Flexible display device

A flexible display device includes a flexible substrate body including a first surface and a second surface opposite to the first surface, a display layer on the first surface of the flexible substrate body, a substrate extension portion bent from a side of the flexible substrate body, the substrate extension portion extending along the second surface of the flexible substrate body and overlapping the flexible substrate body, and a sensor layer interposed between the flexible substrate body and the substrate extension portion to detect a movement input to the display layer.

CROSS REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2015-0189220, filed on Dec. 30, 2015, in the Korean Intellectual Property Office, and entitled: “Flexible Display Device,” is incorporated by reference herein in its entirety.

BACKGROUND

Example embodiments relate to a flexible display device. More particularly, example embodiments relate to a flexible display device having a sensor.

2. Description of the Related Art

A flexible display device includes a flexible display panel and a sensor layer. The sensor layer includes a capacitive type sensor for detecting a movement input by user.

Generally, the sensor layer is embedded in the flexible display panel or is disposed on the surface of the flexible display panel. Accordingly, the flexible display device may be relatively thick owing to a complicated structure, and the sensor layer may have a low sensitivity.

SUMMARY

According to some example embodiments, a flexible display device may include a flexible substrate body including a first surface and a second surface opposite to the first surface, a display layer disposed on the first surface of the flexible substrate body, a substrate extension portion bent from a side of the flexible substrate body, the substrate extension portion extending along the second surface of the flexible substrate body and overlapping the flexible substrate body, and a sensor layer interposed between the flexible substrate body and the substrate extension portion to detect a movement input to the display layer.

In example embodiments, the sensor layer may include an elastic layer having an original shape or a changed shape, wherein the original shape is converted into the changed shape by the movement and the original shape is recovered by an elastic force, and first and second electrodes disposed adjacent to the elastic layer. At least a portion of the elastic layer having the changed shape may be inserted between the first and second electrodes spaced apart from each other.

In example embodiments, the first electrode may be disposed under the second surface of the flexible substrate body and receives a first voltage for detecting the movement input to the display layer. The second electrode may be disposed on the substrate extension portion and receives a second voltage. The first voltage may be converted into the second voltage by the portion of the elastic layer having the changed shape.

In example embodiments, the first voltage may correspond to a square wave.

In example embodiments, the flexible display device may further include a first voltage wire disposed under the second surface of the flexible substrate body and electrically connected to the first electrode to apply the first voltage to the first electrode, and a second voltage wire disposed under the second surface of the flexible substrate body and electrically connected to the second electrode disposed on the substrate extension portion through a connection member.

In example embodiments, the connection member may include a silver paste.

In example embodiments, the first electrode may be in contact with the second surface of the flexible substrate body. The second electrode may be in contact with the substrate extension portion.

In example embodiments, the first and second electrodes may be disposed adjacent to the side of the flexible substrate body.

In example embodiments, the first and second electrodes may extend along the side of the flexible substrate body.

In example embodiments, the substrate extension portion may include a bending portion bent from the side of the flexible substrate body, and an extension portion connected to the bending portion and extending along the second side of the flexible substrate body. The first electrode may be disposed under the second surface of the flexible substrate body and one portion of the bending portion. The second electrode may be disposed on the extension portion and another portion of the bending portion.

In example embodiments, the elastic layer may include a resin having nickel.

In example embodiments, the elastic layer may be in contact with the flexible substrate body and the substrate extension portion.

In example embodiments, the elastic layer may extend along the side of the flexible substrate body.

In example embodiments, the sensor layer may further include a first side wall disposed between the elastic layer and the first and second electrodes and being in contact with a first side of the elastic layer, and a second side wall being in contact with a second side of the elastic layer opposite to the first side of the elastic layer. The first side wall may include a hole through which the portion of the elastic layer having the changed shape passes.

In example embodiments, the first and second side walls may include a plastic material.

In example embodiments, the flexible substrate body and the substrate extension portion may include a polyimide.

In example embodiments, the sensor layer may be divided into first and second regions. The elastic layer may be disposed in the first region. The first and second electrodes may be disposed in the second region. The portion of the elastic layer having the changed shape disposed in the first region may be inserted into between the first and second electrodes disposed in the second region.

In example embodiments, the side of the flexible substrate body may include first and third sides opposite to each other, and second and fourth sides that connect the first side to the third side and are opposite to each other. The substrate extension portion may include first through fourth substrate extension portions that are respectively bent from the first through fourth sides and extend along the second side of the flexible substrate body. The sensor layer may include first through fourth sensor layers that are interposed between the flexible substrate body and the first through fourth substrate extension portions, respectively.

In example embodiments, each of the first through fourth sensor layers may include an elastic layer having an original shape or a changed shape, wherein the original shape is converted into the changed shape by the movement and the original shape is recovered by an elastic force, and first and second electrodes disposed adjacent to the elastic layer. At least a portion of the elastic layer having the changed shape is inserted between the first and second electrodes.

In example embodiments, the flexible display device may include a first voltage wire disposed under the second surface of the flexible substrate body and electrically connected to the first electrode of the first sensor layer, first voltage auxiliary wires disposed under the second surface of the flexible substrate body and electrically connecting the first electrodes of the first through fourth sensor layers to each other, and second voltage wires disposed under the second surface of the flexible substrate body and electrically connected to the second electrodes disposed on the first through fourth substrate extension portions through first through fourth connection members, respectively.

In example embodiments, a flexible display device may include a flexible substrate body including a first surface and a second surface opposite to the first surface, a display layer on the first surface of the flexible substrate body, a substrate extension portion to be bent from a side of the flexible substrate body, and a sensor layer having a first portion on the first surface of the flexible substrate body, a second portion on the second surface of the flexible substrate body, and a third portion on the substrate extension portion the sensor layer to detect a movement input to the display layer, wherein, when bent, the substrate extension portion including the third portion of the sensor layer extends along the second surface of the flexible substrate body and overlaps the first and second portions of the sensor layer.

DETAILED DESCRIPTION

Exemplary embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown.

FIG. 1is a plan view illustrating a flexible display device according to example embodiments.FIG. 2is a perspective view illustrating a flexible display device ofFIG. 1.FIG. 3is a bottom view illustrating a flexible display device ofFIG. 1when a substrate extension portion is unfolded.FIG. 4is a cross-sectional view cut along the line I-I′ ofFIG. 1.FIG. 5is a cross-sectional view cut along the line II-II′ ofFIG. 1.FIG. 6is a cross-sectional view cut along the line ofFIG. 1.FIG. 7is a cross-sectional view cut along the line I-I′ ofFIG. 1when a movement is input. As used herein, movement input may include touch, e.g., of a hand or stylus, gestures, and so forth.

Referring toFIGS. 1 through 7, the flexible display device100may include a flexible substrate body110, a display layer150, first through fourth substrate extension portions120,140,160,180, and first through fourth sensor layers200,300,400,500. As may be seen inFIG. 3, the first and third substrate extension portions120and160may extend from the flexible substrate body110in a second direction D2and second and fourth third substrate extension portions140and180may extend from the flexible substrate body110in a first direction D1, resulting in discontinuities between adjacent regions extending in opposite direction, such that corners are indented to facilitate the bending of the first through fourth substrate extension portions120,140,160,180as illustrated inFIGS. 12, and 4-7.

The flexible display device100may include an active region AA on which an image is displayed, and first to fourth peripheral regions PA1, PA2, PA3, and PA4adjacent to the active region AA and not displaying the image. The active region AA may be referred to as a display region.

For example, the active region AA may correspond to the flexible substrate body110of the flexible display device100. The first peripheral region PA1of the flexible display device100may correspond to the first substrate extension portion120. The second peripheral region PA2of the flexible display device100may correspond to the second substrate extension portion140. The third peripheral region PA3of the flexible display device100may correspond to the third substrate extension portion160. The fourth peripheral region PA4of the flexible display device100may correspond to the fourth substrate extension portion180.

The flexible display device100may include a plurality of scan lines, each of which extends in a first direction D1, and a plurality of data lines, each of which extends in a second direction D2crossing the first direction D1. The flexible display device100may include a plurality of pixels PX. The pixels PX may be electrically connected to the scan lines and the data lines. The scan lines, the data lines, and the pixels PX may be disposed in the active region AA of the flexible display device100.

In addition, the pixels PX may be disposed in a matrix. The scan lines may be electrically connected to a scan driver. The data lines may be electrically connected to a data driver.

The data driver may provide a reference voltage or a pixel data voltage as a data signal to the data lines. For example, the data driver may be mounted on the third substrate extension portion160.

The scan driver may simultaneously or progressively provide a scan signal to the scan lines. The scan driver may be mounted on the second substrate extension portion140.

An emission driver may provide an emission signal to the pixels PX. The emission driver may be mounted under the fourth substrate extension portion180.

The flexible substrate body110may include a first surface102and a second surface104opposite to the first surface102. The flexible substrate body110may include polyimide. Also, the flexible substrate body110may include first through fourth sides112,114,116,118connecting the first surface102and the second surface104.

The display layer150may be disposed on the first surface102of the flexible substrate body110. In one example embodiment, the display layer150may include an organic light emitting layer. Alternatively, the display layer150may include a liquid crystal layer.

The first substrate extension portion120may be bent from the first side112of the flexible substrate body110and may extend along the second surface104of the flexible substrate body110. The first substrate extension portion120may overlap the flexible substrate body110. For example, the first substrate extension portion120may include a bending portion125bent from the first side112of the flexible substrate body110and an extension portion122connected to the bending portion125and extending along the second side104of the flexible substrate body110.

The second substrate extension portion140may be bent from the second side114of the flexible substrate body110and may extend along the second surface104of the flexible substrate body110. The second substrate extension portion140may overlap the flexible substrate body110. For example, the second substrate extension portion140may include a bending portion145bent from the second side114of the flexible substrate body110and an extension portion142connected to the bending portion145and extending along the second side104of the flexible substrate body110.

The third substrate extension portion160may be bent from the third side116of the flexible substrate body110and may extend along the second surface104of the flexible substrate body110. The third substrate extension portion160may overlap the flexible substrate body110. For example, the third substrate extension portion160may include a bending portion165bent from the third side116of the flexible substrate body110and an extension portion162connected to the bending portion165and extending along the second side104of the flexible substrate body110.

The fourth substrate extension portion180may be bent from the fourth side118of the flexible substrate body110and may extend along the second surface104of the flexible substrate body110. The fourth substrate extension portion180may overlap the flexible substrate body110. For example, the fourth substrate extension portion180may include a bending portion185bent from the fourth side118of the flexible substrate body110and an extension portion182connected to the bending portion185and extending along the second side104of the flexible substrate body110.

In one example embodiment, each of the first through fourth substrate extension portions may include a polyimide.

The first sensor layer200may interposed between the flexible substrate body110and the first substrate extension portion120to detect a movement input to the display layer150.

The first sensor layer200may include an elastic layer210and first and second electrodes220,230. The elastic layer210may have an original shape or a changed shape. Here, the original shape is converted into the changed shape by the movement, and the original shape is recovered by an elastic force. The first and second electrodes220,230may be disposed adjacent to the elastic layer210. At least a portion of the elastic layer210having the changed shape may be inserted between the first and second electrodes220,230spaced apart from each other.

For example, the first sensor layer200may be divided into the first and second regions A, B. The elastic layer210may be disposed in the first region A. The first and second electrodes220,230may be disposed in the second region B. Also, at least the portion of the elastic layer210disposed in the first region A may be inserted into between the first electrode220and the second electrode230disposed in the second region B by the movement, e.g., may protrude along the second direction D2into the space between the first and second electrodes220,230.

In one example embodiment, the elastic layer210of the first sensor layer200may include a resin having nickel (Ni).

In addition, the elastic layer210of the first sensor layer200may contact the flexible substrate body110and the first substrate extension portion120. The elastic layer210may extend along the first side112of the flexible substrate body110.

The first electrode220of the first sensor layer200may be disposed under the second surface104of the flexible substrate body110. A first voltage for detecting the movement input to the display layer150may be applied to the first electrode220of the first sensor layer200.

The second electrode230of the first sensor layer200may be disposed on the first substrate extension portion120. A second voltage may be applied to the second electrode230of the first sensor layer200. Here, the first voltage is changed to the second voltage by the portion of the elastic layer210having the changed shape.

Accordingly, a capacitance and a resistance between the first electrode220and the second electrode230, the capacitance and the resistance changed by the movement, may be calculated by measuring the second voltage. Accordingly, the movement can be detected.

For example, the first voltage may correspond to a square wave having a high level and a low level which alternate with each other. The second voltage may correspond to a wave to which the first voltage is changed by the portion of the elastic layer210having the changed shape.

In one example embodiment, the first electrode220may be in contact with the second surface104of the flexible substrate body110. The second electrode230may be in contact with the first substrate extension portion120.

Also, the first and second electrode220,230may be disposed adjacent to the first side112of the flexible substrate body110. The first and second electrode220,230may extend along the first side112of the flexible substrate body110.

The second sensor layer300may interposed between the flexible substrate body110and the second substrate extension portion140to detect the movement input to the display layer150. The second sensor layer300may include an elastic layer310and first and second electrodes320,330. The elastic layer310may have an original shape or a changed shape. The original shape may be converted into the changed shape by the movement input, and the original shape may be recovered by the elastic force. The first and second electrodes320,330may be disposed adjacent to the elastic layer310. At least a portion of the elastic layer310having the changed shape may be inserted between the first and second electrodes320,330spaced apart from each other, e.g., may protrude along the first direction D1into the space between the first and second electrodes320,330.

The third sensor layer400may interposed between the flexible substrate body110and the third substrate extension portion160to detect the movement input to the display layer150. The third sensor layer400may include an elastic layer410and first and second electrodes420,430. The elastic layer410may have an original shape or a changed shape. The original shape is converted into the changed shape by the movement, and the original shape is recovered by the elastic force. The first and second electrodes420,430may be disposed adjacent to the elastic layer410. At least a portion of the elastic layer410having the changed shape may be inserted between the first and second electrodes420,430spaced apart from each other, e.g., may protrude along the second direction D2into the space between the first and second electrodes420,430.

The fourth sensor layer500may interposed between the flexible substrate body110and the fourth substrate extension portion180to detect the movement input to the display layer150. The fourth sensor layer500may include an elastic layer510and first and second electrodes520,530. The elastic layer510may have an original shape or a changed shape. The original shape is converted into the changed shape by the movement, and the original shape is recovered by the elastic force when the movement ceases. The first and second electrodes520,530may be disposed adjacent to the elastic layer510. At least a portion of the elastic layer510having the changed shape may be inserted between the first and second electrodes520,530spaced apart from each other, e.g., may protrude along the first direction D1into the space between the first and second electrodes520,530.

In one example embodiment, each of the elastic layers310,410,510of the second through fourth sensor layers300,400,500may include a material substantially the same as a material included in the elastic layer210of the first sensor layer200. In addition, a shape and a structure of each elastic layer310,410,510of the second through fourth sensor layer300,400,500may be similar to a shape and a structure of the elastic layer210of the first sensor layer200.

A shape and a structure of the first and second electrodes320,330of the second sensor layer300, a shape and a structure of the first and second electrodes420,430of the third sensor layer400, and a shape and a structure of the first and second electrodes520,530of the fourth sensor layer500may be substantially the same as a shape and a structure of the first and second electrodes220,230of the first sensor layer200.

In one example embodiment, the flexible display device100may further include a first voltage wire600disposed under the second surface104of the flexible substrate body110and electrically connected to the first electrode220of the first sensor layer200to apply the first voltage to the first electrode220.

As shown inFIGS. 1 and 2, the first voltage wire600may receive the first voltage via a first voltage pad610in the active region AA and may apply the first voltage to the first electrode220of the first sensor layer200. The flexible display device100may further include first voltage auxiliary wires602,604,606,608disposed under the second surface104of the flexible substrate body110and electrically connecting the first electrodes220,320,420,520of the first through fourth sensor layers200,300,400,500to each other. Accordingly, the first voltage may be applied to the first electrodes320,420,520of the second through fourth sensor layers300,400,500via the first voltage auxiliary wires602,604,606,608.

The flexible display device100may further include second voltage wires700,702,704,706disposed under the second surface104of the flexible substrate body110and electrically connected to the second electrodes230,330,430,530of the first through fourth sensor layers200,300,400,500.

As shown inFIG. 6, the second voltage applied to the second electrode230of the first sensor layer200may be applied to the second voltage pad710through a second voltage auxiliary pad720, a first connection member730, and a second voltage wire700.

In one example embodiment, the first connection member730may include a silver paste. Alternatively, the first connection member730may include a liquid metal or a conductive polymer material. The first connection member730may include a protrusion portion and a reception portion coupled to the protrusion portion.

Similarly, the second voltage applied to the second electrode330of the second sensor layer300may be applied to the second voltage pad712through a second voltage auxiliary pad722, a second connection member, and a second voltage wire702. The second voltage applied to the second electrode430of the third sensor layer400may be applied to the second voltage pad714through a second voltage auxiliary pad724, a third connection member, and a second voltage wire704. The second voltage applied to the second electrode530of the fourth sensor layer500may be applied to the second voltage pad716through a second voltage auxiliary pad726, a fourth connection member, and a second voltage wire706.

Accordingly, a capacitance and a resistance between the first and second electrodes220,230of the first sensor layer200, a capacitance and a resistance between the first and second electrodes320,330of the second sensor layer300, a capacitance and a resistance between the first and second electrodes420,430of the third sensor layer400, and a capacitance and a resistance between the first and second electrodes520,530of the fourth sensor layer500, the capacitances and the resistances changed by the movement, may be calculated by measuring the second voltages, respectively. Therefore, the movement can be detected more accurately.

As shown inFIG. 7, when the pressure (or the movement) is input to the display layer150, e.g., by a user's finger, at least a portion of the elastic layer210disposed in the first region A of the first sensor layer200may be inserted in, e.g., protrude into, the second region B of the first sensor layer200. Accordingly, the capacitance and insulation resistance of the first and second electrode220,230may be changed. Therefore, the movement can be detected by measuring the capacitance and insulation resistance.

In the flexible display device100according to an exemplary embodiment, the first through fourth sensor layers200,300,400,500may be disposed in a space between the flexible substrate body110and one of the first through fourth substrate extension portions120,140,160,180that bend and extend from the flexible substrate body110. Accordingly, the display device may be implemented as a simple structure with a decreased thickness.

In addition, each of the first through fourth sensor layers200,300,400,500can measure a change in the capacitance and resistance between the first and second electrodes by the elastic layers210,310,410,510, thereby improving the sensitivity of the sensor layer.

FIG. 8is a plan view illustrating a flexible display device106according to example embodiments.FIG. 9is a cross-sectional view along the line IV-IV′ ofFIG. 8.FIG. 10is a cross-sectional view along the line IV-IV′ ofFIG. 8when a movement is input. The display device according to the present exemplary embodiment is substantially the same as the display device of the exemplary embodiment described inFIGS. 1 through 7, except that first and second walls are added. Therefore, the same reference numerals will be used to refer to the same or like parts as those described in the previous exemplary embodiment ofFIGS. 1 through 7, and any repetitive explanation concerning the above elements will be omitted.

The display device106may include the flexible substrate body110, the display layer150, first through fourth substrate extension portions120,140,160,180, and first through fourth sensor layers202,302,402,502.

The first sensor layer202may interposed between the flexible substrate body110and the first substrate extension portion120to detect a movement input to the display layer150. The first sensor layer202may include an elastic layer210and first and second electrodes220,230. The elastic layer210may have an original shape or a changed shape. Here, the original shape is converted into the changed shape by the movement, and the original shape is recovered by an elastic force when the movement ceases. The first and second electrodes220,230may be disposed adjacent to the elastic layer210. At least a portion of the elastic layer210having the changed shape may be inserted between the first and second electrodes220,230spaced apart from each other.

For example, the first sensor layer202may be divided into the first and second regions A, B. The elastic layer210may be disposed in the first region A. The first and second electrodes220,230may be disposed in the second region B. Also, at least the portion of the elastic layer210disposed in the first region A may be inserted into between the first electrode220and the second electrode230disposed in the second region B by the movement.

Specifically, the first sensor layer202may further include a first side wall240and a second side wall250, e.g., extending along the third direction D3between the second surface104and the extension portion122. The first side wall240may be disposed between the elastic layer210and the first and second electrodes220,230and may be in contact with a first side212of the elastic layer210. The second side wall250may be in contact with a second side214of the elastic layer210opposite to the first side212of the elastic layer210, e.g., separated along the second direction D1.

The first side wall240may include a hole242through which at least the portion of the elastic layer210having the changed shapes is to pass in response to movement input. Accordingly, at least the portion of the elastic layer210disposed in the first region A may be inserted in the second region B through the hole242of the first side wall240when the movement is input.

In one example embodiment, the first and second side walls240,250may include a plastic material.

The first electrode220of the first sensor layer202may be disposed under the second surface104of the flexible substrate body110. A first voltage for detecting the movement input to the display layer150may be applied to the first electrode220of the first sensor layer202.

The second electrode230of the first sensor layer202may be disposed on the first substrate extension portion120. A second voltage may be applied to the second electrode230of the first sensor layer202. Here, the first voltage is converted into the second voltage by at least the portion of the elastic layer210having the changed shape.

Accordingly, a capacitance and a resistance between the first electrode220and the second electrode230, the capacitance and the resistance changed by the movement, may be calculated by measuring the second voltage, thereby detecting the movement.

Similarly, the second through fourth sensor layers302,402,502may further include the first and second walls.

As shown inFIGS. 9 and 10, when the pressure is input to the display layer150, e.g., by a user's finger, at least a portion of the elastic layer210disposed in the first region A of the first sensor layer202may be inserted in the second region B of the first sensor layer202through the hole242of the first side wall240. As a result, the capacitance and insulation resistance of the first and second electrode220,230may be changed, and the movement of user's finger can be detected by measuring the capacitance and insulation resistance.

Specifically, when the first side wall240and the second side wall250are included, the elastic layer210may be deformed more largely, e.g., due to restrictions on the elastic layer210. Accordingly, the sensitivity of the first through fourth sensor layers202,302,402,502can be improved.

For example, at least the portion of the elastic layer210may be inserted in a space between the first and second electrodes220,230such that the space is sufficiently filled with the portion of the elastic layer210by the movement. Therefore, the capacitance and insulation resistance between the first and second electrode220,230can be changed more largely, thereby improving the sensitivity of the sensor layers202,302,402,502.

FIG. 11is a plan view illustrating a flexible display device1058according to example embodiments.FIG. 12is a cross-sectional view along the line V-V′ ofFIG. 11.FIG. 13is a cross-sectional view along the line V-V′ ofFIG. 11when a movement is input. The display device according to the present exemplary embodiment is substantially the same as the display device of the exemplary embodiment described inFIGS. 8 through 10, except that first and second electrodes are further disposed on the bending portion. Therefore, the same reference numerals will be used to refer to the same or like parts as those described in the previous exemplary embodiment ofFIGS. 8 through 10, and any repetitive explanation concerning the above elements will be omitted.

Referring toFIGS. 11 through 13, the flexible display device108may include the flexible substrate body110, the display layer150, first through fourth substrate extension portions120,140,160,180, and first through fourth sensor layers204,304,404,504.

The first substrate extension portion120may include a bending portion125bent from the first side112of the flexible substrate body110and an extension portion122connected to the bending portion125and extending along the second side104of the flexible substrate body110.

The second substrate extension portion140may include a bending portion145bent from the second side114of the flexible substrate body110and an extension portion142connected to the bending portion145and extending along the second side104of the flexible substrate body110.

The third substrate extension portion160may include a bending portion165bent from the third side116of the flexible substrate body110and an extension portion162connected to the bending portion165and extending along the second side104of the flexible substrate body110.

The fourth substrate extension portion180may include a bending portion185bent from the fourth side118of the flexible substrate body110and an extension portion182connected to the bending portion185and extending along the second side104of the flexible substrate body110.

The first sensor layer204may be interposed between the flexible substrate body110and the first substrate extension portion120to detect a movement input to the display layer150.

The first sensor layer204may include an elastic layer210and first and second electrodes222,232. The elastic layer210may have an original shape or a changed shape. Here, the original shape is converted into the changed shape in response to the movement input, and the original shape is recovered by an elastic force when the movement input ceases. The first and second electrodes222,232may be disposed adjacent to the elastic layer210. At least a portion of the elastic layer210having the changed shape may be inserted between the first and second electrodes222,232spaced apart from each other.

For example, the first sensor layer204may be divided into the first and second regions A, B. The elastic layer210may be disposed in the first region A. The first and second electrodes222,232may be disposed in the second region B. Also, at least the portion of the elastic layer210disposed in the first region A may be inserted between the first electrode222and the second electrode232disposed in the second region B by the movement.

Specifically, the first sensor layer204may further include a first side wall240and a second side wall250. The first side wall240may be disposed between the elastic layer210and the first and second electrodes222,232and may be in contact with a first side212of the elastic layer210. The second side wall250may be in contact with a second side214of the elastic layer210opposite to the first side212of the elastic layer210.

The first side wall240may include a hole242through which at least the portion of the elastic layer210having the changed shape passes. Accordingly, at least the portion of the elastic layer210disposed in the first region A may be inserted in the second region B through the hole242of the first side wall240when the movement is input.

In one example embodiment, the first and second side walls240,250may include a plastic material.

The first electrode222of the first sensor layer204may be disposed under the second surface104of the flexible substrate body110. A first voltage for detecting the movement input to the display layer150may be applied to the first electrode222of the first sensor layer204.

In one example embodiment, the first electrode222of the first sensor layer204may be disposed under the second surface104of the flexible substrate body110and one portion of the bending portion125of the first substrate extension portion120.

The second electrode232of the first sensor layer204may be disposed on the first substrate extension portion120. A second voltage may be applied to the second electrode232of the first sensor layer204. Here, the first voltage is changed to the second voltage by at least the portion of the elastic layer210having the changed shape.

In one example embodiment, the second electrode232of the first sensor layer204may be disposed on the extension portion122of the first substrate extension portion120and another portion of the bending portion125.

Accordingly, a capacitance and a resistance between the first electrode222and the second electrode232, the capacitance and the resistance changed by the movement, may be calculated by measuring the second voltage, thereby detecting the movement. Specifically, the first electrode222may be further disposed under one portion of the bending portion125of the first substrate extension portion120, and the second electrode232may be further disposed on another portion of the bending portion125of the first substrate extension portion120, thereby improving the sensitivity of the first sensor layer204.

The first electrodes of the second through fourth sensor layers304,404,504may be further disposed under one portion of the bending portions145,165,185, respectively. The second electrodes of the second through fourth sensor layers304,404,504may be further disposed on another portion of the bending portions145,165,185, respectively.

As shown inFIGS. 12 and 13, when the pressure is input to the display layer150, e.g., by a user's finger, at least a portion of the elastic layer210disposed in the first region A of the first sensor layer204may be inserted in the second region B of the first sensor layer204. Accordingly, the capacitance and insulation resistance of the first and second electrode222,232may be changed. Therefore, the movement input can be detected by measuring the capacitance and insulation resistance.

Specifically, deformation of the elastic layer210generated by the movement may occur more significantly due to the first and second side walls240,250. At least the portion of the elastic layer210may be inserted adjacent to the bending portion125of the first substrate extension portion120.

The first electrode222may be further disposed under one portion of the bending portion125, and the second electrode232may be further disposed under another portion of the bending portion125. Therefore, changes in the capacitance and insulation resistance between the first and second electrode222,232generated by inserting at least the portion of the elastic layer210may occur more significantly. In result, the sensitivity of the first sensor layer204may increase.

Likewise, the sensitivities of the second through fourth sensor layers304,404,504may increase.

FIG. 14is a plan view illustrating a flexible display device109according to example embodiments.FIG. 15is a perspective view illustrating a flexible display device ofFIG. 15.

The display device according to the present exemplary embodiment is substantially the same as the display device of the exemplary embodiment described inFIGS. 1 through 7, except that the second through fourth substrate extension portions and the second through fourth sensor layers are excluded. Therefore, the same reference numerals will be used to refer to the same or like parts as those described in the previous exemplary embodiment ofFIGS. 1 through 7, and any repetitive explanation concerning the above elements will be omitted.

Referring toFIGS. 14 and 15, the flexible display device109may include the flexible substrate body110, the display layer150, the first substrate extension portion120, and the first sensor layer200.

The first substrate extension portion120may be bent from the first side112of the flexible substrate body110and may extend along the second surface104of the flexible substrate body110, e.g., along the second direction D2. The first substrate extension portion120may overlap the flexible substrate body110when bent.

For example, the first substrate extension portion120may include a bending portion125bent from the first side112of the flexible substrate body110and an extension portion122connected to the bending portion125and extending along the second side104of the flexible substrate body110.

The first sensor layer200may be interposed between the flexible substrate body110and the first substrate extension portion120to detect a movement input to the display layer150. The first sensor layer200may include an elastic layer210and first and second electrodes220,230. The elastic layer210may have an original shape or a changed shape. Here, the original shape is converted into the changed shape in response to the movement input, and the original shape is recovered by an elastic force when the movement input ceases. The first and second electrodes220,230may be disposed adjacent to the elastic layer210. At least a portion of the elastic layer210having the changed shape may be inserted between the first and second electrodes220,230spaced apart from each other.

For example, the first sensor layer200may be divided into the first and second regions A, B. The elastic layer210may be disposed in the first region A. The first and second electrodes220,230may be disposed in the second region B. Also, at least the portion of the elastic layer210disposed in the first region A may be inserted into between the first electrode220and the second electrode230disposed in the second region B by the movement.

In one example embodiment, the flexible display device109may further include a first voltage wire600disposed under the second surface104of the flexible substrate body110and electrically connected to the first electrode220of the first sensor layer200to apply the first voltage to the first electrode220. As shown inFIG. 5, the first voltage wire600may receive the first voltage via a first voltage pad610and may apply the first voltage to the first electrode220of the first sensor layer200.

The flexible display device109may further include a second voltage wire700disposed under the second surface104of the flexible substrate body110and electrically connected to the second electrode230of the first through fourth sensor layer200. As shown inFIG. 6, the second voltage applied to the second electrode230of the first sensor layer200may be applied to the second voltage pad710through a second voltage auxiliary pad720, a first connection member730, and a second voltage wire700.

Accordingly, a capacitance and a resistance between the first and second electrodes220,230of the first sensor layer200may be calculated by measuring the second voltages changed by the movement, thereby detecting the movement.

In the display device109according to example embodiments, the first sensor layer200may be disposed in a space between the flexible substrate body110and the first substrate extension portion120bent from and extending along the flexible substrate body110. Accordingly, the display device may be implemented as a simple structure with a decreased thickness.

By way of summation and review, one or more embodiments provide a flexible display device capable of decreasing a thickness and/or improving a sensitivity of a sensor. In particular, one or more embodiments may include a flexible display device having a sensor layer between a flexible substrate body and a substrate extension portion that is bent from a side of the flexible substrate body and extends along the flexible substrate body. Accordingly, the display device may be implemented as a simple structure to decrease a thickness. Additionally or alternatively, one or more embodiments may include a flexible display device that has a sensor layer including an elastic layer in a first region and first and second electrodes disposed in a second region. At least a portion of the elastic layer may protrude into between the first and second electrodes in response to a movement input. Accordingly, the sensor layer of the display device may have improved sensitivity by measuring a capacitance and a resistance between the first electrode and second electrode.