. 1 in a folded state. Figure 1

[0030] Figure 4 Figure 1

[0031] Figure 5 FIG. 10 is a plan view to illustrate a support plate of the display device of FIG. 1. Figure 4

[0032] Figure 6 Figure 4

[0033] ​​​​​​Figure 7 A block diagram of an electronic device according to an embodiment of the disclosure is illustrated. DETAILED DESCRIPTION

[0034] Hereinafter, a display device according to example embodiments of the disclosure is described in detail with reference to the accompanying drawings. The same reference numbers can be used throughout the drawings to refer to the same or like components and redundant descriptions can be omitted from the following.

[0035] Figure 1 A plan view of a display device DD according to an embodiment of the disclosure is illustrated. In the present specification, a first direction DR1 and a second direction DR2 can define a plane of a plan view. Figure 1 The second direction DR2 can be different from the first direction DR1. For example, the second direction DR2 can be perpendicular to the first direction DR1. Also, a third direction DR3 can be perpendicular to the plane defined by the first direction DR1 and the second direction DR2. Figure 2 and Figure 3 A cross-sectional view of the display device DD of Figure 1 in a folded state is illustrated.

[0036] Referring to Figure 1 , Figure 2 and Figure 3 , a display device DD according to an embodiment of the disclosure can be divided into a display area DA and a non-display area NDA. The non-display area NDA can be located around the display area DA. For example, the non-display area NDA can surround at least a portion of the display area DA. The display area DA can be an area in which an image can be displayed, for example, by generating light or adjusting the transmittance of light provided from an external light source. The non-display area NDA can be an area in which an image is not displayed.

[0037] At least a portion of the display device DD can be flexible, and the display device DD can be folded at a flexible portion, i.e., a foldable area FA. That is, the display area DA can include the foldable area FA such that an external force can bend the foldable area FA, thereby folding the display device DD. A first non-folded area NFA1 and a second non-folded area NFA2 can be adjacent to at least one side of the foldable area FA, and the first non-folded area NFA1 and the second non-folded area NFA2 are not folded during normal use of the display device DD. For example, the foldable area FA can have a folding line FL extending along the second direction DR2. Here, an area that is not folded is referred to as a non-folded area, but this is for convenience of explanation. The expression "non-folded" not only refers to a case in which the non-folded area is rigid due to a lack of flexibility, but also refers to a case in which the non-folded area is flexible but is not folded because the non-folded area has a flexibility that is smaller than the flexibility of the foldable area.

[0038] The display area DA can include a first display area DA1 and a second display area DA2. Specifically, the first display area DA1 and the second display area DA2 can be adjacent to each other in the first direction DR1. The first display area DA1 and the second display area DA2 can be continuously connected to substantially form one display area DA. When the display area DA is folded along the folding line FL as shown in Figure 2 , the first display area DA1 and the second display area DA2 can have an outer folding structure in which the first display area DA1 and the second display area DA2 are exposed to the outside. Alternatively, when the display area DA is folded along the folding line FL as shown in Figure 3 , the display device DD can have an inner folding structure such that the first display area DA1 and the second display area DA2 face each other.

[0039] Figure 1 Embodiments of the display device DD having one foldable area FA are illustrated, but the display device DD according to embodiments of the disclosure is not limited to having one foldable area FA. For example, the display device DD can be folded multiple times or can have multiple foldable areas FA to implement a rollable display device.

[0040] Figure 4 is taken along a line I-I' of Figure 1 .

[0041] Referring to Figure 1 and Figure 4 , the display device DD according to embodiments of the disclosure can include a display panel DP, a polarizing member POL, a cover window CW, a window protection layer PL, a first, second, and third adhesive members AM1, AM2, and AM3, a panel protection film LPF, a barrier layer BRL, and a support plate SM.

[0042] The polarizing member POL can be on the display panel DP. For example, the display panel DP can include a plurality of pixels that generate light to display an image. The polarizing member POL can block external light incident on the display panel DP from the outside, and thus can reduce external light reflection from the display panel DP.

[0043] The cover window CW can be on the polarizing member POL. The cover window CW can be on a first side of the display panel DP. The cover window CW can protect the display panel DP. The cover window CW can have a transparent portion corresponding to the display area DA. The cover window CW can include a polymer material or a thin glass film, etc. to ensure bending.

[0044] In an embodiment, the cover window CW can include ultra-thin toughened glass (UTG). The ultra-thin toughened glass can be strengthened and have a predetermined internal stress distribution. The strengthening can allow the ultra-thin toughened glass to better prevent the occurrence of cracks, the expansion of cracks, and breakage due to external impact. The ultra-thin toughened glass can have different stresses in each region by a strengthening process.

[0045] In an embodiment, the ultra-thin toughened glass of the cover window CW can be a thin film glass that has been chemically strengthened. However, embodiments of the present disclosure are not necessarily limited thereto, and the ultra-thin toughened glass of the cover window CW can be a thin film glass that has been thermally strengthened.

[0046] When the glass is composed of an ultra-thin film or a thin film, the glass can be flexible and can have characteristics that allow the glass to be bent, folded, or rolled up. For example, the cover window CW can include glass such as soda-lime glass, alkali-aluminosilicate glass, borosilicate glass, and lithium-aluminosilicate glass, etc. These can be used alone or in combination with each other. However, embodiments of the present disclosure are not necessarily limited thereto, and the cover window CW can include various types of glass.

[0047] The first adhesive member AM1 can be between the polarizing member POL and the cover window CW. The first adhesive member AM1 can attach the polarizing member POL and the cover window CW to each other. The first adhesive member AM1 can include, for example, an optically clear adhesive (OCA), a pressure sensitive adhesive (PSA), a photocurable resin, or a thermosetting resin, etc. These can be used alone or in combination with each other. Preferably, the first adhesive member AM1 can include a pressure sensitive adhesive.

[0048] The window protection layer PL can be on the cover window CW. The window protection layer PL can perform at least one of a function of preventing scattering, absorbing impact, preventing scratches, preventing fingerprints, and preventing glare of the cover window CW. The window protection layer PL can include a transparent polymer film. For example, the window protection layer PL can include an epoxy resin, a polyurethane, a polyester, a polyethylene terephthalate, a polyethylene naphthalate, a polyimide, a polyarylate, a polycarbonate, a polymethyl methacrylate, an ethyl vinyl acetate, and a polyamide resin, etc. These can be used alone or in combination with each other.

[0049] The panel protection film LPF can be under the display panel DP. The panel protection film LPF can overlap the foldable area FA and the non-foldable area NFA1 and the non-foldable area NFA2. The panel protection film LPF can protect the bottom of the display panel DP. The panel protection film LPF can include a flexible plastic material. For example, the panel protection film LPF can include a polyethylene terephthalate. However, embodiments of the present disclosure are not necessarily limited thereto.

[0050] The isolation layer BRL can be under the display panel DP. The isolation layer BRL can be on a second side of the display panel DP opposite the first side. The isolation layer BRL can increase resistance to compression forces due to external pressure. In addition, the isolation layer BRL can be used to prevent deformation of the display panel DP.

[0051] In an embodiment, the isolation layer BRL can include an elastomer. For example, the elastomer can include thermoplastic polyurethane (TPU), thermoset polyurethane (PU), polyether block amide (PEBA), nitrile rubber (NBR), ethylene-propylene rubber (EPDM), silicone rubber, epoxy material, or polyester block copolymer, etc. These can be used alone or in combination with each other. In one embodiment, the isolation layer BRL can include polyether block amide (PEBA).

[0052] In an embodiment, the tensile modulus of the isolation layer BRL at low temperature (e.g., about -20°C) can be in a range of about 0.7 Gpa to about 1.5 Gpa. When the tensile modulus of the isolation layer BRL at low temperature is less than about 0.7 Gpa, buckling of components disposed under the display panel DP can increase. When the tensile modulus of the isolation layer BRL at low temperature exceeds about 1.5 Gpa, cracks can occur in the window protection layer PL, and resistance or repulsion against folding of the display device DD can increase.

[0053] In an embodiment, the tensile modulus of the isolation layer BRL at room temperature (i.e., about 25°C) can be in a range of about 0.4 Gpa to about 1 Gpa. When the tensile modulus of the isolation layer at room temperature is less than about 0.4 Gpa, buckling of components disposed under the display panel DP can increase. When the tensile modulus of the isolation layer BRL at room temperature exceeds about 1 Gpa, cracks can occur in the window protection layer PL, and resistance or repulsion against folding of the display device DD can increase. In another embodiment, the tensile modulus of the isolation layer BRL at room temperature can have a range of about 25% to about 60% of the tensile modulus at low temperature.

[0054] In an embodiment, the thickness TH of the isolation layer BRL can be in a range of about 25 micrometers (μm) to about 150 micrometers (μm). Preferably, the thickness TH of the isolation layer BRL can be in a range of about 50 micrometers (μm) to about 150 micrometers (μm). More preferably, the thickness TH of the isolation layer BRL can be in a range of about 75 micrometers (μm) to about 100 micrometers (μm). The closer the tensile modulus of the isolation layer BRL is to the upper limit, the thinner the thickness TH of the isolation layer BRL can be, and the closer the tensile modulus of the isolation layer BRL is to the lower limit, the thicker the thickness TH of the isolation layer BRL can be. When the thickness TH of the isolation layer BRL is in the above range, the reliability of the display device DD can be improved.

[0055] The second adhesive member AM2 can be between the panel protection film LPF and the barrier layer BRL. The second adhesive member AM2 can attach the panel protection film LPF and the barrier layer BRL to each other. For example, the second adhesive member AM2 can overlap the foldable area FA and the non-foldable areas NFA1 and NFA2. For example, the second adhesive member AM2 can include an optically transparent adhesive, a pressure sensitive adhesive, a photocurable resin, or a thermosetting resin, etc. These can be used alone or in combination with each other. Preferably, the second adhesive member AM2 can include a pressure sensitive adhesive.

[0056] The support plate SM can be under the barrier layer BRL. Specifically, the support plate SM can face the second side of the display panel DP. The support plate SM can be used to support the display panel DP. In addition, the support plate SM can be used to assist in folding the display panel DP. In addition, the support plate SM can prevent external foreign substances from entering the display panel DP from the outside of the display device DD. In addition, the support plate SM can dissipate or disperse heat generated by the display panel DP.

[0057] At least some portions of the support plate SM can have a rigidity greater than that of the display panel DP. Accordingly, the support plate SM can prevent the display panel DP from being deformed due to external forces applied by a user, etc. For example, the support plate SM can include a first support portion SSP1, a second support portion SSP2, and a stretchable portion SP. The stretchable portion SP can be between the first support portion SSP1 and the second support portion SSP2. The stretchable portion SP can overlap the foldable area FA, the first support portion SSP1 can overlap the first non-foldable area NFA1, and the second support portion SSP2 can overlap the second non-foldable area NFA2. Accordingly, the first support portion SSP1 and the second support portion SSP2 can support the portion of the display panel DP overlapping the first non-foldable area NFA1 and the second non-foldable area NFA2, and the stretchable portion SP can allow and control folding of the display panel DP.

[0058] The stretchable portion SP can have elasticity that allows the display device DD to be folded and unfolded. However, although Figure 4 Only one stretchable portion SP is illustrated, but embodiments of the present disclosure are not necessarily limited thereto. For example, the stretchable portion SP can be formed in plural. Further description of embodiments of the stretchable portion SP is provided below.

[0059] In an embodiment, the support plate SM can include metals and alloys, etc. For example, the support plate SM can include stainless steel (SUS), aluminum, copper alloy, magnesium alloy, or titanium alloy, etc. In another embodiment, the support plate SM can include glass or plastic. For example, the support plate (SM) can include carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP), etc. However, embodiments of the present disclosure are not necessarily limited thereto, and the support plate SM can include various materials.

[0060] The third adhesive member AM3 can be between the barrier layer BRL and the support plate SM. The third adhesive member AM3 can attach the barrier layer BRL and the support plate SM to each other. In an embodiment, the third adhesive member AM3 can overlap the foldable area FA and the non-foldable areas NFA1 and NFA2. That is, the third adhesive member AM3 can continuously extend across the display area DA. In another embodiment, the third adhesive member AM3 can not overlap the foldable area FA, but can overlap the non-foldable areas NFA1 and NFA2. That is, the third adhesive member AM3 can include a first portion overlapping the first non-foldable area NFA1 and a second portion overlapping the second non-foldable area NFA2, the first portion and the second portion being separated from each other.

[0061] The third adhesive member AM3 can include, for example, an optically transparent adhesive, a pressure sensitive adhesive, a photocurable resin, or a thermosetting resin, etc. These can be used alone or in combination with each other. In particular, the third adhesive member AM3 can include a pressure sensitive adhesive.

[0062] The display device DD as described above can be folded or unfolded. For this folding, the display panel DP, the polarizing member POL, the cover window CW, the window protection layer PL, the first adhesive member AM1, the second adhesive member AM2, and the third adhesive member AM3, the panel protection film LPF, the barrier layer BRL, and the support plate SM can be flexible, in particular, in the foldable area FA.

[0063] Figure 5 To illustrate Figure 4 a plan view of the support plate SM.

[0064] Referring to Figure 5 , the support plate SM can include a first support portion SSP1, a second support portion SSP2, and a stretchable portion SP. In the illustrated embodiment, a plurality of openings HL spaced apart from each other can be defined in the stretchable portion SP of the support plate SM. The plurality of openings HL can be formed by, for example, removing a portion of the stretchable portion SP using an etching process or a punching process.

[0065] Each of the plurality of openings HL can have an elongated shape extending in the first direction DR1. That is, a long axis of each of the plurality of openings HL can be parallel to the first direction DR1.

[0066] Each of the plurality of openings HL can have substantially the same planar shape. For example, each of the plurality of openings HL can have a rectangular planar shape. However, embodiments of the present disclosure are not necessarily limited thereto, and each of the plurality of openings HL can have various planar shapes.

[0067] The openings HL can all have the same length l1. The plurality of openings HL can be arranged in rows spaced apart from each other along the first direction DR1 and in columns spaced apart from each other along the second direction DR2. In particular, the openings HL in each column can be spaced apart from each other by a predetermined distance l2 along the first direction DR1. The openings HL in the same row can be arranged in parallel with and interleaved with or interleaved with the openings HL arranged in the adjacent row. However, embodiments of the present disclosure are not necessarily limited to the illustrated examples, and the arrangement of the plurality of openings HL can be varied in various ways.

[0068] Figure 6 An enlarged cross-sectional view of the area A of FIG. 1A is illustrated in FIG. 1B. In particular, Figure 4 An enlarged cross-sectional view of a portion of the display panel DP of FIG. 1A is illustrated in FIG. 1C. Figure 6 An enlarged cross-sectional view of a portion of the display panel DP of FIG. 1A is illustrated in FIG. 1C. Figure 4 An enlarged cross-sectional view of a portion of the display panel DP of FIG. 1A is illustrated in FIG. 1C.

[0069] Referring to Figure 6 The display panel DP can include a substrate 110, a buffer layer 120, a gate insulating layer 140, a transistor TR, an interlayer insulating layer 160, a planarization layer 180, a pixel definition layer PDL, a light emitting element 200, and an encapsulation layer 230. The transistor TR can include an active layer 130, a gate electrode 150, a source electrode 170a, and a drain electrode 170b. The light emitting element 200 can include a lower electrode 190, a light emitting layer 210, and an upper electrode 220, and the encapsulation layer 230 can include a first thin film encapsulation layer 231, a second thin film encapsulation layer 232, and a third thin film encapsulation layer 233.

[0070] A panel protection film LPF can be under the substrate 110. The panel protection film LPF can protect a lower portion of the display panel DP.

[0071] The substrate 110 can include a transparent material or an opaque material. The substrate 110 can include a flexible transparent resin substrate. Examples of the flexible transparent resin substrate which can be used as the substrate 110 can include a polyimide substrate. Alternatively, the substrate 110 can include a quartz substrate (e.g., a synthetic quartz substrate), a calcium fluoride substrate, a soda lime glass substrate, or an alkali-free glass substrate, etc. These can be used alone or in combination with each other.

[0072] The buffer layer 120 can be on the substrate 110. The buffer layer 120 can prevent diffusion of metal atoms or impurities from the substrate 110 into the transistor TR. For example, the buffer layer 120 can include an inorganic material such as silicon oxide and silicon nitride, etc. These can be used alone or in combination with each other.

[0073] An active layer 130 can be disposed on the buffer layer 120. The active layer 130 can include a metal oxide semiconductor, an inorganic semiconductor (e.g., amorphous silicon or polysilicon), or an organic semiconductor. The active layer 130 can include a source region, a drain region, and a channel region between the source region and the drain region. The source region and the drain region can be doped with an impurity (e.g., a P-type impurity or an N-type impurity), and the channel region can not be doped with an impurity.

[0074] A gate insulating layer 140 can be on the buffer layer 120. The gate insulating layer 140 can sufficiently cover the active layer 130 on the substrate 110, and can have a substantially flat upper surface without creating a step around the active layer 130. Alternatively, the gate insulating layer 140 can cover the active layer 130 on the substrate 110, and can be disposed with a uniform thickness along the profile of the active layer 130. The gate insulating layer 140 can include, for example, silicon oxide (SiO x ), silicon nitride (SiN x ), silicon carbide (SiC x ), silicon oxynitride (SiO x N y ), or silicon oxycarbide (SiO x C y ), etc. These can be used alone or in combination with each other.

[0075] A gate electrode 150 can be on the gate insulating layer 140. The gate electrode 150 can overlap the channel region of the active layer 130. The gate electrode 150 can include, for example, a metal, an alloy, a metal nitride, a conductive metal oxide, or a transparent conductive material, etc. These can be used alone or in combination with each other.

[0076] An interlayer insulating layer 160 can be on the gate insulating layer 140. The interlayer insulating layer 160 can sufficiently cover the gate electrode 150 on the substrate 110, and can have a substantially flat upper surface without creating a step around the gate electrode 150. Alternatively, the interlayer insulating layer 160 can cover the gate electrode 150 on the substrate 110, and can be disposed with a uniform thickness along the profile of the gate electrode 150. The interlayer insulating layer 160 can include, for example, silicon oxide, silicon nitride, silicon carbide, silicon oxynitride, or silicon oxycarbide, etc. These can be used alone or in combination with each other.

[0077] A source electrode 170a and a drain electrode 170b can be on the interlayer insulating layer 160. The source electrode 170a can be connected to the source region of the active layer 130 through a contact hole passing through a first portion of the gate insulating layer 140 and the interlayer insulating layer 160, and the drain electrode 170b can be connected to the drain region of the active layer 130 through a contact hole passing through a second portion of the gate insulating layer 140 and the interlayer insulating layer 160. Each of the source electrode 170a and the drain electrode 170b can include, for example, a metal, an alloy, a metal nitride, a conductive metal oxide, or a transparent conductive material, etc. These can be used alone or in combination with each other.

[0078] The transistor TR including the active layer 130, the gate electrode 150, the source electrode 170a, and the drain electrode 170b can be in the display region DA (see Figure 1 ).

[0079] The planarization layer 180 can be provided on the interlayer insulating layer 160. The planarization layer 180 can sufficiently cover the source electrode 170a and the drain electrode 170b. The planarization layer 180 can include an organic material and / or an inorganic material. In an embodiment, the planarization layer 180 can include an organic material. For example, the planarization layer 180 can include an organic material such as a polyimide-based resin, a photoresist, a polyacrylic-based resin, a polyimide-based resin, and a siloxane-based resin, etc. These can be used alone or in combination with each other.

[0080] The lower electrode 190 can be on the planarization layer 180. The lower electrode 190 can be connected to the drain electrode 170b through a contact hole passing through the planarization layer 180. The lower electrode 190 can include, for example, a metal, an alloy, a metal nitride, a conductive metal oxide, or a transparent conductive material, etc. These can be used alone or in combination with each other.

[0081] The pixel definition layer PDL can be on the planarization layer 180. The pixel definition layer PDL can define an opening that exposes at least a portion of an upper surface of the lower electrode 190. The pixel definition layer PDL can include an organic material and / or an inorganic material. For example, the pixel definition layer PDL can include an organic material such as a polyimide-based resin, a photoresist, a polyacrylic-based resin, a polyimide-based resin, and a siloxane-based resin, etc. These can be used alone or in combination with each other.

[0082] The light emitting layer 210 can be on the lower electrode 190. The light emitting layer 210 can be on, inter alia, the portion of the lower electrode 190 exposed through the opening in the pixel definition layer PDL. The light emitting layer 210 can contain at least one of a plurality of light emitting materials (e.g., materials capable of emitting red light, green light, or blue light). Alternatively, the light emitting layer 210 can stack a plurality of light emitting materials capable of generating different colors of light (such as red light, green light, and blue light) so that the light emitting layer 210 as a whole emits white light.

[0083] The upper electrode 220 can be on the pixel definition layer PDL and the light emitting layer 210. The upper electrode 220 can include, for example, a metal, an alloy, a metal nitride, a conductive metal oxide, or a transparent conductive material, etc. These can be used alone or in combination with each other.

[0084] The light emitting element 200 including the lower electrode 190, the light emitting layer 210, and the upper electrode 220 can be in the display region DA (see Figure 1 ). The light emitting element 200 can be electrically connected to the transistor TR.

[0085] A first thin film encapsulation layer 231 can be on the upper electrode 220. The first thin film encapsulation layer 231 can prevent the light emitting layer 210 from being deteriorated or damaged due to permeation of moisture and oxygen, etc. In addition, the first thin film encapsulation layer 231 can also protect the display panel DP from external impact. The first thin film encapsulation layer 231 can include, for example, one or more flexible inorganic materials.

[0086] A second thin film encapsulation layer 232 can be on the first thin film encapsulation layer 231. The second thin film encapsulation layer 232 can improve the flatness of the display panel DP and protect the display panel DP. The second thin film encapsulation layer 232 can include, for example, one or more flexible organic materials.

[0087] A third thin film encapsulation layer 233 can be on the second thin film encapsulation layer 232. The third thin film encapsulation layer 233, together with the first thin film encapsulation layer 231, can prevent the light emitting layer 210 from being deteriorated or damaged due to permeation of moisture and oxygen, etc. In addition, the third thin film encapsulation layer 233, together with the first thin film encapsulation layer 231 and the second thin film encapsulation layer 232, can protect the display panel DP from external impact. The third thin film encapsulation layer 233 can include, for example, one or more flexible inorganic materials.

[0088] Referring again to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 , the display device DD according to an embodiment of the disclosure can include a display panel DP including a flexible foldable area FA and non-foldable areas NFA1 and NFA2 adjacent to the foldable area FA, and a barrier layer BRL disposed under the display panel DP and including an elastomer.

[0089] The tensile modulus of the barrier layer BRL at a low temperature (-20℃) can be within a predetermined range (e.g., about 0.7 Gpa to about 1.5 Gpa), and the tensile modulus of the barrier layer BRL at room temperature can be within a predetermined range (e.g., about 0.4 Gpa to about 1 Gpa). In addition, the thickness TH of the barrier layer BRL can be within a predetermined range (e.g., about 25 micrometers (μm) to about 150 micrometers (μm)). Accordingly, the reliability of the display device DD can be improved.

[0090] Hereinafter, the characteristics of the embodiments of the disclosure are compared with some comparative embodiments.

[0091] Table 1 provided below shows properties of five comparative embodiments and two embodiments according to the present disclosure. In Comparative Embodiment 1, a polyimide (PI) is used to form an isolation layer under a display panel. In Comparative Embodiment 2, a polyethylene terephthalate (PET) is used to form an isolation layer under a display panel. In Comparative Embodiment 3, Comparative Embodiment 4, and Comparative Embodiment 5, a polyether block amide (PEBA) is used to form an isolation layer under a display panel. In Embodiment 1 and Embodiment 2, a polyether block amide (PEBA) is used to form an isolation layer BRL under a display panel DP. In Comparative Embodiment 1, Comparative Embodiment 2, Comparative Embodiment 3, Comparative Embodiment 4, and Comparative Embodiment 5, Embodiment 1, and Embodiment 2, the components formed on the display panel and the components formed under the display panel can be common components of foldable display devices known in the art.

[0092] Table 1 shows the room temperature modulus, low temperature modulus, and thickness of the isolation layers of Comparative Embodiment 1, Comparative Embodiment 2, Comparative Embodiment 3, Comparative Embodiment 4, and Comparative Embodiment 5, and the isolation layer BRL of Embodiment 1 and Embodiment 2. Here, the “room temperature modulus” refers to the tensile modulus at room temperature (i.e., 25°C), and the “low temperature modulus” refers to the tensile modulus at -20°C.

[0093]

[0094]

[0095]

[0096] Table 2 below shows the folding reliability of the display devices according to the comparative embodiments and the embodiments, and shows measured values of repulsion against folding of the display devices. The folding reliability of the display devices was evaluated at -20°C (i.e., low temperature). To evaluate the folding reliability of the display devices, folding and unfolding of the display devices was repeated multiple times. When evaluating the folding reliability of the display devices, “OK” means that no buckling occurred in the components under the display panel, and no cracks occurred in the window protection layer.

[0097]

[0098]

[0099] Referring to Table 2, it can be seen that in Comparative Embodiment 1, Comparative Embodiment 2, Comparative Embodiment 3, Comparative Embodiment, and Comparative Embodiment 4, buckling occurred in the components under the display panel. In Comparative Embodiment 5, it can be seen that cracks occurred in the window protection layer. On the other hand, in Embodiment 1 and Embodiment 2, it can be seen that no buckling occurred in the components under the display panel, and no cracks occurred in the window protection layer.

[0100] Table 2 also indicates that the repulsive force against folding of the display device according to Comparative Example 1, Comparative Example 2, and Comparative Example 5 is greater than the repulsive force against folding of the display device according to Example 1 and Example 2.

[0101] Referring again to Figure 4 From these results, it can be seen that, in the display device DD according to the embodiments of the disclosure, when the barrier layer BRL includes an elastomer, the tensile modulus of the barrier layer BRL at low temperature (-20℃) is in the range of about 0.7 Gpa to about 1.5 Gpa, the tensile modulus of the barrier layer BRL at room temperature is in the range of about 0.4 Gpa to about 1 Gpa, and the thickness TH of the barrier layer BRL is in the range of about 25 micrometers (μm) to about 150 micrometers (μm), it can be seen that the folding reliability of the display device DD at low temperature is excellent.

[0102] Figure 7 A block diagram of an electronic device 900 according to the embodiments of the disclosure is illustrated.

[0103] Referring to Figure 7 In the embodiments, the electronic device 900 can include a processor 910, a memory device 920, a storage device 930, an input / output device 940, a power supply 950, and a display device 960. In this case, the display device 960 can correspond to the display device DD described with reference to Figures 1 to 6 The electronic device 900 can further include several ports capable of communicating with a video card, a sound card, a memory card, and a USB device, etc.

[0104] In the embodiments, the electronic device 900 can be implemented as a television. In another embodiment, the electronic device 900 can be implemented as a smart phone. However, the electronic device 900 is not limited thereto, and for example, the electronic device 900 can be implemented as a mobile phone, a video phone, a smart pad, a smart watch, a tablet personal computer, a vehicle navigation device, a computer monitor, a laptop computer, a head-mounted display (HMD), etc.

[0105] The processor 910 can perform certain computations or tasks. The processor 910 can control the display device 960. In the embodiments, the processor 910 can be a microprocessor, a central processing unit (CPU), and / or an application processor (AP), etc. The processor 910 can be connected to other components through an address bus, a control bus, and a data bus, etc. The processor 910 can also be connected to an extension bus such as a peripheral component interconnect (PCI) bus.

[0106] The memory device 920 can store data required for the operation of the electronic device 900. For example, the memory device 920 can include a non-volatile memory device such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase-change random access memory (PRAM) device, a resistive random access memory (RRAM) device, a nano floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, and a ferroelectric random access memory (FRAM) device, and / or a volatile memory device such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, and a mobile DRAM device, and the like.

[0107] The storage device 930 can include a solid state drive (SSD), a hard disk drive (HDD), and a CD-ROM, and the like.

[0108] The input / output device 940 can include an input device such as a keyboard, a keypad, a touchpad, a touchscreen, and a mouse, and an output device such as a speaker and a printer, and the like.

[0109] The power supply 950 can supply power required for the operation of the electronic device 900. The display device 960 can be connected to other components through a bus or other communication links. In an embodiment, the display device 960 can be included in the input / output device 940.

[0110] The present disclosure can be applied to various display devices. For example, the present disclosure can be applicable to various display devices such as a display device for a vehicle, a ship, and an aircraft, a portable communication device, a display device for exhibition or information transmission, and a medical display device, and the like.

[0111] The foregoing is a summary of embodiments and is not to be construed as a limitation. Although several embodiments have been described, skilled practitioners will readily recognize that many modifications can be made to these embodiments without essentially departing from the novel teachings and advantages of the present disclosure. Accordingly, all such modifications are intended to be included within the scope of the claims defined. It is therefore to be understood that the foregoing is a description of various embodiments and is not to be construed as a limitation. Modifications are intended to be included within the scope of the claims. Accordingly, it is intended that the present disclosure be limited only by the scope of the claims.

Claims

1.A display device comprising: a display panel including a foldable area having flexibility and a non-foldable area adjacent to the foldable area; a cover window on a first side of the display panel; and a spacer layer on a second side of the display panel opposite to the first side and including an elastomer, wherein a tensile modulus of the spacer layer at -20℃ is in a range of 0.7 Gpa to 1.5 Gpa. 2.The display device of claim 1, wherein the tensile modulus of the spacer layer at 25℃ is in a range of 0.4 Gpa to 1 Gpa. 3.The display device of claim 1, wherein the tensile modulus of the spacer layer at 25℃ has a range of 25% to 60% of the tensile modulus at -20℃. 4.The display device of claim 1, wherein the elastomer includes at least one selected from the group consisting of a thermoplastic polyurethane, a thermosetting polyurethane, a polyether block amide, a nitrile rubber, an ethylene-propylene rubber, a silicone rubber, an epoxy material, and a polyester block copolymer. 5.The display device of claim 1, wherein the spacer layer includes a polyether block amide. 6.The display device of claim 1, wherein a thickness of the spacer layer is in a range of 25 micrometers to 150 micrometers. 7.The display device of claim 1, further comprising: a support plate under the spacer layer and facing the second side of the display panel. 8.The display device of claim 7, wherein the support plate includes a metal or an alloy. 9.The display device of claim 7, wherein the support plate includes a carbon fiber reinforced plastic or a glass fiber reinforced plastic. 10.The display device of claim 7, wherein the support plate includes a stretchable portion overlapping the foldable area. 11.The display device of claim 10, wherein a plurality of openings spaced apart from each other is defined in the stretchable portion. 12.The display device of claim 11, wherein each of the plurality of openings has an elongated shape extending in a first direction, and the plurality of openings is arranged along the first direction and a second direction crossing the first direction. 13.The display device of claim 7, further comprising: a panel protection film between the display panel and the spacer layer, the panel protection film including a flexible plastic material; a first adhesive member attaching the panel protection film and the spacer layer; and a second adhesive member attaching the spacer layer and the support plate. 14.The display device of claim 13, wherein the second adhesive member overlaps the foldable area and the non-foldable area. 15.The display device of claim 13, wherein the second adhesive member does not overlap the foldable area and overlaps the non-foldable area. 16.A display device comprising: a display panel including a foldable area having flexibility and a non-foldable area adjacent to the foldable area; a cover window on a first side of the display panel; and ​ ​ a separation layer on a second side of the display panel opposite the first side and including an elastomer; and a support plate under the separation layer facing the second side of the display panel and including a stretchable portion overlapping the foldable area; wherein a tensile modulus of the separation layer at -20 °C is in a range from 0.7 GPa to 1.5 GPa, and the tensile modulus of the separation layer at 25 °C is in a range from 0.4 GPa to 1 GPa. 17.The display device of claim 16, wherein the elastomer includes at least one selected from the group consisting of a thermoplastic polyurethane, a thermosetting polyurethane, a polyether block amide, a nitrile rubber, an ethylene-propylene rubber, a silicone rubber, an epoxy material, and a polyester block copolymer. 18.The display device of claim 16, wherein a thickness of the separation layer is in a range from 25 μm to 150 μm. 19.The display device of claim 16, wherein the support plate includes a metal or an alloy. 20.The display device of claim 16, further comprising: a panel protection film disposed between the display panel and the separation layer, the panel protection film including a flexible plastic material; a first adhesive member attaching the panel protection film and the separation layer; and a second adhesive member attaching the separation layer and the support plate. 21.An electronic device comprising: a display device; and a processor controlling the display device, wherein the display device is the display device of any one of claims 1 to 15 or the display device of any one of claims 16 to 20. ​ ​

Images