Patent Publication Number: US-2015070762-A1

Title: Polarizer, display device having the same, and method of manufacturing the same

Description:
This application claims priority to Korean Patent Application No. 10-2013-0108232, filed on Sep. 10, 2013, and all the benefits accruing therefrom under 35 U.S.C. §119, the content of which in its entirety is herein incorporated by reference. 
     BACKGROUND 
     1. Field 
     The disclosure relates to a polarizer, a display device including the polarizer, and a method of manufacturing the polarizer. More particularly, the disclosure relates to a polarizer with improved reflection efficiency of light, a display device including the polarizer, and a method of manufacturing the polarizer. 
     2. Description of the Related Art 
     In general, metal wires arrayed to be spaced apart from each other selectively transmit or reflect polarized light of an electromagnetic wave. That is, when a pitch of arrangement of the metal wires is shorter than a wavelength of the electromagnetic wave, a polarized light component substantially in parallel to the metal wires is reflected by the metal wires and a polarized light component substantially vertical to the metal wires transmits through the metal wires. 
     A polarizer is manufactured with the above-mentioned phenomenon to have high polarizing efficiency and transmittance and wide viewing angle, which is called a wire grid polarizer. 
     In recent years, the wire grid polarizer is applied to a display device. 
     SUMMARY 
     The disclosure provides a polarizer with improved reflection efficiency of light. 
     The disclosure provides a display device including the polarizer. 
     The disclosure provides a method of manufacturing the polarizer. 
     An exemplary embodiment of the invention provide a polarizer including a base substrate, a metal wire layer disposed on the base substrate, and a plurality of wire grid patterns disposed on the base substrate or the metal wire layer. 
     Another exemplary embodiment of the invention provide a display device including a display panel which displays an image and includes a first substrate and a second substrate disposed opposite to the first substrate and coupled to the first substrate, and a backlight unit disposed at a rear of the display panel and configured to provide light to the display panel, where the first substrate includes a base substrate, an in-cell polarizer disposed on the base substrate, and a pixel array layer disposed on the base substrate and electrically insulated from the in-cell polarizer, and the in-cell polarizer includes a metal wire layer and a plurality of wire grid patterns disposed on the base substrate or the metal wire layer. 
     Another exemplary embodiment of the invention provide a method of manufacturing a polarizer, including sequentially providing first and second metal layers on substantially an entire of a surface of a base substrate, providing photoresist patterns on the second metal layer, providing a co-polymer layer including first and second polymers between the photoresist patterns, heat-treating the co-polymer layer to alternately arrange the first and second polymers, removing the first polymer to form a plurality of grid patterns between the photoresist patterns, where the grid patterns include the second polymer and are spaced apart from each other by a predetermined distance, and etching the second metal layer using the photoresist patterns and the grid patterns as a mask to form wire grid patterns. 
     According to exemplary embodiments described herein, the metal wire layer including the silver nano-wire is disposed on the polarizer, such that the reflectance efficiency and the light utilization efficiency of the polarizer may be improved. 
     In such embodiments, an air gap may be provided in the polarizer, such that the total transmittance of the display device employing the polarizer may be improved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the exemplary embodiments of the invention will become readily apparent by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of an exemplary embodiment of a polarizer, according to the invention; 
         FIG. 2  is a partially enlarged view of a portion I in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of an alternative exemplary embodiment of a polarizer, according to the invention; 
         FIG. 4  is a cross-sectional view of another alternative exemplary embodiment of a polarizer, according to the invention; 
         FIG. 5  is a cross-sectional view of an exemplary embodiment of a display device with an in-cell polarizer; 
         FIG. 6  is an enlarged cross-sectional view of the in-cell polarizer shown in  FIG. 5 ; 
         FIG. 7  is a cross-sectional view of an exemplary embodiment of an in-cell polarizer, according to the invention; 
         FIG. 8  is a cross-sectional view of an alternative exemplary embodiment of an in-cell polarizer, according to the invention; 
         FIG. 9  is a graph showing a reflectance versus wavelength of light incident onto a metal material; 
         FIG. 10  is a graph showing an increase of luminance when an in-cell polarizer includes a metal wire layer; 
         FIG. 11  is a graph showing a luminance distribution at various angles in accordance with A1 and A2 shown in  FIG. 10 ; 
         FIG. 12  is a cross-sectional view of an alternative exemplary embodiment of a display device, according to the invention; 
         FIG. 13  is a partially enlarged view of a portion II in  FIG. 12 ; 
         FIG. 14  is a graph showing an increase of transmittance by an air gap; and 
         FIGS. 15A to 15G  are cross-sectional views showing of an exemplary embodiment of a method of manufacturing an in-cell polarizer, according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The invention will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. The invention may, however, be embodied in many different forms, and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout. 
     It will be understood that when an element or layer is referred to as being “on”, “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the invention. 
     Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper” and the like, 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” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     “About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. 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. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Hereinafter, exemplary embodiments of the invention will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a perspective view of an exemplary embodiment of a polarizer  101 , according to the invention, and  FIG. 2  is a partially enlarged view of the portion I in  FIG. 1 . 
     Referring to  FIGS. 1 and 2 , an exemplary embodiment of the polarizer  101  includes a base substrate  110 , a metal wire layer  121  disposed on the base substrate  110 , and a plurality of wire grid patterns  130  disposed on the metal wire layer  121 . 
     The base substrate  110  may include a material which transmits light, e.g., a silicon substrate. In such an embodiment, the base substrate  110  may have a rectangular shape. The metal wire layer  121  is disposed over an entire of a surface, e.g., an upper surface, of the base substrate  110 . In one exemplary embodiment, for example, the metal wire layer  121  includes a silver nano-wire to diffusively reflect incident light thereto due to a Raman scattering phenomenon of the silver nano-wire. 
     In an exemplary embodiment, each of the wire grid patterns  130  extends substantially in a first direction D1. The first direction D1 may be substantially parallel to two opposing parallel sides among four sides of the base substrate  110 . In such an embodiment, the wire grid patterns  130  are spaced apart from each other with a predetermined distance in a second direction D2, which is substantially perpendicular to the first direction D1, and the wire grid patterns  130  are substantially parallel to each other. 
     The polarizer  101  including the wire grid patterns  130  polarizes the incident light Li. In an exemplary embodiment, an S wave of the incident light Li, which is polarized substantially parallel to an extension direction of the wire grid patterns  130 , i.e., the first direction D1, is reflected by the wire grid patterns  130 , and a P wave of the incident light Li, which is polarized substantially perpendicular to the extension direction of the wire grid patterns  130 , i.e., the second direction D2, transmits through the wire grid patterns  130 . 
     In such an embodiment, where the wire grid patterns  130  has an arrangement pitch T, which is a distance between two adjacent wire grid patterns  130 , the incident light Li transmits through or is reflected by the wire grid patterns  130  in accordance with the polarized direction of the S and P waves when the wavelength of the incident light Li is shorter than the arrangement pitch T of the wire grid patterns  130 . The metal wire layer  121  diffusively reflects the light reflected by the wire grid patterns  130  without being incident to the wire grid patterns  130 , and thus the diffusively-reflected light is re-incident to the wire grid patterns  130 . A portion of the light re-incident to the wire grid patterns  130  transmits through the wire grid patterns  130  and the other portion of the light re-incident to the wire grid patterns  130  is reflected by the wire grid patterns  130 . In such an embodiment, the re-incident of the light is repeated by the metal wire layer  121 , and thus the reflection efficiency of the polarizer  101  may be improved. 
       FIG. 3  is a cross-sectional view of an alternative exemplary embodiment of a polarizer  103 , according to the invention. 
     Referring to  FIG. 3 , an exemplary embodiment of the polarizer  103  includes a base substrate  110 , a plurality of metal wire patterns  123  disposed on the base substrate  110 , and a plurality of wire grid patterns  130  disposed on the metal wire patterns  123 . 
     In one exemplary embodiment, for example, the metal wire patterns  123  are disposed only at regions corresponding to or overlapping the wire grid patterns  130 . In such an embodiment, the metal wire patterns  123  are disposed to correspond to, e.g., to overlap, the wire grid patterns  130  in a one-to-one correspondence and interposed between the base substrate  110  and the wire grid patterns  130 . 
     The configuration and function of the polarizer  103  shown in  FIG. 3  are substantially the same as the configuration and function of the polarizer  101  shown in  FIGS. 1 and 2  except that the metal wire patterns  123  are disposed only at regions corresponding to or overlapping the wire grid patterns  130 , and thus any repetitive detailed description thereof will be omitted. 
       FIG. 4  is a cross-sectional view of another alternative exemplary embodiment of a polarizer  105 , according to the invention. 
     Referring to  FIG. 4 , an exemplary embodiment of the polarizer  105  includes a base substrate  110 , a metal wire layer  121  disposed on a first surface  110   a  of the base substrate  110 , and a plurality of wire grid patterns  130  disposed on a second surface  110   b  of the base substrate  110 , which is opposite to the first surface  110   a.    
     In such an embodiment, the first surface  110   a  may be a lower surface of the base substrate  110 , and the second surface  110   b  may be an upper surface of the base substrate  110 , which is opposite to the lower surface. 
     The configuration and function of the polarizer  105  shown in  FIG. 4  are substantially the same as the configuration and function of the polarizer  101  shown in  FIGS. 1 and 2  except that the metal wire layer  121  is disposed on the surface of the base substrate  110 , which is different from the surface on which the wire grid patterns  130  are disposed, and thus any repetitive detailed description thereof will be omitted. 
       FIG. 5  is a cross-sectional view of an exemplary embodiment of a display device with an in-cell polarizer, and  FIG. 6  is an enlarged cross-sectional view of the in-cell polarizer shown in  FIG. 5 . 
     Referring to  FIG. 5 , an exemplary embodiment of a display device  600  includes a backlight unit  500  to generate light and a display panel  300  to display an image using the light. 
     The backlight unit  500  includes a light source (not shown) that emits the light, a light guide plate  510  that receives the light from the light source and guides the light to the display panel  300 , and a reflective plate  520  that reflects the light leaked from the light guide plate  510  to allow the reflected light to be re-incident to the light guide plate  510 . 
     The backlight unit  500  is disposed adjacent to a rear surface of the display panel  300 , and the light guide plate  510  has a size corresponding to a size of the display panel  300  and outputs the light toward the display panel  300 . The reflective plate  520  has a size corresponding to a size of the lower surface of the light guide plate  510  and includes a material with high reflectance to reflect the light leaked through the lower surface of the light guide plate  510 . 
     The display panel  300  includes a first substrate  350 , a second substrate  380  facing the first substrate  350 , and a liquid crystal layer  390  interposed between the first substrate  350  and the second substrate  380 . 
     The first substrate  350  includes a first base substrate  310 , an in-cell polarizer  320  disposed on the first base substrate  310 , a base insulating layer  330  that covers the in-cell polarizer  320 , and a pixel array layer  340  disposed on the base insulating layer  330 . 
     The display panel  300  includes a display area DA and a non-display area NDA. The in-cell polarizer  320  includes a metal wire layer  321  disposed on the first base substrate  310 . The metal wire layer  321  is disposed over substantially an entire of an inner surface of the first base substrate  310 . The in-cell polarizer  320  further includes a plurality of wire grid pattern  323  disposed on the metal wire layer  321  to correspond to, e.g., to overlap, the display area DA and a first reflective pattern  324  disposed on the metal wire layer  321  to correspond to, e.g., to overlap, the non-display area NDA. 
     Among the light provided from the backlight unit  500 , an S wave, which is polarized substantially parallel to the extension direction of the wire grid patterns  323 , is reflected by the metallic properties, e.g., aluminum, of the wire grid patterns  323 , and a P wave, which is polarized substantially perpendicular to the extension direction of the wire grid patterns  323 , transmits through the wire grid patterns. 
     The first reflective pattern  324  includes a material with high reflectance, e.g., aluminum, to reflect the light provided from the backlight unit  500 . 
     Referring to  FIG. 6 , in an exemplary embodiment, the light reflected by the first reflective pattern  324  is reflected by the reflective plate  520  of the backlight unit  500  and then is re-incident to the display panel  300 . Accordingly, light utilization efficiency may be improved by the first reflective pattern  324  of the in-cell polarizer  320 . 
     In such an embodiment, the light reflected by the first reflective pattern  324  is diffusively reflected by the metal wire layer  321  and then is re-incident to the wire grid pattern  323 . A portion of the light re-incident to the wire grid patterns  323  transmits through the wire grid patterns  323 , and the other portion of the light re-incident to the wire grid patterns  323  is reflected by the wire grid patterns  323 . The re-incident of the light is repeated by the metal wire layer  321 , and thus the reflection efficiency of the in-cell polarizer  320  may be improved. 
     Referring back to  FIG. 5 , the first reflective pattern  324  has a size corresponding to the non-display area NDA and reflects the light incident to the non-display area NDA to reuse the light. In such an embodiment, an amount of the light re-incident to the display area DA is increased by the first reflective pattern  324 . Therefore, in an exemplary embodiment, the light utilization efficiency of the in-cell polarizer  320  may be improved by the first reflective pattern  324 . 
     The base insulating layer  330  is disposed on the upper surface of the in-cell polarizer  320 . The base insulating layer  330  covers the first reflective pattern  324  and the wire grid patterns  323 . In such an embodiment, a space between the wire grid patterns  323 , which are spaced apart from each other, may be filled with the base insulating layer  330 . If the pixel array layer  340  is provided directly on the in-cell polarizer  320 , process defects may occur due to the space between the wire grid patterns  323 . Thus, in such an embodiment, the base insulating layer  330  is disposed between the pixel array layer  340  and the in-cell polarizer  320 . 
     In an exemplary embodiment, the base insulating layer  330  includes an insulating material to electrically insulate the first reflective pattern  324  and the wire grid patterns  323  from the pixel array layer  340 . 
     The pixel array layer  340  includes a thin film transistor TR, an inter-insulating layer  346  and a pixel electrode  347 . The thin film transistor TR includes a gate electrode  341 , a source electrode  344  and a drain electrode  345 . In an exemplary embodiment, the gate electrode  341  is disposed on the base insulating layer  330  and covered by a gate insulating layer  342 . A semiconductor layer  343  is disposed on the gate insulating layer  342  to correspond to, e.g., to overlap, the gate electrode  341 , and the source electrode  344  and the drain electrode  345  are disposed on the semiconductor layer  343  to be spaced apart from each other. 
     The inter-insulating layer  346  is disposed on the gate insulating layer  342  to cover the thin film transistor TR, and the pixel electrode  347  is disposed on the inter-insulating layer  346 . In such an embodiment, a contact hole  346   a  is defined through the inter-insulating layer  346  to expose the drain electrode  345  of the thin film transistor TR, and the pixel electrode  347  is electrically connected to the drain electrode  345  through the contact hole  346   a.    
     The structure of the first substrate  350  in an exemplary embodiment of the invention is not limited to the above-mentioned structure. 
     The second substrate  380  includes a second base substrate  360 , a color filter layer  371  and a black matrix  372 . The second base substrate  360  is disposed to face the first base substrate  310 , and the black matrix  372  is disposed on the second base substrate  360  to correspond to, e.g., to overlap, the non-display area NDA. The color filter layer  371  includes red, green and blue color pixels, and each of the red, green and blue color pixels is disposed to correspond to, e.g., to overlap, at least the display area DA and partially overlaps the black matrix  372 . 
     The liquid crystal layer  390  is disposed between the first substrate  350  and the second substrate  380 . The display panel  300  may further include a spacer  375  disposed between the first substrate  350  and the second substrate  380  to maintain a distance between the first and second substrates  350  and  380 , and thus the liquid crystal layer  390  provided between the first and second substrates  350  and  380  may be effectively prevented from an external pressure. 
     In an exemplary embodiment, a dichroic polarizer  400  is disposed on the display panel  300 . The dichroic polarizer  400  may have a sheet shape and may be attached to the display panel  300 . The dichroic polarizer  400  has a polarizing axis substantially parallel to or vertical to the extending direction of the wire grid patterns  323  of the in-cell polarizer  320 . 
       FIG. 7  is a cross-sectional view of an alternative exemplary embodiment of an in-cell polarizer  320 , according to the invention. 
     Referring to  FIG. 7 , an exemplary embodiment of the in-cell polarizer  320  includes a plurality of metal wire patterns  322   a  disposed on a first base substrate  310  to correspond to, e.g., to overlap, the display area DA and a second reflective pattern  322   b  disposed on the first base substrate  310  to correspond to, e.g., to overlap, the non-display area NDA. 
     In such an embodiment, the in-cell polarizer  320  includes a plurality of wire grid patterns  323  disposed on the metal wire patterns  322   a  to correspond to, e.g., to overlap, the display area DA and a first reflective pattern  324  disposed on the second reflective pattern  322   b  to correspond to, e.g., to overlap, the non-display area NDA. 
     The metal wire patterns  322   a  are disposed only at regions corresponding to or overlapping the wire grid patterns  323 , and the second reflective pattern  322   b  is disposed only at a region corresponding to or overlapping the first reflective pattern  324 . In such an embodiment, the metal wire patterns  322   a  are disposed to correspond to, e.g., to overlap, the wire grid patterns  323  in a one-to-one correspondence and interposed between the first base substrate  310  and the wire grid patterns  323 . 
     The configuration and function of the in-cell polarizer  320  shown in  FIG. 7  are substantially the same as the configuration and function of the in-cell polarizer  320  shown in  FIGS. 5 and 6  except that the metal wire patterns  322   a  are disposed only at the regions corresponding to the wire grid patterns  130 , and thus any repetitive detailed description thereof will be omitted. 
       FIG. 8  is a cross-sectional view showing another alternative exemplary embodiment of an in-cell polarizer  320 , according to the invention. 
     Referring to  FIG. 8 , an exemplary embodiment of the in-cell polarizer  320  includes a metal wire layer  321  disposed on a first surface  310   a  of a first base substrate  310 , a plurality of wire grid patterns  323  disposed on a second surface  310   b  of the first base substrate  310  to correspond to, e.g., to overlap, the display area DA, and a first reflective pattern  324  disposed on the second surface  310   b  of the first base substrate  310  to correspond to, e.g., to overlap, the non-display area NDA. 
     In such an embodiment, the first surface  310   a  may be a lower surface of the first base substrate  310 , and the second surface  310   b  may be an upper surface of the first base substrate  310 , which is opposite to the lower surface. 
     The configuration and function of the in-cell polarizer  320  shown in  FIG. 8  are substantially the same as the configuration and function of the in-cell polarizer  320  shown in  FIGS. 5 and 6  except that the metal wire layer  321  is disposed on the surface of the first base substrate  310 , which is different from the surface on which the wire grid patterns  323  and the first reflective pattern  324  are disposed, and thus any repetitive detailed description thereof will be omitted. 
       FIG. 9  is a graph showing reflectance versus wavelength of light incident onto a metal material. 
     Referring to  FIG. 9 , the reflectance of a metal material is changed in accordance with the wavelength. For instance, aluminum (Al) has the reflectance of about 90% in the wavelength range of about 200 nanometers (nm) to about 5 micrometers (μm). Meanwhile, silver (Ag) has the reflectance lower than the reflectance of aluminum (Al) in the wavelength range of about 200 nm to about 500 nm, but has the reflectance higher than the reflectance of aluminum (Al) in the wavelength range of about 500 nm to about 5 μm. 
     Accordingly, when the in-cell polarizer  320  includes the wire grid patterns  323  of aluminum (Al) and the metal wire layer  321  of silver (Ag), the total reflectance of the in-cell polarizer  320  is higher more than the reflectance of the in-cell polarizer including only a single metal material. 
       FIG. 10  is a graph showing an increase of luminance when an in-cell polarizer includes a metal wire layer, and  FIG. 11  is a graph showing a luminance distribution at various angles in accordance with A1 and A2 shown in  FIG. 10 . 
     In  FIGS. 10 and 11 , “A1” indicates a first case in which the backlight unit includes a diffusion plate and the metal wire layer is omitted from the in-cell polarizer, and “A2” indicates a second case in which the diffusion plate is omitted from the backlight unit and the metal wire layer  321 , e.g., silver nano-wire, is included to the in-cell polarizer  320 . 
     Referring to  FIGS. 10 and 11 , the total luminance of the second case A2 is higher than the total luminance of the first case A1. As shown in  FIG. 10 , the total luminance of the first case A1 is represented at about 1109.44 and the total luminance of the second case A2 is represented at about 1429.22, that is, the total luminance of the second case A2 is higher than that of the first case A1 by about 28.8%. As shown in  FIG. 11 , the luminance of the first case A1 at a side portion of the display device is similar to the luminance of the second case A2 at the side portion of the display device, but the luminance of the second case A2 at a front portion of the display device is higher than the luminance of the first case A1 at the front portion of the display device. 
     Accordingly, the total luminance and the front luminance of the display device  600  are higher in the second case A2 than the total luminance and the front luminance of the display device  600  in the first case A1. 
     As described above, in an exemplary embodiment, where the in-cell polarizer  320  includes the metal wire layer  321 , the luminance of the display device  600  becomes high even though the backlight unit  500  does not include the diffusion plate (or diffusion sheet). 
       FIG. 12  is a cross-sectional view of an alternative exemplary embodiment of a display device, according to the invention, and  FIG. 13  is a partially enlarged view of portion II shown in  FIG. 12 . 
     The display device in  FIG. 12  is substantially the same as the display device shown in  FIG. 5  except for the in-cell polarizer  320 . The same or like elements shown in  FIG. 12  have been labeled with the same reference characters as used above to describe the exemplary embodiments of the display device shown in  FIG. 5  and any repetitive detailed description thereof will hereinafter be omitted or simplified. 
     Referring to  FIGS. 12 and 13 , in an alternative exemplary embodiment of display device, the first substrate  350  includes the first base substrate  310 , the in-cell polarizer  320  disposed on the first surface  310   a  (shown in  FIG. 8 ) of the first base substrate  310 , and the pixel array layer  340  disposed on the second surface  310   b  (shown in  FIG. 8 ) of the first base substrate  310 . 
     The display panel  300  includes the display area DA and the non-display area NDA. The in-cell polarizer  320  further includes the wire grid patterns  323  disposed on the first base substrate  310  to correspond to, e.g., to overlap, the display area DA and the first reflective pattern  324  disposed on the first base substrate  310  to correspond to, e.g., to overlap, the non-display area NDA. The in-cell polarizer  320  includes the metal wire layer  321  to cover the wire grid patterns  323  and the reflective pattern  324 . 
     In one exemplary embodiment, for example, the metal wire layer  321  may include the silver nano-wire. In such an embodiment, a space between the wire grid patterns  323  spaced apart from each other is not filled with the metal wire layer  321 . Accordingly, the in-cell polarizer  320  may include an air gap  323   a  defined by the first base substrate  310 , the metal wire layer  321  and adjacent wire grid patterns  323 . 
       FIG. 14  is a graph showing an increase of transmittance due to the air gap. In  FIG. 14 , a first graph G1 represents the transmittance when the air gap  323   a  does not exist in the in-cell polarizer  320 , and a second graph G2 represents the transmittance when the air gap  323   a  exists in the in-cell polarizer  320 . In  FIG. 14 , an x-axis represents a refractive index of a material filled in the space between the wire grid patterns, e.g., a material of the base insulating layer  330 , when the air gap does not exist. 
     When the space between the wire grid patterns  323  of the in-cell polarizer  320  is filled with the base insulating layer  330  (shown in  FIG. 5 ), the transmittance is higher when the air gap  323   a  exists than that when the air gap  323   a  does not exists regardless of the refractive index of the base insulating layer  330 . As shown in  FIG. 14 , in such an embodiment, where the air gap  323   a  is defined in the in-cell polarizer  320 , the total transmittance of the display device  600  may be improved. 
       FIGS. 15A to 15G  are cross-sectional views showing an exemplary embodiment of a method of manufacturing an in-cell polarizer, according to the invention. 
     Referring to  FIG. 15A , a first metal layer  311  and a second metal layer  312  are sequentially provide, e.g., formed, on a first base substrate  310 . The first and second metal layers  311  and  312  include different metal materials from each other. In one exemplary embodiment, for example, the first metal layer  311  includes silver nano-wire, and the second metal layer  312  includes aluminum (Al). 
     As shown in  FIG. 15B , photoresist patterns  313  are provided on the second metal layer  312 . The photoresist patterns  313  are disposed to correspond to, e.g., to overlap, the non-display area NDA and not disposed in the display area DA. 
     Referring to  FIG. 15C , a space between the photoresist patterns  313  is filled with a co-polymer layer  314 . In an exemplary embodiment, the co-polymer layer  314  is formed to have a height less a height of each photoresist pattern  313 . In one exemplary embodiment, for example, the co-polymer layer  314  includes a first polymer and a second polymer, which are disorderedly aligned in various directions. In such an embodiment, the first polymer may be, but not limited to, polymethylmethacrylate (“PMMA”) and the second polymer may be, but not limited to, polystyrene (“PS”). 
     Then, the co-polymer layer  314  may be heat-treated. When the co-polymer layer  314  is heat-treated, the co-polymer layer  314  is phase separated into first and second polymers  315  and  316  as shown in  FIG. 15D . In an exemplary embodiment, the first and second polymers  315  and  316  may be alternately arranged with each other between the photoresist patterns  313  by the heat-treatment. 
     Then, one of the first and second polymers  315  and  316  is removed, and the other one of the first and second polymers  315  and  316  remains between the photoresist patterns  313  to form a nano-grid pattern  317  as shown in  FIG. 15E . In an exemplary embodiment, the first polymer  315  including PMMA is removed, and the second polymer  316  remains to form the nano-grid pattern  317 . 
     Then, the second metal layer  312  is etched using the nano-grid pattern  317  and the photoresist patterns  313  as a mask, such that the wire grid patterns  323  and the first reflective pattern  324  are provided on the first metal layer  311  as shown in  FIG. 15F . 
     In such an embodiment, the first metal layer  311  may be etched using the wire grid patterns  323  and the first reflective pattern  324  as a mask, such that the metal wire patterns  322   a  corresponding to the wire grid patterns  323  and the second reflective pattern  322   b  corresponding to the first reflective pattern  324  may be provided on the first base substrate  310  as shown in  FIG. 15G . In such an embodiment, the metal wire patterns  322   a  are disposed at an area corresponding to the display area DA and the second reflective pattern  322   b  is disposed at an area corresponding to the non-display area NDA. 
     Although some exemplary embodiments of the invention have been described herein, it is understood that the invention should not be limited to these exemplary embodiments but various changes and modifications can be made by one ordinary skilled in the art within the spirit and scope of the invention as hereinafter claimed.