Patent Publication Number: US-2022221953-A1

Title: Display device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0003666, filed on Jan. 12, 2021 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference in its entirety herein. 
     TECHNICAL FIELD 
     Embodiments of the present inventive concepts relate to a display device. 
     DISCUSSION OF RELATED ART 
     The demand for display devices for displaying images has diversified with the development of the information society. For example, display devices have been applied to various electronic devices such as smart phones, digital cameras, notebook computers, navigation systems, and smart televisions (TVs). 
     A display device may include an input interface, such as a touch sensing unit for sensing a touch from a user. The touch sensing unit includes a plurality of touch electrodes that are driven in a capacitive manner, and can thus detect the touch from the user. 
     The display device may further include various optical devices at the front of the display device, such as an image sensor for capturing an image, a proximity sensor for detecting whether the user is in proximity to the display device, and an illumination sensor for detecting the intensity of illumination of the display device. 
     Since display devices have been applied to various types of electronic devices, display devices with various design features have been implemented. For example, display devices having holes removed from their front and thereby having a widened display area have been developed. When the holes at the front of a display device are removed, optical devices may be disposed to overlap with a display panel. 
     SUMMARY 
     Aspects of the present inventive concepts provide a display device capable of increasing touch sensitivity in a region Where optical sensors are disposed. 
     According to an embodiment of the present inventive concepts, a display device includes a first display area including first pixels, driving electrodes, and sensing electrodes. A second display area includes second pixels, sub-driving electrodes, and sub-sensing electrodes. Auxiliary electrodes are between the first and second display areas. A number of first pixels per unit area of the first display area is greater than a number of second pixels per unit area of the second display area. 
     In an embodiment, the auxiliary electrodes may include a first auxiliary electrode, which is between one of the driving electrodes and one of the sub-driving electrodes, and a second auxiliary electrode, which is between one of the sensing electrodes and one of the sub-sensing electrodes. 
     In an embodiment, the driving electrodes, the first auxiliary electrode, and the sub-driving electrodes may be electrically connected, and the sensing electrodes, the second auxiliary electrode, and the sub-sensing electrodes may be electrically connected. 
     In an embodiment, a maximum width of the first auxiliary electrode may be greater than maximum widths of the driving electrodes and the sub-driving electrodes. 
     In an embodiment, a maximum width of the second auxiliary electrode may be greater than maximum widths of the sensing electrodes and the sub-sensing electrodes. 
     In an embodiment, the auxiliary electrodes may further include a third auxiliary electrode, which is spaced apart from the first and second auxiliary electrodes and may be between another one of the driving electrodes and another one of the sub-driving electrodes, and a fourth auxiliary electrode, which is spaced apart from the first, second, and third auxiliary electrodes and may be between another one of the sensing electrodes and another one of the sub-sensing electrodes. 
     In an embodiment, the display device may further comprise connection electrodes between, and electrically connected to, the sub-driving electrodes. The connection electrodes may overlap with the sub-sensing electrodes. 
     In an embodiment, the sub-driving electrodes and the connection electrodes may be disposed in the same layer. 
     In an embodiment, the connection electrodes may be disposed in a different layer from the sub-driving electrodes. 
     In an embodiment, the first auxiliary electrode may be spaced apart from the driving electrodes and the sub-driving electrodes, and the second auxiliary electrode may be spaced apart from the sensing electrodes and the sub-sensing electrodes. 
     In an embodiment, the first and second auxiliary electrodes may be disposed in a different layer from the driving electrodes, the sub-driving electrodes, the sensing electrodes, and the sub-sensing electrodes. 
     In an embodiment, the first and second auxiliary electrodes may be disposed in the same layer as the driving electrodes, the sub-driving electrodes, the sensing electrodes, and the sub-sensing electrodes. 
     In an embodiment, the display device may further comprise auxiliary touch electrodes between the first auxiliary electrode and the driving electrodes. 
     In an embodiment, the auxiliary touch electrodes may include auxiliary driving electrodes and auxiliary sensing electrodes, and 
     In an embodiment, the auxiliary driving electrodes and the auxiliary sensing electrodes may be spaced apart from the first auxiliary electrode and the driving electrodes. 
     In an embodiment, the auxiliary driving electrodes may completely overlap with the auxiliary sensing electrodes. 
     In an embodiment, the auxiliary touch electrodes may include auxiliary driving electrodes and auxiliary sensing electrodes. The auxiliary driving electrodes may extend in one direction. The auxiliary sensing electrodes may extend in another direction to intersect the auxiliary driving electrodes. 
     In an embodiment, the display device may further comprise an optical device overlapping with the second display area. 
     In an embodiment, the display device may further comprise a polarizing film overlapping with the first display area, but not with the auxiliary electrodes. 
     According to an embodiment of the present inventive concepts, a display device includes a first display area including first pixels, driving electrodes, and sensing electrodes. A second display area includes second pixels, sub-driving electrodes, and sub-sensing electrodes. A polarizing plate overlaps with the first display area. Auxiliary electrodes are between the first and second display areas. The auxiliary electrodes do not overlap with the polarizing plate. 
     In an embodiment, the display device may further comprise an optical device overlapping with the second display area. 
     In an embodiment, the number of first pixels per unit area of the first display area may be greater than the number of second pixels per unit area of the second display area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present inventive concepts will become more apparent by describing in detail embodiments thereof, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a display device according to an embodiment of the present inventive concepts; 
         FIG. 2  is an exploded perspective view of the display device of  FIG. 1  according to an embodiment of the present inventive concepts; 
         FIG. 3  is a plan view of a display panel of  FIG. 1  according to an embodiment of the present inventive concepts; 
         FIG. 4  is a cross-sectional view taken along line A-A′ of  FIG. 3  according to an embodiment of the present inventive concepts; 
         FIG. 5  is a layout view of a touch sensing unit according to an embodiment of the present inventive concepts; 
         FIG. 6  is a layout view of touch nodes of  FIG. 5  according to an embodiment of the present inventive concepts; 
         FIG. 7  is a cross-sectional view taken along line B-B′ of  FIG. 6  according to an embodiment of the present inventive concepts; 
         FIG. 8  is a layout view of an area A of  FIG. 5  according to an embodiment of the present inventive concepts; 
         FIG. 9  is a layout view of an area A- 1  of  FIG. 8  according to an embodiment of the present inventive concepts; 
         FIG. 10A  is a cross-sectional view taken along line C-C′ of  FIG. 9  according to an embodiment of the present inventive concepts; 
         FIG. 10B  is a cross-sectional view taken along line C-C′ of  FIG. 9  according to an embodiment of the present inventive concepts; 
         FIG. 11A  is a layout view of an area A- 2  of  FIG. 8  according to an embodiment of the present inventive concepts; 
         FIG. 11B  is a layout view of an area B- 1  of  FIG. 11A  according to an embodiment of the present inventive concepts; 
         FIG. 12  is a cross-sectional view taken along line D-D′ of  FIG. 11B  according to an embodiment of the present inventive concepts; 
         FIG. 13A  is a layout view of the area A- 2  of  FIG. 8  according to an embodiment of the present inventive concepts; 
         FIG. 13B  is a layout view of an area B- 2  of  FIG. 13A  according to an embodiment of the present inventive concepts; 
         FIG. 14  is a cross-sectional view taken along line E-E′ of  FIG. 13B  according to an embodiment of the present inventive concepts; 
         FIG. 15  is a layout view of the area A of  FIG. 5  according to an embodiment of the present inventive concepts; 
         FIG. 16  is a layout view of an area A- 3  of  FIG. 15  according to an embodiment of the present inventive concepts; 
         FIG. 17  is a cross-sectional view taken along line F-F′ of  FIG. 16  according to an embodiment of the present inventive concepts; 
         FIG. 18  is a cross-sectional view taken along line G-G′ of  FIG. 16  according to an embodiment of the present inventive concepts; 
         FIG. 19  is a cross-sectional view taken along line G-G′ of  FIG. 16  according to an embodiment of the present inventive concepts; 
         FIG. 20  is a layout view of an area A- 4  of  FIG. 15  according to an embodiment of the present inventive concepts; 
         FIG. 21  is a cross-sectional view taken along line H-H′ of  FIG. 17  according to an embodiment of the present inventive concepts; 
         FIG. 22  is a cross-sectional view taken along line H-H′ of  FIG. 17  according to an embodiment of the present inventive concepts; 
         FIG. 23  is a layout view of the area A of  FIG. 5  according to an embodiment of the present inventive concepts; 
         FIG. 24  is a layout view of an area A- 5  of  FIG. 23  according to an embodiment of the present inventive concepts; 
         FIG. 25  is a cross-sectional view taken along line I-I′ of  FIG. 24  according to an embodiment of the present inventive concepts; 
         FIG. 26  is a layout view of the area A- 5  of  FIG. 20  according to an embodiment of the present inventive concepts; 
         FIG. 27  is a cross-sectional view taken along line J-J′ of  FIG. 26  according to an embodiment of the present inventive concepts; 
         FIG. 28  is a layout view of the area A of  FIG. 5  according to an embodiment of the present inventive concepts; 
         FIG. 29  is a layout view illustrating first and second sub-display areas of  FIG. 3  according to an embodiment of the present inventive concepts; 
         FIG. 30  is a cross-sectional view taken along line K-K′ of  FIG. 29  according to an embodiment of the present inventive concepts; 
         FIG. 31  is a layout view illustrating the first and second sub-display areas of  FIG. 3  according to an embodiment of the present inventive concepts; and 
         FIG. 32  is a cross-sectional view taken along line L-L′ of  FIG. 31  according to an embodiment of the present inventive concepts. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present inventive concepts will be described more fully hereinafter with reference to the accompanying drawings. Like reference numerals may refer to like elements throughout the specification and the accompanying drawings. 
     Herein, when two or more elements or values are described as being substantially the same as or about equal to each other, it is to be understood that the elements or values are identical to each other, the elements or values are equal to each other within a measurement error, or if measurably unequal, are close enough in value to be functionally equal to each other as would be understood by a person having ordinary skill in the art. For example, the term “about” 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 (e.g., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations as understood by one of the ordinary skill in the art. Further, it is to be understood that while parameters may be described herein as having “about” a certain. value, according to exemplary embodiments, the parameter may be exactly the certain value or approximately the certain value within a measurement error as would be understood by a person having ordinary skill in the art. Other uses of these terms and similar terms to describe the relationship between components should be interpreted in a like fashion. 
     It will be understood that when a component, such as a film, a region, a layer, or an element, is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another component, it can be directly on, connected, coupled, or adjacent to the other component, or intervening components may be present. When a component, such as a film, a region, a layer, or an element, is referred to as being “directly on”, “directly connected to”, “directly coupled to”, or “directly adjacent to” another component, no intervening components may be present. It will also be understood that when a component is referred to as being “between” two components, it can be the only component between the two components, or one or more intervening components may also be present. It will also be understood that when a component is referred to as “covering” another component, it can be the only component covering the other component, or one or more intervening components may also be covering the other component. Other words use to describe the relationship between elements may be interpreted in a like fashion. 
     It will be further understood that descriptions of features or aspects within each embodiment are available for other similar features or aspects in other embodiments, unless the context clearly indicates otherwise. Accordingly, all features and structures described herein may be mixed and matched in any desirable manner. 
     As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     Spatially relative terms, such as “below”, “lower”, “above”, “upper”, etc., may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation. in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below, 
     When a feature is said to extend, protrude, or otherwise follow a certain direction, it will be understood that the feature may follow said direction in the negative, such as the opposite direction. Accordingly, the feature is not limited to follow exactly one direction, and may follow along an axis formed by the direction, unless the context clearly indicates otherwise. 
       FIG. 1  is a perspective view of a display device according to an embodiment of the present inventive concepts.  FIG. 2  is an exploded perspective view of the display device of  FIG. 1 .  FIG. 3  is a plan view of a display panel of  FIG. 1 . 
     Referring to  FIGS. 1 through 3 , a display device  10  may be applied to a portable electronic device such as a mobile phone, a smartphone, a tablet personal computer (PC), a mobile communication terminal, an electronic notepad, an electronic book, a portable multimedia player (PMP), a navigation device, or an ultramobile PC (UMPC). The display device  10  may also be applied to a television (TV), a notebook computer, a monitor, a billboard, or an Internet-of-Things (IoT) device as a display unit. The display device  10  may also be applied to a wearable device such as a smartwatch, a watchphone, a glasses-type display, or a head-mounted display (HMD). Also, the display device  10  may also be applied to the dashboard of a vehicle, the center fascia of a vehicle, a center information display (CID) in the dashboard of a vehicle, a room mirror display that can replace the rear-view mirror of a vehicle, or an entertainment display at the back of a front seat of a vehicle. However, embodiments of the present inventive concepts are not limited thereto and the display device  10  may be applied to various other small, medium or large sized electronic devices 
     A first direction parallel to the X-axis (hereinafter, the “X direction”) may refer to the direction of the relatively short sides of the display device  10 , for example, the horizontal direction of the display device  10 . A second direction parallel to the Y axis (hereinafter, the “Y direction”) may refer to the direction of the relatively long sides of the display device  10 , for example, the vertical direction of the display device  10 . A third direction parallel to the Z-axis (hereinafter, the “Z direction”) may refer to the thickness direction of the display device  10 . 
     In an embodiment, the display device  10  may have a rectangle-like shape in a plan view. In one example, as illustrated in  FIG. 1 , the display device  10  may have a rectangle-like shape having relatively short sides in the X direction and relatively long sides in the Y direction in a plan view. In an embodiment, the corners where the relatively short sides and the relatively long sides of the display device  10  meet may be rounded to have a predetermined curvature or may be right-angled. However, the planar shape of the display device  10  is not particularly limited, and the display device  10  may be formed in various other shapes such as a nontetragonal polygonal shape, a circular shape, or an elliptical shape in a plan view. 
     The display device  10  may be formed to be flat. Alternatively, one or more pairs of opposing sides of the display device  10  may be curved. In one example, the left and right sides of the display device  10  may be curved. In an example, the upper, lower, left, and right sides of the display device  10  may all be curved. However, embodiments of the present inventive concepts are not limited thereto. 
     The display device  10  may include a cover window  100 , a display panel  300 , a display circuit board  310 , a display driving circuit  320 , a bracket  600 , a main circuit board  700 , optical devices ( 740 ,  750 ,  760 , and  770 ), and a lower cover  900 . 
     The cover window  100  may be disposed above the display panel  300  (e.g., in the Z direction) to cover the front surface of the display panel  300 . Accordingly, the cover window  100  may protect the front surface of the display panel  300 . 
     In an embodiment, the cover window  100  may include a light-transmitting area DA 100 , which corresponds to the display panel  300 , and a light-blocking area NDA 100 , which corresponds to the rest of the display device  10 . The light-blocking area NDA 100  may be formed to be opaque. In an embodiment, the light-blocking area NDA 100  may be formed as a decorative layer formed of patterns that are visible to a user when no image is displayed. 
     The display panel  300  may be disposed below the cover window  100  (e.g., in the Z direction). In an embodiment, the display panel  300  may be a light-emitting display panel including light-emitting elements. In one example, the display panel  300  may be an organic light-emitting display panel using organic light-emitting diodes (OLEDs) that include organic light-emitting layers, a micro-light-emitting diode (mLED) display panel using mLEDs, a quantum-dot light-emitting display panel using quantum-dot light-emitting diodes, or an inorganic light-emitting display panel using inorganic light-emitting elements that include an inorganic semiconductor. The display panel  300  will hereinafter be described as being an organic light-emitting display panel for convenience of explanation and not limitation 
     The display panel  300  may include a display area DA, and the display area DA may include a main display area MDA and a sub-display area SDA. In an embodiment, the size of the main display area MDA may occupy the majority of the display area DA. The sub-display area SDA may be disposed on one side of the main display area MDA, for example, on the upper side of the main display area MDA (e.g., in the Y direction), as illustrated in  FIG. 2 . However, embodiments of the present inventive concepts are not limited thereto and the arrangement of the sub-display area SDA may vary. The main display area MDA may be a first display area, and the sub-display area SDA may be a second display area. As shown in the embodiment of  FIG. 3 , the display panel  300  may further include a non-display area NDA. In an embodiment, the non-display area NDA may fully surround the display area DA (e.g., in the X and Y directions). However, embodiments of the present inventive concepts are not limited thereto. 
     In an embodiment, the main display area MDA may not include a light-transmitting area capable of transmitting light therethrough, but may include only a pixel area having pixels for displaying an image. In an embodiment, the sub-display area SDA may include both a light-transmitting area capable of transmitting light therethrough and a pixel area having pixels for displaying an image. Thus, the sub-display area SDA may have a higher light transmittance than the main display area MDA. 
     Referring to the embodiments of  FIGS. 2 and 3 , the sub-display area SDA may include a plurality of sub-display areas, such as first to fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4 . The first to fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  may be disposed to be spaced apart from one another. Each of the first to fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  may be surrounded by the main display area MDA. 
     In an embodiment, a first sub-display area SDA 1  may overlap with the proximity sensor  740  in the Z direction. Thus, even though the proximity sensor  740  is disposed to overlap with the display panel  300 , the proximity sensor  740  can detect light incident thereupon from the front surface of the display device  10  through the first sub-display area SDA 1 . 
     In an embodiment, a second sub-display area SDA 2  may overlap with the illumination sensor  750  in the Z direction. Thus, even though. the illumination sensor  750  is disposed to overlap with the display panel  300 , the illumination sensor  750  can detect light incident thereupon from the front surface of the display device  10  through the second sub-display area SDA 2 . 
     In an embodiment, a third sub-display area SDA 3  may overlap with the iris sensor  760  in the Z direction. Thus, even though the iris sensor  760  is disposed to overlap with the display panel  300 , the iris sensor  760  can detect light incident thereupon from the front surface of the display device  10  through the third sub-display area SDA 3 . 
     In an embodiment, a fourth sub-display area SDA 4  may overlap with the second camera sensor  770  in the Z direction. Thus, even though the second camera sensor  770  is disposed to overlap with the display panel  300 , the second camera sensor  770  can detect light incident thereupon from the front surface of the display device  10  through the fourth sub-display area SDA 4 . 
       FIGS. 2 and 3  illustrate that the sub-display area SDA includes four sub-display areas, such as the first, second, third, and fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4 . However, embodiments of the present inventive concepts are not limited thereto. For example, in an embodiment, the number of sub-display areas may be dependent on the number of optical devices. For example, the sub-display areas may be disposed to correspond one-to-one to the optical devices. 
     Also, the embodiments of  FIGS. 2 and 3  illustrate that each of the first to fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  has a circular shape. However, embodiments of the present inventive concepts are not limited thereto. For example, each of the first to fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  may have a polygonal or elliptical shape. 
     Also, the embodiments of  FIGS. 2 and 3  illustrate that the first to fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  have the same size. However, embodiments of the present inventive concepts are not limited thereto. For example, the first to fourth sub-display areas SDA 1 , SDA 2 , SDA 3 , and SDA 4  may have different sizes. 
     The display circuit board  310  and the display driving circuit  320  may be attached to one side of the display panel  300 , such as the lower side in the Y direction. However, embodiments of the present inventive concepts are not limited thereto. In an embodiment, the display circuit board  310  may be a flexible printed circuit board (FPCB) that is bendable, a rigid printed circuit board (PCB) that is too rigid to be bendable, or a hybrid PCB that has the characteristics of both a rigid PCB and an FPCB. 
     The display driving circuit  320  may receive control signals and power supply voltages via the display circuit board  310  and may generate and output signals and voltages for driving the display panel  300 . In an embodiment, the display driving circuit  320  may be formed as an integrated circuit (IC) and may be attached on the display panel  300  in a chip-on-glass (COG), chip-on-plastic (COP), or ultrasonic manner. However, embodiments of the present inventive concepts are not limited thereto. For example, in an embodiment, the display driving circuit  320  may be attached on the display circuit board  310 . 
     A touch driving circuit  330  may be disposed on the display circuit board  310 . In an embodiment, the touch driving circuit  330  may be formed as an IC and may be attached on the top surface of the display circuit board  310 . The touch driving circuit  330  may be electrically connected to the touch electrodes of the touch sensor layer of the display panel  300  via the display circuit board  310 . The touch driving circuit  330  may output touch driving signals to the touch electrodes and may detect voltages that the capacitors of the touch electrodes are charged with. 
     The touch driving circuit  330  may generate touch data based on variations in electrical signals detected by the touch electrodes, may transmit the touch data to the main processor  710 , and the main processor  710  may calculate the coordinates of a touch by analyzing the touch data. In an embodiment, a touch may includes a real touch or a proximity touch. A real touch refers to an input occurring when a finger of the user or an object such as a pen is physically touched (e.g., makes direct contact) on a cover window disposed on a sensor electrode layer. A proximity touch refers to an input occurring when a finger of the user or an object such as a pen is close to, but not physically touched on, the cover window. 
     A power supply unit for supplying display driving voltages for driving the display driving circuit  320  may be additionally disposed on the display circuit board  310 . 
     The bracket  600  may be disposed below the display panel  300  (e.g., in the Z direction). In an embodiment, the bracket  600  may be formed of plastic, a metal, or both. In an embodiment, a first camera hole CMH 1 , in which a first camera sensor  720  is inserted, a battery hole BH, ire which a battery  790  is disposed, a cable hole CAH, through which a cable  314  connected to the display circuit board  310  passes, and a light-transmitting hole SH, in which the optical devices ( 740 ,  750 ,  760 , and  770 ) are disposed, may be formed in the bracket  600 . However, embodiments of the present inventive concepts are not limited thereto. For example, the bracket  600  may not include the light-transmitting hole SH and may be formed not to overlap with the sub-display area SDA of the display panel  300 . 
     The main circuit board  700  and the battery  790  may be disposed below the bracket  600  (e.g., in the Z direction). The main circuit board  700  may be a PCB or an FPCB. 
     In an embodiment, the main circuit board  700  may include a main processor  710 , the first camera sensor  720 , a main connector  730 , and the optical devices ( 740 ,  750 ,  760 , and  770 ). The optical devices ( 740 ,  750 ,  760 , and  770 ) may include a proximity sensor  740 , an illumination sensor  750 , an iris sensor  760 , and a second camera sensor  770 . 
     In an embodiment, the first camera sensor  720  may be disposed on both the top and bottom surfaces of the main circuit board  700  (e.g., in the Z. direction), the main processor  710  may be disposed on the top surface of the main circuit board  700  (e.g., in the Z direction), and the main connector  730  may be disposed on the bottom surface of the main circuit board  700  (e.g., in the Z direction). The proximity sensor  740 , the illumination sensor  750 , the iris sensor  760 , and the second camera sensor  770  may be disposed on the top surface of the main circuit board  700  (e.g., in the Z direction). 
     In an embodiment, the main processor  710  may control all the functions of the display device  10 . For example, the main processor  710  may provide digital video data to the display driving circuit  320  through the display circuit board  310  so that the display panel  300  may display an image. Also, the main processor  710  may receive touch data from the touch driving circuit  330 , may determine the coordinates of a touch from the user, and may execute an application corresponding to an icon displayed at the coordinates of the touch. Also, the main. processor  710  may display an image captured by the first camera sensor  720  by converting first image data received from the first camera sensor  720  into digital video data and outputting the digital video data to the display driving circuit  320  via the display circuit board  310 . Also, the main processor  710  may control the display device  10  in accordance with sensor signals from the proximity sensor  740 , the illumination sensor  750 , the iris sensor  760 , and the second camera sensor  770 . 
     The main processor  710  may determine whether there exists an object in the proximity of the front surface of the display device  10  in accordance with a proximity sensor signal input thereto from a proximity sensor  740 . In an embodiment, if there exists an object in the proximity of the front surface of the display device  10  during a call mode where the user talks to another person with the use of the display device  10 , the main processor  710  may not execute an application corresponding to an icon at the touch coordinates of a touch from the user. 
     The main processor  710  may determine the brightness of the front surface of the display device  10  based on an illumination sensor signal input thereto from an illumination sensor  750 . In an embodiment, the main processor  710  may adjust the luminance of an image displayed by the display panel  300 , in accordance with the brightness of the front surface of the display device  10 . 
     The main processor  710  may determine whether an iris image of the user is identical to a previously-stored iris image based on an iris sensor signal input thereto from an iris sensor  760 . In an embodiment, if the iris image of the user is identical to the previously-stored iris image, the main processor  710  may unlock the display device  10  and may display a home screen on the display panel  300 . 
     The main processor  710  may generate digital video data based on second image data received from the second camera sensor  770 . In an embodiment, the main processor  710  may display an image (e.g., a still or moving image) captured by the second camera sensor  770  by outputting the digital video data to the display driving circuit  320  via the display circuit board  310 . 
     The first camera sensor  720  may process a still or moving image obtained by an image sensor and may output the processed image to the main processor  710 . The first camera sensor  720  may be a complementary metal-oxide-semiconductor (CMOS) image sensor or a charge-coupled device (CCD) image sensor. The first camera sensor  720  may be exposed at the bottom of the lower cover  900  by a second camera hole CMH 2  and may thus be able to capture an image of an object or the background below the display device  10 . 
     The cable  314 , which passes through the cable hole CAH of the bracket  600 , may be connected to the main connector  730 . Accordingly, the main circuit board  700  may be electrically connected to the display circuit board  310 . 
     The proximity sensor  740  may be a sensor for detecting whether there exists an object in the proximity of the front surface of the display device  10 . For example, in an embodiment, the proximity sensor  740  may include a light source that outputs light and a light receiver that receives light reflected from an object. The proximity sensor  740  may determine the presence of an object in the proximity of the front surface of the display device  10  based on the amount of light reflected from the object. As the proximity sensor  740  is disposed to overlap (e.g., in the Z direction) with the light-transmitting hole SH, the sub-display area SDA of the display panel  300 , and the light-transmitting area DA 100  of the cover window  100 , the proximity sensor  740  may generate a proximity sensor signal based on whether there exists an object in the proximity of the front surface of the display device  10  and may output the generated proximity sensor signal to the main processor  710 . 
     The illumination sensor  750  may be a sensor for detecting the brightness at the front surface of the display device  10 . The illumination sensor  750  may include a resistor whose resistance varies depending on the brightness of light incident thereupon. In an embodiment, the illumination sensor  750  may determine the brightness at the front surface of the display device  10  based on the resistance of the resistor. Since the illumination sensor  750  is disposed to overlap (e.g., in the Z direction) with the light-transmitting hole SH, the sub-display area SDA of the display panel  300 , and the light-transmitting area DA 100  of the cover window  100 , the illumination sensor  750  may generate an illumination sensor signal based on the brightness at the front surface of the display device  10  and may output the generated illumination sensor signal to the main processor  710 . 
     The iris sensor  760  may be a sensor for determining whether a captured iris image of the user is identical to an iris image stored in advance in a memory. As the iris sensor  760  is disposed to overlap (e.g., in the Z direction) with the light-transmitting hole SH, the sub-display area SDA of the display panel  300 , and the light-transmitting area DA 100  of the cover window  100 , the iris sensor  760  may capture an image of the iris of the user above the display device  10 . The iris sensor  760  may generate an iris sensor signal based on whether the captured iris image of the user is identical to the iris image stored in advance in the memory and may output the generated iris sensor signal to the main processor  710 . 
     The second camera sensor  770  may process image frames obtained by an image sensor, such as a still or moving image, and may output the processed image frames to the main processor  710 . In an embodiment, the second camera sensor  770  may be a CMOS or CCD image sensor. In an embodiment, the pixel quantity of the second camera sensor  770  may be smaller than the pixel quantity of the first camera sensor  720 , and the size of the second camera sensor  770  may also be smaller than the size of the first camera sensor  720 . As the second camera sensor  770  is disposed to overlap (e.g., in the Z direction) with the light-transmitting hole SH of the bracket  600 , the sub-display area SDA of the display panel  300 , and the light-transmitting area DA 100  of the cover window  100 , the second camera sensor  770  may capture an image of an object or the background above the display device  10 . 
     The battery  790  may be disposed not to overlap with the main circuit board  700  in the Z direction. The battery  790  may overlap with the battery hole BR of the bracket  600  (e.g., in the Z direction). 
     A mobile communication module, which can transmit wireless signals to, or receive wireless signals from, at least one of a base station, an external terminal, and a server via a mobile communication network may be further provided in the main circuit board  700 . The wireless signals may include audio signals, video call signals, and various types of data that can be transmitted with text/multimedia messages. 
     The lower cover  900  may be disposed below the main circuit board  700  and the battery  790  (e.g., in the Z direction). The lower cover  900  may be coupled and fixed to the bracket  600 . The lower cover  900  may form the bottom exterior of the display device  10 . In an embodiment, the lower cover  900  may be formed of plastic, a metal, or both. 
     As shown in the embodiment of  FIG. 2 , the second camera hole CMH 2 , which exposes the bottom of the first camera sensor  720 . may be formed in the lower cover  900 . However, embodiments of the present inventive concepts are not limited thereto and the location of the first camera sensor  720  and the locations of the first and second camera holes CMH 1  and CMH 2 , which correspond to the first camera sensor  720  may vary from the locations illustrated in  FIG. 2 . 
       FIG. 4  is a cross-sectional view taken along line A-A′ of  FIG. 3 . 
     Referring to the embodiment of  FIG. 4 , the display panel  300  may include a substrate SUB, a thin-film transistor layer TFTL, a light-emitting element layer EML, air encapsulation layer TFEL, a touch sensing layer TSL, and a polarizing film POL. 
     In an embodiment, the substrate SUB may be formed of an insulating material such as glass, quartz, or a polymer resin. The polymer material may be, for example, polyethersulphone (PES), polyacrylate (PA), polyarylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide (PI), polycarbonate (PC), cellulose triacetate (CAT), cellulose acetate propionate (CAP), a combination thereof. Alternatively, the substrate SUB may include a metallic material. However, embodiments of the present inventive concepts are not limited thereto. 
     The substrate SUB may be a rigid substrate or a flexible substrate that is bendable, foldable, or rollable. In an embodiment in which the substrate SUB is a flexible substrate, the substrate SUB may be formed of polyimide. However, embodiments of the present inventive concepts are not limited thereto. 
     The thin-film transistor layer TFTL may be disposed on the substrate SUB (e.g., in the Z direction). In an embodiment, not only thin-film transistors of each pixel, but also scan lines and data lines may be formed in the thin-film transistor layer TFTL. Each of the thin-film transistors may include a gate electrode, a semiconductor layer, a source electrode, and a drain electrode. 
     The light-emitting element layer EML may be disposed on the thin-film transistor layer TFTL (e.g., in the Z direction). The light-emitting element layer EML may include pixels, which include pixel electrodes, light-emitting layers, and a common electrode, and a pixel-defining film, which defines the pixels. In an embodiment, the light-emitting layers may be organic light-emitting layers including an organic material. In this embodiment, the light-emitting layers may include hole transport layers, organic emission layers, and electron transport layers. As a predetermined voltage is applied to the pixel electrodes and a common voltage is applied to the common electrode via the thin-film transistors in the thin-film transistor layer TFTL, holes from the hole transport layers and electrons from the electron transport layers may move to the organic light-emitting layers. The holes and the electrons may then combine together in the organic light-emitting layers and may thereby emit light. 
     The encapsulation layer TFEL may be disposed on the light-emitting element layer EML (e.g., in the Z direction). The encapsulation layer TFEL may be disposed to cover the thin-film transistor layer TFTL and the light-emitting element layer EML. 
     In an embodiment, the encapsulation layer TFEL may include at least one inorganic film to prevent the penetration of oxygen or moisture into the light-emitting element layer EML. The inorganic film may be a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. However, embodiments of the present inventive concepts are not limited thereto. Also, the encapsulation layer TFEL may include at least one organic film to protect the light-emitting element layer EML from a foreign material such as dust. In an embodiment, the organic film may include an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. However, embodiments of the present inventive concepts are not limited thereto. 
     The touch sensing layer TSL may be disposed on the encapsulation layer TFEL (e.g., in the Z direction). For example, in an embodiment, the touch sensing layer TSL may be disposed directly on the encapsulation layer TFEL. In an embodiment in which the touch sensing layer TSL is disposed directly on the encapsulation layer TFEL, the thickness of the display device  10  can be reduced as compared to an embodiment in which a separate touch panel including the touch sensing layer TSL is attached on the encapsulation layer TFEL, 
     The touch sensing layer TSL may include touch electrodes for detecting a touch from the user in a capacitive manner. For example in an embodiment, the touch sensing layer TSL may detect a touch from the user in at least one of a self-capacitance manner and a mutual-capacitance manner by using the touch electrodes. 
     The polarizing film POL, may be disposed on the touch sensing layer TSL (e.g., in the Z direction) to prevent the degradation of visibility by the reflection of external light. The polarizing film POL may include a linear polarizing plate and a phase delay film such as a quarter-wave (λ/4) plate. 
     The cover window  100  may be disposed on the polarizing film POL (e.g., in the Z direction). In this embodiment, the polarizing film POI: and the cover window  100  may be attached together via an adhesive member such as an optically clear adhesive (OCA) or an optically clear resin (OCR). However, embodiments of the present inventive concepts are not limited thereto. 
       FIG. 5  is a layout view of a touch sensing unit according to an embodiment of the present inventive concepts. 
       FIG. 5  illustrates that the touch sensing layer TSL includes two types of electrodes, for example, driving electrodes TE and sensing electrodes RE, and is driven in a mutual-capacitance manner that applies touch driving signals to the driving electrodes TE and detects mutual capacitance variations in a plurality of touch nodes TN via the sensing electrodes RE. 
     For convenience,  FIG. 5  illustrates only the driving electrodes TE, the sensing electrodes RE, dummy patterns DE, touch lines (TL 1 , TL 2 , and RL), and touch pads (TP 1  and TP 2 ). 
     Referring to the embodiment of  FIG. 5 , the touch sensing layer TSL may include a touch sensing area TSA for detecting a touch from the user and a touch peripheral area TPA around the touch sensing area TSA. For example, as shown in the embodiment of  FIG. 5 , the touch peripheral area TPA may completely surround the touch sensing area TSA (e.g., in the X and Y directions). However, embodiments of the present inventive concepts are not limited thereto. The touch sensing area TSA may overlap with the display area DA (of  FIG. 3 ), and the touch peripheral area TPA may overlap with the non-display area NDA (of  FIG. 3 ). 
     The touch sensing area TSA includes the driving electrodes TE, the sensing electrodes RE, and the dummy patterns DE. The driving electrodes TE and the sensing electrodes RE may be electrodes for forming mutual capacitances to detect a touch from an object or from the user. 
     The sensing electrodes RE may be arranged in parallel in the X direction and the Y direction. For example, in an embodiment, the sensing electrodes RE may be electrically connected in the X direction. The sensing electrodes RE may be connected to one another in the X direction. The sensing electrodes RE may be electrically isolated from one another in the Y direction. Accordingly, a plurality of touch nodes TN ( FIG. 6 ) where mutual capacitances are formed may be disposed at the intersections between the driving electrodes TE and the sensing electrodes RE. The touch nodes TN may correspond to the intersections between the driving electrodes TE and the sensing electrodes RE. 
     The driving electrodes TE may be arranged in parallel in the X direction and the Y direction. In an embodiment, the driving electrodes TE may be electrically isolated from one another in the X direction. The driving electrodes TE may be electrically connected to one another in the Y direction. In one example, referring to  FIGS. 5-6 , the driving electrodes TE may be connected to one another in the Y direction via first connection electrodes BE 1 . 
     The dummy patterns DE may be surrounded (e.g., in the X and Y directions) by the driving electrodes TE or the sensing electrodes RE. The dummy patterns DE may be electrically isolated from the driving electrodes TE or the sensing electrodes RE. The dummy patterns DE may be spaced apart from the driving electrodes TE or the sensing electrodes RE. The dummy patterns DE may be electrically floated. 
       FIG. 5  illustrates that the driving electrodes TE, the sensing electrodes RE, and the dummy patterns DE have a rhombus shape in a plan view. However, embodiments of the present inventive concepts are not limited thereto. For example, in an embodiment, the driving electrodes TE, the sensing electrodes RE, and the dummy patterns DE may have a non-rhombus tetragonal shape, a nontetragonal polygonal shape, a circular shapes, or an elliptical shape in a plan view. 
     The touch lines (TL 1 , TL 2 , and RL) may be disposed in the sensor peripheral area TPA. The touch lines (TL 1 , TL 2 , and RL) may include touch sensing lines RL, which are connected to the sensing electrodes RE, and first touch driving lines TL 1  and second touch driving lines TL 2 , which are connected to the driving electrodes TE. 
     Sensing electrodes RE disposed on one side of the touch sensing area TSA may be connected one-to-one to the touch sensing lines RL. In one example, as illustrated in  FIG. 5 , sensing electrodes RE electrically connected to one another in the X direction and disposed at the right end of the touch sensing area TSA may be connected to the touch sensing lines RL. In an embodiment, the touch sensing lines RL may be connected one-to-one to second touch pads TP 2 . Thus, a touch driving circuit  400  may be electrically connected to the sensing electrodes RE. 
     Driving electrodes TE disposed on one side of the touch sensing area TSA may be connected one-to-one to the first touch driving lines TL 1 , and driving electrodes YE disposed on another side of the touch sensing area TSA may be connected one-to-one to the second touch driving lines TL 2 . In one example, as illustrated in  FIG. 5 , driving electrode YE electrically connected to one another in the Y direction and disposed at the lower end of the touch sensing area TSA may be connected one-to-one to the first touch driving lines TL 1 , and driving electrode TE electrically connected to one another in the Y direction and disposed at the upper end of the touch sensing area TSA may be connected cine-to-one to the second touch driving lines TL 2 . The second touch driving lines TL 2  may be connected to the driving electrodes TE, above the touch sensing area TSA (e.g., in the Y direction) and may pass through the left portion of the touch peripheral area TPA outside the touch sensing area TSA (e.g., in the X direction). 
     The first touch driving lines TL 1  and the second touch driving lines TL 2  may be connected one-to-one to first touch pads TP 1 . Thus, the touch driving circuit  400  may be electrically connected to the driving electrodes TE. As the driving electrodes TE are connected to the first touch driving lines TL 1  and the second touch driving lines TL 2 , on both sides of the touch sensing area TSA, and are thus able to receive touch driving signals, discrepancies that may be caused between touch driving signals applied to the driving electrodes TE on the lower side of the touch sensing area TSA and touch driving signals applied to the driving electrodes TE on the upper side of the touch sensing area TSA, due to RC delays in the touch driving signals, can be prevented. 
     A first touch pad area TPA 1 , in which the first touch pads TP 1  are disposed, may be disposed on one side of a display pad area DPA, in which display pads DP are disposed. A second touch pad area TPA 2 , in which second touch pads TP 2  are disposed, may be disposed on another side of the display pad area DPA. For example, as shown in the embodiment of  FIG. 5 , the first touch pad area TPA 1  may be disposed on a left side of the display pad area DPA (e.g., in the X direction) and the second touch pad area TPA 2  may be disposed on a right side of the display pad area DPA (e.g., in the X direction). However, embodiments of the present inventive concepts are not limited thereto. The display pads DP may be electrically connected to the data lines of the display panel  300 . 
     The display pad area DPA, the first touch pad area TPA 1 , and the second touch pad area TPA 2  may correspond to the pads of the display panel  300 , which are connected to the display circuit board  310  of  FIG. 2 . The display circuit board  310  may be disposed on the display pads DP, the first touch pads TP 1 , and the second touch pads TP 2 . The display pads DP, the first touch pads TP 1 , and the second touch pads TP 2  may be electrically connected to the display circuit board  310  via an anisotropic conductive film and a conductive adhesive member. Thus, the display pads DP, the first touch pads TP 1 , and the second touch pads TP 2  may be electrically connected to the touch driving circuit  400 , which is disposed on the display circuit board  310 . 
     For convenience,  FIG. 5  illustrates that the first sub-display area SDA 1  does not overlap with the driving electrodes TE and the sensing electrodes RE. However, embodiments of the present inventive concepts are not limited thereto. For example, in an embodiment, the second, third, and fourth sub-display areas SDA 2 , SDA 3 , and SDA 4  may not overlap with the driving electrodes TE and the sensing electrodes RE. 
     As the driving electrodes TE and the sensing electrodes RE do not overlap with the first sub-display area SDA 1 , driving electrodes TE adjacent to the first sub-display area SDA 1  may have a different planar shape from driving electrodes that are not adjacent to the first sub-display area SDA 1 . Also, the driving electrodes TE adjacent to the first sub-display area SDA 1  may have a smaller size than the driving electrodes TE that are not adjacent to the first sub-display area SDA 1 . 
     Also, as the sensing electrodes RE do not overlap with the first sub-display area SDA 1 , sensing electrodes RE adjacent to the first sub-display area SDA 1  may have a different planar shape from sensing electrodes RE that are not adjacent to the first sub-display area SDA 1 . Also, the sensing electrodes RE adjacent to the first sub-display area SDA 1  may have a smaller size than the sensing electrodes RE that are not adjacent to the first sub-display area SDA 1 . 
       FIG. 6  is a layout view illustrating touch nodes of  FIG. 5 . 
     Referring to the embodiment of  FIG. 6 , the touch nodes TN may be defined as the intersections between the driving electrodes TE and the sensing electrodes RE. 
     As the driving electrodes TE and the sensing electrodes RE are disposed in the same layer, the driving electrodes TE may be spaced apart from the sensing electrodes RE. That is, gaps may be formed between the driving electrodes TE and the sensing electrodes RE. 
     Also, the dummy patterns DE may be disposed in the same layer as the driving electrodes TE and the sensing electrodes RE. That is, gaps may also be formed between the driving electrodes TE and the dummy patterns DE and between the sensing electrodes RE and the dummy patterns DE. 
     In an embodiment, the first connection electrodes BE 1  may be disposed in a different layer from the driving electrodes TE and the sensing electrodes RE. In an embodiment, the first connection electrodes BE 1  may be formed to be bent at least once. In the embodiment of  FIG. 6 , each of the first connection electrodes BE 1  is formed in the shape of an angle bracket (such as “&lt;” or “&gt;”). However, embodiments of the present inventive concepts are not limited thereto and the planar shape of the first connection electrodes BE 1  may vary. Since each pair of adjacent driving electrodes TE in the Y direction are connected by multiple first connection electrodes BE 1 , the driving electrodes TE can be stably connected in the Y direction, even if one of the first connecting portions CE 1  is disconnected.  FIG. 6  illustrates that every two adjacent driving electrodes TE are connected by one connection electrode BE 1 . However, the number of first connection electrodes BE 1  used to connect every two adjacent driving electrodes TE is not particularly limited. 
     The first connection electrodes BE 1  may overlap with the driving electrodes TE, which are adjacent to one another in the Y direction, in the thickness direction of the substrate SUB (e.g., in the Z direction). The first connection electrodes BE 1  may overlap with the sensing electrodes RE (e.g., in the Z direction). First and second sides of each of the first connection electrodes BE 1  may be connected to a pair of adjacent driving electrodes TE in the Y direction via first touch contact holes TCNT 1 . 
     Due to the presence of the first connection electrodes BE 1 , the driving electrodes TE may be electrically isolated from the sensing electrodes RE at the intersections between the driving electrodes TE and the sensing electrodes RE. Accordingly, mutual capacitances may be formed between the driving electrodes TE and the sensing electrodes RE. 
     The driving electrodes TE, the sensing electrodes RE, and the first connection electrodes BE 1  may have a mesh or fishnet shape in a plan view. Also, the dummy patterns DE may have a mesh or fishnet shape in a plan view. Thus, the driving electrodes TE, the sensing electrodes RE, the first connection electrodes BE 1 , and the dummy patterns DE may not overlap with emission units (EA 11 , EA 12 , EA 13 , and EA 14 ) of each first pixel PX 1 . Accordingly, the brightness of light emitted from the emission units (EA 11 , EA 12 , EA 13 , and EA 14 ) can be prevented from decreasing due to being blocked by the driving electrodes TE, the sensing electrodes RE, the first connection electrodes BE 1 , and the dummy patterns DE. 
     As shown in the embodiment of  FIG. 6 , a first pixel PX 1  may include a first emission unit EA 11 , which emits light of a first color, a second emission unit EA 12 , which emits light of a second color, a third emission unit EA 13 , which emits light of a third color, and a fourth emission unit EA 14 , which emits light of the second color. In one example, the first, second, and third colors may be red, green, and blue, respectively.  FIG. 6  illustrates that the second and fourth emission units EA 12  and EA 14  emit light of the same color. However, embodiments of the present inventive concepts are not limited thereto and the first to fourth emission units EA 11  to EA 14  may emit various different colors. For example, the second and fourth emission units EA 12  and EA 14  may emit light of different colors. 
     The first and second emission units EA 11  and EA 12  may be adjacent to each other in a fourth direction DR 4  that extends between the X and Y directions and is perpendicular to the Z direction. For example, the fourth direction DR 4  may be inclined at an angle of 45 degrees with respect to the X direction. The third and fourth emission units EA 13  and EA 14  may be adjacent to each other in the fourth direction DR 4 . The first and fourth emission units EA 11  and EA 14  may be adjacent to each other in a fifth direction DR 5  that extends between the X and Y directions and is perpendicular to the fourth direction DR 4  and the Z direction. The second and third emission units EA 12  and EA 13  may be adjacent to each other in the fifth direction DR 5 . 
     In an embodiment, the first, second, third, and fourth emission units EA 11 , EA 12 , EA 13 , and EA 14  may have a rhombus or rectangular shape in a plan view. However, embodiments of the present inventive concepts are limited thereto. For example, in an embodiment, the first, second, third, and fourth emission units EA 11 , EA 12 , EA 13 , and EA 14  may have a nontetragonal polygonal shape, a circular shape, or an elliptical shape in a plan view.  FIG. 6  illustrates that the third emission unit EA 13  has a largest size and the second and fourth emission units EA 12  and EA 14  have a smallest size. However, embodiments of the present inventive concepts are not limited thereto and the respective sizes of the first to fourth emission units EA 11  to EA 14  may vary. 
     In an embodiment, second emission units EA 12  and fourth emission units EA 14  may be arranged in odd-numbered rows. The second emission units EA 12  and the fourth emission units EA 14  may be arranged parallel to one another in the X direction, in each of the odd-numbered rows. The second emission units EA 12  and the fourth emission units EA 14  may be alternately arranged in each of the odd-numbered rows. Each of the second emission units EA 12  may have relatively long sides in the fourth direction DR 4  and relatively short sides in the fifth direction DR 5 , and each of the fourth emission units EA 14  may have relatively short sides in the fourth direction DR 4  and relatively long sides in the fifth direction DR 5 . The fourth direction DR 4  may be a diagonal direction between the X direction and the Y direction and may be inclined at an angle of 45 degrees with respect to the X direction. The fifth direction DR 5  may be a direction orthogonal to the fourth direction DR 4 . 
     First emission units EA 11  and third emission units EA 13  may be arranged in even-numbered rows. The first emission units EA 11  and the third emission units EA 13  may be arranged parallel to one another in the X direction, in each of the even-numbered rows. The first emission units EA 11  and the third emission units EA 13  may be alternately arranged in each of the even-numbered rows. 
     The second emission units EA 12  and the fourth emission units EA 14  may be arranged in odd-numbered columns. The second emission units EA 12  and the fourth emission units EA 14  may be arranged parallel to one another in the Y direction, in each of the odd-numbered columns. The second emission units EA 12  and the fourth emission units EA 14  may be alternately arranged in each of the odd-numbered columns. 
     The first emission units EA 11  and the third emission units EA 13  may be arranged in even-numbered columns. The first emission units EA 11  and the third emission units EA 13  may be arranged parallel to one another in the Y direction, in each of the even-numbered columns. The first emission units EA 11  and the third emission units EA 13  may be alternately arranged in each of the even-numbered columns. 
       FIG. 7  is a cross-sectional view taken along line B-B′ of  FIG. 6 . 
     Referring to  FIG. 7 , a barrier film BR may be disposed on the substrate SUB (e.g., directly thereon in the Z direction). The substrate SUB may be formed of an insulating material. such as a polymer resin. In one example, the substrate SUB may be formed of polyimide. The substrate SUB may be a flexible substrate that is bendable, foldable, or rollable. 
     The barrier film BR is a film for protecting the transistors of the thin-film transistor layer TFTL and light-emitting layers  172  of the light-emitting element layer EML from moisture that may infiltrate into the substrate SUB, which is susceptible to moisture. In an embodiment, the barrier film BR may include a plurality of inorganic films that are alternately stacked. In one example, the barrier film BR may be formed as a multilayer in which one or more inorganic films such as a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, and/or an aluminum oxide layer are alternately stacked. 
     Thin-film transistors ST 1  may be disposed on the barrier film BR. The thin-film transistors ST 1  may include active layers ACT 1 , gate electrodes G 1 , source electrodes S 1 , and drain electrodes D 1 . 
     The active layers ACT 1 , the source electrodes S 1 , and the drain electrodes Di of the thin-film transistors ST 1  are disposed on the barrier film BR (e.g., directly thereon in the Z direction). In an embodiment, the active layers ACT 1  of the thin-film transistors ST 1  may include polycrystalline silicon, monocrystalline silicon, low-temperature polycrystalline silicon, amorphous silicon, or an oxide semiconductor. However, embodiments of the present inventive concepts are not limited thereto. The active layers ACT 1 , which overlap with the gate electrodes G 1  in the thickness direction of the substrate SUB (e.g., the Z direction.) may be defined as channel regions. The source electrodes S 1  and the drain electrodes D 1  may be regions that do not overlap with the gate electrodes G 1  in the Z direction. In an embodiment, the source electrodes S 1  and the drain electrodes D 1  may include a silicon or oxide semiconductor doped with ions or impurities and may thus have conductivity. 
     A gate insulating film  130  may be disposed on the active layers ACT 1 , the source electrodes S 1 , and the drain electrodes D 1  of the thin-film transistors ST 1  (e.g., directly thereon. in the Z direction). In an embodiment, the gate insulating film  130  may be formed as an inorganic film such as, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. However, embodiments of the present inventive concepts are not limited thereto. 
     The gate electrodes G 1  of the thin-film transistors ST 1  may be disposed on the gate insulating film  130  (e.g., directly thereon in the Z direction). The gate electrodes G 1  may overlap with the active layers ACT 1  in the Z direction. In an embodiment, the gate electrodes G 1  may be formed as single layers or multilayers including molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), or an alloy thereof. 
     A first interlayer insulating film  141  may be disposed on the gate electrodes G 1  of the thin-film transistors ST 1  (e.g., directly thereon in the Z direction). In an embodiment, the first interlayer insulating film  141  may be formed as an inorganic film such as, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. The first interlayer insulating film  141  may be formed as a multilayer inorganic film. 
     Capacitor electrodes CAB may be disposed on the first interlayer insulating film  141  (e.g., directly thereon in the Z direction). As shown in the embodiment of  FIG. 7 , the capacitor electrodes CAE may overlap with the gate electrodes G 1  of the first thin-film transistors ST 1  in the Z direction. As the first interlayer insulating film  141  has a predetermined dielectric constant, capacitors may be formed by the capacitor electrodes CAE, the gate electrodes G 1 , and the first interlayer insulating film  141 . In an embodiment, the capacitor electrodes CAE may be formed as single layers or multilayers including Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, or an alloy thereof. However, embodiments of the present inventive concepts are not limited thereto. 
     A second interlayer insulating film  142  may be disposed on the capacitor electrodes CAE (e.g., directly thereon in the Z direction). In an embodiment, the second interlayer insulating film  142  may be formed as an inorganic film such as, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. However, embodiments of the present inventive concepts are not limited thereto. The second interlayer insulating film  142  may be formed as a multilayer inorganic film. 
     First anode connection electrodes ANDE 1  may be disposed on the second interlayer insulating film  142  (e.g., directly thereon in the Z direction). The first anode connection electrodes ANDE 1  may be connected to the drain electrodes D 1  of the thin-film transistors ST 1  through first connecting contact holes ANCT 1 , which penetrate the gate insulating film  130 , the first interlayer insulating film  141 , and the second interlayer insulating film  142 . In an embodiment, the first anode connection electrodes ANDE 1  may be formed as single layers or multilayers including Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, or an alloy thereof. However, embodiments of the present inventive concepts are not limited thereto. 
     A first planarization film  160  for planarizing any height differences formed by the thin-film transistors ST 1  may be disposed on the first anode connection electrodes ANDE 1  (e.g., directly thereon in the Z direction). In an embodiment, the first planarization film  160  may be formed as an organic film including an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. 
     Second anode connection electrodes ANDE 2  may be disposed on the first planarization film  160  (e.g., directly thereon in the Z direction). The second anode connection electrodes ANDE 2  may be connected to the first anode connection electrodes ANDE 1  through second connecting contact holes ANCT 2 , which penetrate the first planarization film  160 . In an embodiment, the second anode connection electrodes ANDE 2  may be formed as single layers or multilayers including Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, or an alloy thereof. However, embodiments of the present inventive concepts are not limited thereto. 
     A second planarization film  180  may be disposed on the second anode connection electrodes ANDE 2  and the first planarization film  160  (e.g., directly thereon in the Z direction). In an embodiment, the second planarization film  180  may be formed as an organic film including an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. However, embodiments of the present inventive concepts are not limited thereto. 
     Light-emitting elements LEL and a bank  190  may be disposed on the second planarization film  180  (e.g., directly thereon in the Z direction). The light-emitting elements LEL include a pixel electrodes  171 , light-emitting layers  172 , and a common electrode  173 . 
     The pixel electrodes  171  may be disposed on the second planarization film  180  (e.g., directly thereon in the Z direction). The pixel electrodes  171  may be connected to the second anode connection electrodes ANDE 2  through third connecting contact holes ANCT 3 , which penetrate the second planarization film  180 . 
     In an embodiment that includes a top emission structure that emits light in a direction from the light-emitting layers  172  to the common electrode  173 , the pixel electrodes  171  may be formed of a metallic material with high reflectance such as a stack of Al and Ti (e.g., Ti/Al/Ti), a stack of Al and indium tin oxide (ITO) (e.g., ITO/Al/ITO), a silver-palladium-copper (APC) alloy, or a stack of an APC alloy and ITO (e.g., (TO/APC/ITO). However, embodiments of the present inventive concepts are not limited thereto. 
     The bank  190  may be formed to divide the pixel electrodes  171  on the second planarization film  180  to define first, second, third, and fourth emission units EA 11 , EA 12 , EA 13 , and EA 14 . The bank  190  may be disposed to cover the edges of each of the pixel electrodes  171  and to expose a central portion of the pixel electrodes  171 . In an embodiment, the bank  190  may be formed as an organic film including an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. However, embodiments of the present inventive concepts are not limited thereto. 
     Each of the first, second, third, and fourth emission units EA 11 , EA 12 , EA 13 , and EA 14  may refer to a region in which one of the pixel electrodes  171 , one of the light-emitting layers  172 , and the common electrode  173  are sequentially stacked (e.g., in the Z direction) so that holes from the corresponding pixel electrode  171  and electrons from the common electrode  173  combine together in the corresponding light-emitting layer  172  and thus emit light. 
     The light-emitting layers  172  may be disposed on the pixel electrodes  171  and the bank  190  (e.g., directly thereon). In an embodiment, the light-emitting layers  172  may include an organic material and may emit light of a predetermined color. In one example, the light-emitting layers  172  may include hole transport layers, organic material layers, and electron transport layers. 
     The common electrode  173  may be disposed on the light-emitting layers  172  (e.g., directly thereon in the Z direction). The common electrode  173  may be disposed to cover the light-emitting layers  172 . In an embodiment, the common electrode  173  may be a layer formed in common for all the first, second, third, and fourth emission units EA 11 , EA 12 , EA 13 , and EA 14 . In an embodiment, a capping layer may be formed on the common electrode  173  (e.g., directly thereon in the Z direction). 
     In an embodiment including the top emission structure, the common electrode  173  may be formed of a transparent conductive oxide (TCO) capable of transmitting light therethrough, such as ITO or indium zinc oxide (IZO), or a semitransparent conductive material such as magnesium (Mg), silver (Ag), or an alloy thereof. However, embodiments of the present inventive concepts are not limited thereto. In an embodiment where the common electrode  173  is formed of a semitransparent metallic material, the emission efficiency of the light-emitting elements LEL can be increased due to microcavities. 
     The encapsulation layer TFEL may be disposed on the common electrode  173  (e.g., directly thereon in the Z direction). The encapsulation layer TFEL may include at least one inorganic film to prevent the infiltration of oxygen or moisture into the light-emitting element layer EML. Also, the encapsulation layer TFEL may include at least one organic film to protect the light-emitting element layer EML from a foreign material such as dust. In one example, the encapsulation layer TFEL may include a first encapsulation inorganic film TFE 1 , an encapsulation organic film TFE 2 , and a second encapsulation inorganic film TFE 3 . 
     The first encapsulation inorganic film TFE 1  may be disposed on the common electrode  173  (e.g., directly thereon in the Z direction), the encapsulation organic film TFE 2  may be disposed on the first encapsulation inorganic film TFE 1  (e.g., directly thereon in the Z direction), and the second encapsulation inorganic film TFE 3  may be disposed on the encapsulation organic film TFE 2  (e.g., directly thereon in the Z direction). In an embodiment, the first and second encapsulation inorganic films TFE 1  and TFE 3  may be formed as multilayers in which one or more inorganic films such as a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, and/or an aluminum oxide layer are alternately stacked. However, embodiments of the present inventive concepts are not limited thereto. The encapsulation organic film TFE 2  may be formed as an organic film including an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. However, embodiments of the present inventive concepts are not limited thereto. In sonic embodiments, the numbers of the encapsulation organic film and the encapsulation inorganic film may vary. 
     The touch sensing layer TSL may be disposed on the encapsulation layer TFEL (e.g., directly thereon in the Z direction). The touch sensing layer TSL may include a first touch insulating film TINS 1 , first connection electrodes BE 1 , a second touch insulating film TINS 2 , driving electrodes TE, sensing electrodes RE, and a third touch insulating film TINS 3 . 
     In an embodiment, the first touch insulating film TINS 1  may be formed as an inorganic film such as, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. However, embodiments of the present inventive concepts are not limited thereto. 
     The first connection electrodes BE 1  may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). In an embodiment, the first connection electrodes BE 1  may be formed as single layers or multilayers including Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, or an alloy thereof. However, embodiments of the present inventive concepts are not limited thereto. 
     The second touch insulating film TINS 2  may be disposed on the first connection electrodes BE 1  (e.g., directly thereon in the Z direction). In an embodiment, the second touch insulating film TINS 2  may be formed as an inorganic film such as, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. Alternatively, the second touch insulating film TINS 2  may be formed as an organic film including an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. However, embodiments of the present inventive concepts are not limited thereto. 
     The driving electrodes TE and the sensing electrodes RE may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). Not only the driving electrodes TE and the sensing electrodes RE, but also, the dummy patterns DE, the first touch driving lines TL 1 , the second touch driving lines TL 2 , and the touch sensing lines RL of  FIG. 4 , may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). The driving electrodes TE and the sensing electrodes RE may be formed as single layers or multilayers including Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, or an alloy thereof. 
     The driving electrodes TE and the sensing electrodes RE may overlap with the first connection electrodes BE 1  in the Z direction. The driving electrodes TE may be connected to the first connection electrodes BE 1  through first touch contact holes TCNT 1 , which penetrate the first touch insulating film TINS 1 . 
     The third touch insulating film TINS 3  may be formed on the driving electrodes TE and the sensing electrodes RE (e.g., directly thereon). The third touch insulating film TINS 3  may planarize height differences formed by the driving electrodes TE, the sensing electrodes RE, and the first connection electrodes BE 1 . In an embodiment, the third touch insulating film TINS 3  may be formed as an organic film including an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. However, embodiments of the present inventive concepts are not limited thereto. 
     The polarizing film POI, may be disposed on the touch sensing layer TSL to prevent the degradation of visibility by the reflection of external light. In an embodiment, the polarizing film POE, may include a linear polarizing plate and a phase delay film such as a λ/4 plate. 
       FIG. 8  is a layout view of an area A of  FIG. 5 . 
       FIG. 8  illustrates the first sub-display area SDA 1 , driving electrodes TE and sensing electrodes RE adjacent to the first sub-display area SDA 1 , and auxiliary electrodes TAR 
     Referring to  FIG. 8 , the first sub-display area SDA 1  may include a plurality of sub-touch electrodes. In one example, the first sub-display area SDA 1  may include a first sub-driving electrode STE 1 , a second sub-driving electrode STE 2 , sub-sensing electrodes SRE, and auxiliary electrodes TAE. 
     The first sub-driving electrode STE 1  may be disposed in an upper portion of the first sub-display area SDA 1 . The width of the first sub-driving electrode STE 1  may decrease from the edge to the center of the first sub-display area SDA 1 . In one example, the first sub-driving electrode STE 1  may have a fanlike shape in a plan view (e.g., in a plane defined in the X and Y directions). 
     The second sub-driving electrode STE 2  may be disposed in a lower portion of the first sub-display area SDA 1  (e.g., in the Y direction). The width of the second sub-driving electrode STE 2  (e.g., length in the X direction) may decrease from the edge to the center of the first sub-display area SDA 1 . In one example, the second sub-driving electrode STE 2  may have a fanlike shape in a plan view (e.g., in a plane defined in the X and Y directions). 
     In an embodiment, the first and second sub-driving electrodes STE 1  and STE 2  may be symmetrical with each other in the Y direction with respect to the center of the first sub-display area SDA 1 . The first and second sub-driving electrodes STE 1  and STE 2  may be disposed to be spaced apart from each other (e.g., in the Y direction). 
     The sub-sensing electrodes SRE may be disposed on left and right portions of the first sub-display area SDA 1  (e.g., in the X direction). The width of the sub-sensing electrodes SRE (e.g., length in the Y direction) may decrease from the edge towards the center of the first sub-display area SDA 1 . The sub-sensing electrodes SRE may be disposed between the first and second sub-driving electrodes STE 1  and STE 2 . 
     The adjacent first and second sub-driving electrodes STE 1  and STE 2  may be connected via a plurality of second connection electrodes BE 2  (of  FIGS. 11A and 11B ) that overlap with the sub-sensing electrodes SRE (e.g., in the Z direction). That is, due to the second connection electrodes BE 2 , the first and second sub-driving electrodes STE 1  and STE 2  may be electrically isolated from the sub-sensing electrodes SRE at the intersections between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE. Accordingly, mutual capacitances may be formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE. 
     The first sub-display area SDA 1  may include a plurality of auxiliary electrodes TAE. For example, as shown in the embodiment of  FIG. 8 , the auxiliary electrodes TAE may include first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4 . However, embodiments of the present inventive concepts are not limited thereto and the numbers of the auxiliary electrodes TAE may vary. 
     The first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may be disposed along the edge of the first sub-display area SDA 1 . The auxiliary electrodes TAE, such as the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4 , may be disposed between the first pixels PX 1  ( FIG. 9 ) of the main display area MDA and the second pixels PX 2  ( FIG. 9 ) of the sub-display areas, such as the first sub-display area SDA 1 . The first auxiliary electrode TAE 1  may be disposed on an upper portion of the edge of the first sub-display area SDA 1  (e.g., in the Y direction), and the second auxiliary electrode TAE 2  may be disposed on a lower portion of the edge of the first sub-display area SDA 1  (e.g., in the Y direction). The third auxiliary electrode TAE 3  may be disposed on a left portion of the edge of the first sub-display area SDA 1  (e.g., in the X direction), and the fourth auxiliary electrode TAE 4  may be disposed on a right portion of the edge of the first sub-display area SDA 1  (e.g., in the X direction). 
     The first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may be disposed to be spaced apart from one another. That is, the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may be electrically isolated from one another. 
     As shown in the embodiment of  FIG. 8 , the first auxiliary electrode TAE 1  may be disposed between the first sub-driving electrode STE 1  and the driving electrode TE on the upper outer side of the first sub-display area SDA 1 . The first auxiliary electrode TAE 1  may be connected to the first sub-driving electrode STE 1  and the driving electrode TE on the upper outer side of the first sub-display area SDA 1 . As shown in the embodiment of  FIG. 8 , the second auxiliary electrode TAE 2  may be disposed between the second sub-driving electrode STE 2  and the driving electrode TE on the lower outer side of the first sub-display area SDA 1 . The second auxiliary electrode TAE 2  may be connected to the second sub-driving electrode STE 2  and the driving electrode TE on the lower outer side of the first sub-display area SDA 1 . As the first and second sub-driving electrodes STE 1  and STE 2  are connected by multiple second connection electrodes BE 2 , the driving electrodes TE and the first and second sub-driving electrodes STE 1  and STE 2  may be electrically connected to one another. 
     The third auxiliary electrode TAE 3  may be between the sensing electrode RE outside the left side of the first sub-display area SDA 1  and the sub-sensing electrode SRE (e.g., in the X direction). That is, the third auxiliary electrode TAE 3  may be connected to the sensing electrode RE outside the left side of the first sub-display area SDA 1  and the sub-sensing electrode SRE. The fourth auxiliary electrode TAE 4  may be between the sensing electrode RE outside the right side of the first sub-display area SDA 1  and the sub-sensing electrode SRE (e.g., in the X direction). The fourth auxiliary electrode TAE 4  may be connected to the sensing electrode RE outside the right side of the first sub-display area SDA 1  and the sub-sensing electrode SRE. Accordingly, the sensing electrodes RE and the third and fourth sub-driving electrodes STE 3  and STE 4  may be electrically connected to one another. 
     The first sub-display area SDA 1  may include a plurality of light-transmitting areas TA ( FIGS. 9 and 11A ) to provide light to an optical device such as the proximity sensor  740 . Accordingly, the ratio of the area occupied by the first and second sub-driving electrodes STE 1  and STE 2  per unit area may be less than the ratio of the area occupied by the driving electrodes TE per unit area. Also, the ratio of the area occupied by the sub-sensing electrodes SRE per unit area may be less than the ratio of the area occupied by the sensing electrodes RE per unit area. As a result, mutual capacitances formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE, in the first sub-display area SDA 1 , may be smaller than mutual capacitances formed between the driving electrodes TE and the sensing electrodes RE, in the main display area MDA, and thus, touch sensitivity may be relatively low in the first sub-display area SDA 1 . 
     As illustrated in the embodiment of  FIG. 8 , as the first and second auxiliary electrodes TAE 1  and TAE 2 , which are connected to the first and second sub-driving electrodes STE 1  and STE 2 , respectively, and the third and fourth auxiliary electrodes TAE 3  and TAE 4 , which are connected to the sub-sensing electrodes SRE, are provided along the edge of the first sub-display area SDA 1 , the mutual capacitances formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE, in the first sub-display area SDA 1 , can be strengthened. As a result, the touch sensitivity in the first sub-display area SDA can be increased. 
     The second, third, and fourth sub-display areas SDA 2 , SDA 3 , and SDA 4  of  FIGS. 2 and 3  may be substantially the same as the first sub-display area SDA 1  of  FIG. 8 , and thus, detailed descriptions thereof will be omitted for convenience of explanation. 
       FIG. 9  is a layout view of an area A- 1  of  FIG. 8 .  FIG. 10A  is a cross-sectional view taken along line C-C′ of  FIG. 9 . 
     Referring to  FIGS. 9 and 10A , the first sub-display area SDA 1  may include second pixels PX 2 , the first sub-driving electrode STE 1 , light-transmitting areas TA, and the first auxiliary electrode TAE 1 . 
     Each of the second pixels PX 2  may include a first emission unit EA 21 , which emits light of the first color, a second emission unit EA 22 , which emits light of the second color, a third emission unit EA 23 , which emits light of the third color, and a fourth emission unit EA 24 , which emits light of the second color.  FIG. 9  illustrates that the second and fourth emission units EA 21  and EA 24  emit light of the same color. However, embodiments of the present inventive concepts are not limited thereto. Alternatively, the second and fourth emission units EA 22  and EA 24  may emit light of different colors. 
     The first and second emission units EA 21  and EA 22  may be adjacent to each other in the X direction, the first and fourth emission units EA 21  and EA 24  may be adjacent to each other in the X direction, the second and third emission units EA 22  and EA 23  may be adjacent to each other in the X direction, and the third and fourth emission units EA 23  and EA 24  may be adjacent to each other in the X direction. The second and fourth emission units EA 22  and EA 24  may be adjacent to each other in the Y direction and may be disposed between the first emission unit EA 21  and the third emission unit EA 23  in the X direction. 
     The third emission unit EA 23  may have a largest size, and the second and fourth emission units EA 22  and EA 24  may have a smallest size. The second and fourth emission units EA 22  and EA 24  may have substantially the same size. However, embodiments of the present inventive concepts are not limited thereto and the sizes of the first to fourth emission units EA 21  to EA 24  may vary. 
     In an embodiment, the first emission unit EA 22  of each of the second pixels PX 2  may have a larger size (e.g., area in a plane defined in the X and Y directions) than a first emission unit EA 11  of each of first pixels PX 1 . The second emission unit EA 22  of each of the second pixels PX 2  may have a larger size (e.g., area in a plane defined in the X and Y directions) than a second emission unit EA 12  of each of the first pixels PX 1 . The third emission unit EA 23  of each of the second pixels PX 2  may have a larger size (e.g., area in a plane defined in the X and Y directions) than a third emission unit EA 13  of each of the first pixels PX 1 . The fourth emission unit EA 24  of each of the second pixels PX 2  may have a larger size (e.g., area in a plane defined in the X and Y directions) than a fourth emission unit EA 14  of each of the first pixels PX 1 . 
     The resolution of the main display area MDA may be higher than the resolution of the first sub-display area SDA 1 . That is, the number of first pixels PX 1  per unit area of the main display area MDA may be greater than the number of second pixels PX 2  per unit area of the first sub-display area SDA 1 . The number of emission units (EA 11 , EA 12 , EA 13 , and EA 14 ) per unit area of the main display area MDA may be less than the number of emission units (EA 21 , EA 22 , EA 23 , and EA 24 ) per unit area of the first sub-display area SDA 1 . 
     As shown in the embodiment of  FIG. 9 , a pair of second pixels PX 2  may be disposed adjacent to each other in the Y direction. A first emission unit EA 21  of a first second pixel of the pair of second pixels PX 2  may be adjacent to a third emission unit EA 23  of the second second pixel of the pair of second pixels PX 2  in the Y direction. A fourth emission unit EA 24  of a first second pixel of the pair of second pixels PX 2  may be adjacent to a fourth emission unit EA 24  of the second second pixel of the pair of second pixels PX 2  in the Y direction. 
     The first sub-driving electrode STE 1  may be disposed to surround at least one of the first, second, third, and fourth emission units EA 21 , EA 22 , EA 23 , and EA 24  of each of the second pixels PX 2 . For example, in one embodiment, the first sub-driving electrode STE 1  may be disposed to surround the first and third emission units EA 21  and EA 23  of each of the second pixels PX 2 . Also, the first sub-driving electrode STE 1  may be disposed to surround the second and fourth emission units EA 22  and EA 24  of each of the second pixels PX 2 . 
     In an embodiment, the first sub-driving electrode STE 1  may be disposed between the first and second emission units EA 21  and EA 22  of each of the second pixels PX 2 , between the first and fourth emission units EA 21  and EA 24  of each of the second pixels PX 2 , between the second and third emission units EA 22  and EA 23  of each of the second pixels PX 2 , and between the third and fourth emission units EA 23  and EA 24  of each of the second pixels PX 2 . As shown in the embodiment of  FIG. 9 , the first sub-driving electrode STE 1  may not be disposed between the second and fourth emission units EA 22  and EA 24  of each of the second pixels PX 2 . 
     The first sub-driving electrode STE 1  may be disposed between the first emission unit EA 21  of a first second pixel of a pair of second pixels PX 2  and the third emission unit EA 23  of the second second pixel of the pair of second pixels PX 2 . Also, the first sub-driving electrode STE 1  may be disposed between the third emission unit EA 23  of a first second pixel of the pair of second pixels PX 2  and the first emission unit EA 21  of the second second pixel of the pair of second pixels PX 2 . Also, the first sub-driving electrode STE 1  may be disposed between the fourth emission units EA 24  of the pair of second pixels PX 2 . 
     The first sub-driving electrode STE 1  may be disposed to surround the edges of each pair of second pixels PX 2 . A portion of the first sub-driving electrode STE 1  that surround two pairs of second pixels PX 2  that are adjacent to each other in the X direction may be connected to each other. A portion of the first sub-driving electrode STE 1  that surround two pairs of second pixels PX 2  that are adjacent to each other in the Y direction may be connected to each other. 
     The light-transmitting areas TA may be defined by the first sub-driving electrode STE 1 . The light-transmitting areas TA may include a material capable of transmitting light therethrough. In an embodiment, each of the light-transmitting areas TA may include at least a portion of the substrate SUB, the barrier film BR, the gate insulating film  130 , the first interlayer insulating film  141 , the second interlayer insulating film  142 , the first planarization film  1 . 60 , the. second planarization film  180 , the bank  190 , the first encapsulation inorganic film TFE 1  the encapsulation organic film TFE 2 , the second encapsulation inorganic film TFE 3 , the first touch insulating film TNS 1 , the second touch insulating film TINS 2 , and the third touch insulating film TINS 3 . As a result, light incident upon the light-transmitting areas TA may pass through the light-transmitting areas TA. 
     The first auxiliary electrode TAE 1  may be disposed between the first sub-driving electrode STE 1  and the driving electrodes TE. The first auxiliary electrode TAE 1  may be connected to the first sub-driving electrode TAE 1  and the driving electrodes TE. 
     In an embodiment, the maximum width of the first auxiliary electrode TAE 1  may be greater than the maximum widths of the first sub-driving electrode STE 1  and the driving electrodes TE. Similarly, the maximum width of the second auxiliary electrode TAE 2  may be greater than the maximum widths of the second sub-driving electrode TAE 2  and the driving electrodes TE. Similarly, the maximum width of the third and fourth auxiliary electrodes TAE 3  and TAE 4  may be greater than the maximum widths of the sub-sensing electrodes SRE and the sensing electrodes RE. Due to the addition of the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4 , the mutual capacitances formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE, in the first sub-display area SDA 1 , can be strengthened. 
     As shown in the embodiment of  FIG. 10A , the first sub-driving electrode STE 1  and the first auxiliary electrode TAE 1  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). The second sub-driving electrode STE 2 , the sub-sensing electrodes SRE, and the second, third, and fourth auxiliary electrodes TAE 2 , TAE 3 , and TAE 3  may also be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). That is, the first and second sub-driving electrodes STE 1  and STE 2 , the sub-sensing electrodes SRE, the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may be formed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
     A thin-film transistor ST 1 , a capacitor electrode CAE, a first anode connection electrode ANDE 1 , a second anode connection electrode ANDE 2 , and a third anode connection electrode ANDE 3  of a second pixel PX 2  of  FIG. 10A  may be substantially the same as their respective counterparts of  FIG. 7 , and thus, detailed descriptions thereof will be omitted for convenience of explanation. Also, first, second, third, and fourth emission units EA 21 , EA 22 , EA 23 , and EA 24  of the second pixel PX 2  of  FIG. 10A  may be substantially the same as their respective counterparts of  FIG. 7 , and thus, detailed descriptions thereof will be omitted for convenience of explanation. 
     As illustrated in the embodiments of  FIGS. 9 and 10A , as the first auxiliary electrode TAE 1  is disposed in extra space in the first sub-display area SDA 1  to be connected to the first sub-driving electrode STE 1 , the mutual capacitances formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE, in the first sub-display area SDA 1 , can be strengthened. Accordingly, the touch sensitivity in the first sub-display area SDA 1  can be increased. 
       FIG. 10B  is a cross-sectional view taken along line C-C′ of  FIG. 9 . 
     The embodiment of  FIG. 10B  differs from the embodiment of  FIG. 10A  in that the polarizing film POL is not disposed in the first sub-display area SDA 1 . The embodiment of  FIG. 10B  will hereinafter be described, focusing mainly on the differences with the embodiment of  FIG. 10A . 
     Referring to  FIG. 10B , the polarizing film POL may not be disposed in the first sub-display area SDA 1  to provide more light to an optical device disposed in the first sub-display area SDA 1 , such as the proximity sensor  740 . As a result, the polarizing film POL may not overlap (e.g., in the Z direction) with first, second, third, and fourth emission units EA 21 , EA 22 , EA 23 , and EA 24  of a second pixel PX 2  in the first sub-display area SDA 1 . Also, the polarizing film POL may not overlap (e.g., in the Z direction), with the second sub-driving electrode STE 2  and the sub-sensing electrodes SRE. Also, the polarizing film POL which may include a polarizing plate, may not overlap (e.g., in the Z direction) with the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4 . 
       FIG. 11A  is a layout view of an area A- 2  of  FIG. 8 .  FIG. 11B  is a layout view of an area B- 1  of  FIG. 11A .  FIG. 12  is a cross-sectional view taken along line D-D′ of  FIG. 11B . 
     Referring to the embodiments of  FIGS. 11A, 11B, and 12 , the first and second sub-driving electrodes STE 1  and STE 2  may be connected to each other by a plurality of second connection electrodes BE 2 . Since the first and second sub-driving electrodes STE 1  and STE 2  are connected to each other by a plurality of second connection electrodes BE 2 , the first and to second sub-driving electrodes STE 1  and STE 2  can stably remain connected even if one of the second connection electrodes BE 2  is disconnected.  FIG. 11A  illustrates that the first and second sub-driving electrodes STE 1  and STE 2  are connected to each other by two second connection electrodes BE 2 . However, embodiments of the present inventive concepts are not limited thereto and the number of second connection electrodes BE 2  connected the first and second sub-driving electrodes STE 1  and STE 2  may vary. 
     The first sub-driving electrode STE 1  may be connected to first sides of the second connection electrodes BE 2  through second touch contact holes TCNT 2 . The second sub-driving electrode STE 2  may be connected to second sides of the second connection electrodes BE 2  through third touch contact holes TCNT 3 . The second connection electrodes BE 2  may overlap with the sub-sensing electrodes SRE (e.g., in the Z direction). 
     The first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). That is, the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE may be disposed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
     The second connection electrodes BE 2  may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). That is, the second connection electrodes BE 2  may be formed in the same layer as, and include the same material as, the first connection electrodes BE 1 . 
     The second touch contact holes TCNT 2  may be holes that penetrate the second touch insulating film TINS 2  to expose the second connection electrodes BE 2 . The first sub-driving electrode STE 1  may be connected to the second connection electrodes BE 2  through the second touch contact holes TCNT 2 . 
     The third touch contact holes TCNT 3  may be holes that penetrate the second touch insulating film TINS 2  to expose the second connection electrodes BE 2 . The second sub-driving electrode STE 2  may be connected to the second connection electrodes BE 2  through the third touch contact holes TCNT 3 . 
     Due to the presence of the second connection electrodes BE 2 , the first and second sub-driving electrodes STE 1  and STE 2  may be electrically isolated from the sub-sensing electrodes SRE. Thus, mutual capacitances may be formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE. 
     The number of second pixels PX 2  surrounded by the first sub-driving electrode STE 1  may decrease from the edge towards the center of the first sub-display area SDA 1 . Also, the number of second pixels PX 2  surrounded by the second sub-driving electrode STE 2  may decrease from the edge towards the center of the first sub-display area SDA 1 . Also, the number of second pixels PX 2  surrounded by the sub-sensing electrodes SRE may decrease from the edge towards the center of the first sub-display area SDA 1 . 
       FIG. 13A  is a layout view of the area A- 2  of  FIG. 8 .  FIG. 13B  is a layout view of an area B- 2  of  FIG. 13A .  FIG. 14  is a cross-sectional view taken along line E-E′ of  FIG. 13B . 
     The embodiments of  FIGS. 13A, 13B, and 14  differ from the embodiments of  FIGS. 11A, 11B, and 12  in that the first and second sub-driving electrodes STE 1  and STE 2  and the second connection electrodes BE 2  are disposed in the same layer. The embodiments of  FIGS. 13A, 13B, and 14  will hereinafter be described, focusing mainly on the differences with the embodiment of  FIGS. 11A, 11B, and 12  for convenience of explanation. 
     Referring to the embodiments of  FIGS. 13A, 13B, and 14 , the first and second sub-driving electrodes STE 1  and STE 2  and the second connection electrodes BE 2  may be integrally formed. The first and second sub-driving electrodes STE 1  and STE 2  and the second connection electrodes BE 2  may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction), and the sub-sensing electrodes SRE may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). That is, the first and second sub-driving electrodes STE 1  and STE 2  and the second connection electrodes BE 2  may be disposed in the same layer as, and include the same material as, the first connection electrodes BE 1 . Also, the sub-sensing electrodes SRE may be disposed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
     The second connection electrodes BE 2  may overlap with the sub-sensing electrodes SRE (e.g., in the Z direction). The first and second sub-driving electrodes STE 1  and STE 2  and the connection electrodes BE 2  may be disposed in a different layer from the sub-sensing electrodes SRE. As a result, the first and second sub-driving electrodes STE 1  and STE 2  may be electrically isolated from the sub-sensing electrodes SRE. Thus, mutual capacitances may be formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE. 
       FIG. 15  is a layout view of the area A of  FIG. 5 . 
     The embodiment of  FIG. 15  differs from the embodiment of  FIG. 8  in that the auxiliary electrodes TAE are spaced apart from the driving electrodes TE, the sensing electrodes RE, the first and second sub-driving electrodes STE 1  and STE 2 , and the sub-sensing electrodes SRE. The embodiment of  FIG. 15  will hereinafter be described, focusing mainly on the differences with the embodiment of  FIG. 8  for convenience of explanation. 
     Referring to the embodiment of  FIG. 15 , the first auxiliary electrode TAE 1  may be disposed in an upper left portion of the first sub-display area SDA 1 , and the second auxiliary electrode TAE 2  may be disposed in a lower left portion of the first sub-display area SDA 1 . The third auxiliary electrode TAE 3  may be disposed in a lower right portion of the first sub-display area SDA 1 , and the fourth auxiliary electrode TAE 4  may be disposed in an upper right portion of the first sub-display area SDA 1 . 
     The first sub-driving electrode STE 1  and the sub-sensing electrodes SRE may be disposed on the inside of the first auxiliary electrode TAE 1 . The driving electrodes TE and the sensing electrodes RE may be disposed on the outside of the first auxiliary electrode TAE 1 . The first auxiliary electrode TAE 1  may be spaced apart from the driving electrodes TE, the sensing electrodes RE, the first sub-driving electrode STE 1 , and the sub-sensing electrodes SRE. That is, the first auxiliary electrode TAE 1  may not be connected to (e.g., may not contact) the driving electrodes TE, the sensing electrodes RE, the first sub-driving electrode STE 1 , and the sub-sensing electrodes SRE. 
     Likewise, the second sub-driving electrode STE 2  and the sub-sensing electrodes SRE may be disposed on the inside of the second auxiliary electrode TAE 2 . The driving electrodes TE and the sensing electrodes RE may be disposed on the outside of the second auxiliary electrode TAE 2 . The second auxiliary electrode TAE 2  may be spaced apart from the driving electrodes TE, the sensing electrodes RE, the second sub-driving electrode STE 2 , and the sub-sensing electrodes SRE. That is, the second auxiliary electrode TAE 2  may not be connected to (e.g., may not contact) the driving electrodes TE, the sensing electrodes RE, the second sub-driving electrode STE 2 , and the sub-sensing electrodes SRE. 
     The second sub-driving electrode STE 2  and the sub-sensing electrodes SRE may be disposed on the inside of the third auxiliary electrode TAE 3 . The driving electrodes TE and the sensing electrodes RE may be disposed on the outside of the third auxiliary electrode TAE 3 . The third auxiliary electrode TAE 3  may be spaced apart from the driving electrodes TE, the sensing electrodes RE, the second sub-driving electrode STE 2 , and the sub-sensing electrodes SRE. That is, the third auxiliary electrode TAE 3  may not be connected to (e.g., may not contact) the driving electrodes TE, the sensing electrodes RE, the second sub-driving electrode STE 2 , and the sub-sensing electrodes SRE. 
     The first sub-driving electrode STE 1  and the sub-sensing electrodes SRE may be disposed on the inside of the fourth auxiliary electrode TAE 4 . The driving electrodes TE and the sensing electrodes RE may be disposed on the outside of the fourth auxiliary electrode TAE 4 . The fourth auxiliary electrode TAE 4  may be spaced apart from the driving electrodes TE, the sensing electrodes RE, the first sub-driving electrode STE 1 , and the sub-sensing electrodes SRE. That is, the fourth auxiliary electrode TAE 4  may not be connected to (e.g., may not contact) the driving electrodes TE, the sensing electrodes RE, the first sub-driving electrode STE 1 , and the sub-sensing electrodes SRE. 
     As shown in the embodiment of  FIG. 16 , a driving electrode TE disposed on the upper side of the first sub-display area SDA 1  may be directly connected to the first sub-driving electrode STE 1  through a gap formed between the first and fourth auxiliary electrodes TAE 1  and TAE 4 . A driving electrode TE disposed on the lower side of the first sub-display area SDA 1  may be directly connected to the second sub-driving electrode STE 2  through a gap formed between the second and third auxiliary electrodes TAE 2  and TAE 3 . A sensing electrode RE disposed on the left side of the first sub-display area SDA 1  may be directly connected to the sub-sensing electrodes SRE through a gap formed between the first and second auxiliary electrodes TAE 1  and TAE 2 . A sensing electrode RE disposed on the right side of the first sub-display area SDA 1  may be directly connected to the sub-sensing electrodes SRE through a gap formed between the third and fourth auxiliary electrodes TAE 3  and TAE 4 . Thus, mutual capacitances may be formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes RE, in the first sub-display area SDA 1 . 
     The first auxiliary electrode TAE 1  may be connected to a first auxiliary line TAL 1  between the driving electrode TE disposed on the upper side of the first sub-display area SDA 1  (e.g., in the Y direction) and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1  (e.g., in the X direction). Accordingly, the first auxiliary electrode TAE 1  may be driven in a self-capacitance manner that applies a touch driving signal via the first auxiliary line TAL 1  and detects a charge variation in the self-capacitance formed by the first auxiliary electrode TAE 1 . 
     The second auxiliary electrode TAE 2  may be connected to a second auxiliary line TAL 2  between the driving electrode TE disposed on the lower side of the first sub-display area SDA 1  (e.g., in the Y direction) and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1  (e.g., in the X direction). Accordingly, the second auxiliary electrode TAE 2  may be driven in a self-capacitance manner that applies a touch driving signal via the second auxiliary line TAL 2  and detects a charge variation in the self-capacitance formed by the second auxiliary electrode TAE 2 . 
     The third auxiliary electrode TAE 3  may be connected to a third auxiliary line TAL 3  between the driving electrode TE disposed on the lower side of the first sub-display area SDA 1  (e.g., in the Y direction) and the sensing electrode RE disposed on the right side of the first sub-display area SDA 1  (e.g., in the X direction). Accordingly, the third auxiliary electrode TAE 3  may be driven in a self-capacitance manner that applies a touch driving signal via the third auxiliary line TAL 3  and detects a charge variation in the self-capacitance formed by the third auxiliary electrode TAE 3 . 
     The fourth auxiliary electrode TAE 4  may be connected to a fourth auxiliary line TAL 4  between the driving electrode TE disposed on the upper side of the first sub-display area SDA 1  (e.g., in the Y direction) and the sensing electrode RE. disposed on the right side of the first sub-display area SDA 1  (e.g., in the X direction). Accordingly, the fourth auxiliary electrode TAE 4  may be driven in a self-capacitance manner that applies a touch driving signal via the fourth auxiliary line TAL 4  and detects a charge variation in the self-capacitance formed by the fourth auxiliary electrode TAE 4 . 
     As illustrated in the embodiment of  FIG. 15 , the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may serve as separate touch electrodes from the driving electrodes TE, the sensing electrodes RE, the first and second sub-driving electrodes STE 1  and STE 2 , and the sub-sensing electrodes SRE. Thus, touch input can be detected in the first sub-display area SDA 1  not only through the mutual capacitances formed between the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE, in the first sub-display area SDA 1 , but also through the self-capacitances formed between the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4 . Accordingly, the touch sensitivity in the first sub-display area SDA 1  can be increased. 
     The second, third, and fourth sub-display areas SDA 2 , SDA 3 , and SDA 4  of  FIGS. 2 and 3  may be substantially the same as the first sub-display area SDA 1  of  FIG. 15 , and thus, detailed descriptions thereof will be omitted for convenience of explanation. 
       FIG. 16  is a layout view of an area A- 3  of  FIG. 15 .  FIG. 17  is a cross-sectional view taken along line F-F′ of  FIG. 16 .  FIG. 18  is a cross-sectional view taken along line G-G′ of  FIG. 16 .  FIG. 19  is a cross-sectional view taken along line G-G′ of  FIG. 16 . 
     Referring to the embodiments of  FIGS. 16 through 19 , the first and fourth auxiliary electrodes TAE 1  and TAE 4  may be disposed between the first sub-driving electrodes STE 1  and the driving electrodes TE. The first and fourth auxiliary electrodes TAE 1  and TAE 4  may not be connected to the first sub-driving electrodes STE 1  and the driving electrodes TE. The first and fourth auxiliary electrodes TAE 1  and TAE 4  may be spaced apart from each other. 
     As the first and fourth auxiliary electrodes TAE 1  and TAE 4  are spaced apart from each other, a gap may be formed between the first and fourth auxiliary electrodes TAE 1  and TAE 4 . Thus, the driving electrodes TE may be disposed between the first and fourth auxiliary electrodes TAE 1  and TAE 4 . Accordingly, the driving electrodes TE may extend between the first and fourth auxiliary electrodes TAE 1  and TAE 4  (e.g., in the Y direction) to be directly connected to the first sub-driving electrode STE 1 . 
     As illustrated in the embodiment of  FIG. 17 , the first sub-driving electrode STE 1  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). Also, the second sub-driving electrode STE 2  and the sub-sensing electrodes SRE may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). That is, the first and second sub-driving electrodes STE 1  and STE 2  and the sub-sensing electrodes SRE may be disposed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
     As illustrated in the embodiment of  FIG. 18 , the first and fourth auxiliary electrodes TAE 1  and TAE 4  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). Also, the second and third auxiliary electrodes TAE 2  and TAE 3  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). That is, the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may be disposed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
     However, embodiments of the present inventive concepts are not limited thereto. For example, as illustrated in the embodiment of  FIG. 19 , the first and fourth auxiliary electrodes TAE 1  and TAE 4  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). Also, the second and third auxiliary electrodes TAE 2  and TAE 3  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). The driving electrodes TE may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). The sensing electrodes RE may also be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). That is, the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may be disposed in the same layer as, and include the same material as, the first connection electrodes BE 1  and the second connection electrodes BE 2 . 
       FIG. 20  is a layout view of an area A- 4  of  FIG. 15 .  FIG. 21  is a cross-sectional view taken along line H-H′ of  FIG. 17 .  FIG. 22  is a cross-sectional view taken along line H-H′ of  FIG. 17 . 
     Referring to the embodiments of  FIGS. 20 through 22 , the first auxiliary line TAL 1 , which is connected to the first auxiliary electrode TAE 1 , may be disposed between the driving electrodes TE and the sensing electrodes RE. The first auxiliary line TAL 1  may be spaced apart from the driving electrodes TE and the sensing electrodes RE. The first auxiliary line TAL 1  may be electrically isolated from the driving electrodes TE and the sensing electrodes RE. 
     As illustrated in the embodiment of  FIG. 21 , the first auxiliary electrode TAE 1  and the first auxiliary line TAL 1  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). Also, the second auxiliary electrode TAE 2 , the second auxiliary line TAL 2 , the third auxiliary electrode TAE 3 , the third auxiliary line TAL 3 , the fourth auxiliary electrode TAE 4 , and the fourth auxiliary line TAL 4  may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). That is, the first auxiliary electrode TAE 1 , the first auxiliary line TAL 1 , the second auxiliary electrode TAE 2 , the second auxiliary line TAL 2 , the third auxiliary electrode TAE 3 , the third auxiliary line TAL 3 , the fourth auxiliary electrode TAE 4 , and the fourth auxiliary line TAL 4  may be disposed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
     However, embodiments of the present inventive concepts are not limited thereto. For example, as illustrated in  FIG. 22 , the first and fourth auxiliary electrodes TAE 1  and TAE 4  may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). Also, the second and third auxiliary electrodes TAE 2  and TAD may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). That is, the first, second, third, and fourth auxiliary electrodes TAE 1 , TAE 2 , TAE 3 , and TAE 4  may be disposed in the same layer as, and include the same material as, the first connection electrodes BE 1  and the second connection electrodes BE 2 . 
       FIG. 23  is a layout view of the area A of  FIG. 5 . 
     The embodiment of  FIG. 23  differs from the embodiment of  FIG. 15  in that auxiliary touch electrodes ASE are disposed on the outside of the first sub-display area SDA 1 . The embodiment of  FIG. 23  will hereinafter be described, focusing mainly on the differences with the embodiment of  FIG. 15  for convenience of explanation. 
     Referring to the embodiment of  FIG. 23 , the auxiliary touch electrodes ASE may include first, second, third, fourth, fifth, sixth, seventh, and eighth auxiliary touch electrodes ASE 1 , ASE 2 , ASE 3 , ASE 4 , ASE 5 , ASE 6 , ASE 7 , and ASE 8 . 
     The first auxiliary touch electrode ASE 1  may be disposed between the first auxiliary electrode TAE 1  and the driving electrode TE disposed on the upper side of the first sub-display area SDA 1  (e.g., in the Y direction). The first auxiliary touch electrode ASE 1  may be spaced apart from (e.g., is not connected to) the first auxiliary electrode TAE 1  and the driving electrode TE disposed on the upper side of the first sub-display area SDA 1 . The first auxiliary touch electrode ASE 1  may be electrically isolated from the first auxiliary electrode TAE 1  and the driving electrode TE disposed on the upper side of the first sub-display area SDA 1 . 
     The second auxiliary touch electrode ASE 2  may be disposed between the fourth auxiliary electrode TAE 4  and the driving electrode TE disposed on the upper side of the first sub-display area SDA 1  (e.g., in the Y direction). The second auxiliary touch electrode ASE 2  may be spaced apart from (e.g., is not connected to) the fourth auxiliary electrode TAE 4  and the driving electrode IF disposed on the upper side of the first sub-display area SDA 1 . The second auxiliary touch electrode ASE 2  may be electrically isolated from the fourth auxiliary electrode TAE 4  and the driving electrode TE disposed on the upper side of the first sub-display area SDA 1 . 
     The third auxiliary touch electrode ASE 3  may be disposed between the first auxiliary electrode TAE 1  and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1  (e.g., in the X direction). The third auxiliary touch electrode ASE 3  may be spaced apart from (e.g., is not connected to) the first auxiliary electrode TAE 1  and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1 . The third auxiliary touch electrode ASE 3  may be electrically isolated from the first auxiliary electrode TAE 1  and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1 . 
     The fourth auxiliary touch electrode ASE 4  may be disposed between the second auxiliary electrode TAE 2  and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1  (e.g., in the X direction). The fourth auxiliary touch electrode ASE 4  may be spaced apart from (e.g., is not connected to) the second auxiliary electrode TAE 2  and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1 . The fourth auxiliary touch electrode ASE 4  may be electrically isolated from the second auxiliary electrode TAE 2  and the sensing electrode RE disposed on the left side of the first sub-display area SDA 1 . 
     The fifth auxiliary touch electrode ASE 5  may be disposed between the second auxiliary electrode TAE 2  and the driving electrode TE disposed on the lower side of the first sub-display area SDA 1  (e.g., in the Y direction). The fifth auxiliary touch electrode ASE 5  may be spaced apart from (e.g., is not connected to) the second auxiliary electrode TAE 2  and the driving electrode TE disposed on the lower side of the first sub-display area SDA 1 . The fifth auxiliary touch electrode ASE 5  may be electrically isolated from the second auxiliary electrode TAE 2  and the driving electrode TE disposed on the lower side of the first sub-display area SDA 1 . 
     The sixth auxiliary touch electrode ASE 6  may be disposed between the third auxiliary electrode TAE 3  and the driving electrode TE disposed on the lower side of the first sub-display area Saki (e.g., in the Y direction). The sixth auxiliary touch electrode ASE 6  may be spaced apart from (e.g., is not connected to) the third auxiliary electrode TAE 3  and the driving electrode TE disposed on the lower side of the first sub-display area SDA 1 . The sixth auxiliary touch electrode ASE 6  may be electrically isolated from the third auxiliary electrode TAE 3  and the driving electrode TE disposed on the lower side of the first sub-display area SDA 1 . 
     The seventh auxiliary touch electrode ASE 7  may be disposed between the third auxiliary electrode TAE 3  and the sensing electrode RE disposed on the right side of the first sub-display area SDA 1  (e.g., in the X direction). The seventh auxiliary touch electrode ASE 7  may be spaced apart from (e.g., is not connected to) the third auxiliary electrode TAE 3  and the sensing electrode RE disposed on the right side of the first sub-display area SDA 1 . The seventh auxiliary touch electrode ASE 7  may be electrically isolated from the third auxiliary electrode TAE 3  and the sensing electrode RE disposed on the right side of the first sub-display area SDA 1 . 
     The eighth auxiliary touch electrode ASE 8  may be disposed between the fourth auxiliary electrode TAE 4  and the sensing electrode RE disposed on the right side of the first sub-display area SDA 1  (e.g., in the X direction). The eighth auxiliary touch electrode ASE 8  may be spaced apart from (e.g., is not connected to) the fourth auxiliary electrode TAE 4  and the sensing electrode RE disposed on the right side of the first sub-display area SDA 1 . The eighth auxiliary touch electrode ASE 8  may be electrically isolated from the fourth auxiliary electrode TAE 4  and the sensing electrode RE disposed on the right side of the first sub-display area SDA 1 . 
     As illustrated in the embodiment of  FIG. 23 , the first, second, third, fourth, fifth, sixth, seventh, and eighth auxiliary touch electrodes AES 1 , AES 2 , AES 3 , AES 4 , AES 5 , AES 6 , AES 7 , and AES 8  can detect touch input through capacitances formed by auxiliary driving electrodes ATE and auxiliary sensing electrodes ARE that will be described later with reference to the embodiments of  FIGS. 24 through 27 . Accordingly, the touch sensitivity in the first sub-display area SDA 1  can be increased. 
     The second, third, and fourth sub-display areas SDA 2 , SDA 3 , and SDA 4  of  FIGS. 2 and 3  may be substantially the same as the first sub-display area SDA 1  of  FIG. 23 , and thus, detailed descriptions thereof will be omitted for convenience of description. 
       FIG. 24  is a layout view of an area A- 5  of  FIG. 23 .  FIG. 25  is a cross-sectional view taken along line I-I′ of  FIG. 24 . 
     Referring to the embodiments of  FIGS. 24 and 25 , the first auxiliary touch electrode ASE 1  may include auxiliary driving electrodes ATE and auxiliary sensing electrodes ARE. The auxiliary driving electrodes ATE may completely overlap with the auxiliary sensing electrodes ARE (e.g., in the Z direction). As a result, mutual capacitances may be formed between the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE. 
     In an embodiment, the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE may have a mesh or fishnet structure in a plan view (e.g., in a plane defined in the X and Y directions). Thus, the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE may not overlap with the emission units (EA 1 , EA 2 , EA 3 , and EA 4 ) of each of the first pixels PX 1 . Accordingly, the brightness of light emitted from the emission units (EA 11 , EA 12 , EA 13 , and EA 14 ) can be prevented from decreasing due to being blocked by the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE. 
     As illustrated in the embodiment of  FIG. 25 , the auxiliary driving electrodes ATE may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). That is, the auxiliary driving electrodes ATE may be disposed in the same layer as, and include the same material as, the first connection electrodes BE 1  and the second connection electrodes BE 2 . 
     The auxiliary sensing electrodes ARE may be disposed on the second touch insulating film  2  (e.g., directly thereon in the Z direction). That is, the auxiliary sensing electrodes ARE may be disposed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
       FIG. 26  is a layout view of the area A- 5  of  FIG. 20 .  FIG. 27  is a cross-sectional view taken along line J-J′ of  FIG. 26 . 
     Referring to the embodiments of  FIGS. 26 and 27 , the first auxiliary touch electrode ASE 1  may include auxiliary driving electrodes ATE and auxiliary sensing electrodes ARE. The auxiliary driving electrodes ATE may extend in the fifth direction DR 5 . The auxiliary sensing electrodes ARE may extend in the fourth direction DR 4  and may be arranged in the fifth direction DR 5 . As a result, the auxiliary driving electrodes ATE may intersect the auxiliary sensing electrodes ARE. Thus, mutual capacitances may be formed at the intersections between the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE. 
     As illustrated in  FIG. 26 , in an embodiment in which the auxiliary driving electrodes ATE intersect the auxiliary sensing electrodes ARE, touch sensitivity can be increased so that a proximity touch such as a hover can be detected. If the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE are formed to be wider than the driving electrodes TE and the sensing electrodes RE, touch sensitivity can be further increased. Also, if the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE are formed to be thicker (e.g., length in the Z direction) than the driving electrodes TE and the sensing electrodes RE, touch sensitivity can be further increased. Also, if the thickness of an insulating film between the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE is reduced, touch sensitivity can be further increased. 
     In an embodiment, the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE may have a mesh or fishnet structure in a plan view (e.g., in a plane defined in the X and Y directions). Thus, the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE may not overlap with the emission units (EA 1 , EA 2 , EA 3 , and EA 4 ) of each of the first pixels PX 1  (e.g., in the Z direction). Accordingly, the brightness of light emitted from the emission units (EA 11 , EA 12 , EA 13 , and EA 14 ) can be prevented from decreasing due to being blocked by the auxiliary driving electrodes ATE and the auxiliary sensing electrodes ARE. 
     As illustrated in the embodiment of  FIG. 27 , the auxiliary driving electrodes ATE may be disposed on the first touch insulating film TINS 1  (e.g., directly thereon in the Z direction). That is, the auxiliary driving electrodes ATE may be disposed in the same layer as, and include the same material as, the first connection electrodes BE 1  and the second connection electrodes BE 2 . 
     The auxiliary sensing electrodes ARE may be disposed on the second touch insulating film TINS 2  (e.g., directly thereon in the Z direction). That is, the auxiliary sensing electrodes ARE may be disposed in the same layer as, and include the same material as, the driving electrodes TE and the sensing electrodes RE. 
       FIG. 28  is a layout view of the area A of  FIG. 5 . 
     Referring to  FIG. 28 , the first sub-display area SDA 1  may be surrounded (e.g., in the X and Y directions) by one driving electrode TE. In this embodiment, the first sub-display area SDA 1  may include one auxiliary electrode TAE and one sub-driving electrode STE. As shown in the embodiment of  FIG. 28 , the auxiliary electrode TAE may be disposed along the edge of the first sub-display area SDA 1 . The auxiliary electrode TAE may be disposed to surround the sub-driving electrode STE. The driving electrode TE, the auxiliary electrode TAE, and the sub-driving electrode STE may be electrically connected. 
       FIG. 28  illustrates that the first sub-display area SDA 1  is surrounded by one driving electrode TE. However, embodiments of the present inventive concepts are not limited thereto. For example, in an embodiment the first sub-display area SDA 1  may be surrounded by one sensing electrode RE. In this embodiment, the sensing electrode RE, the auxiliary electrode TAE, and the sub-driving electrode STE may be electrically connected. 
       FIG. 29  is a layout view illustrating first and second sub-display areas of  FIG. 3 .  FIG. 30  is a cross-sectional view taken along line K-K′ of  FIG. 29 . 
     Referring to the embodiments of  FIGS. 29 and 30 , the first pixels PX 1  may be disposed in the main display area MDA. As illustrated in the embodiment of  FIG. 6 , each of the first pixels PX 1  may include first, second, third, and fourth emission units EA 11 , EA 12 , EA 13 , and EA 14 . The first pixels PX 1  have already been described above with reference to  FIG. 6 , and thus, a detailed description thereof will be omitted for convenience of explanation. 
     Each of the second pixels PX 2  may include a pixel emission unit PEA, a pixel driving unit TR, and a pixel connecting unit PC. 
     Pixel emission units PEA may be disposed in the first and second sub-display areas SDA 1  and SDA 2 . The pixel emission units PEA may include first emission units EA 21 , second emission units EA 22 , third emission units EA 23 , and fourth emission units EA 24 , as illustrated in the embodiment of  FIG. 9 . The first emission units EA 21 , the second emission units EA 22 , the third emission units EA 23 , and the fourth emission units EA 24  are substantially the same as their respective counterparts of  FIG. 9 , and thus, detailed descriptions thereof will be omitted for convenience of explanation. 
     The pixel emission units PEA may include a material capable of transmitting light therethrough. In one example, referring to the embodiment of  FIG. 30 , each of the pixel emission units PEA may include a pixel electrode  171 , a light-emitting layer  172 , and a common electrode  173 . In an embodiment, the pixel electrode  171  and the common electrode  173  of each of the pixel emission units PEA may be formed of a TCO capable of transmitting light therethrough, such as ITO or IZO. However, embodiments of the present inventive concepts are not limited thereto. As shown in the embodiment of  FIG. 30 , each of the pixel emission units PEA may include at least a portion of the substrate SUB, the barrier film BR, the gate insulating film  130 , the first interlayer insulating film  141 , the second interlayer insulating film  142 , the first planarization film  160 , the second planarization film  180 , the pixel electrode  171 , the light-emitting layer  172 , the common electrode  173 , the first encapsulation inorganic film TFE 1 , the encapsulation organic film TFE 2 , the second encapsulation inorganic film TFE 3 , the first touch insulating film TINS 1 , the second touch insulating film TINS 2 , and the third touch insulating film TINS 3 . Thus, light incident upon the pixel emission units PEA may pass through the pixel emission units PEA. As the light-transmitting areas TA and the pixel emission units PEA can transmit light therethrough in each of the first and second sub-display areas SDA 1  and SDA 2 , the amount of light incident upon optical devices such as the proximity sensor  740  and the illumination sensor  750  can be increased. 
     Pixel driving units TR may be disposed in the main display area MDA. Each of the pixel driving units TR may include a plurality of thin-film transistors ST 1 . 
     Pixel connecting units PC may connect the pixel driving units TR and the pixel emission units PEA. The pixel connecting units PC may extend from the pixel electrodes  171 , as illustrated in the embodiment of  FIG. 30 . That is, the pixel connecting units PC may be disposed in the same layer as, and include the same material as, the pixel electrodes  171 . The pixel connecting units PC may be disposed on the second planarization film  180 . The pixel connecting units PC may be connected to the second anode connection electrodes ANDE 2  through the third connecting contact holes ANCT 3 . 
     Auxiliary electrodes TAE′ may overlap with the pixel driving units TR (e.g., in the Z direction). In an embodiment, the auxiliary electrodes TAE′ may be driven in a self-capacitance manner that detects charge variations in self-capacitances formed by the auxiliary electrodes TAE′. As the pixel driving units TR are areas that do not emit light, the auxiliary electrodes TAE′ may be formed to overlap with the entire pixel driving units TR. As touch input can be detected through self-capacitances formed by the auxiliary electrodes TAE′, which are disposed around the first and second sub-display areas SDA 1  and SDA 2 , the touch sensitivity around the first and second sub-display areas SDA 1  and SDA 2  can be increased. 
       FIG. 31  is a layout view illustrating the first and second sub-display areas of  FIG. 3 .  FIG. 32  is a cross-sectional view taken along line L-L′ of  FIG. 31 . 
     The embodiment of  FIGS. 31 and 32  differs from the embodiment of  FIGS. 29 and 30  in that the auxiliary electrodes TAE′ are formed in a mesh shape to prevent color filters (CF 1  and CF 2 ), which are provided instead of the polarizing film POL, from becoming visible due to the reflection of external light. Thus, a description of other features of the embodiment of  FIGS. 31 and 32 . will be omitted for convenience of explanation. 
     In a display device according to embodiments of the present inventive concepts, as auxiliary electrodes, which are connected to sub-driving electrodes and sub-sensing electrodes, are disposed in extra space on the edge of a sub-display area, mutual capacitances formed between the sub-driving electrodes and the sub-sensing electrodes can be strengthened. Thus, the touch sensitivity in the sub-display area can be increased. 
     In a display device according to embodiments of the present inventive concepts, the auxiliary electrodes can serve as separate touch electrodes from driving electrodes, sensing electrodes, the sub-driving electrodes, and the sub-sensing electrodes. Thus, touch input can be detected not only through the mutual capacitances formed between the sub-driving electrodes and the sub-sensing electrodes, but also through self-capacitances formed by the auxiliary electrodes. Accordingly, the touch sensitivity in the sub-display area can be increased. 
     In a display device according to embodiments of the present inventive concepts, auxiliary touch electrodes can be disposed around the sub-display area and can detect touch input through the capacitances formed between the sub-driving electrodes and the sub-sensing electrodes. Thus, the touch sensitivity around the sub-display area can be increased. 
     However, the effects of embodiments of the present inventive concepts are not restricted to those set forth herein. 
     While the present inventive concepts have been particularly shown and described to with reference to embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made. therein without departing from the spirit and scope of the present inventive concepts as defined by the following claims. The embodiments of the present inventive concepts described herein should be considered in a descriptive sense only and not for purposes of limitation.