Abstract:
A liquid crystal display element includes: a liquid crystal layer including liquid crystal material reflecting light having a certain wavelength; and an electrode layer configured to apply a driving voltage to the liquid crystal material, wherein an alignment direction of first liquid crystal molecules of the liquid crystal material is a first direction substantially parallel to a liquid crystal display surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority from Japanese Patent Application No. 2009-259194 filed on Nov. 12, 2009, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments discussed herein relate to a liquid crystal display element, a method of manufacturing the liquid crystal display element, and a liquid crystal display device. 
         [0004]    2. Description of Related Art 
         [0005]    A reflective type liquid crystal display element includes a liquid crystal layer in which cholesteric liquid crystals are enclosed. The liquid crystal layer is sandwiched between a pair of substrates. By applying a certain driving voltage to the liquid crystal layer, arrangement of liquid crystal molecules of the liquid crystal layer is controlled and incident external light is modulated, thereby displaying an image. 
         [0006]    Related art is disclosed in Japanese Laid-open Patent Publication No. H10-48600, Japanese Laid-open Patent Publication No. 2001-117109 or Japanese Laid-open Patent Publication No. 2001-311952. 
       SUMMARY 
       [0007]    According to one aspect of the embodiments, a liquid crystal display element includes: a liquid crystal layer including liquid crystal material reflecting light having a certain wavelength; and an electrode layer configured to apply a driving voltage to the liquid crystal material, wherein an alignment direction of first liquid crystal molecules of the liquid crystal material is a first direction substantially parallel to a liquid crystal display surface. 
         [0008]    Additional advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become more apparent to those skilled in the art upon examination of the following or upon learning by practice of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  illustrates an exemplary liquid crystal display element. 
           [0010]      FIG. 2  illustrates an exemplary liquid crystal display element. 
           [0011]      FIG. 3  illustrates an exemplary liquid crystal layer. 
           [0012]      FIG. 4  illustrates an exemplary liquid crystal layer. 
           [0013]      FIG. 5  illustrates an exemplary method of manufacturing a liquid crystal display element. 
           [0014]      FIGS. 6A to 6F  illustrate an exemplary method of manufacturing a liquid crystal display element. 
           [0015]      FIG. 7  illustrates an exemplary photomask. 
           [0016]      FIG. 8  illustrates an exemplary film substrate. 
           [0017]      FIG. 9  illustrates an exemplary film substrate. 
           [0018]      FIG. 10  illustrates an exemplary film substrate. 
           [0019]      FIG. 11  illustrates an exemplary film substrate. 
           [0020]      FIG. 12  illustrates an exemplary reflectivity. 
           [0021]      FIG. 13  illustrates an exemplary contrast ratio. 
           [0022]      FIG. 14  illustrates an exemplary liquid crystal display element. 
           [0023]      FIG. 15  illustrates an exemplary wrapping process. 
           [0024]      FIG. 16  illustrates an exemplary liquid crystal display element. 
           [0025]      FIG. 17  illustrates an exemplary alignment direction of liquid crystal molecules. 
           [0026]      FIGS. 18A to 18C  illustrate an exemplary photomask and an exemplary liquid crystal layer. 
           [0027]      FIG. 19  illustrates an exemplary rubbing process. 
           [0028]      FIGS. 20A and 20B  illustrate an exemplary liquid crystal display element. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0029]    Cholesteric liquid crystals in a liquid crystal layer include liquid crystal molecules having a spiral structure, and the cholesteric liquid crystals transition to a planar state, a focal conic state, or the like when a driving voltage or the like is applied. The light permeability and reflectivity of the cholesteric liquid crystals in the planar state are different from the light permeability and reflectivity of the cholesteric liquid crystals in the focal conic state. In a liquid crystal display element including cholesteric liquid crystals, light permeability and reflectivity vary according to the applied voltage, and the displayed content varies. 
         [0030]    Even when a voltage is not applied to the cholesteric liquid crystals in the planar state or the focal conic state, the display state becomes stable and power consumption may be reduced. In addition, since the cholesteric liquid crystals may include a reflection state, a polarization plate or a color filter may not be used. Therefore, a bi-stable mode using the planar state and the focal conic state may be set. 
         [0031]    When the reflectivity of the planar state is not high, a display may become dark. When the contrast ratio between the planar state and the focal conic state is not high, the display may become unclear. 
         [0032]      FIG. 1  illustrates an exemplary liquid crystal display element. The liquid crystal display element  1  illustrated in  FIG. 1  may be applied to a liquid crystal display device using liquid crystal material that reflects light of specific wavelengths. 
         [0033]    The liquid crystal display element  1  includes a liquid crystal layer  10  and electrode layers  11  and  12 . The liquid crystal layer  10  is sandwiched between the electrode layer  11  and the electrode layer  12 , and a driving voltage for display control is applied to the liquid crystal layer  10 . The display surface of the liquid crystal display element  1  may be provided, for example, on the side of the electrode layer  11 . 
         [0034]    A user U 1  may view, for example, a liquid crystal display device including the liquid crystal display element  1  from a constant direction. The user U 1  may view, for example, the liquid crystal display element  1  from a direction substantially perpendicular to the display surface without rotating the liquid crystal display device. For example, in  FIG. 1 , the visual line D 1  of the user U 1  may be substantially perpendicular to the display surface. 
         [0035]    The liquid crystal layer  10  includes liquid crystal material reflecting light of specific wavelengths. The liquid crystal layer  10  may be arranged so that alignment direction of the liquid crystal molecules near the interface with the electrode layer  11  or the electrode layer  12  is substantially parallel to a binocular direction H 1  linking both eyes of a user viewing the display surface. For example, in  FIG. 1 , the liquid crystal layer  10  is arranged so that the alignment direction of the liquid crystal molecules  10   a  to  10   i  near the interface with the electrode layer  11  is substantially parallel to the binocular direction H 1 . The alignment direction indicates the direction of the molecular axis of a liquid crystal molecule, for example, the major axis direction (longitudinal direction) of the liquid crystal molecule. In the subsequent figures, in order to clarify the description, the liquid crystal molecules may be enlarged. 
         [0036]    Since the reflectivity of the liquid crystals is increased in the direction perpendicular to the major axis directions of the liquid crystal molecules, the alignment direction of the liquid crystal molecules is arranged so as to be substantially parallel to the binocular direction H 1 . For example, as illustrated in  FIG. 1 , when the alignment direction of the liquid crystal molecules  10   a  to  10   i  is substantially parallel to the binocular direction H 1 , the reflectivity to the user U 1  of the liquid crystal molecules  10   a  to  10   i  may be increased in the planar state. Therefore, if the alignment direction of the liquid crystal molecules  10   a  to  10   i  is substantially parallel to the binocular direction H 1 , the display of the liquid crystal element  1  may become brighter. 
         [0037]    When the alignment direction of the liquid crystal molecules  10   a  to  10   i  is substantially parallel to the binocular direction H 1 , the reflectivity of the liquid crystal molecules  10   a  to  10   i  may not vary to the user U 1  in the focal conic state. In the liquid crystal display element  1  illustrated in  FIG. 1 , a difference between the reflectivity of the planar state and the reflectivity of the focal conic state may be increased. Since the contrast ratio of the liquid crystal display element  1  illustrated in  FIG. 1  is high, the display may become clear. 
         [0038]    The reflectivity and the contrast ratio of the planar state of the liquid crystal display element  1  illustrated in  FIG. 1  may be increased. In the liquid crystal display element  1  illustrated in  FIG. 1 , the visibility for the user may be improved. 
         [0039]    In  FIG. 1 , the alignment direction of the liquid crystal molecules located near the interface between the liquid crystal layer  10  and the electrode layer  11  is substantially parallel to the binocular direction H 1 . For example, the alignment direction of the liquid crystal molecules located near the interface between the liquid crystal layer  10  and the electrode layer  12  may be substantially parallel to the binocular direction H 1 . Both the liquid crystal molecules located near the interface between the liquid crystal layer  10  and the electrode layer  11  and the liquid crystal molecules located near the interface between the liquid crystal layer  10  and the electrode layer  12  are substantially parallel to the binocular direction H 1 . 
         [0040]    The viewing direction of the user U 1  may be predicted based on the display direction or the shape of the liquid crystal display device. For example, when the direction of a display target displayed by the liquid crystal display element  1  is decided in advance, the user U 1  may view the liquid crystal display device from a direction substantially perpendicular to the display surface without rotating the liquid crystal display device. For example, in  FIG. 1 , the horizontal direction of the display target displayed by the liquid crystal display element  1  may be the X direction illustrated in  FIG. 1  and the vertical direction of the display target may be the Y direction illustrated in  FIG. 1 . In this case, the user may view the liquid crystal display device without rotating the liquid crystal display device. 
         [0041]    When the viewing direction of the user is predicted, the liquid crystal display element  1  may be manufactured so that the alignment direction of the liquid crystal molecules and the binocular direction H 1  are substantially parallel to each other. The visibility of the manufactured liquid crystal display element  1  for the user may be improved. 
         [0042]    The alignment direction of the liquid crystal molecules may be defined by a given structure of the liquid crystal layer. As liquid crystals, cholesteric liquid crystals and chiral nematic liquid crystals obtained by adding a chiral agent to nematic liquid crystals may be used. 
         [0043]      FIG. 2  illustrates an exemplary liquid crystal display element. The liquid crystal display element  2  illustrated in  FIG. 2  includes a liquid crystal layer  100 , film substrates  131  and  132 , and electrode layers  141  and  142 . In  FIG. 2 , a display surface of the liquid crystal display element  2  may be arranged on the film substrate  131  side. 
         [0044]    The film substrates  131  and  132  illustrated in  FIG. 2  may be transparent substrates made of glass, resin, or the like, and include the electrode layer  141 , the liquid crystal layer  100 , and the electrode layer  142  sandwiched between the film substrates. In the electrode layers  141  and  142 , an electrode pattern may be patterned in advance and the liquid crystal layer  100  may be sandwiched between the electrode layers. 
         [0045]    Cholesteric liquid crystals are enclosed in the liquid crystal layer  100 . As illustrated in  FIG. 2 , the liquid crystal layer  100  includes structures  121  to  125 . The structures  121  to  125  may be photoresists. As illustrated in  FIG. 2 , the structures  121  to  125  may be formed with a certain gap between the structures in a direction perpendicular to the binocular direction H 1  of the user U 1 . The structures  121  to  125  may be formed in a direction substantially parallel to the binocular direction H 1 . Although five structures  121  to  125  are included in the liquid crystal layer  100  in  FIG. 2 , six or more structures may be included in the liquid crystal layer  100 . 
         [0046]    In the liquid crystal layer  100  illustrated in  FIG. 2 , the cholesteric liquid crystal may be injected from the direction D 3  parallel to the binocular direction H 1 . The injected cholesteric liquid crystal flows between the structures  121  to  125  so as to be filled in the liquid crystal layer  100 . For example, the cholesteric liquid crystal flows between the structure  121  and the structure  122  so as to be filled between the structure  121  and the structure  122 . The cholesteric liquid crystal flows between the structure  122  and the structure  123  so as to be filled between the structure  122  and the structure  123 . 
         [0047]    When the cholesteric liquid crystals are injected, the flow direction of the cholesteric liquid crystals and the alignment direction of the liquid crystal molecules included in the cholesteric liquid crystals may be substantially equal or similar. The flow direction of the cholesteric liquid crystals and the major axis direction (molecular axis directions) of the liquid crystal molecules may be substantially equal or similar. For example, in  FIG. 2 , the alignment direction of the liquid crystal molecules included in the liquid crystal layer  100  is substantially equal to the flow direction of the cholesteric liquid crystals and thus is substantially parallel to the binocular direction H 1  linking both eyes of the user. 
         [0048]      FIG. 3  illustrates an exemplary liquid crystal layer.  FIG. 3  may be a cross-sectional view of a plane A of the liquid crystal layer  100  illustrated in  FIG. 2 . As illustrated in  FIG. 3 , the liquid crystal layer  100  includes the structures  121  to  125 . In the liquid crystal layer  100 , the cholesteric liquid crystals may be injected from a direction D 3 . For example, the flow direction of the cholesteric liquid crystals may be directions D 11   a  to  11   f  illustrated in  FIG. 3 . The alignment direction of the liquid crystal molecules  110   a  to  110   j  included in the liquid crystal layer  100  may be substantially equal to the flow direction D 11   a  to  11   f  of the cholesteric liquid crystals, as illustrated in  FIG. 3 . 
         [0049]    The alignment direction of the liquid crystal molecules  110   a  to  110   j  may be substantially parallel to the binocular direction H 1 . For example, the alignment direction of the liquid crystal molecules  110   a  to  110   j  may be substantially horizontal directions when viewed from the perspective of the user U 1 . In the liquid crystal display element  2  illustrated in  FIG. 2 , since the reflectivity and the contrast ratio of the planar state are increased, visibility for the user may be improved. 
         [0050]    Although the structures  121  to  125  are planes in  FIGS. 2 and 3 , the structures  121  to  125  may not be planes.  FIG. 4  illustrates an exemplary liquid crystal.  FIG. 4  is an enlarged view of a region B illustrated in  FIG. 3 . In  FIG. 4 , for example, the structure  123  may include a region  123   a  protruding in the Y direction. For example, the structure  124  may include a region  124   a  protruding in the Y direction. The region  123   a  and the region  124   a  of the structures  121  to  125  included in the liquid crystal layer  100  illustrated in  FIG. 2  may not be adhered. Therefore, as illustrated in  FIG. 4 , when the structures  121  to  125  include protruding regions, the cholesteric liquid crystal flows along the flow direction D 11   d  when being injected into the liquid crystal layer  100 . 
         [0051]      FIG. 5  illustrates an exemplary method of manufacturing a liquid crystal display device. The liquid crystal display device manufactured according to the manufacturing method illustrated in  FIG. 5  may be the liquid crystal display element  2  illustrated in  FIG. 2 . As illustrated in  FIG. 5 , in an operation  101 , a transparent conductive film is formed on the surface of a film substrate so as to form an electrode pattern. An electrode layer is formed on the film substrate. Electrode patterns of at least two film substrates are formed. 
         [0052]    In an operation  102 , a photoresist is formed by a spinner on one of the two film substrates on which the electrode layers are formed. In an operation  103 , a structure defining the flow direction of the cholesteric liquid crystals is formed on the film substrate, on which the photoresist is formed, using a photomask. The structure may be formed such that the flow direction of the cholesteric liquid crystals is substantially parallel to the binocular direction H 1 . 
         [0053]    In an operation  104 , a spacer is formed on the other film substrate and a sealing agent is applied on the other film substrate. A liquid crystal injection port for injecting liquid crystals is formed in a seal wall formed along the sealing agent. In an operation  105 , the film substrate on which the sealing agent is applied and the other film substrate are adhered to each other. The spacer or the sealing agent may be adhered to the other film substrate. Both the film substrates may be pressed and adjusted to fit in between a specified gap. 
         [0054]    In an operation  106 , cholesteric liquid crystals are injected from the liquid injection port by a vacuum injection method or the like. In an operation  107 , the liquid injection port is sealed by a sealing agent or the like. A single-color liquid crystal panel is formed. When a three-layer lamination type liquid crystal display element is formed, the operations S 101  to S 107  are performed on each of a liquid crystal display element selectively reflecting blue light, a liquid crystal display element selectively reflecting green light, and a light crystal display element selectively reflecting red light. For example, the blue, green, and red liquid crystal display elements may be laminated from a display surface in this order. 
         [0055]    The operations S 101  to S 107  illustrated in  FIG. 5  may be performed by one manufacturing apparatus or a plurality of manufacturing apparatuses. For example, the operations S 101  to S 107  may be performed by different manufacturing apparatuses. After a manufacturing apparatus  1 A performs the operations S 101  to S 103 , a manufacturing apparatus  1 B may perform the operations S 104  to S 107 . 
         [0056]      FIGS. 6A to 6F  illustrate an exemplary method of manufacturing a liquid crystal display element. The liquid crystal display device manufactured by the manufacturing method illustrated in  FIG. 6  may be the liquid crystal display device  2  illustrated in  FIG. 2 .  FIGS. 6A to 6F  may be diagrams when viewed from the direction D 3  illustrated in  FIG. 2 . The upper side of  FIG. 6  may be the display surface side. 
         [0057]    As illustrated in  FIG. 6A , a transparent conductive film is formed on a surface of a film substrate  131  so as to form an electrode layer  141 . An electrode layer  142  is formed on a film substrate  132 . In  FIG. 6A , for passive driving, electrodes may be formed on the film substrate  131  and the film substrate  132  so that the electrode layer  141  and the electrode layer  142  are perpendicular to each other. The film substrates  131  and  132  may be, for example, film substrates formed of polyethylene terephthalate with a thickness of about 100 μm. 
         [0058]    Structures setting the flow direction of cholesteric liquid crystals are formed on at least one of the film substrate  131  and the film substrate  132 . In  FIG. 6B , for example, after a photoresist such as an acrylic negative resist is formed on the film substrate  131 , the structures are formed using a photomask. 
         [0059]      FIG. 7  illustrates an exemplary photomask. As illustrated in  FIG. 7 , the photomask  161  includes light transmission portions  161   a  to  161   e  and a light shielding portion  161   f . The light transmission portions  161   a  to  161   e  transmit externally irradiated light. The light shielding portion  161   f  shields externally irradiated light. 
         [0060]    For example, as illustrated in  FIG. 6A , the photomask  161  is arranged on a plane of the film substrate  131 , on which the photoresist is formed, with a certain gap between them. The photomask  161  may be arranged so that the major axis directions of the light transmission portions  161   a  to  161   e  are substantially parallel to the binocular direction H 1 . In this arrangement state, with respect to the photomask  161 , light is irradiated in the direction from the photomask  161  to the film substrate. The photoresist located below the transmission portions  161   a  to  161   e  of the photoresist formed on the film substrate is adhered to the film substrate. 
         [0061]    As illustrated in  FIG. 6B , structures  121  to  125  including the photoresist are adhered on the electrode layer  141  of the film substrate  131 .  FIG. 8  illustrates an exemplary film substrate.  FIG. 8  may be, for example, a diagram of the film substrate  131  illustrated in  FIG. 6B  when viewed from a lower side. As illustrated in  FIG. 8 , the structures  121  to  125  are formed with a specified gap between them in a direction perpendicular to the binocular direction H 1  and are formed so as to be substantially parallel to the binocular direction H 1 . 
         [0062]    As illustrated in  FIG. 6C , a sealing agent  151  is applied on the film substrate  132 .  FIG. 9  illustrates an exemplary film substrate.  FIG. 9  may be a diagram of the film substrate  132  illustrated in  FIG. 6C  when viewed from an upper side. As illustrated in  FIG. 9 , the sealing agent  151  is applied in the vicinities of edges on the plane of the film substrate  132 . The sealing agent  151  may not be applied to parts of the vicinities of the edges of the film substrate  132 . A liquid crystal injection port  151   a  is formed. 
         [0063]    As illustrated in  FIG. 6D , the film substrate  131  and the film substrate  132  are adhered by heating or pressurizing.  FIG. 10  illustrates an exemplary film substrate.  FIG. 10  may be a diagram of the film substrates  131  and  132  illustrated in  FIG. 6D  when viewed from an upper side. In  FIG. 10 , the film substrate  131  may not be illustrated. As illustrated in  FIG. 10 , when the film substrate  131  and the film substrate  132  are adhered, the electrode layer  141  and the electrode layer  142  may be perpendicular to each other. 
         [0064]    As illustrated in  FIG. 6E , cholesteric liquid crystals are injected into the liquid crystal layer  100  formed between the film substrate  131  and the film substrate  132 . As illustrated in  FIG. 6F , the liquid injection port is sealed by a sealing agent  152  or the like. 
         [0065]    For example, in a vacuum state, the film substrates  131  and  132  illustrated in  FIG. 6D  are immersed in cholesteric liquid crystals and exposed to the atmosphere such that cholesteric liquid crystals are injected into the liquid crystal layer  100 .  FIG. 11  illustrates an exemplary film substrate.  FIG. 11  may be a diagram of the film substrates  131  and  132  illustrated in  FIG. 6E  when viewed from an upper side. In  FIG. 11 , the film substrate  121  and the electrode layers  141  and  142  may not be displayed. As illustrated in  FIG. 11 , the cholesteric liquid crystals flow between the structures  121  to  125  so as to be injected into the liquid crystal layer  100 . The cholesteric liquid crystals flow along the flow direction D 11   a  to  11   f  illustrated in  FIG. 11 . 
         [0066]    The liquid crystal display element  2  illustrated in  FIG. 2  is controlled so that the flow direction of the cholesteric liquid crystals at the time of injection is substantially parallel to the binocular direction H 1  of the user U 1  due to the structures included in the liquid crystal layer  100 . Therefore, the alignment direction of the liquid crystal molecules included in the liquid crystal layer  100  is substantially parallel to the binocular direction H 1 . The display of the liquid crystal display element  2  illustrated in  FIG. 2  becomes brighter. Since the contrast ratio of the liquid crystal display element  2  illustrated in  FIG. 2  is high, the display may become clear. 
         [0067]      FIG. 12  illustrates an exemplary reflectivity.  FIG. 12  illustrates the reflectivity of the first liquid crystal display element  2  illustrated in  FIG. 2 , and another second liquid crystal display element.  FIG. 13  illustrates an exemplary contrast ratio.  FIG. 13  illustrates the contrast ratios of the first liquid crystal display element  2  illustrated in  FIG. 2 , and another second liquid crystal display element. As illustrated in  FIG. 12 , in the planar state, the reflectivity of the first liquid crystal display element  2  is higher than the reflectivity of the second liquid crystal display element by about 33%. As illustrated in  FIG. 12 , in the focal conic state, the reflectivity of the first liquid crystal display element  2  and the reflectivity of the second liquid crystal display element are substantially equal to each other. As illustrated in  FIG. 13 , the contrast ratio of the first liquid crystal display element  2  is higher than the contrast ratio of the second liquid crystal display element by about 30%. 
         [0068]    Since the reflectivity and the contrast ratio of the first liquid crystal display element  2  are higher than the reflectivity and the contrast ratio of the second liquid crystal display element, the display becomes bright and clear. 
         [0069]    The liquid crystal layer is sandwiched between the electrode layers  141  and  142 . For example, the liquid crystal display element may include an alignment film. 
         [0070]      FIG. 14  illustrates an exemplary liquid crystal display element. In  FIG. 14 , the elements that are substantially the same as the elements illustrated in  FIG. 2  are denoted by the same reference numerals and the description thereof may be omitted or abbreviated. 
         [0071]    The liquid crystal display element  3  illustrated in  FIG. 14  includes a liquid crystal layer  200 , film substrates  131  and  132 , electrode layers  141  and  142 , and alignment films  271  and  272 . In the liquid crystal display element  3  illustrated in  FIG. 14 , the film substrate  131  side may be a display surface. 
         [0072]    The alignment films  271  and  272  may include a polyimide resin. The alignment film  271  is formed on the electrode layer  141  in a manufacturing operation. The alignment film  272  is formed on the electrode layer  142 . In the alignment films  271  and  272  formed on the electrode layers  141  and  142 , a rubbing process is performed in a binocular direction H 1  and a horizontal direction. When cholesteric liquid crystals are injected into the liquid crystal layer  200 , the alignment direction of liquid crystal molecules may be substantially equal to the rubbing direction. 
         [0073]      FIG. 15  illustrates an exemplary wrapping process. The wrapping process illustrated in  FIG. 15  may be performed on the alignment films illustrated in  FIG. 14 . The alignment film  272  illustrated in  FIG. 15  may be a diagram viewed in the viewing direction of an arrow D 2  illustrated in  FIG. 14 . As illustrated in  FIG. 15 , the rubbing process is performed on the alignment film  272  in the rubbing direction D 12 , which is substantially parallel to the binocular direction H 1 . The rubbing process is performed on the alignment film  271  in the rubbing direction D 12 . 
         [0074]    In the manufacture of the liquid crystal display element  3  illustrated in  FIG. 14 , after the operation S 101  illustrated in  FIG. 5 , a polyimide resin is, for example, formed on the electrode films formed on the film substrates  131  and  132  by a spinner. The rubbing process is performed on the polyimide resin film so as to form the alignment films  271  and  272 . Thereafter, the operations S 102  to S 107  illustrated in  FIG. 5  may be performed. 
         [0075]    In the liquid crystals injected into the liquid crystal layer  200 , the alignment direction of the liquid crystal molecules is controlled so as to be parallel to the binocular direction H 1  by the alignment films  271  and  272  which are subjected to the rubbing process in the direction parallel to the binocular direction H 1 . Since the liquid crystals injected into the liquid crystal layer  200  flow between the structures  121  to  125 , the alignment direction of the liquid crystal molecules is substantially parallel to the binocular direction H 1 . For example, the alignment direction of the liquid crystal molecules of the liquid crystal layer  200  illustrated in  FIG. 14  may be parallel to the binocular direction H 1  according to the flow direction of the liquid crystals and the alignment films  271  and  272 . The reflectivity and the contrast ratio of the planar state of the liquid crystal display element  3  illustrated in  FIG. 14  may be further increased. 
         [0076]    By performing the rubbing process on the alignment films, the alignment direction of the liquid crystal molecules injected into the liquid crystal layer  200  is controlled. By performing an optical alignment process on the alignment films, the alignment direction of the liquid crystal molecules injected into the liquid crystal layer  200  may be controlled so as to be substantially parallel to the binocular direction H 1 . 
         [0077]    Since the alignment direction of the liquid crystal molecules is substantially parallel to the binocular direction H 1  linking both eyes of the user, the reflectivity is improved. The size of the lateral direction, for example, the binocular direction H 1  of the liquid crystal display element, may be large. In this case, when the user views the liquid crystal display element, the user may tilt their head slightly. 
         [0078]      FIG. 16  illustrates an exemplary liquid crystal display element. A liquid crystal layer  300  illustrated in  FIG. 16  may correspond to a cross-sectional view parallel to a display surface. The size of the lateral direction, for example, the binocular direction H 1  of the liquid crystal display element  4  illustrated in  FIG. 16 , may be large. 
         [0079]    The liquid crystal layer  300  illustrated in  FIG. 16  includes a first side section  300 L, a central section  300 C and a second side section  300 R. The first side section  300 L and the second side section  300 R are located on both sides of the liquid crystal layer  300  when the binocular direction H 1  is the lateral direction of the figure. The central section  300 C is located on the center of the liquid crystal layer  300  when the binocular direction H 1  is the lateral direction of the figure. 
         [0080]    In the first side section  300 L and the second side section  300 R, structures  310   a  to  310   h  are formed so that an angle with the binocular direction H 1  becomes a desired angle. For example, the angle of the first side section  300 L may be an angle β and the structures may be formed in a direction to the second side section  300 R. For example, the angle of the second side section  300 R may be an angle β and the structures may be formed in a direction to the first side section  300 L. The angles α and β are greater than 0 degrees and may be less than 90 degrees. The angle α and the angle β may be equal. 
         [0081]      FIG. 17  illustrates an exemplary alignment direction of liquid crystal molecules. The liquid crystal molecules illustrated in  FIG. 17  may be included in the liquid crystal layer  30  illustrated in  FIG. 16 . As illustrated in the upper side of  FIG. 17 , the liquid crystal layer  300  includes structures  321  to  324 . Cholesteric liquid crystals are injected into the liquid crystal layer  300  in a direction D 4  illustrated in  FIG. 17 . For example, the flow direction of the cholesteric liquid crystals may be directions D 31   a  to  31   e  illustrated in  FIG. 17 . As illustrated in  FIG. 16 , the alignment direction of the liquid crystal molecules  310   a  to  310   h  included in the liquid crystal layer  300  may be substantially equal to the flow direction D 31   a  to  31   e  of the cholesteric liquid crystals. 
         [0082]    The lower side of  FIG. 17  is an enlarged diagram of sections C to E illustrated in the upper side of  FIG. 17 . The structures  321  to  324  included in the first side section  300 L and the second side section  300 R may include a combination of an X-direction structure and a Y-direction structure. 
         [0083]    A method of manufacturing the liquid crystal display element  4  illustrated in  FIG. 16  may be substantially equal or similar to the manufacturing method illustrated in  FIG. 5 . The shape of the photomask used in the operation S 103  may be different.  FIGS. 18A to 18C  illustrate an exemplary photomask and an exemplary liquid crystal layer.  FIG. 18A  illustrates a photomask  361  used to manufacture the liquid crystal display device  4  illustrated in  FIG. 16 .  FIGS. 18B and 18C  illustrate a film substrate  331  of the liquid crystal display element illustrated in  FIG. 16 . The viewing direction of the arrow of the film substrate  331  illustrated in  FIG. 18B  may be equal to that of the film substrate  131  illustrated in  FIG. 8 . In addition, the viewing direction of the arrow of the film substrate  331  illustrated in  FIG. 18C  may be equal to that of the film substrate  132  illustrated in  FIG. 11 . 
         [0084]    As illustrated in  FIG. 18A , the photomask  361  includes light transmission portions  361   a  to  361   e  and a light shielding portion  361   f . When the liquid crystal display element  4  illustrated in  FIG. 16  is manufactured, the structures  321  to  325  illustrated in  FIG. 18B  may be formed using the photomask  361  illustrated in  FIG. 18A . For example, as illustrated in  FIG. 18C , when cholesteric liquid crystals are injected into the liquid crystal layer  300 , the flow direction of the cholesteric liquid crystals is set. 
         [0085]    In the liquid crystal display element  4  illustrated in  FIG. 16 , the alignment direction of the liquid crystal molecules on both side sections of the liquid crystal layer  300  is inclined with respect to the binocular direction H 1 . Therefore, in the liquid crystal display element  4  illustrated in  FIG. 16 , reflectivity may be improved even when the size of the lateral direction, for example, the direction X, of the liquid crystal display element is large and the user views the liquid crystal display element while tilting his or her head. Since the alignment direction of the liquid crystal molecules on both side sections is inclined, even when the user views both side sections of the liquid crystal display element while tilting his or her head, the alignment direction of the liquid crystal molecules is parallel when viewed from the user. 
         [0086]    For example, as illustrated in  FIG. 16 , the user U 1  may view the first side section  300 L while tilting his or her head. The binocular direction H 2  linking both eyes of the user U 1  whose head tilts and the alignment direction of the liquid crystal molecules  310   a  to  310   h  located on the first side section  300 L may become parallel to each other. The reflectivity and the contrast ratio of the liquid crystal display element  4  illustrated in  FIG. 16  may be improved. 
         [0087]    The rubbing process may be performed on the alignment film used in the liquid crystal display elements  4  illustrated in  FIG. 16  in substantially the same direction as the flow direction of the cholesteric liquid crystals.  FIG. 19  illustrates an exemplary rubbing process. The rubbing process illustrated in  FIG. 19  may be performed on the alignment film  371  illustrated in  FIG. 16 . As illustrated in  FIG. 19 , in section  371 L corresponding to the first side section  300 L of the liquid crystal layer  300  illustrated in  FIG. 17  of the alignment film  371 , an angle with the binocular direction H 1  may be an angle α. The rubbing process may be performed in a direction D 13  to a section  371 R corresponding to the second side section  300 R. In a section  371 R corresponding to the second side section  300 R of the liquid crystal layer  300  illustrated in  FIG. 17  of the alignment film  371 , an angle with the binocular direction H 1  may be an angle β. The rubbing process may be performed in a direction D 15  to a section  371 L corresponding to the first side section  300 L. In a section  371 C corresponding to the central section  300 C of the liquid crystal layer  300  illustrated in  FIG. 17  of the alignment film  371 , the rubbing process may be performed in a direction parallel to the binocular direction H 1 . 
         [0088]    The flow direction of the cholesteric liquid crystals at the time of injection is set using the structures. The flow direction of the cholesteric liquid crystals at the time of injection may be set without using the structures. 
         [0089]      FIGS. 20A and 20B  illustrate an exemplary liquid crystal display element. As illustrated in  FIG. 20A , in a liquid crystal display element  5 , a sealing agent  451  is applied to a film substrate  431  in a manufacturing operation. The sealing agent  451  is applied to the film substrate  431  such that a plurality of liquid crystal injection ports  451   a  to  451   c  is formed. The liquid crystal injection ports  451   a  to  451   c  are formed on a side section of the film substrate  431  with a specified gap between the ports when the binocular direction H 1  is the lateral direction of the figure. 
         [0090]    The cholesteric liquid crystals injected into the liquid crystal injection ports  451   a  to  451   c  flow along the flow direction D 41   a  to D 41   e  illustrated in  FIG. 20B . Since the flow direction of the cholesteric liquid crystals and the alignment direction of the liquid crystal molecules are substantially equal, as illustrated in  FIG. 20B , the flowing cholesteric liquid crystals may be substantially parallel to the binocular direction H 1 . 
         [0091]    In the liquid crystal display element  5  illustrated in  FIG. 20 , the plurality of liquid crystal inject ports is formed and the flow direction of the cholesteric liquid crystals at the time of injection is set by the locations of the liquid crystal injection ports. In the liquid crystal display element  5  illustrated in  FIG. 20 , structures setting the flow direction of the cholesteric liquid crystals may not be formed. 
         [0092]    Example embodiments of the present invention have been described in accordance with the above advantages. It will be appreciated that these examples are merely illustrative of the invention. Many variations and modifications will be apparent to those skilled in the art.