Patent Publication Number: US-2018045994-A1

Title: Liquid crystal display

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 10-2016-0101227 filed in the Korean Intellectual Property Office on Aug. 9, 2016, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     (a) Technical Field 
     This disclosure relates to a display device. 
     (b) Description of the Related Art 
     A display device such as a liquid crystal display or an organic light emitting diode display is manufactured by forming various layers and elements on a substrate. Typically, in the case of the liquid crystal display, a liquid crystal layer is formed between two substrates. A voltage is applied to a pixel electrode and a common electrode of the liquid crystal display to generate an electric field, and polarization of incident light is thereby controlled by adjusting the alignment of liquid crystal molecules of the liquid crystal layer to display an image. In the case of the organic light emitting diode display, excitons generated by combining electrons supplied from a cathode with holes supplied from an anode in an organic emission layer release energy for light emission. 
     According to a recent technique that has been being developed, a plurality of microcavities having tunnel-type structures are disposed on one substrate, and liquid crystal is injected into the microcavities. Then, a capping layer is used to seal the microcavities to manufacture the liquid crystal display. This liquid crystal display employs one substrate, and thus is weight-light and is advantageous in reducing a bezel width and forming a curved display panel, but may be vulnerable to moisture transmission. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY 
     Exemplary embodiments have been made in an effort to provide a display device capable of reducing a peripheral area of the display panel and improving reliability. 
     An exemplary embodiment provides a display device including: a substrate including a display area and a peripheral area; a pixel layer disposed in the display area; a driver layer disposed in the peripheral area; a first optical film disposed above the pixel layer and the driver layer; a second optical film disposed below the substrate; and a sealant disposed between the first optical film and the second optical film to overlap the first optical film and the second optical film in a thickness direction of the substrate. 
     A first side surface of the sealant may contact a side surface of the substrate. 
     A second side surface of the substrate and side surfaces of the first optical film and the second optical film may be in a same plane. 
     The pixel layer may include a liquid crystal layer disposed in a plurality of microcavities and a roof layer disposed on the liquid crystal layer. 
     The display device may further include a capping layer disposed above the pixel layer and the driver layer, and the first side surface of the sealant may contact a side surface of the capping layer. 
     The display device may further include: a first adhesive layer disposed between the capping layer and the first optical film; and a second adhesive layer disposed between the substrate and the second optical film, wherein a top surface of the sealant may contact the first adhesive layer, and a bottom surface of the sealant may contact the second adhesive layer. 
     At least one of the first optical film and the second optical film may serve as a polarization film. 
     The driver layer may include a gate driver that includes a plurality of stages and a plurality of signal lines for transferring clock signals to the stages, and the sealant may not overlap the stages and the signal lines. 
     The display device may further include a transparent electrode layer and an inorganic insulating layer disposed between the capping layer and the driver layer to cover the driver layer. 
     The display device may further include a pad unit disposed in the peripheral area, and the first optical film may overlap the pad unit in a thickness direction of the substrate. 
     Another exemplary embodiment provides a display device including: a substrate including a display area and a peripheral area; a pixel layer disposed in the display area; a driver layer disposed in the peripheral area; an optical film disposed above the pixel layer and the driver layer; and a sealant disposed between the optical film and the substrate to overlap the optical film and the substrate in a thickness direction of the substrate. 
     The display device may further include a capping layer disposed above the pixel layer and the driver layer, and a first side surface of the sealant may contact a side surface of the capping layer. 
     A second side surface of the sealant and side surfaces of the optical film and the substrate may be in a same plane. 
     The sealant may have a first portion that contacts the optical film and a second portion that contacts a side surface of the substrate. 
     The display device may further include an adhesive layer disposed between the capping layer and the optical film, and a surface of the sealant may contact the adhesive layer. 
     The sealant may have a third portion that contacts the adhesive layer. 
     The pixel layer may include a liquid crystal layer disposed in a plurality of microcavities and a roof layer disposed on the liquid crystal layer. 
     The driver layer may include a gate driver that includes a plurality of stages and a plurality of signal lines for transferring clock signals to the stages, and the sealant may overlap the stages and the signal lines. 
     The display device may further include a transparent electrode layer and an inorganic insulating layer disposed between the capping layer and the driver layer to cover the driver layer. 
     The display device may further include a pad unit disposed in the peripheral area, and the first optical film may overlap the pad unit in a thickness direction of the substrate. 
     The optical film may serve as a polarization film. 
     According to the exemplary embodiments, it is possible to provide a display device capable of preventing moisture penetration while reducing a peripheral area of a display panel, and ameliorating a defective outer appearance caused by a sealant. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic top plan view illustrating a display device according to an exemplary embodiment of the present invention. 
         FIG. 2  illustrates a cross-section taken along a line II-II′ of  FIG. 1  according to an exemplary embodiment. 
         FIG. 3  illustrates a manufacturing process of the display device shown in  FIG. 2 . 
         FIG. 4  illustrates a cross-section taken along the line II-II′ of  FIG. 1  according to an exemplary embodiment. 
         FIG. 5  illustrates a cross-section taken along the line II-II′ of  FIG. 1  according to an exemplary embodiment. 
         FIG. 6  illustrates a cross-section taken along the line II-II′ of  FIG. 1  according to an exemplary embodiment. 
         FIG. 7  illustrates a cross-section taken along a line VII-VII′ of  FIG. 1  according to an exemplary embodiment. 
         FIG. 8  illustrates a cross-section taken along the line VII-VII′ of  FIG. 1  according to an exemplary embodiment. 
         FIG. 9  illustrates a cross-section taken along the line VII-VII′ of  FIG. 1  according to an exemplary embodiment. 
         FIG. 10  is a layout view illustrating four pixel areas that are adjacently disposed in a display device according to an exemplary embodiment of the present invention. 
         FIG. 11  illustrates a cross-section taken along a line XI-XI′ of  FIG. 10  according to an exemplary embodiment. 
         FIG. 12  illustrates a cross-section taken along a line XII-XII′ of  FIG. 10  according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. 
     Like reference numerals designate like elements throughout the specification. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it may be directly on the other element, or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. Unless otherwise noted in the specification, “overlap” means that at least part of a layer, film, region, or substrate overlaps another element when viewed in a plan view. 
     A display device according to an exemplary embodiment of the present invention will now be described in detail with reference to the drawings. Although a liquid crystal display is exemplarily employed as a display device, the present invention may be applied to another flat panel display such as an organic light emitting diode display. 
       FIG. 1  is a schematic top plan view illustrating a display device according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 1 , the display device includes a display panel  300 , a data driver  460  serving as a driver for generating and/or processing various signals, and a signal controller  600 . 
     The display panel  300  includes a display area DA for displaying images and a peripheral area PA positioned around the display area DA. In the peripheral area PA, a gate driver  500  for applying gate signals to gate lines G 1 -Gn and the like is formed. The peripheral area PA includes a sealing area SA in which a sealant for preventing moisture and the like from penetrating the display panel  300  is disposed. The sealing area SA may be disposed to surround an edge of the display panel  300 . The display area DA is also referred to as an active area, and the peripheral area PA is also referred to as a non-display area (or an inactive area). 
     In the display area DA, pixels PX are disposed in a matrix shape, for example. Each of the pixels PX may include a transistor, a liquid crystal capacitor, and a storage capacitor. The liquid crystal capacitor includes a liquid crystal layer. The liquid crystal layer is filled in the microcavities in every pixel area or in every plurality of pixel areas (not illustrated). In the case that an organic light emitting diode display is employed as the display device, each of the pixels PX may include a switching transistor, a driving transistor, a storage capacitor, and a light-emitting device. 
     In the display area DA, the gate lines G 1 -Gn and data lines D 1 -Dm are disposed. The gate lines G 1 -Gn may extend in a substantially row direction (horizontal direction), and the data lines D 1 -Dm may extend in a substantially column direction (vertical direction) that crosses the row direction. Each of the pixels may be connected with a gate line and a data line to receive a gate signal and a data signal therefrom. 
     The data lines D 1 -Dm of the display area DA receive a data voltage from the data driver  460 , which is an integrated circuit chip mounted on a flexible printed circuit film connected with a pad unit PP of the display panel  300 . Alternatively, the data driver  460  may be mounted in the peripheral area PA of the display panel  300  in a form of an integrated circuit chip. In  FIG. 1 , the data driver  460  is illustrated to be positioned at an upper side of the display panel  300 . However, the data driver  460  may be positioned at a lower side of the display panel  300 . 
     The gate driver  500  is integrated in the peripheral area PA of the display panel  300 . In  FIG. 1 , the gate driver  500  is illustrated as being positioned in a left peripheral area of the display panel  300 . However, the gate driver  500  may be positioned in a right peripheral area thereof or may be positioned in the left and right peripheral areas. The gate driver  500  may be provided in a form of an integrated circuit chip. 
     The gate driver  500  and the data driver  460  are controlled by the signal controller  600 . A printed circuit board (PCB)  400  may be disposed outside the flexible printed circuit film  450  to transfer signals from the signal controller  600  to the data driver  460  and the gate driver  500 . 
     The signals transferred from the signal controller  600  to the gate driver  500  include signals such as vertical start signals and clock signals, as well as signals for supplying voltages of particular levels (e.g., low voltages corresponding to gate-off voltages). According to another exemplary embodiment, the signals transferred from the signal controller  600  to the gate driver  500  may include two or more kinds of vertical start signals, clock signals, and/or low voltages. The gate driver  500  includes stages ST 1 -STn serving as circuits for generating and outputting gate signals including gate-on voltages and gate-off voltages by using the signals and signal lines SL for transferring the signals to the stages ST 1 -STn. The stages ST 1 -STn may be arranged to be subordinately connected with each other in a column direction, and may be referred to as shift registers. 
     The signal lines SL may be positioned at an outer perimeter of the display area DA, like the stages ST 1 -STn, and may extend in a substantially column direction. Some signal lines (e.g., signal lines for transferring a low voltage) may be positioned between the stages ST 1 -STn and the display area DA. Among the signal lines SL, signal lines for transferring clock signals may be most distant from the stages ST 1 -STn. Although being illustrated as one line in  FIG. 1 , the signal lines SL may include a number of signal lines corresponding to a number of signals applied to the gate driver  500 , or more or less. 
     A common voltage line (not illustrated) for transferring a common voltage to a common electrode of the display area DA may be positioned in the peripheral area PA around the gate driver  500 . Further, a repair line (not illustrated) may be disposed in the peripheral area PA. The repair line may instead be used, for example, to transmit the signal when the data line and the like are broken and cause a defect. 
     So far, an overall structure of the display device has been discussed. Hereinafter, a structure of the vicinity of the gate driver  500  in which a sealant is disposed will be described in more detail. 
       FIG. 2  illustrates a cross-section taken along a line II-II′ of  FIG. 1  according to an exemplary embodiment, and  FIG. 3  illustrates a manufacturing process of the display device shown in  FIG. 2 . 
     To simplify the drawing and to clarify the present invention, in  FIG. 2  and  FIG. 3 , layers in which the gate driver  500  is formed and layers of the display area in which pixels are disposed are respectively illustrated as single layers, which are referred to as a gate driver layer GL and a pixel layer PL. Further,  FIG. 1  may also be referred to without special description. 
     Referring to  FIG. 2 , the display panel  300  includes a substrate  110 , and a gate driver layer GL and a pixel layer PL disposed on the substrate  110 . The substrate  110  may be formed of a material such as glass to prevent moisture transmission from below the substrate  110 . The substrate  110  may be a flexible substrate formed of a polymer film, and may be formed of, e.g., a plastic such as polyimide, polyamide, or polyethylene terephthalate. In this case, the substrate  110  may include a barrier layer for preventing penetration of moisture and the like, and the barrier layer may include an organic material such as a silicon nitride (SiNx) or a silicon oxide (SiOx). 
     The gate driver layer GL includes a stage ST and signal lines SL. The display panel  300  includes a fan-out layer FL between the gate driver layer GL and the display area DA. In the fan-out layer FL, some of the gate lines G 1 -Gn positioned outside the display area DA are disposed. A signal line for transferring a specific level of voltage may be disposed in the fan-out layer FL. 
     A capping layer  390  is disposed on the gate driver layer GL, the fan-out layer FL, and the pixel layer PL to cover these layers GL, FL, and PL. The capping layer  390  may include an organic material and/or an inorganic material, and may be formed throughout substantially the entire surface of the substrate  110  except for the vicinity of the pad unit PP of the display panel  300 . Although not shown, a light blocking member (also referred to as a black matrix) may be formed between the capping layer  390  and the gate driver layer GL and the fan-out layer FL to prevent light leakage (leakage of light from a backlight) or external light reflection by a metal or the like. 
     A first optical film  810  and a second optical film  820  are respectively disposed above and below the capping layer  390 . The first optical film  810  is attached to the capping layer  390  through a first adhesive layer  710  positioned therebelow, and the second optical film  820  is attached to the substrate  110  through a second adhesive layer  720  positioned thereabove. The first adhesive layer  710  and the second adhesive layer  720  may be a pressure sensitive adhesive (PSA) or an optically clear adhesive (OCA). The display device may be postured such that the first optical film  810  of the display panel  300  faces the outside (i.e., a user), and may be positioned such that the second optical film  820  of the display panel  300  faces the outside. When a liquid crystal display is used as the display device, each of the first optical member  810  and the second optical member  820  may be formed of a polarization film. 
     Basically, the first optical film  810 , which covers the display area DA, also covers the gate driver layer GL up to an edge of the substrate  110 , and is disposed to extend from an edge of the substrate  110  to the outside of the substrate  110 , together with the first adhesive layer  710 . Similarly, the second optical film  820  is disposed to extend from an edge of the substrate  110  to the outside of the substrate  110 , together with the second adhesive layer  720 . A sealant  50  is disposed between extensions of the first optical film  810  and the second optical film  820 . Accordingly, the gate driver layer GL may be surrounded by the substrate  110 , the first optical film  810 , and the sealant  50  to block moisture penetration to the gate driver layer GL from a bottom surface, a top surface, and a side surface by the substrate  110 , the first optical film  810  and the first adhesive layer  710 , and the sealant  50 , respectively. 
     The moisture penetration may cause corrosion of wires and circuits, and moisture penetrating along interfaces between layers may increase gaps between the layers. According to the present exemplary embodiment, although the display panel  300  includes one substrate  110 , and no substrate is covered on the gate driver layer GL, it is possible to effectively prevent the moisture penetration by the optical films  810  and  820  and the sealant  50 . Further, since the interface between the capping layer  390  and the sealant  50  through which moisture would easily penetrate are not exposed to the outside, the moisture penetration can be prevented through the interface. Accordingly, although the sealant  50  is formed to have a narrower width, it is possible to block the moisture penetration. Further, it is possible to reduce a width of the peripheral area PA by at least as much as a degree to which the width of the sealant  50  is reduced. 
     To increase the ability for preventing the moisture transmission, at least one of the first optical film  810  and the first optical film  710  may include a barrier layer including, e.g., an organic material, and the sealant  50  may include a moisture absorbent. 
     A top surface and a bottom surface of the display panel  300  are respectively confined by the first optical film  810  and the second optical film  820 , and the sealant  50  is disposed between the first and second optical films  810  and  820 . Accordingly, an outer appearance of the display panel  300  is not deteriorated, and a smooth surface is provided by the first and second optical films  810  and  820 . Further, although a lifting phenomenon of a layer such as an inorganic layer occurs in, e.g., the sealing area SA by the action of static electricity, it is covered by the optical films  810  and  820  such that it is not exposed. 
     The top surface of the sealant  50  may contact the first adhesive layer  710 , and the bottom surface thereof may contact the second adhesive layer  720 . A side surface of the sealant  50  may contact side surfaces of the substrate  110  and the capping layer  390 . Another side surface of the sealant  50  may be positioned in substantially the same plane as those of the first optical film  810  and the second optical film  820 . As a result, an externally exposed side surface of the sealant  50  may be aligned or flush with side surfaces of the first optical film  810 , the first adhesive layer  710 , the second adhesive layer  720 , and the second optical film  820  so as to form one plane. 
     Referring to  FIG. 3 , such a structure of the sealant  50  may be formed by respectively attaching the first optical film  810  and the second optical film  820  above the capping layer  390  and below the substrate  110  with wide margins and filling the sealant  50  between the first optical film  810  and the second optical film  820  and curing it, and then cut edges of the first optical film  810 , the first adhesive layer  710 , the sealant  50 , the second adhesive layer  720 , and the second optical film  820 , all together. The sealant  50  that is in a liquid form before the curing may be filled in a space confined by the first adhesive layer  710 , the capping layer  390 , the substrate  110 , and the second adhesive layer  720  by a capillary force. The cutting may be performed by using, e.g., femtosecond laser. 
     Hereinafter, other exemplary embodiments of the present invention will be described with reference to  FIG. 4  to  FIG. 6  based on differences with the exemplary embodiment of  FIG. 2 . 
       FIG. 4 ,  FIG. 5 , and  FIG. 6  illustrate a cross-section taken along a line II-II′ of  FIG. 1  according to exemplary embodiments, respectively. 
     Referring to  FIG. 4 , the gate driver layer GL, the fan-out layer FL, and the pixel layer PL are disposed on the substrate  110 , and these layers GL, FL, and PL are covered with the capping layer  390 . The first optical film  810  is attached to the capping layer  390  thereabove by using the first adhesive layer  710 , and the second optical film  820  is attached to the substrate  110  therebelow by using the second adhesive layer  720 . The first optical film  810  completely covers the gate driver layer GL, and a side surface thereof is substantially parallel with a side surface of the substrate  110  on the same plane. 
     When an organic light emitting diode display is employed as a display device, the capping layer  390  may be a thin film encapsulation layer for preventing penetration of moisture or oxygen from the outside. In the case of the organic light emitting diode display, the first optical film  810  may be an anti-reflective layer, and the second optical film  820  may not be included. 
     The sealant  50  may be disposed between the first optical film  810  and the substrate  110 . A top surface of the sealant  50  may contact the first adhesive layer  710 , and a bottom surface thereof may contact the substrate  110 . A side surface of the sealant  50  may contact a side surface of the capping layer  390 , and another side surface thereof may be substantially parallel with side surfaces of the first optical film  810 , the first adhesive layer  710 , the substrate  110 , the second adhesive layer  720 , and the second optical film  820  in the same plane. For example, such a structure of the sealant  50  may be formed by attaching the first optical film  810  and the second optical film  820 , by filling the sealant  50  in a space confined by the first adhesive layer  710 , the capping layer  390 , and the substrate  110  and curing it, and cutting edges of the first optical film  810 , the first adhesive layer  710 , the sealant  50 , the substrate  110 , the second adhesive layer  720 , and the second optical film  820 . 
     The gate driver layer GL is completely surrounded by the substrate  110 , the first optical film  810 , and the sealant  50 , and thus moisture penetration to the gate driver layer GL may be blocked from a bottom surface thereof by the substrate  110 , from a top surface thereof by the first optical film  810  and the first adhesive layer  710 , and from a side surface thereof by the sealant  50 . Moisture that may penetrate from a lower portion of the gate driver layer GL may be blocked by the substrate  110 . Accordingly, the second optical film  820  may be disposed to cover less than the illustrated area, e.g., to such a degree so as to cover the display area DA. 
     A transparent electrode layer  270 ′ and an inorganic insulating layer  350 ′ are disposed between the capping layer  390  and the gate driver layer GL and fan-out layer FL. The transparent electrode layer  270 ′ may be an electrode layer formed of indium tin oxide (ITO) or indium zinc oxide (IZO), which is used to form a common electrode in the display area DA, and the inorganic insulating layer  350 ′ may serve as a lower insulating layer between a roof layer and the common electrode, which are described later, in the display area DA and may include an organic material such as a silicon nitride (SiNx) or a silicon oxide (SiOx). The transparent electrode layer  270 ′ and the inorganic insulating layer  350 ′ may serve as a barrier layer for blocking moisture penetration to the gate driver layer GL. At least one of the transparent electrode layer  270 ′ and the inorganic insulating layer  350 ′ may be omitted. A light blocking member (not illustrated) may be disposed between the capping layer  390  and the gate driver  500  and fan-out layer FL. 
     Referring to  FIG. 5 , the sealant  50  is disposed between the substrate  110  and the first optical film  810  as in the exemplary embodiment of  FIG. 4 . However, the sealant  50  is disposed on side surfaces of the first optical film  810 , the substrate  110 , and the second optical film  820 , unlike in the exemplary embodiment of  FIG. 4 . Referring to  FIG. 6 , compared with the exemplary embodiment of  FIG. 5 , the sealant  50  is disposed on side surfaces of the first optical film  810 , the substrate  110 , and the second optical film  820 , while the first adhesive layer  710  instead of the sealant  50  is disposed between the substrate  110  and the first optical film  810 . The side surfaces of the first optical film  810 , the first adhesive layer  710 , the substrate  110 , the second adhesive layer  720 , and the second optical film  820  may be substantially parallel with each other in the same plane (e.g., flush with each other). In the exemplary embodiments of  FIG. 5  and  FIG. 6 , the sealant  50  seals the side surface of the display panel, and thus moisture penetration to, e.g., an interface between the first adhesive layer  710  and the sealant  50  or an interface between the substrate  110  and the sealant  50 , may be more efficiently prevented. 
     So far the structure for preventing moisture penetration has been described based on the vicinity of the left edge of the display panel  300  in which the gate driver  500  is disposed. However, this structure (particularly, a relationship between the substrate, the capping layer, the optical film, and the sealant) may be applied to another edge of the display panel  300 . However, the vicinity of an edge at which the pad unit PP is disposed may require a flexible printed circuit film  450  to be attached thereto, and thus may have a structure that is slightly different from the aforementioned structure. This will be described with reference to  FIG. 7 ,  FIG. 8 , and  FIG. 9 . 
       FIG. 7 ,  FIG. 8  and  FIG. 9  illustrate cross-sections taken along a line VII-VII′ of  FIG. 1  according to exemplary embodiments, respectively. 
     Referring to  FIG. 7  and  FIG. 8 , the pad unit PP and the pixel layer PL are disposed on the substrate  110 . The capping layer  390  covers the pixel layer PL, but is not disposed on the pad unit PP to which the flexible printed circuit film  450  is bonded. The first optical film  810  is attached to the capping layer  390  thereabove by the first adhesive layer  710 , and the second optical film  820  is attached to the substrate  110  therebelow by the second adhesive layer  720 . The first optical film  810  is disposed to expose the pad unit PP for bonding of the flexible printed circuit film  450 . Accordingly, a side surface of the first optical film  810  may be disposed between the pad unit PP and the capping layer  390 .  FIG. 7  illustrates an example in which the side surface of the first optical film  810  is disposed closer to the pad unit PP, and  FIG. 8  illustrates an example in which the side surface of the first optical film  810  substantially coincides with a side surface of the capping layer  390 . The sealant  50  is formed to seal the side surfaces of the first optical film  810 , the first adhesive layer  710 , and the capping layer  390  above the pad unit PP and the flexible printed circuit film  450 . In the exemplary embodiment of  FIG. 7 , the sealant  50  is also disposed in a space confined by the first adhesive layer  710 , the capping layer  390 , and the substrate  110 . 
     Referring to  FIG. 9 , the first optical film  810  covers the pad unit PP, and the side surfaces of the first optical film  810  and the substrate  110  are disposed in substantially the same plane. The sealant  50  may be disposed between the first optical film  810  and the substrate  110 , as in the exemplary embodiment of  FIG. 4 . For example, this structure may be formed by attaching the flexible printed circuit film  450  to the pad unit PP, attaching the first optical film  810  to the capping layer  390  thereabove such that a side surface thereof substantially coincides with the side surface of the substrate  110 , and injecting the sealant  50  into a space confined by the substrate  110 , the capping layer  390 , and the first adhesive layer  710 . 
     So far, the display device according to an exemplary embodiment of the present invention has been described based on the peripheral area. Hereinafter, the display device according to an exemplary embodiment of the present invention will be described based on the pixel areas with reference to  FIG. 10 ,  FIG. 11 , and  FIG. 12 .  FIG. 1  to  FIG. 9  may also be referred to without special description. 
       FIG. 10  is a layout view illustrating four pixel areas that are adjacently disposed in a display device according to an exemplary embodiment of the present invention,  FIG. 11  illustrates a cross-section taken along a line XI-XI′ of  FIG. 10  according to an exemplary embodiment, and  FIG. 12  illustrates a cross-section taken along a line XII-XII′ of  FIG. 10  according to an exemplary embodiment. 
       FIG. 10  illustrates a 2×2 portion of the pixel areas, and these pixel areas may be repeatedly arranged up/down and right/left in the display panel in a plan view. 
     Referring to  FIG. 10  to  FIG. 12 , various layers and elements constituting the display layer PL are disposed on the substrate  110  formed of transparent glass or plastic, the capping layer  390  and the first optical film  810  are disposed on the display layer PL, and the second optical film  820  is disposed below the substrate  110 . 
     Specifically, a gate line  121  and a storage electrode line  131  are disposed on the substrate  110 . A gate electrode  124  is formed at a portion of the gate line  121 . The storage electrode line  131  is mainly extended in a row direction to transfer a predetermined voltage such as a common voltage. The storage electrode line  131  may include a pair of vertical portions  135   a  that are extended in a substantially column direction, and a horizontal portion  135   b  that connects ends of the pair of vertical portions  135   a.  The gate line  121 , the gate electrode  124 , and the storage electrode line  131  may be formed of a same material at a same layer, and are referred to as a gate conductor. The gate conductor may be formed of a metal such as aluminum (Al), silver (Ag), copper (Cu), molybdenum (Mo), chromium (Cr), tantalum (Ta), or titanium (Ti), or an alloy thereof. 
     A gate insulating layer  140  is disposed on the gate conductor. A semiconductor  151  and a semiconductor  154  are disposed on the gate insulating layer  140  such that the semiconductor  151  is positioned below a data line  171 , and the semiconductor  154  is positioned below a source electrode  173  and the drain electrode  175  and is positioned at a channel portion of a transistor Q. 
     A data line  171  and a drain electrode  175  connected with the source electrode  173  are disposed on the semiconductors  151  and  154  and the gate insulating layer  140 . The data line  171 , the source electrode  173 , and the drain electrode  175  may be formed of a same material at a same layer, and are referred to as a data conductor. The data conductor may be formed of a metal such as aluminum, copper, molybdenum, chromium, tantalum, or titanium, or an alloy thereof. 
     Ohmic contacts (not shown) may be disposed between the data conductor and the semiconductors  151  and  154 . 
     The gate electrode  124 , the source electrode  173 , and the drain electrode  175  constitute the transistor Q together with the semiconductor  154 . Meanwhile, in the peripheral area PA, the stages ST 1 -STn of the gate driver  500  may include transistors having a stacking structure that is the same as the transistors of the pixel areas. 
     A first passivation layer  180   a  is disposed on the data conductor. The first passivation layer  180   a  may include an organic material such as a silicon nitride and a silicon oxide. A second passivation layer  180   b  and a third passivation layer  180   c  are disposed on the first passivation layer  180   a.  The second passivation layer  180   b  may include an organic material, and the third passivation layer  180   c  may include an inorganic material. One or two layers of the first passivation layer  180   a,  the second passivation layer  180   b,  and the third passivation layer  180   c  may be omitted. 
     A contact hole  185  is formed to extend through the first passivation layer  180   a,  the second passivation layer  180   b,  and the third passivation layer  180   c,  and the drain electrode  175  is connected with a pixel electrode  191  disposed on the third passivation layer  180   c  through the contact hole  185 . The pixel electrode  191  may be formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The pixel electrode  191  has an overall shape that is quadrangular, and includes a cross-shaped stem including a horizontal stem  191   a  and a vertical stem  191   b  that crosses the horizontal stem  191   a.  The pixel electrode  191  is divided into four subregions by the horizontal stem  191   a  and the vertical stem  191   b,  and each of the subregions includes a plurality of minute branches  191   c.  The pixel electrode  191  may further include an outer stem  191   d  that contacts the minute branches  191   c  at an outer perimeter. 
     The pixel electrode  191  includes an extension  197 , which is connected with a lower end of the vertical stem  191   b  and has a larger area than the vertical stem  191   b,  and is connected with the drain electrode  175  through the contact hole  185  in the extension  197  to receive a data voltage from the drain electrode  175 . 
     The foregoing description of the transistor Q and the pixel electrode  191  is merely an example, and a structure of the thin film transistor and a design of the pixel electrode may be modified to improve side visibility. 
     A light blocking member  220  is disposed to cover a region where the transistor Q is disposed on the pixel electrode  191 . The light blocking member  220  may be disposed along an extending direction of the gate line  121 . Meanwhile, in the peripheral area PA, the light blocking member  220  may be disposed to cover the gate driver layer GL and the like. An insulating layer  181  formed of a silicon nitride or a silicon oxide may be disposed on the light blocking member  220 . 
     A lower alignment layer  11  is disposed on the pixel electrode  191 , and an upper alignment layer  21  is disposed at such a portion so as to face the lower alignment layer  11 . A microcavity  305  is formed between the lower alignment layer  11  and the upper alignment layer  21 . A liquid crystal material including liquid crystal molecules  310  is injected into the microcavity  305  to form a liquid crystal layer. The microcavity  305  may be formed along a column direction. An alignment material for forming the alignment layers  11  and  21  and the liquid crystal material including the liquid crystal molecules  310  may be injected into the microcavity  305 . The microcavity  305  includes an entrance region  307  for such injecting. Meanwhile, the lower alignment layer  11  and the upper alignment layer  21  are merely distinguished depending on a position. As shown in  FIG. 12 , the lower alignment layer  11  and the upper alignment layer  21  may be connected with each other along a side surface of the microcavity  305 . 
     The microcavity  305  may be divided into a plurality of microcavities  305  in the row direction by a plurality of trenches  308  that are disposed at such a portion to overlap the gate line  121 , and the microcavities  305  may be formed in the column direction. Further, the microcavity  305  may be divided into a plurality of microcavities  305  in a horizontal direction by a partition  320  to be described later, and the microcavities  305  may be formed in the row direction in which the gate line  121  is extended. Each of the microcavities  305  may correspond to one or more pixel areas. 
     A common electrode  270  is disposed on the upper alignment layer  21 , and a lower insulating layer  350  is disposed on the common electrode  270 . The common electrode  270  receives a common voltage and generates an electric field together with the pixel electrode  191  to which a data voltage is applied to determine a direction in which the liquid crystal molecules  310  disposed in the microcavity  305  between the two electrodes are inclined. The common electrode  270  constitutes a capacitor together with the pixel electrode  191  to maintain an applied voltage even after the transistor is turned off. The lower insulating layer  350  serves as an inorganic insulating layer formed of a silicon nitride or a silicon oxide. Meanwhile, each of the common electrode  270  and the lower insulating layer  350  may be formed in the peripheral area PA as the transparent electrode layer  270 ′ and an inorganic insulating layer  350 ′ to serve as a barrier layer for blocking moisture penetration to the gate driver layer GL. 
     An example in which the common electrode  270  is disposed above the microcavity  305  is illustrated. However, the common electrode  270  may be disposed below the microcavity  305  (accordingly, below the liquid crystal layer), thereby accomplishing liquid crystal driving according to a coplanar electrode (CE) mode. 
     A roof layer  360  is disposed on the lower insulating layer  350 . The roof layer  360  plays a supporting role in forming the microcavity  305 , which is a space formed between the pixel electrode  191  and the common electrode  270 . The roof layer  360  may include a photoresist, or other organic materials. Alternatively, the roof layer  360  may be formed as a color filter. In this case, as shown in  FIG. 12 , color filters of respective different colors may overlap the partition  320   
     The partition  320  is disposed between the microcavities  305  adjacent in the row direction. The partition  320  serves to fill separated spaces in the row direction. The partition  320  may be disposed in a direction in which the data line  171  is extended, to partition or define the microcavity  305 . The roof layer  360  may include an organic material. 
     An upper insulating layer  370  is disposed on the roof layer  360 . The upper insulating layer  370  may be formed of an inorganic material such as a silicon nitride or a silicon oxide. The upper insulating layer  370  may also be disposed in the peripheral area PA to serve as a barrier layer. 
     A capping layer  390  is disposed on the upper insulating layer  370 . The capping layer  390  may also be disposed on the trenches  308  to cover the entrance region  307  of the microcavities  305  exposed by the trenches  308 . The capping layer  390  may include an organic material or an organic material. The capping layer  390  may also be disposed in the peripheral area PA. For example, the capping layer  390  may cover an entire area of the substrate  110  except for the pad unit PP and the sealing area SA. 
     The first adhesive layer  710  and the first optical film  810  are disposed above the capping layer  390 , and the second adhesive layer  720  and the second optical film  820  are disposed below the substrate  110 . The first optical film  810  and the second optical film  820  not only serve to polarize light introduced into the display panel in, e.g., a liquid crystal display or an organic light emitting diode display, but also serve to prevent moisture penetration to the display panel together with the sealant  50  in the peripheral area PA with the same configuration as the aforementioned exemplary embodiments of the present invention. 
     While this invention has been described in connection with exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.