KR20210097249A - Display device - Google Patents

Abstract

A display device is provided. The display device is a display device including a first non-folding area and a second non-folding area. The display device includes a display panel disposed on the first non-folding area and the second non-folding area; a step compensation layer disposed on the display panel in the first non-folding area; a protective window disposed on the step compensation layer and positioned in the first non-folding area; a light transmission control layer positioned on the display panel in the second non-folding area. The thickness of the light emission control layer is equal to a sum of the thickness of the step difference compensation layer and the thickness of the protective window.

Description

display device

The present invention relates to a display device.

An electronic device such as a smart phone or a tablet PC may have a transparent display. The transparent display unit is a display unit that allows the user to see the other side (eg, the rear side) through one side (eg, the front side) of the transparent display unit. That is, on the transparent display unit, an object located in the rear is projected on the front.

Also, the electronic device may have a foldable display device in which a screen can be folded into a plurality of parts. The foldable display device may be, for example, a flexible display device. Such a foldable display provides flexibility to the display by replacing the glass substrate surrounding the liquid crystal of the organic light emitting diode (OLED) with a plastic film.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display device capable of adjusting the transmittance of light transmitted through all or part of a display surface of the display device.

Another object of the present invention is to provide a display device capable of externally recognizing an image and an image displayed on a display surface when the display device is in-folded.

The problems of the present invention are not limited to the problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an exemplary embodiment, a display device includes a first non-folding area and a second non-folding area, and a display disposed over the first non-folding area and the second non-folding area. a panel, a step compensation layer disposed on the display panel in the first non-folding area, a protective window disposed on the step compensation layer, and disposed in the first non-folding area, and the display of the second non-folding area and a light emission control layer disposed on the panel, wherein the thickness of the light emission control layer is equal to the sum of the thickness of the step difference compensation layer and the thickness of the protective window.

The light transmission control layer may include a polymer dispersed liquid crystal layer.

The refractive index anisotropy of the polymer dispersed liquid crystal layer may be 0.1 to 0.25.

The transmittance control layer may control transmittance in the range of 5% to 95%.

The display device may further include a protective film disposed on the light transmission control layer and the protective window, and disposed over the first non-folding area and the second non-folding area.

The display panel of the second non-folding area may include a display light-transmitting area including a plurality of pixels and at least one light-transmitting part.

The display panel of the second non-folding area may include a display-only area including a plurality of pixels but not including the light-transmitting part.

The display light-transmitting area may be a double-sided emission type display panel.

The display device may further include a lower step compensation layer disposed under the display-only area and a lower light-transmitting control layer disposed under the display light-transmitting area.

The thickness of the lower light transmission control layer may be the same as the thickness of the lower step compensation layer.

The light transmission control layer may have a thickness of 0.3 μm to 0.5 μm or 0.1 μm to 0.7 μm.

The light transmission control layer may include at least one liquid crystal molecule, and the refractive index anisotropy of the liquid crystal molecule may be 0.10 to 0.25.

A display device according to an exemplary embodiment includes a first non-folding area, a second non-folding area, and a folding line disposed between the first non-folding area and the second non-folding area; A display device in-folding based on a line, the display panel including a display-only area disposed in the first non-folding area and a display transmissive area disposed in the second non-folding area, and the second non-folding area a light-transmitting control layer disposed in an area, wherein the display panel includes a pixel and a light-transmitting part, wherein the light-transmitting part has a higher light transmittance than the pixel and is disposed only in the display light-transmitting area.

and an active area including a first display area overlapping the first non-folding area and a second display area overlapping the second non-folding area, wherein the resolution of the first display area is set to a resolution of the second display area may be larger than the resolution of

The pixels and the light-transmitting portion disposed in the display light-transmitting area may be alternately arranged and may have the same area.

A protective window and a step compensation layer may be further included in the first non-folding region, and a sum of a thickness of the protective window and a thickness of the step compensation layer may be equal to a thickness of the light transmission control layer.

The light transmission control layer may have a thickness of 0.3 μm to 0.5 μm or 0.1 μm to 0.7 μm.

The light transmission control layer may include at least one liquid crystal molecule, and the refractive index anisotropy of the liquid crystal molecule may be 0.10 to 0.25.

The display light-transmitting area may be a double-sided emission type display panel.

A lower step compensation layer disposed below the display-only area and a lower light emission control layer disposed below the display light transmitting area, wherein the thickness of the lower light transmission control layer may be the same as that of the lower step compensation layer can

The details of other embodiments are included in the detailed description and drawings.

A display device capable of adjusting transmittance of light transmitted through all or part of a display surface of the display device may be provided.

When the display device is in-folded, it is possible to provide a display device capable of externally recognizing an image and an image displayed on the display surface.

Effects according to the embodiments are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a perspective view of a display device according to an exemplary embodiment;
FIG. 2 is a perspective view illustrating an in-folding state of the display device of FIG. 1 according to an exemplary embodiment;
3 is a cross-sectional view of a display device according to an exemplary embodiment in an unfolded state.
4 is a cross-sectional view of a display device in an in-folded state according to an exemplary embodiment.
5 is a cross-sectional view of a pixel and a light transmitting part of a display panel according to an exemplary embodiment.
6 is a cross-sectional view of a pixel and a light transmitting part of a display panel according to another exemplary embodiment.
7 is a schematic diagram illustrating an arrangement of pixels and a light transmitting unit for each area of a display panel according to an exemplary embodiment;
8 is a cross-sectional view of a light transmission control layer according to an exemplary embodiment.
9 is a cross-sectional view illustrating an example of a light blocking device in a light blocking mode.
10 is a cross-sectional view illustrating an example of a light blocking device in a transmission mode.
11 is a graph illustrating transmittance of a light transmission control layer according to a ratio and voltage of a liquid crystal.
12 is a perspective view illustrating a display device operating in a non-folding state according to an exemplary embodiment;
13 is a perspective view illustrating a display device operating in a folded state according to an exemplary embodiment;
14 is a perspective view illustrating a change in transmittance of a second display area according to an angle between a first non-folding area and a second non-folding area of the display device according to an exemplary embodiment;
15 is a cross-sectional view of a display device according to another exemplary embodiment.
16 is a perspective view illustrating a display device operating in a non-folding state according to another exemplary embodiment;
17 is a cross-sectional view of a display device according to another exemplary embodiment.
18 is a perspective view illustrating a display device operating in a folded state according to another exemplary embodiment;
19 is a perspective view of a display device according to another exemplary embodiment.
20 is a perspective view illustrating a state in which the display device of FIG. 19 is multi-folded.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

Reference to an element or layer “on” of another element or layer includes any intervening layer or other element directly on or in the middle of the other element or layer. Like reference numerals refer to like elements throughout.

Although the first, second, etc. are used to describe various elements, these elements are not limited by these terms, of course. These terms are only used to distinguish one component from another. Accordingly, it goes without saying that the first component mentioned below may be the second component within the spirit of the present invention.

Hereinafter, specific embodiments will be described with reference to the accompanying drawings.

1 is a perspective view of a display device according to an exemplary embodiment; FIG. 2 is a perspective view illustrating an in-folding state of the display device of FIG. 1 according to an exemplary embodiment;

In the drawing, a first direction DR1 represents a horizontal direction of the display device 1 in a plan view, and a second direction DR2 represents a vertical direction of the display device 1 in a plan view. In addition, the thickness direction (third direction) represents the thickness direction of the display device 1 . The first direction DR1 and the second direction DR2 intersect perpendicularly to each other, and the thickness direction (third direction) is a direction intersecting the plane on which the first direction DR1 and the second direction DR2 are placed. Both the first direction DR1 and the second direction DR2 intersect perpendicularly. However, it should be understood that the directions mentioned in the embodiments refer to relative directions, and the embodiments are not limited to the mentioned directions.

The display device 1 displays a screen or an image through an active area AAR to be described later, and various devices including the active area AAR may be included therein. Examples of the display device 1 include, but are not limited to, a smartphone, a mobile phone, a tablet PC, a PDA (Personal Digital Assistant), a PMP (Portable Multimedia Player), a television, a game console, a wrist watch type electronic device, and a head mount. Various consumer electronics including displays, personal computer monitors, notebook computers, car navigation systems, car dashboards, digital cameras, camcorders, external billboards, electronic billboards, various medical devices, various inspection devices, active areas (AARs) such as refrigerators and washing machines, etc. , IoT devices, and the like.

The display device 1 may have a rectangular or square shape in plan view. The display device 1 may have a rectangular shape with vertical edges or a rectangular shape with rounded edges on a plane. The display device 1 may include two short sides arranged in a horizontal direction (first direction DR1 ) and two long sides arranged in a vertical direction (second direction DR2 ).

The display device 1 includes an active area AAR and a non-active area NAR. The active area AAR of the display device 1 may include a display area. Also, when the display device 1 has a touch function, a touch area, which is an area in which a touch input is sensed, may also be included in the active area AAR.

The shape of the active area AAR may correspond to the shape of the display device 1 to which the active area AAR is applied. For example, when the display device 1 is rectangular in plan view, the shape of the active area AAR may also be rectangular.

The active area AAR may include a plurality of pixels. A pixel becomes the basic unit for displaying a screen. The pixel may include, but is not limited to, a red pixel, a green pixel, and a blue pixel. The plurality of pixels may be alternately arranged on a plane. For example, the pixels may be arranged in a matrix direction, but the present invention is not limited thereto.

Each pixel may include a light emitting area (refer to 'EMA' in FIG. 5 ). The light emitting region may be defined as a region in which a light emitting material, for example, an organic light emitting layer is disposed. The size of the organic light emitting layer on a plane may be smaller than the size of the pixel. An area in the pixel in which a light emitting material such as an organic light emitting layer is not disposed may be defined as a non-emission area ('NEA' in FIG. 5 ). A circuit or wirings for driving a pixel may be disposed in the non-emission area, but is not limited thereto.

The non-active area NAR may surround the active area AAR. The non-active area NAR may include a non-display area where no display is made. The non-active area NAR may surround all sides of the active area AAR, but is not limited thereto, and the non-active area NAR may not be disposed near at least some of the four sides of the active area AAR. . The bezel area of the display device 1 may be configured as a non-active area NAR.

The active area AA may be divided into a first display area DA1 and a second display area DA2 depending on whether or not the light-transmitting part TA is included. According to an embodiment, the first display area DA1 may correspond to a portion overlapping the first non-folding area NFA1 of the active area AAR, and the second display area DA2 may be the active area AAR. ) may correspond to a portion overlapping the second non-folding area NFA2, but is not limited thereto. The first display area DA1 overlaps the display-only area (refer to '11' of FIG. 3 ) in the thickness direction (the third direction DR3 ), and the second display area DA2 is the display transmissive area (see '11 ' of FIG. 3 ). Refer to '12') and the thickness direction (third direction DR3) may overlap.

The first display area DA1 is an area that does not transmit light and only displays, and may not include a light-transmitting part (refer to 'TA' in FIGS. 5 to 7 ). The second display area DA2 is a display area while transmitting light, and may include a plurality of light transmitting parts (refer to 'TA' in FIGS. 5 to 7 ) separated from each other.

The light transmitting part (refer to 'TA' in FIGS. 5 to 7 ) is a region that does not emit light by itself, and transmits light in the thickness direction. The light may include not only light of a visible wavelength, but also light of a near-infrared and/or infrared wavelength. The light transmitted by the light-transmitting part (refer to 'TA' in FIGS. 5 to 7 ) may further include near-ultraviolet and/or ultraviolet-wavelength light.

Although the non-emission area ('NEA' in FIG. 5) of each pixel does not emit light by itself, the light-transmitting part (refer to 'TA' in FIGS. 5 to 7) has a higher light transmittance than these non-emission areas. Here, the light transmittance is the transmittance of light in a direction passing through each region and means transmittance of light traveling in the thickness direction. Accordingly, the second display area DA2 including the light-transmitting part (refer to 'TA' in FIGS. 5 to 7 ) is the first display area (see 'TA' in FIGS. 5 to 7 ) not including the light-transmitting part (see 'TA' in FIGS. 5 to 7 ). It has a higher light transmittance than DA1). The second display area DA2 may be used for various purposes. A method of using the second display area DA2 is not limited thereto, but for example, the second display area DA2 is used as a transparent display. In this case, other components are not disposed on the rear surface of the second display area DA2 , and an object positioned on the rear surface may be checked through the second display area DA2 like a window.

The display device 1 may be a foldable display device. As used herein, a foldable display device is a foldable display device, and refers to a display device that can have both a folding state and a non-folding state. In addition, folding typically includes, but is not limited to, folding at an angle of about 180°, and when the folding angle exceeds or falls short of 180°, for example, 90° or more and less than 180° or 120° or more and less than 180°. Even when it is bent at an angle, it may be understood as being folded. In addition, the folding state may be referred to as a folding state when it is in a bent state out of a non-folding state, even if complete folding is not performed. For example, even if it is bent at an angle of 90° or less, it may be expressed as being in a folded state to distinguish it from a non-folding state as long as the maximum folding angle is 90° or more.

The display device 1 may include a folding line FDA (or a folding area). The display device 1 may be folded based on the folding line FDA. Folding may be divided into in-folding, in which the display surface of the display device 1 is folded toward the inside, and out-folding, in which the display surface of the display device 1 is folded toward the outside. Although FIG. 2 illustrates a state in which the display device 1 is in-folded, the present invention is not limited thereto, and the display device 1 may be folded in an out-folding manner. Also, the display device 1 may be folded using only one of an in-folding method and an out-folding method, or both in-folding and out-folding may be performed. In the case of a display device in which both in-folding and out-folding are performed, in-folding and out-folding may be performed based on the same folding line (FDA), and different methods of folding such as in-folding dedicated folding line and out-folding dedicated folding line may be used. It may include a plurality of folding lines to perform.

The folding line FDA may have an extension direction parallel to one side of the display device 1 . For example, the folding line FDA may extend in the same direction as the vertical direction of the display device 1 (the second direction DR2 in FIG. 1 ). The folding line FDA may also have a predetermined width in the first direction DR1 . In this case, the width of the folding line FDA in the first direction DR1 may be much smaller than the width in the second direction DR2 .

The display device 1 may include a non-folding area NFA disposed around the folding line FDA. The non-folding area NFA includes a first non-folding area NFA1 positioned on one side of the first direction DR1 of the folding line FDA and a second second positioned on the other side of the first direction DR1 of the folding line FDA. A non-folding area NFA2 may be included. The width of the first non-folding area NFA1 and the second non-folding area NFA2 in the first direction DR1 may be the same, but is not limited thereto.

In an exemplary embodiment, the display device 1 may be folded by folding the display panel 10 or the layers, panels, and substrates stacked thereon, and thus the corresponding members are all flexible. In some embodiments, the display panel 10 or at least some of the members stacked thereon may have a shape separated based on the folding line FDA. In this case, the separated member positioned in the non-folding area NFA may not have a flexible characteristic.

The active area AAR/non-active area NAR and the folding line FDA/non-folding area NFA of the display device 1 described above may overlap each other at the same position. For example, the specific location may be the active area AAR and the first non-folding area NFA1 at the same time. Another specific location may be the non-active area NAR and the first non-folding area NFA1 at the same time. Another specific location may be an active area AAR and a folding line FDA arrangement area.

In an embodiment, the active area AAR of the display device 1 may be disposed over both the first non-folding area NFA1 and the second non-folding area NFA2 . Furthermore, the active area AAR may also be located in the folding line FDA corresponding to the boundary between the first non-folding area NFA1 and the second non-folding area NFA2 . That is, the active area AAR of the display device 1 may be continuously disposed regardless of boundaries of the non-folding area NFA and the folding line FDA. However, the present invention is not limited thereto, and the active area AAR may be located in only one of the first non-folding area NFA1 and the second non-folding area NFA2, and the first non-folding area NFA1 and the second non-folding area NFA2. 2 The active area AAR may be disposed in the non-folding area NFA2 , but the active area AAR may not be disposed in the folding line FDA.

Hereinafter, the cross-sectional structure of the above-described display device 1 will be described.

3 is a cross-sectional view of a display device according to an exemplary embodiment in an unfolded state. 4 is a cross-sectional view of a display device in an in-folded state according to an exemplary embodiment.

3 and 4 , the display device 1 includes a display panel 10 , a polarizing member POL sequentially stacked on one side of the display panel 10 in the thickness direction (the third direction DR3 ), and a first The step compensation layer 20 and the protective window 30 disposed in the non-folding area NFA1, the light transmission control layer 40 disposed in the second non-folding area NFA2, the protective film 50, and the display panel ( 10) may include a polymer film layer PF and a cushion layer CU sequentially stacked on the other side in the thickness direction (third direction DR3). At least one coupling member, such as an adhesive layer or an adhesive layer, may be disposed between the respective stacking members to couple adjacent stacking members. However, the present invention is not limited thereto, and another layer may be further disposed between each layer, and some of the stacking members may be omitted.

The display panel 10 is a panel for displaying a screen or an image, and examples thereof include an organic light emitting display panel (OLED), an inorganic light emitting display panel (inorganic EL), a quantum dot light emitting display panel (QED), and a micro LED display panel (micro). -LED), nano-LED display panel (nano-LED), plasma display panel (PDP), field emission display panel (FED), cathode ray display panel 10 (CRT) as well as self-luminous display panels such as liquid crystal display panels (LCD), an electrophoretic display panel (EPD), and the like). Hereinafter, an organic light emitting display panel will be described as an example of the display panel 10 , and unless a special distinction is required, the organic light emitting display panel applied to the embodiment will be simply abbreviated as a display panel. However, the embodiment is not limited to the organic light emitting display panel, and other display panels listed above or known in the art may be applied within the scope sharing the technical idea.

The display panel 10 may include a display-only area 11 disposed in the first non-folding area NFA1 and a display transmissive area 12 disposed in the second non-folding area NFA2 . The display-only area 11 may include only the pixel PX, and the display light-transmitting area 12 may include the pixel PX and the light-transmitting part (refer to 'TA' of FIGS. 5 to 7 ). The display-only area 11 and the display light-transmitting area 12 may have separate structures, and may be spaced apart from each other in the vicinity of the folding line FDA, but is not limited thereto. For example, the display-only area 11 and the display light-transmitting area 12 may be integrally formed.

Hereinafter, reference is made to FIGS. 5 to 7 to describe a detailed structure of the display panel 10 .

5 is a cross-sectional view of a pixel and a light transmitting part of a display panel according to an exemplary embodiment.

First, a cross-sectional structure of the pixel PX will be described in detail with reference to FIG. 5 . The display panel 10 includes a substrate 100 , a buffer layer 105 , a semiconductor layer 110 , a first insulating layer 121 , a first conductive layer 130 , a second insulating layer 122 , and a second conductive layer. 140 , the third insulating layer 123 , the third conductive layer 150 , the fourth insulating layer 124 , the fourth conductive layer 160 , the fifth insulating layer 125 , and the fifth conductive layer 170 . ), a pixel defining layer 126 including an opening exposing the fifth conductive layer 170 , an organic layer 190 disposed in the opening of the pixel defining layer 126 , and the organic layer 190 and the pixel defining layer 126 . ) may include a sixth conductive layer 180 disposed on it. Each of the above-described layers may be formed of a single film, but may also be formed of a laminate film including a plurality of films. Another layer may be further disposed between each layer.

The substrate 100 supports respective layers disposed thereon. The substrate 100 may be made of an insulating material such as a polymer resin. Examples of the polymer material include polyethersulphone (PES), polyacrylate (PA), polyarylate (PAR), polyetherimide (PEI), and polyethylene napthalate (PEN). ), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polycarbonate (PC), cellulose triacetate ( cellulose triacetate: CAT), cellulose acetate propionate (CAP), or a combination thereof. The substrate 100 may be a flexible substrate capable of bending, folding, rolling, or the like. Examples of the material constituting the flexible substrate include, but are not limited to, polyimide (PI).

A buffer layer 105 is disposed on the substrate 100 . The buffer layer 105 may prevent diffusion of impurity ions, prevent penetration of moisture or external air, and perform a surface planarization function. The buffer layer 105 may include silicon nitride, silicon oxide, or silicon oxynitride. The buffer layer 105 may be omitted depending on the type of the substrate 100 or process conditions.

A semiconductor layer 110 is disposed on the buffer layer 105 . The semiconductor layer 110 forms a channel of the thin film transistor of the pixel PX. The semiconductor layer 110 may include polycrystalline silicon. However, the present invention is not limited thereto, and the semiconductor layer 110 may include single crystal silicon, low-temperature polycrystalline silicon, amorphous silicon, or an oxide semiconductor. The oxide semiconductor is, for example, a binary compound (ABx), a ternary compound (ABxCy) containing indium, zinc, gallium, tin, titanium, aluminum, hafnium (Hf), zirconium (Zr), magnesium (Mg), etc. , may include a four-component compound (ABxCyDz).

The first insulating layer 121 may be a gate insulating layer having a gate insulating function. The first insulating layer 121 may include a silicon compound, a metal oxide, or the like. For example, the first insulating layer 121 may include silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, tantalum oxide, hafnium oxide, zirconium oxide, titanium oxide, or the like. These may be used alone or in combination with each other. The first insulating layer 121 may be a single layer or a multi-layered layer including stacked layers of different materials.

The first insulating layer 121 is disposed on the semiconductor layer 110 , and may generally be disposed over the entire surface of the substrate 100 .

The first conductive layer 130 is disposed on the first insulating layer 121 . The first conductive layer 130 may be a first gate conductive layer. The first conductive layer 130 may include a gate electrode 131 of the thin film transistor of the pixel PX, a scan line connected thereto, and a storage capacitor first electrode 132 .

The first conductive layer 130 includes molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium ( Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and may include one or more metals selected from copper (Cu). The first conductive layer 130 may be a single layer or a multilayer layer.

A second insulating layer 122 may be disposed on the first conductive layer 130 . The second insulating layer 122 may be an interlayer insulating layer. The second insulating layer 122 may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, or zinc oxide.

The second conductive layer 140 is disposed on the second insulating layer 122 . The second conductive layer 140 may be a second gate conductive layer. The second conductive layer 140 may include a storage capacitor second electrode 140 . The second conductive layer 140 includes molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium ( Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and may include one or more metals selected from copper (Cu). The second conductive layer 140 may be made of the same material as the first conductive layer 130 , but is not limited thereto. The second conductive layer 140 may be a single layer or a multilayer layer.

A third insulating layer 123 is disposed on the second conductive layer 140 . The third insulating layer 123 may be an interlayer insulating layer. The third insulating layer 123 may be formed of an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, polyacrylates resin, or epoxy resin. ), phenolic resin, polyamides resin, polyimides rein, unsaturated polyesters resin, polyphenylenethers resin, polyphenyl It may include an organic insulating material such as polyphenylenesulfides resin or benzocyclobutene (BCB). The third insulating layer 123 may be a single layer or a multilayer layer formed of a stack of different materials.

A third conductive layer 150 is disposed on the third insulating layer 123 . The third conductive layer 150 may be a first source/drain conductive layer. The third conductive layer 150 may include the first electrode 151 and the second electrode 152 of the thin film transistor of the pixel PX. The first electrode 151 and the second electrode 152 of the thin film transistor are connected to the semiconductor layer ( 110) may be electrically connected to the source region and the drain region. The first power voltage electrode 153 of the pixel PX may also be formed of the third conductive layer 150 .

The third conductive layer 150 includes aluminum (Al), molybdenum (Mo), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium ( Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and may include one or more metals selected from copper (Cu). The third conductive layer 150 may be a single layer or a multilayer layer. For example, the third conductive layer 150 may be formed in a stacked structure of Ti/Al/Ti, Mo/Al/Mo, Mo/AlGe/Mo, Ti/Cu, or the like.

A fourth insulating layer 124 is disposed on the third conductive layer 150 . The fourth insulating layer 124 covers the third conductive layer 150 . The fourth insulating layer 124 may be a via layer. The fourth insulating layer 124 includes acrylic resin (polyacrylates resin), epoxy resin (epoxy resin), phenolic resin (phenolic resin), polyamides resin (polyamides resin), polyimide resin (polyimides rein), unsaturated polyester It may include an organic insulating material such as unsaturated polyesters resin, polyphenyleneethers resin, polyphenylenesulfides resin, or benzocyclobutene (BCB).

A fourth conductive layer 160 is disposed on the fourth insulating layer 124 . The fourth conductive layer 160 may be a second source/drain conductive layer. The fourth conductive layer 160 may include a data line of the pixel PX, a connection electrode 162 , and first power voltage lines 161 and 163 . The first power voltage line 161 may be electrically connected to the first electrode 151 of the thin film transistor of the pixel PX through a contact hole passing through the fourth insulating layer 124 in the pixel PX. The connection electrode 162 may be electrically connected to the second electrode 152 of the thin film transistor of the pixel PX through a contact hole penetrating the fourth insulating layer 124 . The first power voltage line 163 may also be electrically connected to the first power voltage electrode 153 through a contact hole passing through the fourth insulating layer 124 .

The fourth conductive layer 160 includes aluminum (Al), molybdenum (Mo), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium ( Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and may include one or more metals selected from copper (Cu). The fourth conductive layer 160 may be a single layer or a multilayer layer. The fourth conductive layer 160 may be made of the same material as the third conductive layer 150 , but is not limited thereto.

A fifth insulating layer 125 is disposed on the fourth conductive layer 160 . The fifth insulating layer 125 covers the fourth conductive layer 160 . The fifth insulating layer 125 may be a via layer. The fifth insulating layer 125 may include the same material as the above-described fourth insulating layer 124 , or may include one or more materials selected from the exemplified materials of the fourth insulating layer 124 .

A fifth conductive layer 170 is disposed on the fifth insulating layer 125 . The anode electrode, which is the pixel electrode, may be formed of the fifth conductive layer 170 . The anode electrode is electrically connected to the connection electrode 162 made of the fourth conductive layer 160 through a contact hole penetrating the fifth insulating layer 125, and is connected to the second electrode 152 of the thin film transistor through it. can The anode electrode may at least partially overlap the emission area EMA of the pixel PX.

The fifth conductive layer 170 may be, but is not limited to, indium-tin-oxide (ITO), indium-zinc-oxide (IZO), and zinc oxide (ZnO). ), a material layer with a high work function of indium oxide (In2O3) and silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), lead (Pd), gold (Au), nickel ( Ni), neodium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), or a reflective material layer such as a mixture thereof may have a laminated structure in which layers are stacked. A layer having a high work function may be disposed above the reflective material layer and disposed close to the organic layer 190 . The fifth conductive layer 170 may have a multilayer structure of ITO/Mg, ITO/MgF, ITO/Ag, and ITO/Ag/ITO, but is not limited thereto.

A pixel defining layer 126 may be disposed on the fifth conductive layer 170 . The pixel defining layer 126 may at least partially overlap the non-emission area NEA of the pixel PX. The pixel defining layer 126 may include an opening exposing the fifth conductive layer 170 . The pixel defining layer 126 may be formed of an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, polyacrylates resin, or epoxy resin. , phenolic resin, polyamides resin, polyimides rein, unsaturated polyesters resin, polyphenylenethers resin, polyphenylene It may include an organic insulating material such as polyphenylenesulfides resin or benzocyclobutene (BCB). The pixel defining layer 126 may be a single layer or a multi-layered layer including stacked layers of different materials.

An organic layer 190 is disposed in the opening of the pixel defining layer 126 . The organic layer 190 may include an organic emission layer, a hole injection/transport layer, and an electron injection/transport layer. The organic layer 190 may overlap the emission area EMA.

A sixth conductive layer 180 is disposed on the organic layer 190 and the pixel defining layer 126 . The common electrode, the cathode electrode, may be formed of the sixth conductive layer 180 . The cathode electrode may be disposed not only in the emission area EMA of the pixel PX but also in the non-emission area NEA. That is, the cathode electrode may be disposed on the front surface of each pixel PX. The sixth conductive layer 180 is Li, Ca, LiF/Ca, LiF/Al, Al, Mg, Ag, Pt, Pd, Ni, Au Nd, Ir, Cr, BaF, Ba, or a compound or mixture thereof (eg, For example, a material layer having a small work function such as a mixture of Ag and Mg) may be included. The sixth conductive layer 180 may further include a transparent metal oxide layer disposed on the material layer having a small work function.

Although not shown in the drawings, an encapsulation layer may be disposed on the sixth conductive layer 180 . The encapsulation film may include an inorganic film. In an embodiment, the encapsulation film may include a first inorganic film, an organic film on the first inorganic film, and a second inorganic film on the organic film.

Next, the cross-sectional structure of the light transmitting part TA will be described. The light transmitting part TA has a structure in which some layers are removed from among the stacked structures of the pixels PX. Since the light-transmitting part TA is an area that does not emit light, it is possible to omit layers corresponding to the anode electrode, the organic light emitting layer, the cathode electrode, and the like. Due to the omission of the layer, the light transmitting part TA may have a higher transmittance than the pixel PX.

In detail, the sixth conductive layer 180 serving as a cathode is not disposed on the light transmitting part TA. The cathode electrode is a common electrode, and in the case of the pixel PX, the sixth conductive layer 180 is disposed over the entire area, but is removed in the light transmitting part TA to form the light transmitting opening OP. The light transmitting opening OP may be defined by the sixth conductive layer 180 . In a top-emitting panel, the cathode transmits light to some extent, but also reflects or absorbs a significant amount of light. Since the sixth conductive layer 180 serving as a cathode is not disposed in the light transmitting portion TA, transmittance higher than that of the non-emission area NEA of the pixel PX may be secured.

Also, the fifth conductive layer 170 serving as an anode electrode may not be disposed on the light transmitting part TA. In the top emission type panel, the anode electrode includes the reflective material layer as described above. In the light transmitting part TA, the fifth conductive layer 170 itself is not disposed so that light can be transmitted in the thickness direction. Also, since the organic layer 190 is not disposed on the light transmitting part TA, a higher transmittance may be maintained. Furthermore, a semiconductor layer or other conductive layer may not be disposed on the light transmitting part TA.

Accordingly, the exemplary laminated structure of the light transmitting part TA is as shown in FIG. 6A , the substrate 100 , the buffer layer 105 , the first insulating layer 121 , the second insulating layer 122 , and the third insulating layer. 123 , the fourth insulating layer 124 , the fifth insulating layer 125 , and the pixel defining layer 126 .

6 is a cross-sectional view of a pixel and a light transmitting part of a display panel according to another exemplary embodiment. 6 illustrates that insulating layers of the light transmitting part TA may be further omitted in the structure of FIG. 5 .

Referring to FIG. 6 , as shown by the solid line in FIG. 6 , in the light transmitting part TA, the pixel defining layer 126 , the fifth insulating layer 125 , the fourth insulating layer 124 , and the third insulating layer ( 123 ), the second insulating layer 122 , the first insulating layer 121 , and the buffer layer 105 are all removed, and the surface of the substrate 100 may be exposed. The light transmitting opening OP includes the sixth conductive layer 180 , the pixel defining layer 126 , the fifth insulating layer 125 , the fourth insulating layer 124 , the third insulating layer 123 , and the second insulating layer ( 122 ), the first insulating layer 121 , and the buffer layer 105 . The substrate 100 may not be removed even in the light transmitting part TA. That is, the substrate 100 may overlap the light-transmitting part TA, and may not include a through hole in the light-transmitting part TA. In the case of the embodiment of FIG. 6 , since many insulating layers are additionally removed as described above, the transmittance of the light transmitting part TA may be further improved compared to the embodiment of FIG. 5 .

As another example, as shown by a dotted line in FIG. 6 , the pixel defining layer 126 , the fifth insulating layer 125 , the fourth insulating layer 124 , the third insulating layer 123 , and the Some of the second insulating layer 122 , the first insulating layer 121 , and the buffer layer 105 may be removed. For example, although not limited thereto, all of the layers positioned above the fourth insulating layer 124 corresponding to the via layer may be removed to form the light-transmitting opening OP.

7 is a schematic diagram illustrating an arrangement of pixels and a light transmitting unit for each area of a display panel according to an exemplary embodiment.

Referring to FIG. 7 , in the present exemplary embodiment, the first display area DA1 and the second display area DA2 include a red pixel PX_R, a green pixel PX_G, and a blue pixel PX_B, respectively. In the illustrated embodiment, the size of the pixel PX for each color is the same, and the pixel PX of the first display area DA1 and the pixel PX of the second display area DA2 have the same size. The second display area DA2 further includes a light transmitting part TA in addition to the pixel PX. The size of the light transmitting part TA is the same as the size of the pixel PX, but is not limited thereto.

In the first display area DA1 , pixels PX of the same color are arranged in the second direction DR2 , and pixels PX of different colors are alternately arranged in the first direction DR1 . For example, in the first display area DA1 , the red pixel PX_R, the green pixel PX_G, the blue pixel PX_B, the red pixel PX_R, the green pixel PX_G, The blue pixels PX_B are arranged in order.

In the second display area DA2 , the pixels PX and the light transmitting part TA are alternately arranged in the first direction DR1 . Pixels PX of different colors are arranged in the first direction DR1 . For example, in the second display area DA2 , the red pixel PX_R, the light-transmitting part TA, the green pixel PX_G, the light-transmitting part TA, the blue pixel PX_B, They are arranged in the order of the light transmitting units TA. In the second direction DR2 , pixels PX of the same color are arranged or light transmitting units TA are arranged. In the second display area DA2 , the number of pixels PX and the number of the light-transmitting portions TA may be the same. Also, in the second display area DA2 , the area of the pixel PX and the area of the light transmitting part TA may be the same. That is, the area of the light transmitting part TA with respect to the total area of the second display area DA2 may be 50%.

When the pixel PX and the light-transmitting part TA are alternately arranged in the second display area DA2 (that is, when the light-transmitting part TA is mixed between the pixels PX), the pixel PX Compared to a case in which the light transmitting part TA having a large area is formed without the intervention of the light transmitting part TA, the existence of the light transmitting part TA may not be easily recognized. Accordingly, despite the presence of the light transmitting part TA, the pixels PX are alternately arranged so that the user of the display panel cannot distinguish whether the corresponding area is the first display area DA1 or the second display area DA2. screen can be displayed. At the same time, as described above, the second display area DA2 may be used as a transparent display or a light sensing path by transmitting light through the light transmitting part TA.

Meanwhile, in the embodiment of FIG. 7 , the number of pixels PX and the number of light transmitting parts TA in the second display area DA2 are the same. Assuming that each pixel PX of the first display area DA1 and the second display area DA2 and the light transmitting part TA have the same size, the pixel PX of the second display area DA2 is The number is half of the number of pixels PX in the first display area DA1 . That is, the number of pixels PX in the second display area DA2 per unit area becomes half the number of pixels PX in the first display area DA1 per unit area, so that the resolution is half. As a result, the display panel may be divided into a high resolution area having a relatively high resolution and a low resolution area having a relatively low resolution. If the high-resolution region and the low-resolution region are interspersed in the display panel 10 , in some cases, the user may recognize the corresponding region and thus the image quality may deteriorate. can lower

Referring back to FIGS. 3 and 4 , a polarizing member POL may be disposed on the display panel 10 . The polarizing member POL polarizes the passing light. The polarizing member POL may serve to reduce reflection of external light.

The step compensation layer 20 and the protective window 30 may be disposed in the first non-folding area NFA1 on the polarization member POL. Although the drawing shows that the protective window 30 is disposed on the step compensation layer 20 , the present invention is not limited thereto, and the step compensation layer 20 may be disposed on the protective window 30 . The light transmission control layer 40 may be disposed in the second non-folding area NFA2 on the polarization member POL. The light emission control layer 40 may be disposed on the same layer as the step compensation layer 20 (eg, a polarizing member POL), but is not limited thereto, and the step compensation layer 20 may be disposed on the protective window ( When disposed on the upper portion of the 30 , the light transmission control layer 40 may be disposed on the same layer as the protective window 30 . That is, the light transmission control layer 40 may be disposed outside the step compensation layer 20 and/or the protection window 30 .

The step compensation layer 20 may be made of a transparent material. The step compensation layer 20 may be in the form of a film cured after applying a resin, or may be made of transparent glass or plastic. However, the material constituting the step compensation layer 20 is not limited thereto, and may be a bonding layer disposed between the polarization layer POL and the protective window 30 . In this case, the thickness of the bonding layer disposed between the polarization layer POL and the protective window 30 may be greater than the thickness of the bonding layer disposed between the polarization layer POL and the light transmission control layer 40 .

The step compensation layer 20 compensates for a difference between the thickness of the protective window 30 disposed in the first non-folding area NFA1 and the thickness of the light transmission control layer 40 disposed in the second non-folding area NFA2. can do it Specifically, the thickness of the light transmission control layer 40 may be greater than the thickness of the protective window 30 . As the step compensation layer 20 is disposed on the protective window 30 , the thickness difference is compensated for. can do it That is, the sum of the thickness TH1 of the step compensation layer 20 and the thickness TH2 of the protective window 30 may be substantially equal to the thickness TH3 of the light transmission control layer 40 . The upper surface of the light transmission control layer 40 is at the same height as the upper surface of the protective window 30 , and may be substantially on the same plane or on an extended surface of the upper surface of the protective window 30 . Accordingly, it is possible to compensate for a step difference that may occur between the active area AAR of the first non-folding area NFA1 and the active area AAR of the second non-folding area NFA2 of the display device 1 , The user may recognize that the active area AAR of the display device 1 is entirely flat. That is, the screen displayed on the display device 1 recognized by the user may be natural without bending as a whole.

The protective window 30 may be made of a transparent material. The protective window 30 may include, for example, glass or plastic. When the protective window 30 includes glass, the glass may be Ultra Thin Glass (UTG) or thin glass. When the protective window 30 includes plastic, the plastic may be, for example, transparent polyimide, but is not limited thereto.

The light transmission control layer 40 may adjust the transmittance of light coming from the outside of the light transmission control layer 40 . Although not limited thereto, the transmittance of light passing through the light transmission control layer 40 is not limited thereto, but may be, for example, 0% to 96%. That is, the transmittance of light passing through the light transmission control layer 40 may be changed within the range of 0% to 96%. Also, the light transmission control layer 40 may have a thickness of 0.3 μm to 0.5 μm in the third direction DR3 . However, the thickness of the light transmission control layer 40 is not limited thereto and may have a thickness of 0.1 μm to 0.7 μm.

By disposing the light emission control layer 40 on the upper portion of the display panel 10 , that is, on the path of light emitted from the display panel 10 , the light emission control layer 10 can be controlled without on/off control of the display panel 10 . ) by adjusting the transmittance of the display device 1 , images and images may not be displayed in all or a part of the active area AAR of the display device 1 . That is, when the user does not want the images and images displayed on the display device 1 to be viewed by others, the transmittance of the light transmission control layer 40 is adjusted so that the images and images of the display device 1 are not viewed by others. Or, it can be made to be recognized in a unclear manner.

Hereinafter, reference is made to FIGS. 8 to 11 to describe the light transmission control layer 40 in detail.

8 is a cross-sectional view of a light transmission control layer according to an exemplary embodiment. 9 is a cross-sectional view illustrating an example of a light blocking device in a light blocking mode, and FIG. 10 is a cross-sectional view illustrating an example of a light blocking device in a transmission mode. 11 is a graph showing the transmittance of the light transmittance control layer according to the ratio of liquid crystal and the voltage.

Referring to FIG. 8 , the light emission control layer 40 includes a first liquid crystal layer substrate 410 , a first liquid crystal layer electrode 420 , a liquid crystal layer 430 , a second liquid crystal layer electrode 440 , and a second liquid crystal layer. and a layered substrate 450 .

The first liquid crystal layer substrate 410 and the second liquid crystal layer substrate 450 may be a transparent glass substrate or a plastic film. For example, the first liquid crystal layer substrate 410 and the second liquid crystal layer substrate 450 include cellulose resins such as triacetyl cellulose (TAC) or diacetyl cellulose (DAC), and COP (Norbornene derivatives). Acrylic resin such as cyclic olefin polymer), COC (cyclic olefin copolymer), PMMA (poly(methylmethacrylate)), polyolefin such as PC (polycarbonate), PE (polyethylene) or PP (polypropylene), PVA (polyvinyl alcohol) Polyester such as , PES (poly ether sulfone), PEEK (polyetheretherketone), PEI (polyetherimide), PEN (polyethylenenaphthalate), PET (polyethyleneterephthalate), PI (polyimide), PSF (polysulfone), or fluoride resin, etc. It may be a sheet or film comprising a, but is not limited thereto.

A first liquid crystal layer electrode 420 is provided on the first liquid crystal layer substrate 410 , and a second liquid crystal layer electrode 440 is provided on the second liquid crystal layer substrate 450 . The first and second electrodes 420 and 440 may be transparent electrodes. For example, the first and second electrodes 420 , 440 may be formed of silver oxide (eg, AgO or Ag2O or Ag2O3 ), aluminum oxide (eg, Al2O3 ), tungsten oxide (eg WO2 or WO3 or W2O3 ), magnesium Oxides (eg MgO), molybdenum oxides (eg MoO3), zinc oxides (eg ZnO), tin oxides (eg SnO2), indium oxides (eg In2O3), chromium oxides (eg CrO3 or Cr2O3), antimony Oxides (eg Sb2O3 or Sb2O5), titanium oxides (eg TiO2), nickel oxides (eg NiO), copper oxides (eg CuO or Cu2O), vanadium oxides (eg V2O3 or V2O5), cobalt oxides (eg; CoO), iron oxide (e.g. Fe2O3 or Fe3O4), niobium oxide (e.g. Nb2O5), indium tin oxide (e.g. Indium Tin Oxide, ITO), indium zinc oxide (e.g. Indium Zinc Oxide, IZO), aluminum doped It may be zinc oxide (eg, Aluminum doped Zinc Oxide, ZAO), aluminum doped tin oxide (eg, Aluminum Tin Oxide, TAO), or antimony tin oxide (eg, Antimony Tin Oxide, ATO), but is not limited thereto.

The liquid crystal layer 430 may be disposed between the first liquid crystal layer substrate 410 and the second liquid crystal layer substrate 450 . The liquid crystal layer 430 may be a polymer dispersed liquid crystal layer (PDLC). 8 illustrates that one liquid crystal layer 430 is disposed between the first liquid crystal layer substrate 410 and the second liquid crystal layer substrate 450, but is not limited thereto. That is, the plurality of liquid crystal layers 430 may be disposed between the first liquid crystal layer substrate 410 and the second liquid crystal layer substrate 450 . The refractive index anisotropy of the liquid crystal layer 430 is not limited thereto, but may be 0.10 to 0.25 or 0.05 to 0.30. In addition, the dielectric anisotropy of the liquid crystal layer 430 is not limited thereto, but may be 3 to 30 or 10 to 20.

The liquid crystal layer 430 includes a polymer 431 and a plurality of droplets 432 . Each of the plurality of droplets 432 may include a plurality of liquid crystals 433 (or liquid crystal molecules). That is, the plurality of liquid crystals 433 may be dispersed into a plurality of droplets 432 by the polymer 431 . The plurality of liquid crystals 433 may be nematic liquid crystals whose arrangement is changed by the vertical electric field of the first and second electrodes 420 and 440 , that is, the electric field in the third direction DR3 . not limited

Although not shown in the drawing, the plurality of droplets 432 may further include a plurality of dichroic dyes to implement a black light blocking mode. The plurality of dichroic dyes may be light-absorbing dyes. For example, the plurality of dichroic dyes may be a black dye that absorbs all light in a visible light wavelength band or a specific color (eg red) that absorbs light other than a wavelength band of a specific color (eg, red). It may be a dye that reflects light in a wavelength band of Accordingly, as the plurality of droplets 432 include the plurality of dichroic dyes, the liquid crystal layer 430 may absorb light and block the light.

The liquid crystal layer 430 may be implemented in a light blocking mode that blocks light by controlling the voltage applied to the first and second electrodes 420 and 440 or a transmission mode that transmits light. That is, by controlling the voltage applied to the first and second electrodes 420 and 440 , the light blocking and transmission modes of the light transmission control layer 40 may be varied. Hereinafter, a light blocking mode and a transmission mode of the liquid crystal layer 430 will be described in detail with reference to FIGS. 9 and 10 .

Referring to FIG. 9 , no voltage is applied to the first and second electrodes 420 and 440 , or the first voltage applied to the first liquid crystal layer electrode 420 and the second liquid crystal layer electrode 440 are applied. When the difference between the second voltages is smaller than the threshold, the plurality of liquid crystals 433 of the liquid crystal layer 430 are arranged randomly or randomly. In this case, the light incident on the liquid crystal layer 430 is scattered by the liquid crystals 433 . Accordingly, the liquid crystal layer 430 may block light incident to the light emission control layer 40 from passing through the light emission control layer 40 in the light blocking mode.

Although not shown in the drawing, the liquid crystal layer 430 may further include a voltage supply unit for supplying a predetermined voltage to each of the first and second electrodes 420 and 440 . By controlling the arrangement of the plurality of liquid crystals 433 included in the liquid crystal layer 430 according to the voltage applied to the first liquid crystal layer electrode 420 and the voltage applied to the second liquid crystal layer electrode 440 , the incident light is reduced. It may be implemented in a light blocking mode that blocks or a transmission mode that transmits incident light.

Referring to FIG. 10 , when the difference between the first voltage applied to the first liquid crystal layer electrode 420 and the second voltage applied to the second liquid crystal layer electrode 440 is greater than a threshold, the plurality of liquid crystal layers 430 is The liquid crystals 433 of the are arranged in the third direction DR3 by the vertical electric field formed between the first liquid crystal layer electrode 420 and the second liquid crystal layer electrode 440 , that is, the electric field in the third direction DR3 . do. At this time, the plurality of liquid crystals 433 are arranged in the direction in which light is incident, and since the refractive index between the polymer 431 of the liquid crystal layer 430 and the first liquid crystal 433 is minimized, the liquid crystal layer 430 is The scattering of the incident light is minimized. Accordingly, most of the light incident on the liquid crystal layer 430 may pass through the liquid crystal layer 430 as it is.

Referring to FIG. 11 , FIG. 11 is a graph showing results according to Experimental Examples 1 to 4 below, and shows that the light transmission control layer 40 may have various transmittances. Specifically, the light transmission control layer 40 may not only change into a transmission mode for transmitting light and a light blocking mode for blocking light, but also have a transmittance of 0% to 96% or 0% to 99%, , the transmittance of the light transmission control layer 40 may be adjusted within the above transmittance range. That is, the transmittance of the light-transmitting control layer 40 may be adjusted, and may vary depending on the ratio of the polymer 431 to the liquid crystal 433 and the voltage applied to the light-transmitting control layer 40 .

Hereinafter, the ratio of the liquid crystal 433 to the polymer 431 and the transmittance of the light transmission control layer 40 according to the voltage applied to the light transmission control layer 40 will be described in detail through experimental examples.

<Experimental Example 1>

The voltage applied to the light transmission control layer 40 was 10V, and the transmittance of the light transmission control layer 40 according to the ratio of the polymer 431 to the liquid crystal 433 was confirmed. The results according to Experimental Example 1 are shown in Table 1 below.

Transmittance (%) Ratio of liquid crystal to polymer (%) 95 30 90 25 85 20 80 17 75 18 70 13 65 12.5 60 11 55 10.8 50 10 45 9.5 40 8 35 7.5 30 7 25 6.5 20 6 15 5 10 2 5 One

<Experimental Example 2>

The voltage applied to the light transmission control layer 40 was 8V, and the transmittance of the light transmission control layer 40 according to the ratio of the polymer 431 to the liquid crystal 433 was confirmed. The results according to Experimental Example 1 are shown in Table 2 below.

Transmittance (%) Ratio of liquid crystal to polymer (%) 95 35 90 29 85 26 80 23 75 22 70 20 65 15 60 14 55 13.5 50 12 45 10 40 9 35 8 30 7.5 25 7 20 6.5 15 5.5 10 3 5 2

<Experimental Example 3>

The voltage applied to the light transmission control layer 40 was 5V, and the transmittance of the light transmission control layer 40 according to the ratio of the polymer 431 to the liquid crystal 433 was confirmed. The results according to Experimental Example 1 are shown in Table 3 below.

Transmittance (%) Ratio of liquid crystal to polymer (%) 95 40 90 38 85 35 80 30 75 28 70 25 65 22 60 20 55 18 50 16 45 15 40 10 35 9 30 8 25 7.5 20 7 15 6 10 5 5 3

<Experimental Example 4>

The voltage applied to the light transmission control layer 40 was 3V, and the transmittance of the light transmission control layer 40 according to the ratio of the polymer 431 to the liquid crystal 433 was confirmed. The results according to Experimental Example 1 are shown in Table 4 below.

Transmittance (%) Ratio of liquid crystal to polymer (%) 95 50 90 47 85 45 80 40 75 35 70 33 65 28 60 27 55 25 50 23 45 20 40 18 35 15 30 13 25 12 20 10 15 7 10 6 5 3

11, Experimental Examples 1 to 4 and Tables 1 to 4, the transmittance of the light transmission control layer 40 depends on the ratio of the polymer 431 to the liquid crystal 433, and the transmittance of the light transmission control layer 40 is 5 It was confirmed that it can be adjusted in the range between % and 95%.

Again, referring to FIGS. 3 and 4 , a protective film 50 may be disposed on the protective window 30 and the light transmission control layer 40 . The protective film 50 may perform at least one of scattering prevention, shock absorption, engraving prevention, fingerprint prevention, and glare prevention of the protective window 30 and the light transmission control layer 40 . The protective film 50 may be omitted.

A polymer film layer PF may be disposed under the display panel 10 . Polymer film layer (PF) is, for example, polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polysulfone (PSF), polymethyl meta acrylates (PMMA), triacetyl cellulose (TAC), cycloolefin polymers (COP), and the like.

A cushion layer CU may be disposed under the polymer film layer PF. The cushion layer CU increases durability against shocks that may be applied in the thickness direction (the third direction DR3) of the display device 1 , and when the display device 1 is dropped, it improves the drop shock. can play a role in The cushion layer CU may include polyurethane or the like.

Although not shown, a metal plate may be further disposed under the cushion layer SUB or the polymer film layer PF. The metal plate may include, for example, a metal having excellent thermal conductivity, such as copper or silver.

In order to facilitate folding of the display device 1 , some layers of the display device 1 may be separated based on the folding line FDA. For example, the protective window 30 and the light transmission control layer 40 disposed on the display panel may be separated from each other based on the folding line FDA. In this case, the protective window 30 and the light transmission control layer 40 may be spaced apart from each other in the non-folding state. In the non-folding state, the protection window 30 and the light transmission control layer 40 may each not overlap the folding line FDA, but is not limited thereto.

Although the display-only area 11 and the display light-transmitting area 12 may also be separated based on the folding line FDA, if they have sufficient ductility, regardless of the folding line FDA and the non-folding area NFA They may be connected integrally.

When the display device 1 is in-folded based on the folding line FDA, as shown in FIG. 4 , the second non-folding area NFA2 may overlap the first non-folding area NFA1 in the thickness direction. there is. The polymer film layer (PF), the cushion layer (CU), the polarizing member (POL), the protective film 50, etc. that are connected regardless of the folding line (FDA) form a cross-sectional curve along the width direction of the folding line (FDA). can be bent to achieve

As the display device 1 is in-folded based on the folding line FDA, portions adjacent to the folding line FDA of the display-only area 11 and the display transmissive area 12 are adjacent to the folding line FDA, respectively. The region may be bent to form a curve in cross-section along the width direction. In addition, portions of the protective window 30 and the light transmission control layer 40 adjacent to the folding line FDA may be bent to form a curved cross-sectional view along the width direction in an area adjacent to the folding line FDA, respectively. However, the present invention is not limited thereto, and at least a portion of the display-only area 11 , the display light-transmitting area 12 , the protective window 30 , and the light-transmitting control layer 40 may be formed by the display device 1 through the folding line FDA. Despite being in-folded as a reference, it may not be bent. Even in this case, since the display-only area 11 and the display light-transmitting area 12 and between the protection window 30 and the light-transmitting control layer 40 are spaced apart, the display device 1 can be smoothly folded. there is.

Hereinafter, reference will be made to FIG. 12 to describe an operation of the display device 1 in the non-folding state according to an exemplary embodiment.

12 is a perspective view illustrating a display device operating in a non-folding state according to an exemplary embodiment;

Referring to FIG. 12 , transmittance through which light is transmitted in the second display area DA2 of the display device 1 may vary. That is, as the transmittance through which light is transmitted in the light transmission control layer 40 is adjusted, the transmittance in the second display area DA2 may be adjusted. Accordingly, user convenience can be improved.

In more detail, since the second display area DA2 includes the display light-transmitting area 12 including the transmission part TA and the light-transmitting control layer 40 , when the light-transmitting control layer 40 is changed to the transmission mode , since light not only transmits through the display transmissive area 12 but also through the light transmittance control layer 40 , the display device 1 , specifically, the display device 1 , passes through the second display area DA2 . ), an object positioned behind the second non-folding area NFA2 may be visually recognized. In this state, the second display area DA2 may display an image and an image. That is, through the second display area DA2 , the user may visually recognize an object positioned at the rear of the display device 1 , and simultaneously view the reverse image and image displayed in the second display area DA2 . Accordingly, according to the user's convenience, the user can check the object located at the rear of the display device 1 through the second display area DA2, or check the object displayed on the second display area DA2 at the same time. Images and images can be visually recognized. In addition, by variously changing the transmittance of light through the light transmission control layer 40 , the sharpness of an object positioned at the rear of the display device 1 that can be checked through the second display area DA2 may be adjusted.

In the drawings, the image and the image displayed on the first display area DA1 are illustrated as separate images and the image displayed on the second display area DA2 , but the present invention is not limited thereto. For example, when both the first display area DA1 and the second display area DA2 display an image and an image, one image and An image may be displayed. That is, one image and one image are displayed in the entire area of the first display area DA1 and the second display area DA2, that is, the active area ( AAR) may also be indicated.

When the light transmission control layer 40 is changed to the light blocking mode, the user may no longer check the object disposed behind the display device 1 . That is, when it is not desired to visually recognize an object disposed behind the display device 1 through the second display area DA2 according to the user's convenience, the light emission control layer 40 is changed to the light blocking mode and the display device It can be changed so that the object located in the rear of (1) is no longer recognized by the user.

Hereinafter, reference is made to FIG. 13 to describe an operation of the display device 1 in a folded state according to an exemplary embodiment.

13 is a perspective view illustrating a display device operating in a folded state according to an exemplary embodiment;

Referring to FIG. 13 , transmittance through which light is transmitted in the second display area DA2 of the display device 1 may vary. That is, as the transmittance through which light is transmitted in the light transmission control layer 40 is adjusted, the transmittance in the second display area DA2 may be adjusted. Accordingly, user convenience can be improved.

More specifically, when the light transmission control layer 40 is in the light blocking mode in the in-folded state of the display device 1 , the user cannot view the image and the image displayed in the first display area DA1 . However, when the light transmission control layer 40 is changed to the transmission mode, light not only transmits through the display light transmitting area 12 , but also transmits light through the light emission control layer 40 , so that in the first display area DA1 The displayed image and image may be viewed from the outside through the rear surface of the second non-folding area NFA2. That is, the user may visually recognize the image and the image displayed in the first display area DA1 through the rear surface of the second non-folding area NFA2 . Therefore, according to the user's convenience, the user changes the light transmission control layer 40 to the transmission mode, and sees the image and the image displayed in the first display area DA1 through the rear surface of the second non-folding area NFA2. Alternatively, the light transmission control layer 40 may be changed to the light blocking mode so that the image and the image displayed in the first display area DA1 are not viewed from the outside.

Hereinafter, a change in transmittance of the light transmission control layer 40 according to an angle at which the display device 1 according to an exemplary embodiment is folded will be described.

14 is a perspective view illustrating a change in transmittance of a second display area according to an angle formed by a first non-folding area and a second non-folding area of the display device according to an exemplary embodiment;

Referring to FIG. 14 , the transmittance of light through the second display area DA2 of the display device 1 may vary depending on an angle between the first non-folding area NFA1 and the second non-folding area NFA2. there is. That is, according to the degree to which the display device 1 is folded, the transmittance through which light is transmitted through the light transmission control layer 40 may be adjusted, and user convenience may be improved.

More specifically, in the process of folding the display device 1 in the unfolded state, the angle between the first non-folding area NFA1 and the second non-folding area NFA2 may vary, and accordingly, the light transmission control layer In (40), the transmittance through which light transmits may vary. Although not limited thereto, for example, when the light transmission control layer 40 is in a light blocking mode in a non-folding state, as the display device 1 is folded, the first non-folding area NFA1 and the second non-folding area When the angle between the NFA2 is equal to or less than a predetermined angle, the light transmission control layer 40 may be changed to a transmission mode. Alternatively, the transmittance of the light transmission control layer 40 may gradually change according to an angle between the first non-folding area NFA1 and the second non-folding area NFA2 . Accordingly, the user may adjust the transmittance of the light transmission control layer 40 by simply folding the display device 1 without a separate manipulation for the user's convenience. In addition, even when the display device 1 is folded in the light-blocking state of the light emission control layer 40 , images and images displayed on the first display area DA1 in the non-folding state can be viewed through the second display area DA2 . can

In this case, although not shown in the drawing, the display device 1 may further include an angle sensing unit that detects an angle change between the first non-folding area NFA1 and the second non-folding area NFA2. The angle sensor may include, but is not limited to, a roughness sensor (not shown) and a hall sensor (not shown).

Hereinafter, another embodiment of the display device will be described. In the following embodiments, redundant descriptions are omitted or simplified for the same components as those already previously described, and differences will be mainly described.

15 is a cross-sectional view of a display device according to another exemplary embodiment. 16 is a perspective view illustrating a display device operating in a non-folding state according to another exemplary embodiment;

15 and 16 , the display device 1_1 according to the present exemplary embodiment includes a light emission control layer 40_1 , wherein the light emission control layer 40_1 is disposed below the display panel 10 . There is a difference from the 3 embodiment.

More specifically, the light emission control layer 40_1 according to the present exemplary embodiment is not disposed above the display panel 10 , that is, between the display panel 10 and the protective film 50 in the drawing, and the display panel 10 . is disposed under the display panel 10 and the polymer film layer PF. In other words, the light transmission control layer 40_1 may be disposed on the second non-folding area NFA2 and may be disposed under the display light transmission area 10 .

A step compensation layer 20_1 may be disposed on a side surface of the light transmission control layer 40_1 . That is, the step compensation layer 20_1 may be disposed on the first non-folding area NFA1 and may be disposed under the display-only area 10 . In this case, the thickness of the light-transmitting control layer 40_1 and the thickness of the step compensation layer 20_1 may be the same, and the light-emitting control layer 40_1 and the step compensation layer 20_1 are adjacent to each other in the area adjacent to the folding line FDA. may be spaced apart.

In this case, in addition to the above-described operation of the display device 1_1 in the non-folding state, when the display device 1_1 according to the present exemplary embodiment is unfolded, the display device 1_1 according to the present exemplary embodiment may additionally operate. can have more Although not limited thereto, for example, in a non-folding state of the display device 1_1 , the second display area DA2 may display an object disposed behind the display device 1_1 through the second display area DA2 . An image and an image may be displayed in the second display area DA2 while preventing visual recognition. That is, the light transmission control layer 40_1 may display an image in the second display area DA2 while in the light blocking mode.

Even in this case, the user may adjust the transmittance of light in the second display area DA2 according to the user's convenience, and the user's convenience may be improved.

17 is a cross-sectional view of a display device according to another exemplary embodiment. 18 is a perspective view illustrating a display device operating in a folded state according to another exemplary embodiment;

Referring to FIGS. 17 and 18 , the display device 1_2 according to the present exemplary embodiment further includes a lower light emission control layer 40_2, and the display light transmission area 12_2 is a double-sided emission type display panel. There is a difference from the embodiment.

More specifically, the display device 1_2 according to the present exemplary embodiment includes the light emission control layer 40 , but a lower light emission control layer disposed below the display light transmission area 12_2 in the second non-folding area NFA2. (40_2) may be further included. In addition, a lower step compensation layer 20_2 may be disposed outside the lower light transmission control layer 40_2 . That is, under the display panel 10 , the lower step compensation layer 20_2 is disposed in the second non-folding area NFA1 , and the lower light transmission control layer 40_2 is disposed in the second non-folding area NFA2 . can The lower light transmission control layer 40_2 and the lower step compensation layer 20_2 may be spaced apart from each other in the vicinity of the folding line FDA. The thickness of the lower light transmission control layer 40_2 and the thickness of the lower step compensation layer 20_2 may be the same.

In addition, the display transmissive area 12_2 according to the present exemplary embodiment may be a double-sided emission type display panel. In this case, the anode electrode 170 and the cathode electrode 180 of the display transmissive region 12_2 may be formed of a material that transmits light. Light emitted from the display transmissive area 12_2 may be directed toward upper and lower portions of the display transmissive area 12_2 . That is, light emitted from the display light-transmitting area 12_2 may be emitted from the display light-transmitting area 12_2 toward the light-transmitting control layer 40 and the lower light-transmitting control layer 40_2 .

In addition to the above-described operating state of the display device 1_2 in the in-folding state, when the display device 1_2 according to the present exemplary embodiment is in-folded, the display device 1_2 according to the present exemplary embodiment may further have an additional operating state. can Although not limited thereto, for example, when the light emission control layer 40 is in the light blocking mode and the lower light emission control layer 40_2 is in the light transmission mode, the image and the image displayed in the first display area DA1 are displayed in the second ratio. While not being viewed through the folding area NFA2 , the second non-folding area NFA2 may display an image and an image displayed in the second display area DA2 through the rear surface of the display device 1_2 . In this state, the light emission control layer 40 may be changed to the light transmission mode, and in this case, the second non-folding area NFA2 may display an image displayed in the second display area DA2 through the rear surface of the display device 1_2 and While displaying the image, the image and the image displayed in the first display area DA1 may be displayed. That is, the user may simultaneously view the image and image displayed on the first display area DA1 and the image and image displayed on the second display area DA2 . Accordingly, the user can visually recognize images and images of various types.

That is, the user may adjust the transmittance of light in the second display area DA2 according to the user's convenience, and the user's convenience may be further improved.

19 is a perspective view of a display device according to another exemplary embodiment.

20 is a perspective view illustrating a state in which the display device of FIG. 19 is multi-folded.

19 and 20 , the display device according to the present exemplary embodiment is different from the exemplary embodiment of FIG. 1 in that it includes a plurality of folding lines.

More specifically, the display device 10_3 according to the present exemplary embodiment includes a first folding line FDA1 and a second folding line FDA2 , and includes a first non-folding area NFA1 and a second non-folding area ( NFA2 ) and a third non-folding area NFA3 , and may include a first display area DA1 , a second display area DA2 , and a third display area DA3 . The first non-folding area NFA1 , the second non-folding area NFA2 , and the third non-folding area NFA3 , the first display area DA1 , the second display area DA2 , and the third display area DA3 may be divided by the first folding line FDA1 and the second folding line FDA2 , respectively.

The display device 10_3 may be folded based on the first folding line FDA1 and the second folding line FDA2 . In the drawing, the display device 10_3 is illustrated as being out-folded along the first folding line FDA1 and in-folded along the second folding line FDA2 , but the present invention is not limited thereto.

The light transmission control layer 40 and the display light transmission area 12 of the display panel 10 may be disposed in the third display area DA3 of the display device 10_3 . In this case, the user may adjust the transmittance of the third display area DA3 while the display device 10_3 is folded, and accordingly, the screen and the image displayed on the second display area DA2 may be viewed. there is.

Even in this case, the user may adjust the transmittance of light in the third display area DA3 according to the user's convenience, and the user's convenience may be improved.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. you will be able to understand Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

1: display device
10: display panel
POL: Polarizing member
20: step compensation unit
30: protection window
40: light transmission control layer
50: protective film

Claims (20)

A display device including a first non-folding area and a second non-folding area, the display device comprising:
a display panel disposed over the first non-folding area and the second non-folding area;
a step compensation layer disposed on the display panel in the first non-folding area;
a protective window disposed on the step compensation layer and positioned in the first non-folding area; and
a light transmission control layer positioned on the display panel in the second non-folding area;
A thickness of the light transmission control layer is equal to a sum of a thickness of the step difference compensation layer and a thickness of the protective window. According to claim 1,
The light transmission control layer includes a polymer dispersed liquid crystal layer. 3. The method of claim 2,
The refractive index anisotropy of the polymer dispersed liquid crystal layer is 0.1 to 0.25. According to claim 1,
The transmittance control layer controls transmittance in a range of 5% to 95%. According to claim 1,
and a protective film disposed on the light transmission control layer and the protective window, and disposed over the first non-folding area and the second non-folding area. According to claim 1,
The display panel of the second non-folding area includes a display light-transmitting area including a plurality of pixels and at least one light-transmitting part. 7. The method of claim 6,
The display panel of the second non-folding area includes a display-only area including a plurality of pixels but not including the light-transmitting part. 7. The method of claim 6,
The display light transmitting area is a double-sided light emitting display panel. 9. The method of claim 8,
The display device further comprising: a lower step compensation layer disposed under the display-only area; and a lower light emission control layer disposed under the display light-transmitting area. 10. The method of claim 9,
A thickness of the lower light emission control layer is the same as a thickness of the lower step compensation layer. According to claim 1,
The thickness of the light transmission control layer is 0.3 μm to 0.5 μm or 0.1 μm to 0.7 μm. 12. The method of claim 11,
The light transmission control layer includes at least one liquid crystal molecule, and the refractive index anisotropy of the liquid crystal molecule is 0.10 to 0.25. A display device comprising: a first non-folding area; a second non-folding area;
a display panel including a display-only area disposed in the first non-folding area and a display transmissive area disposed in the second non-folding area; and
a light transmission control layer disposed on the second non-folding area;
The display panel includes a pixel and a light-transmitting part, wherein the light-transmitting part has a higher light transmittance than the pixel and is disposed only in the display light-transmitting area. 14. The method of claim 13,
and an active area including a first display area overlapping the first non-folding area and a second display area overlapping the second non-folding area, wherein a resolution of the first display area is set to a resolution of the second display area A display device that is larger than the resolution of the device. 14. The method of claim 13,
The pixels and the light-transmitting portions disposed in the display light-transmitting area are alternately arranged and have the same area. 14. The method of claim 13,
The display device further includes a protective window and a step compensation layer in the first non-folding region, wherein a sum of a thickness of the protective window and a thickness of the step compensation layer is equal to a thickness of the light transmission control layer. 14. The method of claim 13,
The thickness of the light transmission control layer is 0.3 μm to 0.5 μm or 0.1 μm to 0.7 μm. 18. The method of claim 17,
The light transmission control layer includes at least one liquid crystal molecule, and the refractive index anisotropy of the liquid crystal molecule is 0.10 to 0.25. 14. The method of claim 13,
The display light transmitting area is a double-sided light emitting display panel. 20. The method of claim 19,
A display further comprising: a lower step compensation layer disposed under the display-only area and a lower light emission control layer disposed under the display light transmitting area, wherein the thickness of the lower light transmission control layer is the same as the thickness of the lower step compensation layer Device.

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