Patent Publication Number: US-2022238821-A1

Title: Display device having a support plate

Description:
This application claims priority to Korean Patent Application No. 10-2021-0011293, filed on Jan. 27, 2021 in the Korean Intellectual Property Office, the disclosure of which is herein incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a display device and, more specifically, to a display device including a support plate. 
     DISCUSSION OF THE RELATED ART 
     Display devices are frequently used to display many different types of information. For example, display devices are being employed by a variety of electronic devices such as smart phones, digital cameras, laptop computers, satellite navigation devices, and smart televisions. 
     Recently, flexible display devices have been introduced to provide a wide display screen while providing for a more portable form factor when not in use. For example, a bendable display device in which the display panel can be bent, a rollable display device in which the display panel can be rolled, and a foldable display device in which the display panel can be folded, etc. are under the development. 
     Many display devices incorporate elements for detecting a touch, such as a touch of a user&#39;s finger or that of an electronic stylus pen, particularly, an active stylus. By using a touch input with an electronic stylus pen, such a display device can sense the touch input more precisely than a display device using only a touch input by a part of the user&#39;s body, such as a finger. 
     SUMMARY 
     A display device includes a display panel having a front surface where images are displayed; a rear-side layer disposed on a rear surface of the display panel, including a plurality of conductive patterns and having first surface unevenness on a front surface thereof; and a support plate disposed between the display panel and the rear-side layer and having a flat surface on a front surface thereof, wherein the support plate includes glass or ceramic. 
     A display device includes a display panel having a front surface where images are displayed and including a folding area that is bendable and a first non-folding area extended from a first folding line disposed on one side of the folding area; a rear-side layer disposed on a rear surface of the display panel and having first surface unevenness on a front surface thereof; and a support plate disposed between the display panel and the rear-side layer and including a pattern portion overlapping the folding area and including a plurality of openings, and a first flat portion overlapping the first non-folding area and having a flat surface on a front surface thereof. 
     A display device includes a front stack structure; a rear stack structure; and a display panel disposed between the front stack structure and the rear stack structure and having a display area and a non-display area at least partially surrounding the display area, the display panel further having a folding area and a non-folding area disposed on two opposite sides of the folding area. The rear stack structure includes a plurality of conductive patterns having an uneven surface and a support plate comprising glass or ceramic. 
     The front stack structure may include a window, a window protection film, and a polarizing film. The rear stack structure may further include a panel-bottom protection film, a buffer layer, a digitizer layer, a shielding layer, and a heat dissipation layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects and features of the present disclosure will become more apparent by describing in detail embodiments thereof with reference to the attached drawings, in which: 
         FIG. 1  is a perspective view of a display device according to an embodiment of the present disclosure when the display device is in an unfolded state; 
         FIG. 2  is a perspective view showing the display device of  FIG. 1  when it is in a folded state; 
         FIG. 3  is a perspective view of a display device according to an embodiment of the present disclosure when it is in an unfolded state; 
         FIG. 4  is a perspective view showing the display device of  FIG. 3  when it is in a folded state; 
         FIG. 5  is a schematic cross-sectional view, taken along line V-V′ of  FIG. 1 ; 
         FIG. 6  is a cross-sectional view showing an example of the display panel of  FIG. 5 ; 
         FIG. 7  is an exploded, perspective view of the display device according to the structure of  FIG. 5 ; 
         FIG. 8  is a cross-sectional view showing an example of a display device taken along line VII-VII′ of  FIG. 7 ; 
         FIG. 9  is an exploded perspective view showing an example of the first digitizer layer of  FIG. 7 ; 
         FIG. 10  is a cross-sectional view showing an example of the first digitizer layer, taken along line IX-IX′ of  FIG. 9 ; 
         FIG. 11  is a perspective view showing an example of the support plate of  FIG. 8 ; 
         FIG. 12  is a side view of the folding area of the support plate of  FIG. 11 ; 
         FIG. 13  is a plan view of the support plate of  FIG. 11 ; 
         FIG. 14  is an enlarged view of area A of  FIG. 13 . 
         FIG. 15  is a flowchart illustrating an example of a method of fabricating the support plate of  FIG. 11 ; 
         FIG. 16  is a plan view showing the process of forming a pattern on a glass plate using a laser of  FIG. 15 ; 
         FIG. 17  is a cross-sectional view of a display device according to an embodiment of the present disclosure; 
         FIG. 18  is a cross-sectional view of a display device according to an embodiment of the present disclosure; 
         FIG. 19  is a cross-sectional view of a display device according to an embodiment of the present disclosure; and 
         FIG. 20  is a perspective view of the support plate of  FIG. 19 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Specific structural and functional descriptions of embodiments of the invention disclosed herein are provided for illustrative purposes. The invention may be embodied in many different forms without departing from the spirit and significant characteristics of the present disclosure. Therefore, the embodiments of the invention disclosed herein are not necessarily limiting on the invention. 
     It will be understood that when an element is referred to as being related to another element such as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or intervening elements may be present therebetween. In contrast, it should be understood that when an element is referred to as being related to another element such as being “directly coupled” or “directly connected” to another element, there are no intervening elements present. Other expressions that explain the relationship between elements, such as “between,” “directly between,” “adjacent to,” or “directly adjacent to,” should be construed in the same way. 
     Throughout the specification and drawings, the same reference numerals may refer to the same or like parts. 
     It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not necessarily be limited by these terms. These terms are only to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein. 
     As used herein, “a”, “an,” “the,” and “at least one” do not denote a limitation of quantity, and are intended to include both the singular and plural, unless the context clearly indicates otherwise. For example, “an element” has the same meaning as “at least one element,” unless the context clearly indicates otherwise. “At least one” is not to be construed as limiting “a” or “an.” “Or” means “and/or.” As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. 
     Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element&#39;s relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below. 
     However, it is noted that when one structure is said to have a top surface and a bottom surface, other structures may share a common frame of reference and so top surfaces and bottom surfaces thereof may be in the same direction as the top and bottom surfaces of the one structure, respectively. For example, all top surfaces may point in a first direction and all bottom surfaces may point in a second direction that is opposite to the first direction. 
     “About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” or “approximately” can mean within one or more standard deviations, or within ±30%, 20%, 10% or 5% of the stated value. 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a perspective view of a display device according to an embodiment of the present disclosure when the display device is in an unfolded state.  FIG. 2  is a perspective view showing the display device of  FIG. 1  when it is in a folded state. 
     A display device  10  displays images and videos in a display area DA. The display device  10  may be included within a smart phone, a mobile phone, a tablet computer, a personal digital assistant (PDA), a portable multimedia player (PMP), a television set, a game console, a wristwatch-type wearable electronic device, a head-mounted display, a personal computer monitor, a laptop computer, a vehicle satellite navigation system, a car instrument cluster, a digital camera, a camcorder, an outdoor billboard, an electronic billboard, various medical apparatuses, various inspection devices, various home appliances including a display area such as a refrigerator and a laundry machine, and/or Internet of things (IoT) devices, etc. Examples of the foldable display device to be described later include, but are not necessarily limited to including, a foldable smartphone, a tablet computer, a laptop computer, etc. 
     As shown in  FIGS. 1 and 2 , a first direction X may refer to a direction parallel to a side of the display device  10 , for example, the horizontal direction of the display device  10 , when viewed from the top. A second direction Y may refer to a direction parallel to another side of the display device  10  that meet the side of the display device  10 , for example, the vertical direction of the display device  10 , when viewed from the top. A third direction Z may refer to the thickness direction of the display device  10 . 
     The display device  10  may have a substantially rectangular shape or a square shape when viewed from the top. The display device  10  may be a rectangle having right-angular corners or rounded corners, when viewed from the top. The display device  10  may include four sides or edges. The display device  10  may include a pair of shorter sides extended in the first direction X and a pair of longer sides extended in the second direction Y, when viewed from the top. 
     As used herein, the term “extended in a direction” means that a longest dimension of the element is arranged in the indicated direction. 
     The display device  10  may include a front surface and a rear surface. As used herein, the front surface may refer to a surface (first surface) located on one side of one plane, and the rear surface may refer to a surface (second surface; the opposite surface) located on the opposite side of the plane. For example, when the front surface refers to the upper surface of an element, the rear surface refers to the lower surface of the element. 
     At least one of the front surface and the rear surface of the display device  10  may be a display surface. According to an embodiment of the present disclosure, the display surface may be located on the front surface of the display device  10 , and no image may be displayed on the rear surface. In the following description, images are displayed only on the front surface of the display devices according to the embodiments of the present disclosure. It is, however, to be understood that the display device may be a double-sided display device in which images are displayed on both front and rear surfaces. 
     The display device  10  may be divided into a display area DA for displaying an image or a video and a non-display area NDA disposed around the display area DA, when viewed from the top, depending on whether images are displayed or not. 
     The display area DA may include a plurality of pixels. Each of the pixels is a unit for displaying an image. The pixels may include, but is not necessarily limited to including, a red pixel, a green pixel, and a blue pixel. The pixels may further include a white pixel. A plurality of pixels may be arranged sequentially and repeatedly when viewed from the top. For example, the pixels may be arranged in, but is not necessarily limited to, a matrix. The pixels may be disposed exclusively within the display area DA and there might be no pixels within the non-display area NDA. 
     The non-display area NDA may be proximate to the display area DA. A black matrix is disposed in the non-display area NDA to prevent leakage of light from adjacent pixels. 
     The non-display area NDA may at least partially surround the display area DA as shown in  FIGS. 1 and 2 . For example, the display area DA may have a rectangular shape, and the non-display area NDA may be disposed along each of the four sides of the display area DA. It is, however, to be understood that the present disclosure is not necessarily limited thereto. The display area DA may be partially surrounded by the non-display area NDA. For example, the non-display area NDA may be disposed only along three sides of the display area DA. In such case, the other side of the display area DA may form an edge of the display device  10 . 
     The display device  10  may be a foldable device. As used herein, a foldable display device refers to a display device that can be folded to a noticeable extent (such as one in which opposite ends meet each other) without cracking or otherwise breaking and can be repeatedly switched between a folded state and an unfolded state. 
     The display device  10  may include a folding area FDA, a first non-folding area NFA 1 , and a second non-folding area NFA 2 . The display device  10  can be bent or folded at the folding area FDA, while it cannot be bent or folded at the first non-folding area NFA 1  and the second non-folding area NFA 2 . 
     Thus, the folding area FDA is bendable while the first and second non-folding areas NFA 1  and NFA 2  are not bendable. As used herein, the phrase “bendable” means that the element may be bent, folded, flexed, or rolled, to a non-trivial and visible extent without cracking or otherwise breaking. 
     The first non-folding area NFA 1  may be disposed on one side of the folding area FDA, and the second non-folding area NFA 2  may be disposed on the opposite side of the folding area FDA. 
     The folding area FDA may be defined by a first folding line FL 1  and a second folding line FL 2  and may be bent or folded. The first folding line FL 1  may be the boundary between the folding area FDA and the first non-folding area NFA 1 , and the second folding line FL 2  may be the boundary between the folding area FDA and the second non-folding area NFA 2 . 
     The first folding line FL 1  and the second folding line FL 2  may be extended in parallel in the first direction X. The first folding line FL 1  and the second folding line FL 2  may traverse the display device  10  along the first direction X. The first folding line FL 1  and the second folding line FL 2  may have a predetermined interval along the extension direction. According to the embodiment of  FIGS. 1 and 2 , the display device  10  can be folded in the second direction Y. As a result, the width of the display device  10  in the second direction Y may be reduced to about half, so that the display device  10  is easier to carry than when the device is in the non-folded state. 
     The length of the first folding line FL 1  may be equal to the length of the second folding line FL 2 . The length may be equal to the width of the folding area FDA in the first direction X. The width of the first non-folding area NFA 1  in the first direction X may be equal to that of the second non-folding area NFA 2 . The width of the non-folding areas may be equal to the width of the folding area FDA in the first direction X. 
     When the first folding line FL 1  and the second folding line FL 2  are extended in the first direction X, the width of the folding area FDA in the second direction Y may be smaller than the width in the first direction X. 
     The width of the folding area FDA in the second direction Y may be smaller than the width of the first non-folding area NFA 1  and the width of the second non-folding area NFA 2  in the second direction Y. 
     The width of the first non-folding area NFA 1  may be, but is not necessarily limited to being, equal to that of the second non-folding area NFA 2  in the second direction Y. In some embodiments, the widths of the first non-folding area NFA 1  and the second non-folding area NFA 2  in the second direction Y may be larger than the widths of the first non-folding area NFA 1  and the second non-folding area NFA 2  in the first direction X, respectively. It is, however, to be understood that the present disclosure is not necessarily limited thereto. 
     Each of the display area DA and the non-display area NDA may overlap at least one of the folding area FDA, the first non-folding area NFA 1 , and the second non-folding area NFA 2 . In the example shown in  FIGS. 1 and 2 , each of the display area DA and the non-display area NDA overlaps the folding area FDA, the first non-folding area NFA 1  and the second non-folding area NFA 2 . As shown in  FIGS. 1 and 2 , the display area DA may be continuously disposed regardless of the boundaries of the non-folding areas NFA 1  and NFA 2  and the folding lines FL 1  and FL 2 . It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the display area DA may be disposed in the first non-folding area NFA 1  while the display area DA might not be disposed in the second non-folding area NFA 2 . The display area DA may be disposed in the first non-folding area NFA 1  and the second non-folding area NFA 2  while the display area DA might not be disposed on at least one of the folding lines FL 1  and FL 2 . 
     According to an embodiment of the present disclosure, the display device  10  can be folded as the display panel  1000  (see  FIG. 5 ) or a layer, a panel and a substrate stacked thereon have flexibility so that they all are each able to be folded. According to some embodiments of the present disclosure, the display panel  1000  or at least some of the elements stacked thereon may be disconnected where they overlap the folding line FDA. The disconnected elements located in the non-folding areas NFA 1  and NFA 2 , respectively, might not have flexible characteristics. 
       FIG. 3  is a perspective view of a display device according to an embodiment of the present disclosure when it is in an unfolded state.  FIG. 4  is a perspective view showing the display device of  FIG. 3  when it is in a folded state. 
     The embodiment of  FIGS. 3 and 4  is substantially identical to the embodiment of  FIGS. 1 and 2  except that a first folding line FL 1  and a second folding line FL 2  are extended in the second direction Y and the display device  11  can be folded in the first direction X, so that the width of the display device  11  in the first direction X can be reduced by approximately half, which is convenient for the user to carry the display device  11  when it is in the folded state. The following description will focus on the difference and it is to be understood that elements not described here are at least similar to corresponding elements that have been described elsewhere in the instant disclosure. 
     Referring to  FIGS. 3 and 4 , the first folding line FL 1  and the second folding line FL 2  of the display device may be extended in parallel in the second direction Y. The first folding line FL 1  and the second folding line FL 2  may traverse the display device  11  along the second direction Y. The first folding line FL 1  and the second folding line FL 2  may have a predetermined interval along the extension direction. According to the embodiment of  FIGS. 3 and 4 , the display device can be folded in the first direction X. As a result, the width of the display device in the first direction X may be reduced to about half, so that the display device is easy to carry when in the folded state. 
     When the first folding line FL 1  and the second folding line FL 2  are extended in the second direction Y, the width of the folding area FDA in the first direction X may be smaller than the width in the second direction Y. 
     The width of the folding area FDA in the first direction X may be smaller than the width of the first non-folding area NFA 1  and the width of the second non-folding area NFA 2  in the first direction X. 
     Hereinafter, a panel, a film, a member, etc. forming the above-described display device will be described in detail. 
       FIG. 5  is a schematic cross-sectional view, taken along line V-V′ of  FIG. 1 . 
     Referring to  FIG. 5 , a display device  10  according to an embodiment includes a display panel  1000 , a front stack structure  2000  disposed on the front surface of the display panel  1000 , and a rear stack structure  3000  disposed on the rear surface of the display panel  1000 . 
     The display panel  1000  displays images and may include a self-luminous display panel such as an organic light-emitting display panel (OLED), an inorganic light-emitting display panel (inorganic EL), a quantum-dot light-emitting display panel (QED), a micro LED display panel (micro-LED), a nano LED display panel (nano-LED), a plasma display panel (PDP), a field emission display panel (FED) and a cathode ray display panel (CRT), as well as a light-receiving display panel such as a liquid-crystal display panel (LCD) and an electrophoretic display panel (EPD) In the following description, the organic light-emitting display panel will be described as an example of the display panel  1000 , and the organic light-emitting display panel will be simply referred to as the display panel  1000  unless specifically stated otherwise. It is, however, to be understood that the embodiments of the present disclosure are not necessarily limited to the organic light-emitting display panel, and any other display panel listed above or well known in the art may be employed without departing from the scope of the present disclosure. 
       FIG. 6  is a cross-sectional view showing an example of the display panel of  FIG. 5 . 
     Referring to  FIG. 6 , the display panel  1000  may include a substrate SUB, a circuit driving layer DRL disposed on the substrate SUB, an emissive layer EML disposed on the circuit driving layer DRL, an encapsulation layer ENL disposed on the emissive layer EML, and a touch layer TSL disposed on the encapsulation layer ENL. 
     The substrate SUB may be a flexible substrate including a flexible polymer material such as polyimide. Accordingly, the display panel  1000  may be curved, bent, folded, or rolled. In some embodiments, the substrate SUB may include a plurality of sub-substrates overlapping one another in the thickness direction with barrier layers disposed therebetween. In such a case, each of the sub-substrates may be a flexible substrate. 
     The circuit-driving layer DRL may be disposed on the substrate SUB. The circuit-driving layer DRL may include a circuit for driving an emissive layer EML of each pixel. The circuit-driving layer DRL may include a plurality of thin-film transistors. 
     The emissive layer EML may be disposed on the circuit-driving layer DRL. The emissive layer EML may include an organic emitting layer. The emissive layer EML may emit light with various luminances depending on driving signals transmitted from the circuit-driving layer DRL. 
     The encapsulation layer ENL may be disposed on the emissive layer EML. The encapsulation layer ENL may include at least one inorganic layer to prevent permeation of oxygen or moisture into the emissive layer EML. In addition, the encapsulation layer ENL may include at least one organic film to protect the emissive layer EML from particles such as dust. 
     The touch layer TSL may be disposed on the encapsulation layer ENL. The touch layer TSL may sense a touch input and may perform the functions of a touch sensor. The touch layer TSL may include a plurality of sensing regions and sensing electrodes. 
     Although the touch sensor is integrated into the display panel  1000  in the form of the touch layer TSL in the example of  FIG. 6 , the present disclosure is not necessarily limited thereto. For example, the touch sensor may be implemented as a panel or film separate from the display panel  1000  and attached to the display panel  1000 . In addition, the touch sensor may be omitted. 
     Referring back to  FIG. 5 , the front stack structure  2000  may be disposed on the front surface of the display panel  1000  where images are displayed. The rear stack structure  3000  may be disposed on the rear surface of the display panel  1000 . The front stack structure  2000  and the rear stack structure  3000  may each include layers performing different functions. An example of the arrangement of the display panel  1000  and the stack structures  2000  and  3000  are shown in  FIGS. 7 and 8 . 
       FIG. 7  is an exploded, perspective view of the display device according to the embodiment of  FIG. 5 .  FIG. 8  is a cross-sectional view showing an example of a display device taken along line VII-VII′ of  FIG. 7 . 
     Referring to  FIGS. 7 and 8 , the front stack structure  2000  may include, for example, a window  2200 , a window protection film  2300 , a polarizing film  2100  and/or adhesive layers attaching them together. The rear stack structure  3000  disposed on the rear surface of the display panel  1000  where no image is displayed may include a panel-bottom protection film  3100 , a support plate  3200 , a buffer layer  3400 , a digitizer layer  3300 , a shielding layer  3500  and/or a heat dissipation layer  3600 . 
     More specifically, the polarizing film  2100  may be attached on the front surface of the display panel  1000  by a first adhesive layer AD 1 . The polarizing film  2100  can reduce reflection of external light. 
     A window  2200  may be disposed on the polarizing film  2100 . The window  2200  may be made of a transparent material, and may include, for example, glass or plastic. When the window  2200  includes glass, an ultra thin glass (UTG) having a thickness of 0.1 mm or less may be employed in order to have flexible properties. When the window  2200  is made of plastic, the window  2200  may include, but is not necessarily limited to, a transparent polyimide film. The window  2200  may be attached to the front surface of the polarizing film  2100  by a second adhesive layer AD 2 . 
     The window protection film  2300  is disposed on the window  2200 . The window protection film  2300  may be attached to the front surface of the window  2200  by a third adhesive layer AD 3 . The window protection film  2300  may perform at least one function including anti-scattering when the window  2200  is broken, shock absorption, anti-scratch, anti-fingerprint, and anti-glare. The window protection film  2300  may be made of a resin or a film having flexible properties. 
     Each of the first to third adhesive layers AD 1 , AD 2  and AD 3  may include a transparent adhesive film or a transparent adhesive resin. 
     The front stack structure  2000  may further include a light-blocking layer  2400 . The light-blocking layer  2400  may be disposed in the non-display area NDA. The light-blocking layer  2400  may include a material that can block light. For example, the light-blocking layer  2400  may include an inorganic black pigment such as carbon black or an organic black pigment. Although the light-blocking layer  2400  is formed on the rear surface of the window protection film  2300  in the drawings, the present disclosure is not necessarily limited thereto. The light-blocking layer  2400  may be disposed on the front and/or rear surface of the window  2200 , or may be disposed on the front surface of the window protection film  2300 . 
     All of the elements of the above-described front stack structure  2000  may be disposed across the first non-folding area NFA 1 , the folding area FDA, and the second non-folding area NFA 2  of the display device  10 . When the display device  10  is in a folded state, the front stack structure  2000  is folded together. Accordingly, all of the layers of the front stack structure  2000  may be formed of a foldable material or structure. Unlike the rear stack structure  3000  to be described later, the front stack structure  2000  disposed on the front surface of the display panel  1000  where images are displayed may have the same thickness and shape in the folding area FDA as well as the first non-folding area NFA 1  and the first non-folding area NFA 1 . It is, however, to be understood that the embodiments of the present disclosure are not necessarily limited thereto. 
     The panel-bottom protection film  3100  may be disposed on the rear surface of the display panel  1000 . The panel-bottom protection film  3100  may be attached to the rear surface of the display panel  1000  by a fourth adhesive layer AD 4 . The panel-bottom protection film  3100  can support the display panel  1000  and protect the rear surface of the display panel  1000 . The panel-bottom protection film  3100  may include, but is not necessarily limited to including, a plastic film such as a polyethylene terephthalate (PET) film. 
     Although the panel-bottom protection film  3100  is integrally formed and disposed in the first non-folding area NFA 1 , the folding area FDA and the second non-folding area NFA 2  in the example shown in  FIGS. 7 and 8 , the present disclosure is not necessarily limited thereto. For example, the panel-bottom protection film  3100  may be disconnected at the folding area FDA and disposed in the first non-folding area NFA 1  and the second non-folding area NFA 2  in order to facilitate the folding of the display device  10 . 
     The digitizer layer  3300  may be disposed on the rear surface of the panel-bottom protection film  3100 . The digitizer layer  3300  may include electrodes for sensing proximity or contact of an electronic stylus pen such as an active stylus pen supporting an electromagnetic resonance (EMR) technology. The electrodes may be implemented as a conductive pattern including a conductive material such as a metal. The conductive patterns of the digitizer layer  3300  may sense a magnetic field or an electromagnetic signal. For example, when an electronic stylus pen is placed on the front surface of the display device  10  and a magnetic field or an electromagnetic signal is generated through the electronic stylus pen, the generated magnetic field or electromagnetic signal may be input to the conductive patterns of the digitizer layer  3300 . The digitizer layer  3300  may determine coordinates input by the electronic stylus pen by analyzing the magnitude of the magnetic field or electromagnetic signal input for each location. 
     The digitizer layer  3300  may be disconnected at the folding area FDA in order to facilitate folding of the display device  10 . In such case, the digitizer layer  3300  may include a first digitizer layer  3310  disposed in the first non-folding area NFA 1  and a second digitizer layer  3320  disposed in the second non-folding area NFA 2 . The distance between the first digitizer layer  3310  and the second digitizer layer  3320  in the second direction Y may be smaller than the width of the folding area FDA in the second direction Y. According to this structure, the display device  10  can be smoothly folded, while an area not detected by the electronic stylus pen in the folding area FDA can be reduced. 
     Although the digitizer layer  3300  overlaps with the non-display areas NDA 1  and NDA 2  at least partially in the example shown in  FIG. 8 , the present disclosure is not necessarily limited thereto. For example, the digitizer layer  3300  may overlap with the display area DA but not with the non-display area NDA. 
     Hereinafter, the structure of the digitizer layer  3300  will be described in more detail with reference to  FIGS. 9 and 10 . Hereinafter, only the structure of the first digitizer layer  3310  will be described for convenience of illustration. It is to be understood that the second digitizer layer  3320  may also have substantially the same structure. 
       FIG. 9  is an exploded perspective view showing an example of the first digitizer layer of  FIG. 7 .  FIG. 10  is a cross-sectional view showing an example of the first digitizer layer, taken along line IX-IX′ of  FIG. 9 . 
     As shown in  FIGS. 9 and 10 , the first digitizer layer  3310  may include a first base layer  3311 , first conductive patterns  3312  disposed on the front surface of the first base layer  3311 , a first adhesive layer  3314  disposed on the front surface of the first conductive patterns  3312 , a first cover layer  3316  disposed on the front surface of the first adhesive layer  3314 , second conductive patterns  3313  disposed on the rear surface of the first base layer  3311 , a second adhesive layer  3315  disposed on the rear surface of the second conductive patterns  3313 , and a second cover layer  3317  disposed on the rear surface of the second adhesive layer  3315 . 
     The base layer  3311  serves as a substrate on which the first conductive patterns  3312  and the second conductive patterns  3313  are disposed. The base layer  3311  may include an insulating material. For example, the base layer  3311  may include, but is not necessarily limited to including, polyimide. 
     The first conductive patterns  3312  may be disposed on the front surface of the base layer  3311 . Each of the first conductive patterns  3312  and the second conductive patterns  3313  may include a metal material such as copper (Cu), silver (Ag), nickel (Ni) and/or tungsten (W). 
     Each of the first conductive patterns  3312  may be extended in the first direction X. The plurality of first conductive patterns  3312  may be arranged in the second direction Y. Each of the first conductive patterns  3312  may have a shape of a closed loop structure (e.g., a rectangle) when viewed from the top. 
     The second conductive patterns  3313  may be disposed on the rear surface of the base layer  3311 . Each of the second conductive patterns  3313  may be extended in the second direction Y. The plurality of second conductive patterns  3313  may be arranged in the first direction X. Each of the second conductive patterns  3313  may have a shape of a closed loop structure (e.g., a rectangle) when viewed from the top. 
     The first conductive patterns  3312  and the second conductive patterns  3313  may cross each other when viewed from the top. The magnetic field or electromagnetic signal output from the electronic stylus pen may be absorbed by the first conductive patterns  3312  and the second conductive patterns  3313 . It is possible to determine which position of the first digitizer layer  3310  the electronic stylus pen is closest to based on the conductive patterns crossing one another. 
     In some embodiments, at least some of the first conductive patterns  3312  and the second conductive patterns  3313  may generate magnetic field upon receiving an input current, and the generated magnetic field or electromagnetic signal may be absorbed by the electronic stylus pen. The electronic stylus pen may output the absorbed magnetic field again, and the magnetic field output by the electronic stylus pen may be absorbed by the first conductive patterns  3312  and the second conductive patterns  3313 . The first conductive patterns  3312  and the second conductive patterns  3313  may convert the magnetic field or the electromagnetic signal output from the electronic stylus pen into an electric signal. 
     When the first conductive patterns  3312  have a rectangular closed loop structure when viewed from the top, the distance between sides of a rectangle facing each other may be greater than the distance between adjacent rectangles. Accordingly, the density of the first conductive patterns  3312  may vary along the second direction Y. For example, the first conductive patterns  3312  may have a higher density between adjacent rectangles, while may have a lower density in one rectangle. The area where the first conductive pattern  3312  is disposed protrudes by the thickness of the first conductive pattern  3312  from the area where the first conductive pattern  3312  is not disposed, and thus level differences are formed on the surface. 
     The second conductive patterns  3313  also have an arrangement similar to that of the first conductive patterns  3312 . For example, the distance between the sides of one rectangle that face each other is larger than the distance between adjacent rectangles, so that the density of the second conductive patterns  3313  may vary along the first direction X. 
     Although each of the first conductive patterns  3312  and the second conductive patterns  3313  has a rectangular loop structure when viewed from the top in the example shown in  FIG. 9 , embodiments of the present disclosure are not necessarily limited thereto. Each of the first conductive patterns  3312  and the second conductive patterns  3313  may have a variety of types of loop structures, including a circle, a polygon such as a pentagon and a hexagon, etc. when viewed from the top. 
     The first cover layer  3316  may be disposed over the first conductive patterns  3312 . The first cover layer  3316  may include an insulating material. For example, the first cover layer  3316  may include polyimide. The first cover layer  3316  may have flexible properties. The first cover layer  3316  may be attached over the base layer  3311  and the first conductive patterns  3312  by the first adhesive layer  3314  including a pressure sensitive adhesive. 
     The second cover layer  3317  may be disposed on the second conductive patterns  3313 . The second cover layer  3317  may include an insulating material having flexible properties. For example, the second cover layer  3317  may include polyimide. The second cover layer  3317  may have flexible properties. The second cover layer  3317  may be attached over the base layer  3311  and the second conductive patterns  3313  by the second adhesive layer  3315  including a pressure sensitive adhesive. 
     Each of the first cover layer  3316  and the second cover layer  3317  of the first digitizer layer  3310  has flexible characteristic, and thus they may reflect the level differences formed by the first conductive patterns  3312  and the second conductive patterns  3313 . 
     For example, the level differences created by the first conductive patterns  3312  may be reflected on the front surface shape of the first adhesive layer  3314  thereon, which also affect the first cover layer  3316  having flexible characteristics, such that a first surface unevenness may be formed on the front surface of the first cover layer  3316 . The first surface unevenness may generally reflect the surface level differences created by the first conductive patterns  3312 , with the level differences somewhat reduced. 
     Likewise, the level differences created by the second conductive patterns  3313  may be reflected on the rear surface shape of the second adhesive layer  3315  thereunder, which also affect the second cover layer  3317  having flexible characteristics, such that a second surface unevenness may be formed on the rear surface of the second cover layer  3317 . 
     The first surface unevenness and the second surface unevenness may affect the surface shapes of other elements attached thereto. For example, if an additional flexible film is attached to the front surface of the first digitizer layer  3310 , the flexible film may also have surface unevenness affected by the first surface unevenness. If such surface unevenness is reflected up to the panel-bottom protection film  3100  close to the rear surface of the display panel  1000 , the surface unevenness may be noticed by external light. To address such an issue, the support plate  3200  that blocks sequential transfer of the surface unevenness is interposed between the first digitizer layer  3310  and the panel-bottom protection film  3100 . A detailed description thereof will be given later. 
     Referring back to  FIGS. 7 and 8 , the support plate  3200  may be disposed between the panel-bottom protection film  3100  and the digitizer layer  3300 . The support plate  3200  may be attached on the rear surface of the panel-bottom protection film  3100  by a fifth adhesive layer AD 5 . The fifth adhesive layer AD 5  may be a pressure sensitive adhesive. The fifth adhesive layer AD 5  may be disconnected at the folding area FDA in order to facilitate the folding of the display device  10 . 
     The support plate  3200  may be disposed on the rear surface of the panel-bottom protection film  3100  to support the display panel  1000  together with the panel-bottom protection film  3100  and can protect the rear surface of the display panel  1000 . The support plate  3200  may be disposed on the front surface of the digitizer layer  3300  to support the digitizer layer  3300  and can protect the front surface of the digitizer layer  3300 . 
     The support plate  3200  may be made of glass or ceramic having a relative permeability in the range of approximately 1.0 to 1 so that so that the magnetic field or electromagnetic signal transmitted from the front surface of the display device  10  or generated by the electrode patterns of the digitizer layer  3300  is not deformed. As used here, the term “relative permeability” μ r  is a ratio of magnetic permeability of a medium μ to the magnetic permeability of free space μ 0 , which is 4π×10 −7  H/m. Thus, μ r =μ/μ 0 . Materials such as glass and ceramic have a stronger hardness than polymer films such as polyimide. Therefore, even though the digitizer layer  3300  including the first surface unevenness is attached by pressing it on the rear surface of the support plate  3200 , the support plate  3200  can resist so that its shape is not changed by the first surface unevenness of the digitizer layer  3300 . For example, by employing the support plate  3200  having a flat front surface, the front surface of the support plate  3200  can maintain the flat shape even though the digitizer layer  3300  including the first surface unevenness is pressed on its rear surface. Therefore, irrespective of whether the digitizer layer  3300  has the first surface unevenness and how large the size of the first surface unevenness is, if any, the first surface unevenness are not transferred to the panel-bottom protection film  3100  disposed on the front surface of the digitizer layer  3300 . 
     The width of the support plate  3200  in the second direction Y may be smaller than the width of the digitizer layer  3300  in the second direction Y. The digitizer layer  3300  may protrude in the second direction Y from the edge of the support plate  3200 . According to this structure, even if an external force is applied to the side surface of the display device  10 , the digitizer layer  3300  is impacted first, and thus it may help to prevent the support plate  3200 , including glass or ceramic, from being broken. 
     The thickness of the support plate  3200  may be larger than the thickness of the digitizer layer  3300 . If the thickness of the support plate  3200  is larger than the thickness of the digitizer layer  3300 , it may be helpful in preventing the transfer of the first surface unevenness on the front surface of the digitizer layer  3300  to the support plate  3200 . It is, however, to be understood that embodiments of the present disclosure are not necessarily limited thereto. 
       FIG. 11  is a perspective view showing an example of the support plate of  FIG. 8 .  FIG. 12  is a side view of a folding area of the support plate of  FIG. 11 .  FIG. 13  is a plan view of the support plate of  FIG. 11 .  FIG. 14  is an enlarged view of area A of  FIG. 13 . 
     Referring to  FIG. 11 , the support plate  3200  may include flat portions  3210  disposed in the non-folding areas NFA 1  and NFA 2 , and a pattern portion  3220  disposed in the folding area FDA. The pattern portion  3220  may include one or more openings OP. The flat portions  3210  may include a first flat portion  3211  disposed in the first non-folding area NFA 1  and a second flat portion  3212  disposed in the second non-folding area NFA 2 . The first flat portion  3211 , the pattern portion  3220  and the second flat portion  3212  of the support plate  3200  may be integrally formed. For example, the first flat portion  3211  and the second flat portion  3212  may be connected by a plurality of bars BAR of the pattern portion  3220  and may be integrally formed. 
     More specifically, the front and rear surfaces of the first flat portion  3211  and the second flat portion  3212  may be flat. It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the front surfaces of the first flat portion  3211  and the second flat portion  3212  may be flat, while the rear surfaces might not be flat. In such case, the rear surface of each of the first flat portion  3211  and the second flat portion  3212  may include an uneven surface for covering the level differences on the front surface of the digitizer layer  3300 . 
     The first flat portion  3211  may be disposed in the first non-folding area NFA 1 . The width of the first flat portion  3211  in the second direction Y may be substantially equal to the width of the first non-folding area NFA 1 . In such case, one side surface of the first flat portion  3211  may be disposed on the first folding line FL 1 . It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the width of the first flat portion  3211  in the second direction Y may be shorter than the width of the first non-folding area NFA 1 . 
     The second flat portion  3212  may be disposed in the second non-folding area NFA 2 . The width of the second flat portion  3212  in the second direction Y may be substantially equal to the width of the second non-folding area NFA 2 . In such case, one side surface of the second flat portion  3212  may be disposed on the second folding line FL 2 . It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the width of the second flat portion  3212  in the second direction Y may be shorter than the width of the second non-folding area NFA 2 . 
     The pattern portion  3220  may be disposed in the folding area FDA. The width of the pattern portion  3220  in the second direction Y may be substantially equal to the width of the folding area FDA. In such case, one side surface of the pattern portion  3220  may be disposed on the first folding line FL 1 , and the opposite side surface of the pattern portion  3220  may be disposed on the second folding line FL 2 . It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the width of the pattern portion  3220  in the second direction Y may be smaller than the width of the folding area FDA, and one side surface and the opposite side surface of the pattern portion  3220  may be disposed in the folding area FDA. 
     The pattern portion  3220  may overlap the folding area FDA. The pattern portion  3220  may include a plurality of openings OP to reduce the folding stress of the display device  10 . Accordingly, the density of the support plate  3200  in the folding area FDA may be smaller than the density of the support plate  3200  in the first non-folding area NFA 1  and the second non-folding area NFA 2 . 
     Although the pattern portion  3220  is integrally formed, it is defined as including a plurality of bars BAR in the following description for convenience of illustration. The plurality of bars BAR may be separated from one another by the openings OP disposed adjacent to one another. 
     The openings OP may include closed slits CSLT and open slits OSLT. The closed slits CSLT refer to the openings OP that are entirely surrounded by the bars BAR, and the open slits OSLT refer to the openings OP that are partially surrounded by the bars BAR and have at least a side open to the outside. The open slits OSLT may have a bay shape curved inward from one side of the support plate  3200  when viewed from the top. 
     Each of the closed slits CSLT and the open slits OSLT may have a rectangular shape when viewed from the top. In such case, the width of the rectangular shape in the first direction X may be larger than the width of the rectangular shape in the second direction Y. For example, the width of each of the closed slits CSLT and the open slits OSLT in the first direction X may be less than ⅔ the width of the folding area FDA in the first direction X. According to this structure, the support plate  3200  can reduce folding stress at the folding area FDA, and the display device  10  can be bent smoothly. It is, however, to be understood that this is merely illustrative. For example, the closed slits CSLT may have a diamond shape in which the width of the diagonal line parallel to the first direction X is longer than the width of the diagonal line parallel to the second direction Y, and the open slits OSLT may have a triangular shape. 
     Herein, the thickness of each of the plurality of openings OP is equal to the thickness of the flat portions  3210  of the support plate  3200 , for example. It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the thickness of each of the plurality of openings OP may be smaller than the thickness of the flat portions  3210  of the support plate  3200 . 
     The plurality of closed slits CSLT may be defined by the plurality of bars BAR and the plurality of open slits OSLT. Hereinafter, a plurality of bars BAR, a plurality of closed slits CSLT and a plurality of open slits OSLT will be described with reference to  FIGS. 12 to 14 . 
       FIG. 12  is a side view of the folding area of the support plate of  FIG. 11 .  FIG. 13  is a plan view of the support plate of  FIG. 11 .  FIG. 14  is an enlarged view of area A of  FIG. 13 . 
     Referring to  FIGS. 12 and 13 , the plurality of bars BAR may be extended in the first direction X. The plurality of bars BAR may be arranged in the second direction Y. The open slits OSLT may be disposed between adjacent ones of the plurality of bars BAR. 
     The thickness of each of the plurality of bars BAR may be substantially equal to the thickness of the flat portions  3210 , but the present disclosure is not necessarily limited thereto. For example, the thickness of each of the plurality of bars BAR may be smaller than the thickness of the flat portions  3210 . In such case, the support plate  3200  may have a bay shape in which the rear surface is curved inward in the third direction DR 3  at the folding area FDA. 
     If the width Wbar of the plurality of bars BAR is larger than the width Woslt of the open slits OSLT, the display device  10  might not be easily bent at the folding area FDA. Therefore, the width Wbar of the bars BAR may be smaller than or substantially equal to the width Woslt of the open slits OSLT. 
     Referring to  FIG. 14 , the plurality of bars BAR may include a plurality of horizontal bars HBAR, a plurality of vertical bars VBAR, and a plurality of connection bars CBAR. Hereinafter, an arrangement and connection relationship of a plurality of bars BAR will be described. 
     The plurality of horizontal bars HBAR may include a first horizontal bar HBAR 1 , a second horizontal bar HBAR 2 , a third horizontal bar HBAR 3 , and a fourth horizontal bar HBAR 4 . The first horizontal bar HBAR 1 , the second horizontal bar HBAR 2 , the third horizontal bar HBAR 3  and the fourth horizontal bar HBAR 4  may be extended in the first direction X and may be arranged in the second direction Y. For example, as shown in  FIG. 13 , the second horizontal bar HBAR 2  may be disposed on one side of the first horizontal bar HBAR 1 , the third horizontal bar HBAR 3  may be disposed on one side of the second horizontal bar HBAR 2 , and the fourth horizontal bar HBAR 4  may be disposed on one side of the third horizontal bar HBAR 3 . 
     The plurality of vertical bars VBAR may include a first vertical bar VBAR 1 , a second vertical bar VBAR 2 , a third vertical bar VBAR 3 , and a fourth vertical bar VBAR 4 . The first vertical bar VBAR 1 , the second vertical bar VBAR 2 , the third vertical bar VBAR 3  and the fourth vertical bar VBAR 4  may be extended in the second direction Y. 
     The first vertical bar VBAR 1  may be disposed between one end of the first horizontal bar HBAR 1  and one end of the second horizontal bar HBAR 2 . The end of the first horizontal bar HBAR 1  and the end of the second horizontal bar HBAR 2  may be connected by the first vertical bar VBAR 1 . 
     The second vertical bar VBAR 2  may be disposed between the other end of the first horizontal bar HBAR 1  and the other end of the second horizontal bar HBAR 2 . The other end of the first horizontal bar HBAR 1  and the other end of the second horizontal bar HBAR 2  may be connected by the second vertical bar VBAR 2 . 
     The third vertical bar VBAR 3  may be disposed between one end of the third horizontal bar HBAR 3  and one end of the fourth horizontal bar HBAR 4 . The end of the third horizontal bar HBAR 3  and the end of the fourth horizontal bar HBAR 4  may be connected by the third vertical bar VBAR 3 . 
     The fourth vertical bar VBAR 4  may be disposed between the other end of the third horizontal bar HBAR 3  and the other end of the fourth horizontal bar HBAR 4 . The other end of the third horizontal bar HBAR 3  and the other end of the fourth horizontal bar HBAR 4  may be connected by the fourth vertical bar VBAR 4 . 
     The plurality of connection bars CBAR may include a first connection bar CBAR 1 , a second connection bar CBAR 2 , a third connection bar CBAR 3 , and a fourth connection bar CBAR 4 . The first connection bar CBAR 1 , the second connection bar CBAR 2 , the third connection bar CBAR 3  and the fourth connection bar CBAR 4  may be extended in the second direction Y. 
     The first connection bar CBAR 1  may be disposed between the first horizontal bar HBAR 1  and the second horizontal bar HBAR 2 . The first horizontal bar HBAR 1  and the second horizontal bar HBAR 2  may be connected by the first connection bar CBAR 1 . The first connection bar CBAR 1  may be disposed between the first vertical bar VBAR 1  and the second vertical bar VBAR 2  in the first direction X. 
     Each of the second connection bar CBAR 2  and the third connection bar CBAR 3  may be disposed between the second horizontal bar HBAR 2  and the third horizontal bar HBAR 3 . The second horizontal bar HBAR 2  and the third horizontal bar HBAR 3  may be connected by the second connection bar CBAR 2 . The second horizontal bar HBAR 2  and the third horizontal bar HBAR 3  may be connected by the third connection bar CBAR 3 . The second connection bar CBAR 2  and the third connection bar CBAR 3  may overlap in the first direction X. 
     The fourth connection bar CBAR 4  may be disposed between the third horizontal bar HBAR 3  and the fourth horizontal bar HBAR 4 . The third horizontal bar HBAR 3  and the fourth horizontal bar HBAR 4  may be connected by the fourth connection bar CBAR 4 . The fourth connection bar CBAR 4  may be disposed between the third vertical bar VBAR 3  and the fourth vertical bar VBAR 4  in the first direction X. 
     The plurality of open slits OSLT may include first open slits OSLT 1  and second open slits OSLT 2 . 
     Each of the first open slits OSLT 1  may be defined as an opening OP surrounded by the second horizontal bar HBAR 2 , the third horizontal bar HBAR 3  and the third connection bar CBAR 3 . Each of the second open slits OSLT 2  may be defined as an opening OP surrounded by the second horizontal bar HBAR 2 , the third horizontal bar HBAR 3  and the second connection bar CBAR 2 . The first open slits OSLT 1  and the second open slits OSLT 2  may overlap each other in the first direction X. 
     The plurality of closed slits CSLT may include first closed slits CSLT 1 , second closed slits CSLT 2 , third closed slits CSLT 3 , fourth closed slits CSLT 4 , and fifth closed slits CSLT 5 . 
     Each of the first closed slits CSLT 1  may be defined as an opening OP surrounded by the second connection bar CBAR 2 , the third connection bar CBAR 3 , the second horizontal bar HBAR 2  and the third horizontal bar HBAR 3 . Each of the second closed slits CSLT 2  may be defined as an opening OP surrounded by the first horizontal bar HBAR 1 , the second horizontal bar HBAR 2 , the second vertical bar VBAR 2  and the first connection bar CBAR 1 . Each of the third closed slits CSLT 3  may be defined as an opening OP surrounded by the first horizontal bar HBAR 1 , the second horizontal bar HBAR 2 , the first vertical bar VBAR 1  and the first connection bar CBAR 1 . Each of the fourth closed slits CSLT 4  may be defined as an opening OP surrounded by the third horizontal bar HBAR 3 , the fourth horizontal bar HBAR 4 , the fourth vertical bar VBAR 4  and the fourth connection bar CBAR 4 . Each of the fifth closed slits CSLT 5  may be defined as an opening OP surrounded by the third horizontal bar HBAR 3 , the fourth horizontal bar HBAR 4 , the third vertical bar VBAR 3  and the fourth connection bar CBAR 4 . 
     As such, the pattern portion  3220  includes a grid pattern formed by the plurality of bars BAR, the plurality of closed slits CSLT and the plurality of open slits OSLT, so that the display device  10  can be smoothly folded in the folding area FDA. In addition, as the support plate  3200  includes the plurality of bars BAR connected to one another in the folding area FDA, and the first flat portion  3211 , the pattern portion  3220  and the second flat portion  3212  are integrally formed, the support plate  3200  can remain aligned as the display device  10  is in an unfolded state even when the display device  10  is in an unfolded state, and can stably support the display panel  1000  and the digitizer layer  3300 . 
     Referring back to  FIGS. 7 and 8 , the buffer layer  3400  may be disposed between the support plate  3200  and the digitizer layer  3300 . The buffer layer  3400  may be attached to the rear surface of the support plate  3200  by a sixth adhesive layer AD 6 , and may be attached to the front surface of the digitizer layer  3300  by a seventh adhesive layer AD 7 . 
     Each of the sixth adhesive layer AD 6  and the seventh adhesive layer AD 7  may be disconnected at the folding area FDA so that the display device  10  is smoothly folded. The sixth adhesive layer AD 6  and the seventh adhesive layer AD 7  may be pressure sensitive adhesives. 
     The buffer layer  3400  can absorb external impact to prevent damage to the support plate  3200  and the digitizer layer  3300 . In addition, the buffer layer  3400  can prevent particles such as dust from flowing into the pattern portion  3220  of the support plate  3200  from the rear surface of the display device  10 . 
     For example, the buffer layer  3400  may include an elastic material such as a rubber and a sponge formed by foaming a urethane-based material or an acrylic-based material. Since the buffer layer  3400  has elasticity, it may have a thickness of approximately 10 μm or less in order to facilitate the folding of the display device  10 . Accordingly, the front surface of the buffer layer  3400  may have a shape in which the first surface unevenness of the front surface of the digitizer layer  3300  are somewhat reduced. Accordingly, when the buffer layer  3400  is attached to the front surface of the digitizer layer  3300 , the front surface of the buffer layer  3400  may include a third surface unevenness reflecting the first surface unevenness of the digitizer layer  3300 . 
     The shielding layer  3500  may be disposed on the rear surface of the digitizer layer  3300 . The shielding layer  3500  may include magnetic metal powder (MMP), so that a magnetic field or an electromagnetic signal that has passed through the digitizer layer  3300  may flow into the shielding layer  3500 . Therefore, the shielding layer  3500  can reduce the emission of a magnetic field or an electromagnetic signal to the rear surface of the display device  10 . 
     The shielding layer  3500  may be disconnected at the folding area FDA in order to facilitate the folding of the display device  10 . In such case, the shielding layer  3500  may include a first shielding layer  3510  disposed in the first non-folding area NFA 1  and a second shielding layer  3520  disposed in the second non-folding area NFA 2 . The width of the first shielding layer  3510  in the second direction Y may be substantially equal to the width of the first digitizer layer  3310  in the second direction Y, and the width of the second shielding layer  3520  in the second direction Y may be substantially equal to the width of the second digitizer layer  3320  in the second direction Y. The distance between the first shielding layer  3510  and the second shielding layer  3520  in the second direction Y may be smaller than the width of the folding area FDA. According to this structure, while the display device  10  can be smoothly folded in the folding area FDA, it may be helpful in reducing the emission of a magnetic field or an electric signal to the rear surface of the display device  10 . 
     The heat dissipation layer  3600  is disposed on the shielding layer  3500 . The heat dissipation layer  3600  may be a metal film such as a copper alloy, copper, nickel, ferrite and silver having excellent thermal conductivity. Accordingly, heat generated in the display device  10  can be released to the outside by the heat dissipation layer  3600 . 
     The heat dissipation layer  3600  may be disconnected at the folding area FDA in order to facilitate the folding of the display device  10 . In such case, the heat dissipation layer  3600  may include a first heat dissipation layer  3610  disposed in the first non-folding area NFA 1  and a second heat dissipation layer  3620  disposed in the second non-folding area NFA 2 . The distance between the first heat dissipation layer  3610  and the second heat dissipation layer  3620  in the second direction Y may be smaller than the width of the folding area FDA. According to this structure, the display device  10  can be smoothly folded in the folding area FDA and the area of the heat dissipation layer  3600  can be increased, so that it may be helpful in releasing heat generated in the display device  10 . 
     As shown in  FIGS. 7 and 8 , in the display device  10 , according to the embodiment of the present disclosure, the support plate  3200  including a hard material that does not change easily by external pressure is disposed on the digitizer layer  3300 , so that the support plate  3200  can block sequential transfer of the surface unevenness even if there is surface unevenness formed by the conductive patterns on the front surface of the digitizer layer  3300 . Therefore, irrespective of whether the digitizer layer  3300  has the first surface unevenness and how large the size of the first surface unevenness is, if any, the surface unevenness is not transferred to the panel-bottom protection film  3100  disposed on the front surface of the digitizer layer  3300 . In addition, since the support plate  3200  includes the plurality of openings OP in the folding area FDA, the display device  10  can be folded smoothly. 
       FIG. 15  is a flowchart illustrating an example of a method of fabricating the support plate of  FIG. 11 .  FIG. 16  is a plan view showing the process of forming a pattern on a glass plate using a laser of  FIG. 15 . 
     Referring first to  FIG. 15 , a pattern is formed on a glass plate using a laser (step S 100 ). 
     When a laser  30  is directed onto some regions of a glass plate  40 , the etch rate of the regions  50  exposed by the laser  30  may be increased compared to the other regions not exposed the laser  30 . For example, the etch rate of the regions  50  exposed by the laser  30  may be approximately ten times higher than the etch rate of the regions not exposed by the laser  30 . 
     The laser  30  may be a Bessel beam laser, and a picosecond infrared laser may be applied. The energy of the Bessel beam may be 16 μJ, and the pulse repetition rate may be 30 kHz. It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the Bessel beam laser may be a nanosecond UV laser. 
     Subsequently, the glass plate  40  is etched (step S 200 ). 
     The etching may be carried out by wet etching in which the glass plate  40  is etched through chemical reaction using an etching solution. The etching solution may include at least one of hydrofluoric acid (HF) and a hydrofluoric acid-based diluted etching solution. 
     When an etching process is carried out on the glass plate  40 , the etch rate of the regions  50  exposed by the laser  30  is higher than that of the other regions, and thus the regions  50  may be selectively etched and removed. As a result, the openings OP having the same shape as the pattern exposed by the laser  30  may be formed. In this manner, the support plate  3200  including the above-described various shapes of the openings OP can be fabricated. 
     Although a method of forming the pattern by the laser  30  and using wet etching is illustrated in the example shown in  FIG. 15 , the present disclosure is not necessarily limited thereto. For example, the support plate  3200  may be fabricated by cutting the glass plate  40  using the laser  30 . It is to be noted that the glass plate  40  may have a tapered shape, i.e., the width of the front surface may be different from the width of the rear surface where the glass plate  40  is cut using the laser  30 . 
     In contrast, when the support plate  3200  is fabricated by forming the pattern by the Bessel beam laser and then using wet etching, a plurality of support plates  3200  including substantially the same pattern as shown in  FIG. 16  can be fabricated simultaneously. Accordingly, it is appropriate for mass production, and it may be helpful in making the uniform widths of the front and rear surfaces of the pattern. 
       FIG. 17  is a cross-sectional view of a display device according to an embodiment of the present disclosure. 
     The arrangement of  FIG. 17  is different from the arrangement of  FIG. 7  in that a support plate  3200 ′ is disconnected at the folding area. Description will focus on the difference and it is to be understood that elements not described here are at least similar to corresponding elements that have been described elsewhere in the instant disclosure. 
     The support plate  3200 ′ may be disconnected at the folding area FDA in order to facilitate the folding of the display device. The support plate  3200 ′ may include a first support plate  3210 ′ and a second support plate  3220 ′. The first support plate  3210 ′ may be disposed in the first non-folding area NFA 1 , and the second support plate  3220 ′ may be disposed in the second non-folding area NFA 2 . The distance between the first support plate  3210 ′ and the second support plate  3220 ′ in the second direction Y may be smaller than the width of the folding area FDA in the second direction Y. Accordingly, the area in which the support plate  3200  is not disposed in the folding area FDA is reduced, so that the display panel  1000  and the digitizer layer  3300  can be stably supported. 
     The width of the first support plate  3210 ′ in the second direction Y may be smaller than the width of the first digitizer layer  3310  in the second direction Y. In this instance, one side surface of the first support plate  3210 ′ and one side surface of the first digitizer layer  3310  overlap each other at the folding area FDA, and the opposite side surface of the first support plate  3210 ′ and the opposite side surface of the first digitizer layer  3310  might not overlap each other. For example, the first digitizer layer  3310  may have a shape protruding in the second direction Y from the first support plate  3210 ′. It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the width of the first support plate  3210 ′ in the second direction Y may be substantially equal to the width of the first digitizer layer  3310  in the second direction Y. 
     The width of the second support plate  3220 ′ in the second direction Y may be smaller than the width of the second digitizer layer  3320  in the second direction Y. In this instance, one side surface of the second support plate  3220 ′ and one side surface of the second digitizer layer  3320  overlap each other at the folding area FDA, and the opposite side surface of the second support plate  3220 ′ and the opposite side surface of the second digitizer layer  3320  might not overlap each other. For example, the second digitizer layer  3320  may have a shape protruding in the second direction Y from the second support plate  3220 ′. It is, however, to be understood that the present disclosure is not necessarily limited thereto. For example, the width of the second support plate  3220 ′ in the second direction Y may be substantially equal to the width of the second digitizer layer  3320  in the second direction Y. 
     When the width of the support plate  3200 ′ in the second direction Y is larger than the width of the digitizer layer  3300  in the second direction Y, the digitizer layer  3300  receives an impact first when an external force is applied to the side surface of the display device  12 , so that it may be helpful in preventing the support plate  3200 ′ including glass, ceramic etc. from being broken. 
       FIG. 18  is a cross-sectional view of a display device according to an embodiment of the present disclosure. 
     The embodiment of  FIG. 18  is different from the embodiment of  FIG. 7  in that a digitizer layer  3300 ′ is integrally formed and is disposed between the panel-bottom protection film  3100  and the support plate  3200 , and that a rear-side layer having an uneven front surface is a shielding layer  3500 . Description will focus on the differences and it is to be understood that elements not described here are at least similar to corresponding elements that have been described elsewhere in the instant disclosure. 
     The digitizer layer  3300 ′ may be integrally formed and disposed in the first non-folding area NFA 1 , the second non-folding area NFA 2  and the folding area FDA. Accordingly, it is possible to recognize a touch using a stylus pen also in the folding area FDA. 
     The shielding layer  3500  includes magnetic metal powder (MMP) and thus it has the front surface having surface unevenness including regular pits and/or bumps, like an orange peel. Accordingly, it may be the rear-side layer having surface unevenness. 
     The support plate  3200  may be disposed between the digitizer layer  3300 ′ and the shielding layer  3500 . Accordingly, the surface level differences transferred to the panel-bottom protection film  3100  can be reduced compared to the structure in which the shielding layer  3500  is disposed on the rear surface of the digitizer layer  3300 ′ and the digitizer layer  3300 ′ is disposed on the rear surface of the panel-bottom protection film  3100 , i.e., the support plate  3200  is not disposed. 
     According to the embodiment of  FIG. 18 , it is possible to prevent the surface unevenness of the shielding layer  3500  from being transferred to the front surface of the display device, and to recognize the pen is recognized by the digitizer layer  3300 ′ even in the folding area FDA. 
       FIG. 19  is a cross-sectional view of a display device according to an embodiment of the present disclosure.  FIG. 20  is a perspective view of the support plate of  FIG. 19 . 
     The embodiment of  FIGS. 19 and 20  is different from the embodiment of  FIG. 7  in that a flat portion  3210 ″ of a support plate  3200 ″ is made of glass while a pattern portion  3220 ″ is made of ceramic. Description will focus on the differences and it is to be understood that elements not described here are at least similar to corresponding elements that have been described elsewhere in the instant disclosure. 
     In forming a plurality of openings OP″ in the pattern portion  3220 ″ of the support plate  3200 ″, it is more helpful to process the pattern portion  3220 ″ made of ceramic than the pattern portion  3220 ″ made of glass. 
     In this instance, the pattern portion  3220 ″ and the flat portions  3210 ″ of the support plate  3200 ″ are not formed integrally, and thus adhesive layers AD 8  and AD 9  to attach the pattern portion  3220 ″ with the flat portions  3210 ″ may be further included. The adhesive layers AD 8  and AD 9  may be pressure sensitive adhesives. 
     Although embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the present disclosure.