FLEXIBLE DISPLAY AND ELECTRONIC DEVICE INCLUDING THE SAME

An example flexible display includes a panel layer and a cover layer disposed on one surface of the panel layer. The cover layer includes a first portion and a second portion that extends from the first portion in a first direction. The first portion includes a first base portion having a first thickness and a first connecting portion that extends from the first base portion and has a gradually decreasing thickness. The second portion includes a second base portion that is connected with the first connecting portion and that has a second thickness smaller than the first thickness and a reinforcing portion that protrudes from an edge of the second base portion that faces in a second direction perpendicular to the first direction. The reinforcing portion includes an edge portion that protrudes from a partial region of the second base portion to have a third thickness and a second connecting portion that extends from the edge portion toward the second base portion and has a gradually decreasing thickness.

BACKGROUND

Field

The disclosure relates to a flexible display and an electronic device including the same.

Description of Related Art

An electronic device may include a flexible display. Such electronic devices may, for example, include a foldable electronic device, a slidable electronic device, or a rollable electronic device. The electronic device may be deformed to extend or reduce a display region visually exposed on an outer surface of the electronic device. For example, the flexible display may be disposed in the electronic device in a bendable, foldable, or rollable form.

SUMMARY

In a case of the electronic device configured such that the flexible display performs a sliding, bending, and/or rolling operation, a compressive load may be concentrated on an edge portion of the display when the electronic device is driven. As the compressive load is concentrated, a buckling phenomenon may occur in the display, which may lead to delamination or damage of the display.

According to various example embodiments of the disclosure, the strength of an edge portion of a display may be improved by forming a reinforcing portion on a glass cover (e.g., thin glass) applied to the display.

A flexible display according to an example embodiment may include a panel layer and a cover layer disposed on one surface of the panel layer. The cover layer includes a first portion and a second portion that extends from the first portion in a first direction. The first portion includes a first base portion having a first thickness and a first connecting portion that extends from the first base portion and has a gradually decreasing thickness. The second portion includes a second base portion that is connected with the first connecting portion and that has a second thickness smaller than the first thickness and a reinforcing portion that protrudes from an edge of the second base portion that faces in a second direction perpendicular to the first direction. The reinforcing portion includes an edge portion that protrudes from a partial region of the second base portion to have a third thickness and a second connecting portion that extends from the edge portion toward the second base portion and has a gradually decreasing thickness.

A slidable electronic device according to an example embodiment may include a first structure, a second structure connected to the first structure so as to slide, and a display configured such that a size of a region exposed on a front surface of the electronic device is changed in response to sliding of the second structure relative to the first structure, the display being formed in a structure in which a plurality of layers are stacked. The plurality of layers includes include a panel layer and a cover layer disposed on one surface of the panel layer, and the cover layer includes a first portion and a second portion that extends from the first portion in a first direction. The first portion includes a first base portion having a first thickness and a first connecting portion that extends from the first base portion and has a gradually decreasing thickness, and the second portion includes a second base portion that is connected with the first connecting portion and that has a second thickness smaller than the first thickness and a reinforcing portion that protrudes from an edge of the second base portion that faces in a second direction perpendicular to the first direction. The reinforcing portion includes an edge portion that protrudes from a partial region of the second base portion to have a third thickness and a second connecting portion that extends from the edge portion toward the second base portion and has a gradually decreasing thickness.

A foldable electronic device according to an example embodiment may include a first housing, a second housing connected to the first housing so as to be rotatable, and a display disposed in the first housing and the second housing and partially folded or unfolded in response to relative rotation of the first housing and the second housing, the display being formed in a structure in which a plurality of layers are stacked. The plurality of layers includes a panel layer and a cover layer disposed on one surface of the panel layer, and the cover layer includes a first portion and a second portion that extends from the first portion in a first direction. The first portion includes a first base portion having a first thickness and a first connecting portion that extends from the first base portion and has a gradually decreasing thickness, and the second portion includes a second base portion that is connected with the first connecting portion and that has a second thickness smaller than the first thickness and a reinforcing portion that protrudes from an edge of the second base portion that faces in a second direction perpendicular to the first direction. The reinforcing portion includes an edge portion that protrudes from a partial region of the second base portion to have a third thickness and a second connecting portion that extends from the edge portion toward the second base portion and has a gradually decreasing thickness.

An electronic device according to the various example embodiments may improve the strength of the edge portion of the display by forming a reinforcing portion on the glass cover (e.g., thin glass) applied to the display.

In addition, the disclosure may provide various effects that are directly or indirectly recognized.

With regard to description of the drawings, identical or similar reference numerals may be used to refer to identical or similar components.

DETAILED DESCRIPTION

Hereinafter, various example embodiments of the disclosure may be described with reference to accompanying drawings. Accordingly, those of ordinary skill in the art will recognize that modifications, equivalents, and/or alternatives on the various example embodiments described herein can be variously made without departing from the scope and spirit of the disclosure.

FIG.1is a view illustrating a default state of an example electronic device according to various embodiments.FIG.2is a view illustrating an extended state of the example electronic device according to various embodiments.

Referring toFIGS.1and2, the electronic device100according to an embodiment may include a first structure110, a second structure120, and a display130.

The electronic device100ofFIGS.1and2may be an electronic device of a slidable type or a rollable type and may include a default state (e.g., a closed mode, a reduction mode, or a slide-in mode) and an extended state (e.g., an open mode or a slide-out mode). The default state and the extended state of the electronic device100may be determined depending on the position of the second structure120relative to the first structure110. The electronic device100may be changed between the default state and the extended state by a user operation or a mechanical operation.

The default state may refer, for example, to a state in which the area (or size) of the display130visually exposed on a front surface (e.g., a surface facing in the +z-axis direction) of the electronic device100is relatively reduced. The extended state may refer, for example, to a state in which the area (or size) of the display130visually exposed on the front surface of the electronic device100is relatively extended. For example, the area of the display130visually exposed on the front surface of the electronic device100in the extended state may be larger than the area of the display130visually exposed on the front surface of the electronic device100in the default state, and the area of the display130visually exposed on the front surface of the electronic device100may be largest when the electronic device100is in the extended state. The electronic device100may be deformed through a plurality of intermediate states defined between the default state and the extended state. For example, the plurality of intermediate states may refer, for example, to a plurality of states in which the area of the display130visually exposed on the front surface has a medium (or intermediate) size that is larger than that in the default state and smaller than that in the extended state.

The default state may refer, for example, to a closed state in which a first side surface122and a second side surface124of the second structure120are located in the first structure110so that the second structure120is closed to the first structure110. The extended state may refer, for example, to an opened state in which the first side surface122and the second side surface124of the second structure120move out of the first structure110so that the second structure120is open to the first structure110.

The first structure110and the second structure120may be coupled to slide relative to each other. The second structure120may be coupled to one side of the first structure110so as to slide. For example, the first structure110may be a fixed structure, and the second structure120may be a structure movable relative to the first structure110. The second structure120may be coupled to the one side of the first structure110(e.g., the +x-axis direction) so as to slide relative to the first structure110in opposite directions S1and S2(e.g., the +x/−x-axis directions).

According to various embodiments, the first structure110may refer, for example, to a fixed member, a fixed housing, a fixed case, or a main body. The second structure120may refer, for example, to a sliding structure, a sliding member (a slider), a sliding housing, a sliding case, or a sliding body.

The electronic device100may be changed between the default state and the extended state as the second structure120slides relative to the first structure110. For example, the electronic device100in the default state (e.g., the state ofFIG.1) may be changed to the extended state (e.g., the state ofFIG.2) as the second structure120moves relative to the first structure110in the first direction S1. In contrast, the electronic device100in the extended state may be changed to the default state as the second structure120moves relative to the first structure110in the second direction S2.

The size of a region of the display130exposed on the front surface of the electronic device100may be changed in response to a sliding operation of the second structure120. In a state in which the display130is supported by at least one of the first structure110or the second structure120, at least a portion of the display130may rotate and/or linearly move based on the sliding operation of the second structure120, and thus the region of the display130exposed on the front surface of the electronic device100may be extended or retracted. The display130may at least partially include a flexible portion. For example, the display130may be a flexible display.

The display130may include a default region130aand an extended region130bthat extends from the default region130ain one direction (e.g., the −x-axis direction in the drawings). The default region130amay form the front surface of the electronic device100. For example, the default region130amay remain exposed on the front surface irrespective of the states of the electronic device100. The area of the extended region130bexposed on the front surface of the electronic device100may vary depending on the states of the electronic device100. For example, in any states between the default state and the extended state and in the extended state, at least a portion of the extended region130bmay form the front surface of the electronic device100together with the default region130a. The area of the extended region130bexposed on the front surface of the electronic device100may vary depending on the distance by which the second structure120slides relative to the first structure110. For example, as the second structure120moves in the first direction S1in the default state, the size of the extended region130bexposed on the front surface of the electronic device100may be gradually increased. In contrast, as the second structure120moves in the second direction S2in the extended state, the size of the extended region130bexposed on the front surface of the electronic device100may be gradually decreased.

The default region130aand the extended region130bof the display130may be distinguished from each other depending on whether the default region130aand the extended region130bare exposed on the front surface of the electronic device100in the default state. The default region130amay refer, for example, to a partial region of the display130visually exposed on the front surface of the electronic device100in the default state. The extended region130bmay refer, for example, to another region of the display130that is located in an inner space of the first structure110in the default state so as not to be exposed on the front surface of the electronic device100and is at least partially moved out of the inner space of the first structure110in the extended state so as to be visually exposed on the front surface of the electronic device100. In the illustrated embodiment, the inner space of the first structure110may be formed by a plate part112and a first sidewall part114and a second sidewall part116formed on opposite sides of the plate part112in a lengthwise direction of the plate part112(e.g., a direction perpendicular to the sliding directions S1and S2or the y-axis direction).

In example embodiments of the disclosure, the default region130aand the extended region130bof the display130are not physically separated regions and do not mean that the shapes or properties differ from each other. For example, the extended region130bmay be understood as indicating the remaining region other than the default region130ain the entire region of the display130. In various embodiments, the default region130amay be understood, for example, as a fixedly exposed display region or a main display region, and the extended region130bmay be understood as a variably exposed display region or a sub-display region.

According to the illustrated embodiment, the direction in which the extended region130bextends from the default region130amay be opposite to the first sliding direction S1in which the second structure120moves when the electronic device100is extended. For example, the extended region130bmay extend from the default region130ain the second sliding direction S2. As the second structure120slides relative to the first structure110, the extended region130bmay move into the first structure110(e.g., a slide-in operation), or may move out of the first structure110(e.g., a slide-out operation).

However, the electronic device100and the display130are not limited to the illustrated embodiment. According to various embodiments, the electronic device100may be configured such that the extended region130bof the display130slides into the second structure120, or slides out of the second structure120, depending on a sliding operation of the second structure120. In this case, the extended region130bof the display130may extend from the default region130ain the first sliding direction S1. The extended region130bmay be located in the second structure120in the default state, and, when the electronic device100is changed to the extended state, the extended region130bmay move out of the second structure120and may be exposed on the front surface of the electronic device100.

The display130may form a screen display region that is visually exposed on the front surface of the electronic device100and on which predetermined visual information (or a screen) is displayed. For example, in the default state, the screen display region may be formed by the default region130a. In the extended state, the screen display region may be formed by at least a portion of the extended region130band the default region130a. In the extended state, the electronic device100may display a screen on the default region130aand a portion of the extended region130band thus may provide a screen display region that is extended or enlarged when compared to that in the default state.

The default state may include a state in which an exposed region of the display130has a first size, and the extended state may include a state in which the exposed region of the display130has a second size greater than the first size. For example, the first size may be a minimum size of the exposed region of the display130, and the second size may be a maximum size of the exposed region of the display130. In a deformation operation of the electronic device100, a plurality of intermediate states may be defined between the default state and the extended state. The plurality of intermediate states may include any states in which the size of the exposed region of the display130is larger than the first size in the default state and smaller than the second size in the extended state.

The electronic device100may maintain the current deformed state even though an external force is not applied in the default state and the extended state. According to various embodiments, the electronic device100may be configured to maintain the shape even though an external force is not applied in at least one of the plurality of intermediate states. For example, at least one free-stop state may be provided between the default state and the extended state, and in the free-stop state, the electronic device100may maintain the current state even without an external force.

FIGS.3A and3Bare views illustrating the display of the example electronic device according to various embodiments.FIG.4is a view illustrating a plurality of layers of the display according to various embodiments.

FIG.3Aillustrates the shape of the display130when the electronic device (e.g., the electronic device100ofFIGS.1and2) is in the default state.FIG.3Billustrates the shape of the display130when the electronic device100is in the extended state. For example,FIG.3Amay be a view in which the remaining components other than the display130are omitted in the electronic device100ofFIG.1, andFIG.3Bmay be a view in which the remaining components other than the display130are omitted in the electronic device100ofFIG.2.FIG.4illustrates a stacked structure of the plurality of layers included in the display130.

Referring toFIGS.3A and3B, the display130of the electronic device100according to an embodiment (e.g., the display130ofFIGS.1and2) may include a fixed part132having a fixed shape and a variable part134extending from the fixed part132and having a variable shape.

The shape of the fixed part132may be fixedly maintained irrespective of the states of the electronic device100. For example, at least a portion of the fixed part132may be fixedly supported on a structure (e.g., the second structure120) of the electronic device100. The variable part134may extend from the fixed part132so as to have shape variability and may be partially deformed as the state of the electronic device100is changed. For example, the variable part134may be at least partially deformed to be flat or curved while partially rotating and linearly moving in response to an operation in which the state of the electronic device100is changed.

The variable part134may include a rolling part136deformed while rotating and linearly moving depending on a change of state of the electronic device100and an extending part138extending from the rolling part136. The extending part138may extend from the rolling part136to face the fixed part132or the rolling part136depending on the states of the electronic device100and may remain flat. For example, the rolling part136may be disposed between the fixed part132and the extending part138, and the extending part138may have a smaller size (or area) than the fixed part132and the rolling part136.

However, the shape of the display130is not limited to the illustrated embodiment. According to various embodiments, the variable part134of the display130may not include the extending part138and may be entirely formed of the rolling part136. Furthermore, according to various embodiments, in the display130, the extending part138may extend from the rolling part136so as to have a width (e.g., a distance measured in the x-axis direction) smaller than that in the embodiment illustrated inFIGS.3A and3B.

The fixed part132may form a substantially flat surface. For example, the fixed part132may maintain a shape in which most of the region is formed to be flat, but one edge region is curved. The variable part134may be partially deformed to be flat or curved when the display130is slid in or out depending on a change of state of the electronic device100. For example, the fixed part132may remain substantially flat in the default state (e.g., the state ofFIG.1) and the extended state (e.g., the state ofFIG.2) of the electronic device100. In the default state, a portion of the rolling part136adjacent to the fixed part132may be curved, and the rest of the variable part134(e.g., the remaining portion of the rolling part136and the extending part138) may be flat while facing the fixed part132. In the extended state, a portion of the rolling part136adjacent to the fixed part132may be disposed side by side with the fixed part132and may be flat, and the rest of the rolling part136may be curved. In the default state and the extended state, the extending part138of the variable part134may remain flat while being parallel to the fixed part132.

According to the embodiment illustrated inFIGS.1,2,3A, and3B, the fixed part132may form the default region (e.g., the default region130aofFIGS.1and2) together with a portion of the variable part134. The remaining portion of the variable part134may form the extended region (e.g., the extended region130bofFIG.2). For example, a surface of the fixed part132and a surface of a portion of the variable part134may form the default region130a. According to the illustrated embodiment, a portion of the variable part134may be included in the default region130a, and the remaining portion of the variable part134may be included in the extended region130b. However, the illustrated embodiment is illustrative, and according to various embodiments, in the default state, the variable part134of the display130may be hidden by the first structure (e.g., the first structure110ofFIGS.1and2) so as not to be exposed on the front surface of the electronic device100. In this case, it may be understood that the default region130ais formed by the fixed part132and the extended region130bis formed by the variable part134.

Referring toFIG.4, the display130according to an embodiment may include a plurality of layers. For example, the display130may be formed in a structure in which a plurality of layers140,150,160, and170are stacked one above another. The fixed part132and the variable part134of the display130described with reference toFIG.3may be divided from each other in the width direction of the display130(e.g., the x-axis direction) based on whether the shape is deformed. Both the fixed part132and the variable part134may be formed of the plurality of layers having a stacked structure. For example, one portion (or section) of each of the plurality of layers may be included in the fixed part132of the display130, and another portion (or section) may be included in the variable part134of the display130.

The plurality of layers included in the display130may include the panel layer140, the reinforcing layer150, the cover layer160, a first protective layer172, and/or a second protective layer174. For example, the reinforcing layer150, the cover layer160, and the protective layer170may be sequentially stacked on the panel layer140, and the protective layer170may form a surface of the display130exposed outside the electronic device100.

However, the stacked structure of the display130illustrated inFIG.4is illustrative, and the disclosure is not limited thereto. According to various embodiments, at least one of the first protective layer172or the second protective layer174may be omitted from the display130. Furthermore, according to various embodiments, the display130may further include an additional protective film (not illustrated), and the protective film may be attached so as to be removable when the electronic device100is used.

The panel layer140may display a specified screen and/or image in relation to an operation and/or function of the electronic device100. The panel layer140may include a pixel layer (not illustrated) that includes a plurality of light emitting elements, an encapsulation layer (not illustrated) that seals the light emitting elements, a touch sensor layer (not illustrated) that includes touch electrodes, a wiring layer (not illustrated) that includes transistors electrically connected with the light emitting elements, and/or a polarization layer (not illustrated) that prevents reflection of external light to secure visibility. For example, the polarization layer may include a poly ethylene terephthalate (PET) film, a tri-acetyl cellulose (TAC) film, a cycle-olefin polymer (COP) film, or a poly-vinyl alcohol (PVA) film. A stacked structure of the panel layer140is not limited to the above-described example, and the panel layer140may additionally include other layers or omit one or more of the layers.

The panel layer140may, for example, include at least one of a liquid crystal display (LCD) panel, a light emitting diode (LED) display panel, an organic light emitting diode (OLED) display panel, a microelectromechanical systems (MEMS) display panel, a transparent display panel, or an electronic paper display panel.

The reinforcing layer150and the cover layer160may be disposed between the panel layer140and the protective layer170. The reinforcing layer150may be disposed between the panel layer140and the cover layer160, and the cover layer160may be disposed between the reinforcing layer150and the protective layer170. The reinforcing layer150and the cover layer160may be formed of a light transmitting material capable of passing light emitted from the panel layer140. The reinforcing layer150may be attached to the cover layer160and the panel layer140. For example, the reinforcing layer150may couple the cover layer160and the panel layer140. The reinforcing layer150may, for example, be formed of a transparent adhesive and/or a transparent resin. For example, the reinforcing layer150may include an optical clear resin (OCR), an optical clear adhesive (OCA), a pressure sensitive adhesive (PSA), or a photosensitive adhesive (e.g., a UV resin).

The cover layer160may include a first surface160a(e.g., a surface facing in the −z-axis direction) that faces toward the panel layer140and a second surface160b(e.g., a surface facing in the +z-axis direction) that faces away from the first surface160a. The reinforcing layer150may be attached to the first surface160aof the cover layer160, and the protective layer179(e.g., the first protective layer172) may be attached to the second surface160bof the cover layer160.

The cover layer160may, for example, be formed of glass or a polymer film. For example, the cover layer160may be formed of an ultra-thin glass (UTG) material, a PI material, or a PET material. The cover layer160may partially have different thicknesses. For example, the cover layer160may have different thicknesses to correspond to the fixed part132and the variable part134of the display130. Furthermore, the cover layer160may be formed such that in a region corresponding to the variable part134, an edge portion is thicker than a central portion. The specific shape of the cover layer160will be described below in detail with reference toFIGS.5,6,7A, and7B.

Between the cover layer160and the panel layer140, the reinforcing layer150may compensate for a thickness difference of the cover layer160and may improve the strength of the display130. The reinforcing layer150may have different thicknesses to correspond to the shape of the cover layer160. For example, the reinforcing layer150may be formed to correspond to the thickness of the cover layer160, and thus the reinforcing layer150and the cover layer160may form a uniform flat surface. The reinforcing layer150may compensate for a change in the thickness of the cover layer160such that an empty space (e.g., an air gap or an air layer) is not formed between the panel layer140and the cover layer160. Accordingly, the visibility of the panel layer140may be improved and/or supplemented. The specific shape of the reinforcing layer150will be described below in detail together with the cover layer160with reference toFIGS.8A and8B.

The protective layer170may form one surface of the display130. The protective layer170may be disposed on (or attached to) one surface (e.g., the second surface160b) of the cover layer160and may protect other layers (e.g., the cover layer160, the reinforcing layer150, and the panel layer140) included in the display130from an external impact. For example, the protective layer170may protect the thin cover layer160and may prevent or reduce scattering when the cover layer160is cracked. The protective layer170may, for example, include a glass material, or may be implemented with a film layer or a coating layer. The protective layer170may include a flexible material. The protective layer170may be formed of a transparent material having a high light transmittance.

The protective layer170may prevent the cover layer160from being contaminated by dust or oil. For example, the protective layer170may include an anti-smudge coating or an anti-fingerprint coating that prevents a mark, such as a fingerprint due to user contact, from being formed on a surface of the cover layer160.

The protective layer170may include the first protective layer172and the second protective layer174. The first protective layer172may be stacked on top of the cover layer160, and the second protective layer174may be stacked on top of the first protective layer172. For example, the cover layer160may be disposed between the first protective layer172and the reinforcing layer150, and the first protective layer172may be disposed between the cover layer160and the second protective layer174. An adhesive layer (not illustrated) may be disposed between the first protective layer172and the cover layer160and between the first protective layer172and the second protective layer174. One surface of the second protective layer174may form a surface of the display130exposed outside the electronic device100. According to various embodiments, the first protective layer172may be implemented with a protective film layer made of a flexible material, and the second protective layer174may be implemented with a hard coating layer or an anti-fingerprint coating layer. The illustrated embodiment is illustrative. The protective layer170may include only one of the first protective layer172and the second protective layer174, and the display130may not include the protective layer170.

FIG.5is a view illustrating an example cover layer of the display according to various embodiments.FIG.6is an enlarged view illustrating a portion of the cover layer according to various embodiments.

FIG.5is a plan view of the first surface (e.g., the first surface160aofFIG.4) of the cover layer (e.g., the cover layer160ofFIG.4) facing the panel layer (e.g., the panel layer150ofFIG.4) based on the stacked structure of the display illustrated inFIG.4(e.g., the display130ofFIGS.1to4). For example,FIG.5may be a view illustrating the shape of the cover layer160when the display130illustrated inFIG.3is unfolded flat.

FIG.6is an enlarged view of portion E of the cover layer160illustrated inFIG.5.

Referring toFIGS.5and6, the cover layer160of the display130according to an embodiment may be formed in a shape in which the thickness varies in a first direction (e.g., the x-axis direction) and a second direction (e.g., the y-axis direction) perpendicular to each other on a surface of the display130. The first direction and the second direction may be defined as directions that are parallel to the width direction W and the lengthwise direction L of the cover layer160, respectively. For example, the thickness of the cover layer160may vary in the width direction W and the lengthwise direction L of the cover layer160(or the display130). For example, one portion and another portion of the cover layer160disposed in the width direction W may have different thicknesses. For example, one portion and another portion of the cover layer160disposed in the lengthwise direction L may have different thicknesses.

In embodiments of the disclosure, the width direction W may be a direction parallel to the sliding directions of the electronic device100(e.g., the sliding directions S1and S2ofFIGS.1to3), and the lengthwise direction L may be a direction that is perpendicular to the sliding directions S1and S2, but is parallel to a surface (e.g., the first surface160aor the second surface160b) of the cover layer160. A thickness may be a distance measured in a direction perpendicular to the width direction W and the lengthwise direction L. For example, the thickness of the cover layer160may be defined as a distance measured in a direction perpendicular to the first surface160a(or, the second surface160b) of the cover layer160.

The cover layer160may include a first portion161and a second portion162extending from the first portion161. When the electronic device100is driven, the first portion161may be fixedly maintained without being deformed, and the second portion162may be deformed. For example, when the display130slides as the electronic device100is driven, the first portion161may remain flat without being deformed, and the second portion162may be partially deformed to flat or curved.

The first portion161may correspond to the fixed part132of the display130that has a fixed shape, and the second portion162may correspond to the variable part134of the display130that has a variable shape. For example, the first portion161of the cover layer160may be a portion (or section) included in the fixed part132of the display130, and the second portion162of the cover layer160may be a portion (or section) included in the variable part134of the display130. When the display130ofFIG.3is viewed, the first portion161may be understood as a portion of the entire cover layer160that is located in the fixed part132(or a portion overlapping the fixed part132), and the second portion162may be understood as a portion of the entire cover layer160that is located in the variable part134(or a portion overlapping the variable part134).

The first portion161may include a first base portion163and a first connecting portion164that extends from the first base portion163and that is connected with the second portion162. The first connecting portion164may connect the first base portion163and the second portion162and may have a gradually decreasing thickness toward the second portion162. For example, the first connecting portion164may obliquely connect the first base portion163that has a first thickness and a second base portion165of the second portion162that has a second thickness smaller than the first thickness. According to various embodiments, the first connecting portion164may be formed to have a specified inclination.

The second portion162may include the second base portion165and reinforcing portions166protruding from opposite edge portions of the second base portion165that face away from each other in the lengthwise direction L. The reinforcing portions166may include a first reinforcing portion166aprotruding from one edge portion (e.g., the +y-axis direction) of the second base portion165and a second reinforcing portion166bprotruding from an opposite edge portion (e.g., the −y-axis direction) of the second base portion165. The first reinforcing portion166aand the second reinforcing portion166bmay be formed in substantially the same shape. For example, the first reinforcing portion166aand the second reinforcing portion166bmay be symmetrical to each other with respect to the center of the second base portion165. AlthoughFIG.6illustrates an enlarged view of one edge portion of the cover layer160on which the second reinforcing portion166bis formed, an opposite edge portion of the cover layer160on which the first reinforcing portion166ais formed may also be identical to the illustrated example.

The reinforcing portions166may extend from at least portions of a surface of the second base portion165(e.g., a surface165sofFIGS.7A and7B) to have a specified thickness. For example, the reinforcing portions166may protrude from the surface165sof the second base portion165in a direction substantially perpendicular to the surface165s. The surface165sof the second base portion165may be a partial region of the first surface160aof the cover layer160that corresponds to the second base portion165.

Each of the reinforcing portions166may include an edge portion167that forms an edge of the second portion162in the lengthwise direction L and a second connecting portion168that extends from the edge portion167and that is connected to the surface165sof the second base portion165. The second connecting portion168may connect the edge portion167and the surface165sof the second base portion165and may have a gradually decreasing thickness from the edge portion167toward the surface165sof the second base portion165. For example, the second connecting portion168may obliquely connect the edge portion167protruding to a third thickness from a partial region of the surface165sof the second base portion165and other partial regions of the surface165sof the second base portion165. According to various embodiments, the second connecting portion168may be formed to have a specified inclination.

According to various embodiments, at least part of the second portion162of the cover layer160may remain bent irrespective of the states of the electronic device100. For example, when the state of the electronic device100is changed, at least a portion of the variable part134of the display130may move while remaining curved without being deformed flat in a sliding operation, and at least part of the second portion162corresponding thereto may remain bent. In the case of the above embodiment, the reinforcing portion166may not be formed on a bending maintaining portion of the second portion162of the cover layer160that remains bent. Accordingly, tensile stress applied to the bending maintaining portion may be reduced, and fatigue failure may be prevented or decreased.

One end of the reinforcing portion166may be connected with the first portion161. For example, one end (e.g., an end in the +x-axis direction) of the reinforcing portion166that is adjacent to the boundary between the first portion161and the second portion162may be connected with the first portion161. According to the illustrated embodiment, the reinforcing portion166and the first portion161may form substantially the same plane. For example, the edge portion167of the reinforcing portion166may be connected with the first base portion163while forming substantially the same plane. The sum of the second thickness of the second base portion165(e.g., T2ofFIGS.7A and7B) and the third thickness of the edge portion167(e.g. T3ofFIG.7A) may be substantially the same as the first thickness of the first base portion163(e.g., T1ofFIG.7B). However, the illustrated embodiment is illustrative, and according to various embodiments, the first base portion163may further protrude beyond the reinforcing portion166based on the surface of the second base portion165(e.g., refer toFIGS.9,10A, and10B).

In the display130according to a embodiment of the disclosure, the cover layer160may have different thicknesses depending on a part (e.g., the fixed part132) that maintains the form (or shape) irrespective of the states of the electronic device100and a part (e.g., the variable part134) that is deformed based on the states of the electronic device100. Accordingly, the flexibility of the display130may be improved, and resistance to sliding (or, bending) may be reduced.

In the display130according to an embodiment of the disclosure, the cover layer160may have different thicknesses in the lengthwise direction L on a portion (e.g., the second portion162) of the cover layer160that corresponds to the variable part134that is deformed based on the state of the electronic device100. Accordingly, the strength of a longitudinal edge portion of the display130may be improved, and delamination or damage due to buckling may be prevented.

FIG.7Ais a sectional view of the example cover layer in the lengthwise direction according to various embodiments.FIG.7Bis a sectional view of the example cover layer in the width direction according to various embodiments.

FIG.7Ais a sectional view of the cover layer160taken along line A-A′ inFIG.5.FIG.7Bis a sectional view of the cover layer160taken along line B-B′ inFIG.5. For example,FIG.7Amay be a sectional view of the second portion162of the cover layer169in the lengthwise direction, andFIG.7Bmay be a sectional view of the first portion161and the second portion162of the cover layer160in the width direction.

Referring toFIGS.5,7A, and7B, the cover layer160according to an embodiment may include the first portion161and the second portion162extending from the first portion161in the width direction W. As illustrated inFIG.7B, the first portion161may include the first base portion163and the first connecting portion164disposed between the first base portion163and the second portion162(e.g., the second base portion165). As illustrated inFIG.7A, the second portion162may include the second base portion165and the reinforcing portions166protruding (or extending) to a predetermined thickness from the second base portion165in a direction substantially perpendicular to the surface165s. The reinforcing portions166may include the first reinforcing portion166aand the second reinforcing portion166bthat are formed on the opposite sides of the second base portion165in the lengthwise direction (e.g., the y-axis direction).

The first base portion163of the first portion161may have the first thickness T1. The second base portion165of the second portion162may have the second thickness T2. The first connecting portion164of the first portion161may be disposed between the first base portion163and the second base portion165. The first connecting portion164may have a variable thickness portion between the first base portion163and the second base portion165, and the thickness of the first connecting portion164may gradually decrease from the first thickness T1to the second thickness T2with an approach to the boundary between the first connecting portion164and the second base portion165from the boundary between the first connecting portion164and the first base portion163. The first connecting portion164may include a first inclined surface164sthat obliquely connects a surface (e.g., a surface facing in the −z-axis direction) of the first base portion163and a surface (e.g., a surface facing in the −z-axis direction) of the second base portion165. The first inclined surface164smay have a first inclination angle A1.

The reinforcing portions166of the second portion162may have the third thickness T3. For example, the edge portion167of each of the reinforcing portions166may protrude or extend from the surface165sof the second base portion165by the third thickness t3in a direction substantially perpendicular to the surface165s, and the second connecting portion168may have a gradually decreasing thickness from the edge portion167toward the surface165sof the second base portion165. For example, the second connecting portion168may include a second inclined surface168sthat obliquely connects a surface167sof the edge portion167and the surface165sof the second base portion165. The second inclined surface168smay have a second inclination angle A2. In the illustrated embodiment, the second inclined surface168smay be formed to be flat. However, this is illustrative, and, according to various embodiments, the second inclined surface168smay be formed to be curved (e.g., refer toFIGS.15A and15B).

According to the embodiment ofFIGS.5,7A and7B, the surface167sof the edge portion167and a surface163sof the first base portion163may form substantially the same plane. For example, the first thickness T1of the first base portion163may be substantially the same as the sum of the second thickness T2of the second base portion165and the third thickness T3of the reinforcing portion166(e.g., the edge portion167).

The cover layer160according to an embodiment of the disclosure may include the reinforcing portion166formed thereon and thus may improve the strength and reduce delamination of the edge portion of the display130. The effect of improving buckling resistance and preventing (or reducing) delamination depending on an increase in the thickness of the reinforcing portion166may be shown in Table 1 below.

Table 1 above shows results obtained by measuring buckling critical load and bending amount when the thickness of the reinforcing portion166(e.g., the edge portion167) is increased. For example, the thickness ratio of the reinforcing portion is the ratio of the third thickness T3of the edge portion167to the second thickness T2of the second base portion165. The existing ratio means that the reinforcing portion166is not formed. 10% means that the ratio of the third thickness T3to the second thickness T2is 10%, and 50% means that the third thickness T3is half of the second thickness T2. Referring to Table 1 above, it can be seen that when the thickness of the reinforcing portion166is increased, the buckling critical load for compressive load is increased and thus the buckling resistance is improved. In addition, referring to Table 1 above, it can be seen that when the same compressive load is applied, the amount of bending is reduced as the thickness of the reinforcing portion166is increased and thus the effect of preventing delamination and damage is improved.

The first inclined surface164aof the first connecting portion164and the second inclined surface168sof the second connecting portion168may have different inclinations. The first inclination angle A1of the first inclined surface164sand the second inclination angle A2of the second inclined surface168smay differ from each other. For example, the first inclination angle A1may be smaller than the second inclination angle A2. However, this is illustrative, and, according to various embodiments, the first inclination angle A1and the second inclination angle A2may be equal to each other.

The first inclination angle A1of the first inclined surface164sof the first connecting portion164may be determined in consideration of visibility, and the second inclination angle A2of the second inclined surface168sof the second connecting portion168may be determined in consideration of a repulsive force in a sliding operation. For example, if the first inclination angle A1is too large, the inclined shape of the first inclined surface164smay be visible when the display130is viewed. The second inclination angle A2may be hidden by a printed layer that is formed on the periphery of the protective layer (e.g., the protective layer170ofFIG.4) as an edge portion of the display130, and thus the upper limit value considering visibility may be greater than the first inclination angle A1. If the second inclination angle A2is too small, the sliding (or, bending or folding) performance of the display130may be deteriorated due to an increase in a repulsive force and/or driving resistance. Equations for determining or calculating the first inclination angle A1and the second inclination angle A2will be described below in detail with reference toFIGS.8A and8B.

FIG.8Ais a sectional view of the example display in the lengthwise direction according to various embodiments.FIG.8Bis a sectional view of the example display in the width direction according to various embodiments.

FIG.8Ais a view in which the reinforcing layer150, the panel layer140, and the protective layer170are additionally disposed under and on the cover layer160in the sectional view of the cover layer160ofFIG.7Ain the lengthwise direction L.

FIG.8Bis a view in which the reinforcing layer150, the panel layer140, and the protective layer170are additionally disposed under and on the cover layer160in the sectional view of the cover layer160ofFIG.7Bin the width direction W.

Referring toFIGS.8A and8B, the display130according to an example embodiment may be formed in a structure in which a plurality of layers are stacked one above another, and the plurality of layers may include the panel layer140, the reinforcing layer150, the cover layer160, the first protective layer172, and the second protective layer174. The reinforcing layer150and the panel layer140may be attached to the first surface160a(e.g., the surface facing in the −z-axis direction) of the cover layer160, and the protective layer170may be attached to the second surface160b(e.g., the surface facing in the +z-axis direction) of the cover layer160.

Among the plurality of layers, the panel layer140, the reinforcing layer150, and the protective layer170may be substantially the same as the panel layer (e.g., the panel layer140ofFIG.4), the reinforcing layer (e.g., the reinforcing layer150ofFIG.4), and the protective layer (e.g., the protective layer170ofFIG.4) described above with reference toFIG.4. Hereinafter, the above descriptions will not be repeated.

The reinforcing layer150may be disposed between the cover layer160and the panel layer140, and the opposite surfaces of the reinforcing layer150may be attached to the cover layer160and the panel layer140. The reinforcing layer150may be formed in a shape corresponding to a change in the thickness of the cover layer160to fill the space between the cover layer160and the panel layer140. For example, the reinforcing layer150may be coupled with the cover layer160and may form one layer disposed between the protective layer170and the panel layer140to have a uniform thickness. The reinforcing layer150may compensate for the thickness difference of the cover layer160, and thus an air layer (e.g., an air gap) may not be formed between the cover layer160and the panel layer140when the cover layer160is coupled (or attached) to the panel layer140.

As illustrated inFIG.8A, the reinforcing layer150may include a first thickness compensating portion151corresponding to the edge portion167of the reinforcing portion166, a second thickness compensating portion153corresponding to the second connecting portion168of the reinforcing portion166, and a third thickness compensating portion155corresponding to the second base portion165of the second portion162. The second thickness compensating portion153may have a gradually increasing thickness from the first thickness compensating portion151toward the third thickness compensating portion155. The second thickness compensating portion153may be formed in an inclined shape to correspond to the second inclined surface168sof the second connecting portion168. In various embodiments, the second thickness compensating portion153may be changed to correspond to the shape of the second connecting portion168.

As illustrated inFIG.8B, the reinforcing layer150may include a fourth thickness compensating portion157corresponding to the first base portion163of the first portion161of the cover layer160, a fifth thickness compensating portion159corresponding to the first connecting portion164of the first portion161, and the third thickness compensating portion155corresponding to the second base portion165of the second portion162. The fifth thickness compensating portion159may have a gradually increasing thickness from the fourth thickness compensating portion157toward the third thickness compensating portion155. The fifth thickness compensating portion159may be formed in an inclined shape to correspond to the first inclined surface164sof the first connecting portion164. In various embodiments, the fifth thickness compensating portion159may be changed to correspond to the shape of the first connecting portion164.

According to the embodiment illustrated inFIG.8B, the first connecting portion164may include the first inclined surface164s, and the first inclination angle A1of the first inclined surface164smay be determined based on Equation 1 below.

In Equation 1 above, O/A is the width of a distortion region, dl is the width of the first inclined surface164s, d2is the height of the first inclined surface164s, n1is the refractive index of the cover layer160, n2is the refractive index of the reinforcing layer150, and t1is the maximum thickness of the cover layer160(e.g., the thickness of the first base portion163). The first inclination angle A1of the first inclined surface164smay be defined as

For example, based on Equation 1, the first inclination angle A1may be determined based on the width of the distortion region in which the first inclined surface164sis not visible to the naked eyes.

In various embodiments, the first inclined surface164smay not be visible to the naked eyes when the distortion region has a width of about 0.13 mm or less, and the first inclination angle A1may be calculated based on Equation 1 based on the range. According to various embodiments, the first inclination angle A1may range from about 1° to about 10°, but is not limited thereto.

According to the embodiment illustrated inFIG.8A, the second connecting portion168may include the second inclined surface168s, and the second inclination angle A2of the second inclined surface168smay be determined based on Equation 2 and Equation 3 below.

In Equation 2 above, F represents a repulsive force, E represents the Young's modulus of a material (e.g., glass) of which the cover layer160is formed, Iedgerepresents the second moment of inertia of the second portion162(e.g., a bending portion), R represents the bending radius of the second portion162, and tfrepresents the thickness of the variable part134of the display130.

In Equation 3 above, w1is the distance (e.g., the length in the y-axis direction) between the reinforcing portions166, w2is the width of the edge portion167of the reinforcing portion166, a is the width of the second connecting portion168of the reinforcing portion166, t2is the thickness of the second base portion165, t3is the thickness of the reinforcing portion166, and t4represents the sum of the thicknesses of the second base portion165and the reinforcing portion166. For example, a may be the width of the second inclined surface168s, and t3may be the height of the second inclined surface168s.

The second inclination angle A2of the second inclined surface168smay be defined as

and may be determined based on Equation 2 and Equation 3 above. According to various embodiments, the second inclination angle A2may range from about 0.01° to about 0.6°, but is not limited thereto.

In an embodiment in which the first base portion163of the first portion161and the edge portion167of the reinforcing portion166are formed at the same height, the sum of the thicknesses of the second base portion165and the reinforcing portion166may be substantially the same as the thickness of the first base portion163, and t4may be equal to t1of Equation 1.

FIG.9Ais a sectional view of a second portion of an example cover layer in a lengthwise direction according to various embodiments.FIG.9Bis a sectional view of a second portion of an example cover layer in a lengthwise direction according to various embodiments.

FIGS.9A and9Bare views illustrating cover layers160′ and160″ according to example embodiments in which in the cover layer described with reference to the previous drawings (e.g., the cover layer160ofFIGS.6and7A), the second inclined surface (e.g., the second inclined surface168sofFIGS.6and7A) of the second connecting portion (e.g., the second connecting portion168ofFIGS.6and7A) is changed to a curved surface rather than a flat surface. Referring toFIGS.9A and9B, the second portions162′ and162″ of the cover layers160′ and160″ according to example embodiments may include a second base portion165and a reinforcing portion166protruding from the second base portion165. The reinforcing portion166may include an edge portion167having a constant thickness and a second connecting portion168′ or168″ extending from the edge portion167and having a gradually decreasing thickness. The descriptions about the structure and configuration of the cover layer160described above with reference to the previous drawings may be identically applied to the cover layers160′ and160″ illustrated inFIGS.9A and9B.

Unlike the cover layer160illustrated inFIG.7A, the second connecting portions168′ and168″ of the cover layers160′ and160″ illustrated inFIGS.9A and9Bmay include a concave surface168s′ or a convex surface168s″ rather than an inclined flat surface (e.g., the second inclined surface168sofFIG.7A).

Referring toFIG.9A, the cover layer160′ may be formed such that the second connecting portion168′ of the reinforcing portion166has an inclined structure including the concave surface168s′. For example, the concave surface168s′ may be a curved surface formed to be concave in a direction (e.g., the +z-axis direction) toward a surface165sof the second base portion165. Since the second connecting portion168′ has a gradually decreasing thickness, the concave surface168′ may be formed to connect a surface167sof the edge portion167and the surface165sof the second base portion165.

When the second connecting portion168′ is formed in a form including the concave surface168s′ as illustrated inFIG.9A, the total volume of the reinforcing portion166(e.g., the volume or size of the second connecting portion168′) may be reduced, and thus a repulsive force and/or driving resistance may be additionally decreased.

Referring toFIG.9B, the cover layer160″ may be formed such that the second connecting portion168″ of the reinforcing portion166has an inclined structure including the convex surface168s″. For example, the convex surface168s″ may be a curved surface formed to be convex in a direction (e.g., the −z-axis direction) in which a surface165sof the second base portion165faces. Since the second connecting portion168″ has a gradually decreasing thickness, the convex surface168s″ may be formed to connect a surface167sof the edge portion167and the surface165sof the second base portion165.

When the second connecting portion168″ is formed in a form including the convex surface168s″ as illustrated inFIG.9B, the thickness variation structure of the second connecting portion168″ may be less visible to the naked eye, and thus visibility may be improved.

FIG.10is an enlarged view illustrating a portion of an example cover layer according to various embodiments.FIG.11Ais a sectional view of the example cover layer in a lengthwise direction according to various embodiments.FIG.11Bis a sectional view of the example cover layer in a width direction according to various embodiments.

FIGS.10,11A, and11Bare views illustrating a cover layer180of a second embodiment in which in the cover layer160of the first embodiment described above with reference toFIGS.6,7A, and7B, the thickness of the first base portion163of the first portion161is greater than the sum of the thicknesses of the reinforcing portion166and the second base portion165.

Referring toFIGS.10,11A, and11B, the cover layer180according to an embodiment may include a first portion181and a second portion182. The first portion181may include a first base portion183and a first connecting portion184, and the second portion182may include a second base portion185and a reinforcing portion186. The reinforcing portion186may include an edge portion187and a second connecting portion188. For example, a first reinforcing portion186aand a second reinforcing portion186bmay be formed on opposite sides of the second base portion185in the lengthwise direction (e.g., the y-axis direction). Each of the first reinforcing portion186aand the second reinforcing portion186bmay include the edge portion187and the second connecting portion188.

The description of the cover layer according to the first embodiment (e.g., the cover layer160ofFIGS.6,7A, and7B) may be identically applied to the cover layer180according to the second embodiment. Components included in the cover layer180according to the second embodiment may be substantially the same as, or similar to, the components (e.g., the first portion161and the second portion162ofFIGS.6,7A, and7B) included in the cover layer160according to the first embodiment. For example, the first base portion183, the first connecting portion184, the second base portion185, the reinforcing portion186, the edge portion187, and the second connecting portion188of the cover layer180according to the second embodiment may correspond to as the first base portion163, the first connecting portion164, the second base portion165, the reinforcing portion166, the edge portion167, and the second connecting portion168of the cover layer160illustrated inFIGS.6,7A, and7B. Hereinafter, repetitive descriptions will be omitted, and the following description will be focused on changed portions.

The cover layer180may be formed such that the first base portion183of the first portion181further protrudes beyond the reinforcing portion186from the second base portion185(e.g., a surface185sof the second base portion185). For example, the first base portion183may be located in a higher position than the edge portion187of the reinforcing portion186by a predetermined height H1based on the second base185. Due to the height difference H1, one end of the reinforcing portion186that is adjacent to the boundary between the first portion181and the second portion182may be connected with the first connecting portion184of the first portion181. Unlike in the cover layer160of the first embodiment, a surface187sof the edge portion187and a surface183sof the first base portion183may be connected with a step in the cover layer180of the second embodiment.

The first base portion183of the first portion181may have a first thickness T1. The second base portion185of the second portion182may have a second thickness T2. The edge portion187of the reinforcing portions166may have a third thickness T3. The first connecting portion184may obliquely connect the first base portion183and the second base portion185, and the second connecting portion188may obliquely connect the edge portion187and the second base portion185.

The first thickness T1of the first base portion183may be greater than the sum of the second thickness T2of the second base portion185and the third thickness T3of the edge portion187(e.g., T1>T2+T3). For example, the surface187sof the edge portion187may be located at the same height as the third thickness T3based on the surface185sof the second base portion185, the surface183sof the first base portion183may be located at a height (H2=T1−T2) corresponding to the difference between the first thickness T1and the second thickness T2based on the surface185sof the second base portion185, and the height H2of the first base portion183may be greater than the height (e.g., the third thickness T3) of the edge portion187(e.g., T1−T2>T3).

By increasing the thickness of the first base portion183of the first portion181, the cover layer180according to the second embodiment may improve the strength of the first portion181corresponding to the fixed part of the display130(e.g., the fixed part132ofFIG.3). The first portion181may be a portion included in the fixed part132of the display130, the shape of which is fixed without being deformed when the electronic device100is driven. The first portion181may not increase the driving resistance of the display130even though the thickness is increased.

FIG.12is a view illustrating an example cover layer of the display according to various embodiments.FIG.13is an enlarged view illustrating a portion of the example cover layer according to various embodiments.FIG.14Ais a sectional view of a second portion of the example cover layer in a lengthwise direction according to various embodiments.FIG.14Bis a sectional view of the second portion of the example cover layer in a width direction according to various embodiments.

FIG.13is an enlarged view of portion F of the cover layer190illustrated inFIG.12.

FIG.14Ais a sectional view of the example cover layer190taken along line C-C′ inFIG.12.FIG.14Bis a sectional view of the example cover layer190taken along line D-D′ inFIG.12. For example,FIG.14Bmay be a sectional view of the second portion192, on which reinforcing portions196are formed, in the width direction.

FIGS.12,13,14A, and14Bare views illustrating the example cover layer190according to a third embodiment in which one reinforcing portion (e.g., the reinforcing portion166ofFIGS.6and7Aor the reinforcing portion186ofFIGS.10and11A) is not continuously connected and the plurality of reinforcing portions196are spaced apart from each other, unlike in the cover layers according to the first embodiment and the second embodiment described with reference to the previous drawings (e.g., the cover layer160ofFIGS.6and7Aand the cover layer180ofFIGS.10and11A).

Referring toFIGS.12,13,14A, and14B, the cover layer190according to an embodiment may include a first portion191and a second portion192. The first portion191may include a first base portion193and a first connecting portion194, and the second portion192may include a second base portion195and the plurality of reinforcing portions196. For example, a first plurality of reinforcing portions196aand a second plurality of reinforcing portions196bmay be formed on opposite sides of the second base portion195in the lengthwise direction L (e.g., the y-axis direction). The first plurality of reinforcing portions196aand the second plurality of reinforcing portions196bmay be formed in substantially the same shape.

The descriptions about the structure and configuration of the cover layer160described above with reference to the previous drawings may be applied to the cover layer190illustrated inFIGS.12,13,14A, and14B. For example, the first base portion193, the first connecting portion194, the second base portion195, the reinforcing portions196, an edge portion197, and second connecting portions198and199of the cover layer190according to the third embodiment may correspond to the first base portion163, the first connecting portion164, the second base portion165, the reinforcing portion166, the edge portion167, and the second connecting portion168of the cover layer160illustrated inFIGS.6,7A, and7B. Hereinafter, repetitive descriptions will be omitted, and the following description will be focused on changed portions.

The plurality of reinforcing portions196may protrude from the second base portion195of the second portion192and may be spaced apart from each other by a specified gap in the width direction W (e.g., the x-axis direction). For example, the plurality of reinforcing portions196may be provided in a form in which protrusions are arranged in the width direction W on an edge portion of the second base portion195in the lengthwise direction L (e.g., the y-axis direction). For example, based onFIG.13, the plurality of reinforcing portions196may include a first protrusion1961, a second protrusion1962spaced apart from the first protrusion1961in the width direction W, and a third protrusion1963spaced apart from the second protrusion1962in the width direction W.

According to various embodiments, the plurality of reinforcing portions196including the protrusions spaced apart from each other may be understood as an integrally extending reinforcing portion having cut-away portions formed thereon.

The cover layer190may include the plurality of reinforcing portions196spaced apart from each other. Accordingly, the total volume of the reinforcing portions196may be reduced. Thus, the strength of an edge portion of the display130may be improved, and a repulsive force and/or driving resistance may be decreased.

Each of the plurality of reinforcing portions196may include an edge portion197protruding to a specified thickness from the second base portion195and a plurality of second connecting portions198and199obliquely extending from the edge portion197toward the second base portion195. For example, the plurality of second connecting portions198and199may include the first sub-connecting portion198that connects the edge portion197and the second base portion195in the lengthwise direction L and the second sub-connecting portion199that extends in the width direction W so as to be disposed between the plurality of reinforcing portions196adjacent to each other. The first sub-connecting portion198and the second sub-connecting portion199may have substantially the same inclination angle. However, this is illustrative, and, according to various embodiments, first sub-connecting portion198and the second sub-connecting portion199may have different inclination angles.

FIG.15is a sectional view of the display in the width direction according to various embodiments.

FIG.15is a view in which the reinforcing layer150, the panel layer140, and the protective layer170are additionally disposed under and on the cover layer190in the sectional view of the cover layer190ofFIG.14Bin the width direction W.

Referring toFIG.15, the display130according to an embodiment may be formed in a structure in which a plurality of layers are stacked one above another, and the plurality of layers may include the panel layer140, the reinforcing layer150, the cover layer190, the first protective layer172, and the second protective layer174. For example, the plurality of layers ofFIG.15may correspond to the plurality of layers ofFIG.4(e.g., the panel layer140, the reinforcing layer150, the cover layer160, the first protective layer172, and the second protective layer174ofFIG.4), respectively.

The reinforcing layer150may be disposed between the cover layer190and the panel layer140and may be formed in a shape corresponding to a change in the thickness of the cover layer190to fill the space between the cover layer190and the panel layer140. The reinforcing layer150may include a plurality of depressions150rcorresponding to the plurality of reinforcing portions196of the cover layer190.

The plurality of reinforcing portions196may be spaced apart from each other by a specified gap G. The gap G between the plurality of reinforcing portions196may be determined in consideration of improvement of buckling resistance and filling of the reinforcing layer150. For example, if the gap G between the plurality of reinforcing portions196is too narrow, the reinforcing layer150may not sufficiently fill between the reinforcing portions196adjacent to each other, and therefore bubbles may be generated. Accordingly, the bubbles may be visible on the display130, or a delamination phenomenon may occur due to expansion of the bubbles. Furthermore, if the gap G between the plurality of reinforcing portions196is too wide, an influence on improvement of buckling resistance and improvement of the strength of an edge portion may be insignificant.

FIG.16Ais a view illustrating an example electronic device according to various embodiments.FIG.16Bis a view illustrating an example electronic device according to various embodiments.FIG.17is a view illustrating a cover layer of a display included in the example electronic devices ofFIGS.16A and16B.

The previous drawings illustrate various embodiments of the flexible display included in the slidable electronic device (e.g., the slidable electronic device100ofFIGS.1and2) and the cover layer included in the flexible display, and the disclosed embodiments have been described based on the slidable electronic device100. However, the thickness variation structure of the cover layer is not limited to the slidable electronic device100and may be applied to various types of electronic devices including a flexible display.

Hereinafter, a cover layer240applied to a flexible display230of the foldable electronic device200aor200bwill be described with reference toFIGS.16A,16B, and17.

Referring toFIGS.16A and16B, the foldable electronic device200aor200baccording to an embodiment may include a first housing210, a second housing220connected to the first housing210so as to be rotatable, and the display230disposed in the first housing210and the second housing220and formed to be foldable. Although not illustrated, the first housing210and the second housing220may be connected by a hinge so as to be rotatable.

As illustrated inFIG.16A, the foldable electronic device200aof an in-folding type may be folded inward such that one part of one surface of the display230on which a screen is displayed partially faces another part. As illustrated inFIG.16B, the foldable electronic device200bof an out-folding type may be folded outward such that one part of an opposite surface facing away from the one surface of the display230on which the screen is displayed partially faces another part.

The display230may include a pair of fixed parts231and232that are not deformed in folding and unfolding operations of the foldable electronic device200aor200band a variable part233disposed between the pair of fixed parts231and232and partially deformed in the folding and unfolding operations of the foldable electronic device200aor200b. For example, the display230may include the first fixed part231that is at least partially disposed in the first housing210and that remains substantially flat, the second fixed part232that is at least partially disposed in the second housing220and that remains substantially flat, and the variable part233disposed between the first fixed part231and the second fixed part232and deformed to be flat or curved. According to various embodiments, the first fixed part231, the second fixed part232, and the variable part233may be referred to as a first flat part, a second flat part, and a folding part or a bending part, respectively.

The foldable electronic device200aor200bmay be folded or unfolded about a folding axis FA. The first housing210and the second housing220may be folded or unfolded about the folding axis FA. The folding axis FA may refer, for example, to a central axis about which the display230is folded or unfolded. For example, when the display230is viewed from above, the folding axis FA may overlap the folding part233of the display230, and the display230may be folded or unfolded about the folding axis FA.

According to various embodiments, the foldable electronic device200aor200bmay be changed to a folded state in which the variable part233is curved and an unfolded state in which the variable part233is flat. For example, when the foldable electronic device200aor200bis in the folded state, the variable part233may form a curved surface having a predetermined curvature, and the first fixed part231and the second fixed part232may be disposed while forming a predetermined included angle. When the foldable electronic device200aor200bis in the unfolded state, the variable part233may form substantially the same plane as the first fixed part231and the second fixed part232, and the first fixed part231and the second fixed part232may be disposed side by side to face in the same direction.

The display230of the foldable electronic device200aor200bmay have a structure substantially the same as the stacked structure of the display described with reference toFIG.4(e.g., the display130ofFIG.4). For example, the display230may include a panel layer (e.g., the panel layer140ofFIG.4), a reinforcing layer (e.g., the reinforcing layer150ofFIG.4), a cover layer (e.g., the cover layer160ofFIG.4), and a protective layer (e.g., the protective layer170ofFIG.4).

FIG.17is a plan view of one surface (e.g., the first surface160aof the cover layer160ofFIG.4) of the cover layer240facing the panel layer140as viewed from above.

Referring toFIG.17, the cover layer240included in the display230of the foldable electronic device200aor200bmay include a pair of first portions241and a second portion242disposed between the pair of first portions241. In the folding and unfolding operations of the foldable electronic device200aor200b, the pair of first portions241may be fixedly maintained without being deformed, and the second portion242may be deformed. For example, when the display230is folded or unfolded to correspond to a state of the foldable electronic device200aor200b, the pair of first portions241may remain flat without being deformed, and the second portion242may be deformed to flat or curved.

The cover layer240of the foldable electronic device200aor200bmay be formed such that the thickness varies in a first direction from the first fixed part231to the second fixed part232of the display230and a second direction that is perpendicular to the first direction and in which the variable part233extends. For example, the first direction may be a width direction W, and the second direction may be a lengthwise direction L. For example, the second direction and the lengthwise direction L may be parallel to the folding axis FA of the display230.

The pair of first portions241may correspond to the fixed parts231and232of the display230that have a fixed shape, and the second portion242may correspond to the variable part233of the display230that has a variable shape. The first portions241may include a first sub-portion241acorresponding to the first fixed part231and a second sub-portion241bcorresponding to the second fixed part232. The second portion242may be disposed between the first sub-portion241aand the second sub-portion241b. For example, the first sub-portion241aof the cover layer240may be a portion (or section) included in the first fixed part231of the display230, the second sub-portion241bof the cover layer240may be a portion (or section) included in the second fixed part232of the display230, and the second portion242of the cover layer240may be a portion (or section) included in the variable part233of the display230.

Each of the pair of first portions241may include a first base portion243and a first connecting portion244that extends from the first base portion243and that is connected with the second portion242. The first connecting portion244may connect the first base portion243and the second portion242and may have a gradually decreasing thickness toward the second portion242. The first base portion243and the first connecting portion244may correspond to the first base portion (e.g., the first base portion163ofFIG.6) and the first connecting portion (e.g., the first connecting portion164ofFIG.6) of the cover layer illustrated inFIGS.5and6(e.g., the cover layer160ofFIGS.5and6).

The second portion242may include a second base portion245and reinforcing portions246protruding from opposite edge portions of the second base portion245that face away from each other in the lengthwise direction. Each of the reinforcing portions246may include an edge portion247that forms an edge of the second portion242in the lengthwise direction L and a second connecting portion248that extends from the edge portion247and that is connected to a surface of the second base portion245. The second connecting portion248may connect the edge portion247and the surface of the second base portion245and may have a gradually decreasing thickness from the edge portion247toward the surface of the second base portion245. The second base portion245, the edge portion247, and the second connecting portion248may correspond to the second base portion (e.g., the second base portion165ofFIGS.5and6), the edge portion (e.g., the edge portion167ofFIG.6), and the second connecting portion (e.g., the second connecting portion168ofFIG.6) of the cover layer240illustrated inFIGS.5and6.

The cover layer240of the foldable electronic device200aor200bmay be configured such that a thickness change occurs in a direction perpendicular to the folding axis FA through a difference in thickness between the first portions241and the second portion242and a thickness change occurs in the direction of the folding axis FA through the reinforcing portions246formed on the second portion242.

The previous descriptions of the various embodiments of the cover layer included in the slidable electronic device100may be applied to the cover layer240included in the foldable electronic device200aor200b.

FIG.18is a flowchart illustrating an example method of manufacturing an example cover layer of a display according to various embodiments.FIG.19is a view illustrating an operation of the example manufacturing method ofFIG.18.FIG.20Ais a view illustrating an operation of the example manufacturing method ofFIG.18.FIG.20Bis a view illustrating an operation of the example manufacturing method ofFIG.18.

FIG.19illustrates an example masking operation330in the example manufacturing method300ofFIG.18.FIGS.20A and20Billustrate an example etching operation350in the example manufacturing method300ofFIG.18.

Referring toFIG.18, the method300of manufacturing a cover layer (e.g., the cover layer160ofFIGS.5,6,7A, and7B) according to an embodiment may include an operation310of processing a glass plate, a masking operation330, an etching operation350, and an operation370of delaminating masking and cleaning the glass plate.

In the operation310of processing the glass plate, the glass plate may be processed in a desired shape to correspond to the width and length of the display (e.g., the display130ofFIGS.1and2or the display230ofFIGS.16A and16B). The processed glass plate may have a uniform thickness.

In the masking operation330, a portion of the processed glass plate that is to be formed relatively thick may be masked using an acid resistant and/or alkali resistant coating solution. For example, masking may be performed by applying a coating solution to portions that correspond to a first portion (e.g., the first portion161ofFIGS.5,6,7A, and7B) and reinforcing portions (e.g., the reinforcing portions166ofFIGS.5,6,7A, and7B) of the cover layer160.

Referring toFIG.19representing the masking operation330, a first coating solution420may be applied to a region of the glass plate410that corresponds to the first portion161, and a second coating solution430may be applied to regions corresponding to the reinforcing portions166. For example, a region to which no coating solution is applied may be a region that corresponds to a second base portion (e.g., the second base portion165ofFIGS.5,6,7A, and7B) of a second portion (e.g., the second portion162ofFIGS.5,6,7A, and7B). The first coating solution420and the second coating solution430may have different chemical resistances. For example, the inclination of the first portion161(e.g., the first inclined surface164sofFIG.7B) and the inclination of the reinforcing portions166(e.g., the second inclined surface168sofFIG.7A) may be formed to be different from each other by masking the glass plate using the first coating solution420and the second coating solution430having different chemical resistances.

In the etching operation350, the glass plate subjected to the masking may be soaked or dipped in an etching solution. The thickness of the remaining portion of the glass plate other than the masked portion may be uniformly reduced. In the etching operation350, the glass plate may be processed in a form in which the masked portion and the unmasked portion have different thicknesses. Various acidic or basic solutions may be used as the etching solution. For example, ammonium fluoride (NH4F), sulfuric acid (H2SO4), nitric acid (HNO3), fluoro silicic acid (H2SiF6), sodium hydroxide (NaOH), or hydrofluoric acid (HF) may be used as the etching solution. The manufacturing method300may adjust the width and thickness of a relatively thick portion (e.g., the first portion161or the reinforcing portions166) of the cover layer160based on a masking area and etching time.

Referring toFIGS.20A and20Brepresenting the etching operation350, when the etching operation350is performed, different inclinations may be formed depending on the chemical resistances of the coating solutions. For example, the first coating solution420applied to the region corresponding to the first portion161may be a coating solution having a lower chemical resistance than the second coating solution430applied to the regions corresponding to the reinforcing portions166. Since the first coating solution420and the second coating solution430have different chemical resistances, the first coating solution420may be delaminated more than the second coating solution430while the masked glass plate410is dipped in a specific etching solution for a predetermined period of time. Accordingly, a portion of the glass plate from which the first coating solution420is delaminated may be corroded with a gentle slope (a small slope)411, and a portion of the glass plate from which the second coating solution430is delaminated may be corroded with a steep slope (a large slope)413. According to the etching operation illustrated inFIGS.20A and20B, the cover layer (e.g., the cover layer160ofFIGS.7A and7B) in which the first inclined surface164sof the first portion161has a smaller inclination angle than the second inclined surfaces168sof the reinforcing portions166may be manufactured.

In the operation370of delaminating the masking and cleaning the glass plate, the masking remaining after the etching operation350may be removed, and the glass plate may be cleaned.

FIG.21is a block diagram of an example electronic device in a network environment according to various embodiments.

The electronic device501ofFIG.21may be referred to as the slideable electronic device100ofFIGS.1and2or the foldable electronic devices200aand200bofFIGS.20A and20B.

Referring toFIG.21, the electronic device501in the network environment500may communicate with an electronic device502via a first network598(e.g., a short-range wireless communication network), or at least one of an electronic device504or a server508via a second network599(e.g., a long-range wireless communication network). According to an embodiment, the electronic device501may communicate with the electronic device504via the server508. According to an embodiment, the electronic device501may include a processor520, memory530, an input module550, a sound output module555, a display module560, an audio module570, a sensor module576, an interface577, a connecting terminal578, a haptic module579, a camera module580, a power management module588, a battery589, a communication module590, a subscriber identification module (SIM)596, or an antenna module597. In various embodiments, at least one of the components (e.g., the connecting terminal578) may be omitted from the electronic device501, or one or more other components may be added in the electronic device501. In various embodiments, some of the components (e.g., the sensor module576, the camera module580, or the antenna module597) may be implemented as a single component (e.g., the display module560).

The processor520may execute, for example, software (e.g., a program540) to control at least one other component (e.g., a hardware or software component) of the electronic device501coupled with the processor520, and may perform various data processing or computation. According to an embodiment, as at least part of the data processing or computation, the processor520may store a command or data received from another component (e.g., the sensor module576or the communication module590) in volatile memory532, process the command or the data stored in the volatile memory532, and store resulting data in non-volatile memory534. According to an embodiment, the processor520may include a main processor521(e.g., a central processing unit (CPU) or an application processor (AP)), or an auxiliary processor523(e.g., a graphics processing unit (GPU), a neural processing unit (NPU), an image signal processor (ISP), a sensor hub processor, or a communication processor (CP)) that is operable independently from, or in conjunction with, the main processor521. For example, when the electronic device501includes the main processor521and the auxiliary processor523, the auxiliary processor523may be adapted to consume less power than the main processor521, or to be specific to a specified function. The auxiliary processor523may be implemented as separate from, or as part of, the main processor521.

The auxiliary processor523may control at least some of functions or states related to at least one component (e.g., the display module560, the sensor module576, or the communication module590) among the components of the electronic device501, instead of the main processor521while the main processor521is in an inactive (e.g., sleep) state, or together with the main processor521while the main processor521is in an active state (e.g., executing an application). According to an embodiment, the auxiliary processor523(e.g., an image signal processor or a communication processor) may be implemented as part of another component (e.g., the camera module580or the communication module590) functionally related to the auxiliary processor523. According to an embodiment, the auxiliary processor523(e.g., the neural processing unit) may include a hardware structure specified for artificial intelligence model processing. An artificial intelligence model may be generated by machine learning. Such learning may be performed, e.g., by the electronic device501where the artificial intelligence is performed or via a separate server (e.g., the server508). Learning algorithms may include, but are not limited to, e.g., supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning. The artificial intelligence model may include a plurality of artificial neural network layers. The artificial neural network may be a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN), deep Q-network or a combination of two or more thereof, but is not limited thereto. The artificial intelligence model may, additionally or alternatively, include a software structure other than the hardware structure. The memory530may store various data used by at least one component (e.g., the processor520or the sensor module576) of the electronic device501. The various data may include, for example, software (e.g., the program540) and input data or output data for a command related thereto. The memory530may include the volatile memory532or the non-volatile memory534.

The program540may be stored in the memory530as software, and may include, for example, an operating system (OS)542, middleware544, or an application546.

The input module550may receive a command or data to be used by another component (e.g., the processor520) of the electronic device501, from the outside (e.g., a user) of the electronic device501. The input module550may include, for example, a microphone, a mouse, a keyboard, a key (e.g., a button), or a digital pen (e.g., a stylus pen).

The sound output module555may output sound signals to the outside of the electronic device501. The sound output module555may include, for example, a speaker or a receiver. The speaker may be used for general purposes, such as playing multimedia or playing record. The receiver may be used for receiving incoming calls. According to an embodiment, the receiver may be implemented as separate from, or as part of the speaker.

The display module560may visually provide information to the outside (e.g., a user) of the electronic device501. The display module560may include, for example, a display, a hologram device, or a projector and control circuitry to control a corresponding one of the display, hologram device, and projector. According to an embodiment, the display module560may include a touch sensor adapted to detect a touch, or a pressure sensor adapted to measure the intensity of force incurred by the touch.

The audio module570may convert a sound into an electrical signal and vice versa. According to an embodiment, the audio module570may obtain the sound via the input module550, or output the sound via the sound output module555or a headphone of an external electronic device (e.g., an electronic device502) directly (e.g., wiredly) or wirelessly coupled with the electronic device501.

A connecting terminal578may include a connector via which the electronic device501may be physically connected with the external electronic device (e.g., the electronic device502). According to an embodiment, the connecting terminal578may include, for example, a HDMI connector, a USB connector, a SD card connector, or an audio connector (e.g., a headphone connector).

The camera module580may capture a still image or moving images. According to an embodiment, the camera module580may include one or more lenses, image sensors, image signal processors, or flashes.

The power management module588may manage power supplied to the electronic device501. According to an embodiment, the power management module588may be implemented as at least part of, for example, a power management integrated circuit (PMIC).

The battery589may supply power to at least one component of the electronic device501. According to an embodiment, the battery589may include, for example, a primary cell which is not rechargeable, a secondary cell which is rechargeable, or a fuel cell.

The communication module590may support establishing a direct (e.g., wired) communication channel or a wireless communication channel between the electronic device501and the external electronic device (e.g., the electronic device502, the electronic device504, or the server508) and performing communication via the established communication channel. The communication module590may include one or more communication processors that are operable independently from the processor520(e.g., the application processor (AP)) and supports a direct (e.g., wired) communication or a wireless communication. According to an embodiment, the communication module590may include a wireless communication module592(e.g., a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module594(e.g., a local area network (LAN) communication module or a power line communication (PLC) module). A corresponding one of these communication modules may communicate with the external electronic device via the first network598(e.g., a short-range communication network, such as Bluetooth™, wireless-fidelity (Wi-Fi) direct, or infrared data association (IrDA)) or the second network599(e.g., a long-range communication network, such as a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., LAN or wide area network (WAN)). These various types of communication modules may be implemented as a single component (e.g., a single chip), or may be implemented as multi components (e.g., multi chips) separate from each other. The wireless communication module592may identify and authenticate the electronic device501in a communication network, such as the first network598or the second network599, using subscriber information (e.g., international mobile subscriber identity (IMSI)) stored in the subscriber identification module596.

According to an embodiment, commands or data may be transmitted or received between the electronic device501and the external electronic device504via the server508coupled with the second network599. Each of the electronic devices502or504may be a device of a same type as, or a different type, from the electronic device501. According to an embodiment, all or some of operations to be executed at the electronic device501may be executed at one or more of the external electronic devices502,504, or508. For example, if the electronic device501should perform a function or a service automatically, or in response to a request from a user or another device, the electronic device501, instead of, or in addition to, executing the function or the service, may request the one or more external electronic devices to perform at least part of the function or the service. The one or more external electronic devices receiving the request may perform the at least part of the function or the service requested, or an additional function or an additional service related to the request, and transfer an outcome of the performing to the electronic device501. The electronic device501may provide the outcome, with or without further processing of the outcome, as at least part of a reply to the request. To that end, a cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used, for example. The electronic device501may provide ultra low-latency services using, e.g., distributed computing or mobile edge computing. In an embodiment, the external electronic device504may include an internet-of-things (IoT) device. The server508may be an intelligent server using machine learning and/or a neural network. According to an embodiment, the external electronic device504or the server508may be included in the second network599. The electronic device501may be applied to intelligent services (e.g., smart home, smart city, smart car, or healthcare) based on 5G communication technology or IoT-related technology.

A flexible display130according to an example embodiment may include a panel layer140and a cover layer160disposed on one surface of the panel layer. The cover layer may include a first portion161and a second portion162that extends from the first portion in a first direction. The first portion may include a first base portion163having a first thickness T1and a first connecting portion164that extends from the first base portion and has a gradually decreasing thickness. The second portion may include a second base portion165that is connected with the first connecting portion and that has a second thickness T2smaller than the first thickness and a reinforcing portion166that protrudes from an edge of the second base portion that faces in a second direction perpendicular to the first direction. The reinforcing portion may include an edge portion167that protrudes from a partial region of the second base portion to have a third thickness T3and a second connecting portion168that extends from the edge portion toward the second base portion and has a gradually decreasing thickness.

In an example embodiment, the first connecting portion may include a first inclined surface164sthat obliquely connects a surface163sof the first base portion and a surface165sof the second base portion, and the second connecting portion may include a second inclined surface168sthat obliquely connects a surface167sof the edge portion and the surface of the second base portion.

In an example embodiment, the first inclined surface may have a first inclination angle A1, and the second inclined surface may have a second inclination angle A2different from the first inclination angle.

In an example embodiment, the first inclination angle may be smaller than the second inclination angle.

In an example embodiment, the first thickness of the first base portion may be substantially the same as a sum of the second thickness of the second base portion and the third thickness of the edge portion.

In an example embodiment, the reinforcing portion may be connected to the first portion such that the edge portion forms the same plane as the first base portion.

In an example embodiment, the first thickness of the first base portion183may be greater than the sum of the second thickness of the second base portion185and the third thickness of the edge portion187.

In an example embodiment, the first base portion may further protrude beyond the edge portion by a first height H1based on the second base portion, and the first height may be equal to the first thickness minus the sum of the second thickness and the third thickness.

In an example embodiment, the flexible display may further include a reinforcing layer150disposed between the panel layer and the cover layer, and the reinforcing layer may be formed in a shape corresponding to a thickness change of the cover layer.

In an example embodiment, the reinforcing portion196may include a plurality of protrusions1961,1962, and1963which are spaced apart from each other by a specified gap in the first direction.

In an example embodiment, the flexible display may further include a reinforcing layer150disposed between the panel layer and the cover layer, and the reinforcing layer may include a plurality of depressions150rcorresponding to the plurality of protrusions.

In an example embodiment, the first portion may remain substantially flat, and the second portion may be partially deformed to be flat or curved.

A slidable electronic device100according to an example embodiment of the disclosure may include a first structure110, a second structure120connected to the first structure so as to slide, and a display130configured such that a size of a region exposed on a front surface of the electronic device is changed in response to sliding of the second structure relative to the first structure, the display being formed in a structure in which a plurality of layers are stacked. The plurality of layers may include a panel layer140and a cover layer160disposed on one surface of the panel layer, and the cover layer may include a first portion161and a second portion162that extends from the first portion in a first direction. The first portion may include a first base portion163having a first thickness T1and a first connecting portion164that extends from the first base portion and has a gradually decreasing thickness, and the second portion may include a second base portion165that is connected with the first connecting portion and that has a second thickness smaller than the first thickness and a reinforcing portion166that protrudes from an edge of the second base portion that faces in a second direction perpendicular to the first direction. The reinforcing portion may include an edge portion167that protrudes from a partial region of the second base portion to have a third thickness T3and a second connecting portion168that extends from the edge portion toward the second base portion and has a gradually decreasing thickness.

In an example embodiment, the first connecting portion may include a first inclined surface164sthat obliquely connects a surface163sof the first base portion and a surface165sof the second base portion, and the second connecting portion may include a second inclined surface168sthat obliquely connects a surface167sof the edge portion and the surface of the second base portion.

In an example embodiment, the first inclined surface may have a first inclination angle A1, and the second inclined surface may have a second inclination angle A2different from the first inclination angle.

In an example embodiment, the display may include a fixed part132, the shape of which is fixedly maintained when the second structure slides, and a variable part (e.g., a rollable part or a rolling part)134that extends from the fixed part and that is deformed to be flat or curved in response to sliding of the second structure. The first portion may be included in the fixed part of the display, and the second portion may be included in the variable part of the display.

In an example embodiment, the first direction may be substantially parallel to sliding directions S1and S2in which the second structure slides relative to the first structure.

A foldable electronic device200aor200baccording to an example embodiment of the disclosure may include a first housing210, a second housing220connected to the first housing so as to be rotatable, and a display230disposed in the first housing and the second housing and partially folded or unfolded in response to relative rotation of the first housing and the second housing, the display being formed in a structure in which a plurality of layers are stacked. The plurality of layers may include a panel layer140and a cover layer160or240disposed on one surface of the panel layer, and the cover layer may include a first portion161or241and a second portion162or242that extends from the first portion in a first direction. The first portion may include a first base portion163or243having a first thickness T1and a first connecting portion164or244that extends from the first base portion and has a gradually decreasing thickness, and the second portion may include a second base portion165or245that is connected with the first connecting portion and that has a second thickness T2smaller than the first thickness and a reinforcing portion166or246that protrudes from an edge of the second base portion that faces in a second direction perpendicular to the first direction. The reinforcing portion may include an edge portion167or247that protrudes from a partial region of the second base portion to have a third thickness T3and a second connecting portion168or248that extends from the edge portion toward the second base portion and has a gradually decreasing thickness.

In an example embodiment, the first connecting portion may include a first inclined surface164sthat obliquely connects a surface163sof the first base portion and a surface165sof the second base portion, and the second connecting portion may include a second inclined surface168sthat obliquely connects a surface167sof the edge portion and the surface of the second base portion.

In an example embodiment, the first inclined surface may have a first inclination angle A1, and the second inclined surface may have a second inclination angle A2different from the first inclination angle.

In an example embodiment, the display may include a first fixed part231at least partially disposed in the first housing and formed to be flat, a second fixed part232at least partially disposed in the second housing and formed to be flat, and a variable part (e.g., a foldable part or a folding part)233disposed between the first fixed part and the second fixed part. The first portion may be included in the first fixed part and the second fixed part of the display, and the second portion may be included in the variable part of the display.

In an example embodiment, the first portion may include a first sub-portion241acorresponding to the first fixed part and a second sub-portion241bcorresponding to the second fixed part, and the second portion may be disposed between the first sub-portion and the second sub-portion.

In an example embodiment, the first direction may be substantially perpendicular to a folding axis FA of the display, and the second direction may be substantially parallel to the folding axis of the display.

In an example embodiment, the first direction may be substantially parallel to a direction in which the first fixed part and the second fixed part extend from opposite sides of the variable part.